Bulletin #54 – No Limits: How To Break Through Plateaus

A very common problem amongbodybuilders, especially advanced body-builders, is hitting a plateau. What to dowhen you hit a plateau is one of the mostfrequently asked questions I receive. Theanswers are highly individualized depend-ing on the specific problem, but I can giveyou some general guidelines to help youtroubleshoot the difficulty. The main pointis that if you’re not making progress in yourbodybuilding goals, then you’re not doingwhat it takes to make you better. As obvi-ous as that sounds, many people fail torealize this. A lot of people stick with thesame program month after month, some-times even for years, without seeing anyreal change in their physiques. They keepwaiting for it to start working – for some-thing to happen. A good rule of thumb isthat you should see some improvement onat least a monthly basis. Take inventory ofyour progress at regular intervals, say atthe beginning of every month. If you likewhat you see and you’re making goodprogress, keep doing what you’re doing.On the other hand, if a month goes by andyou haven’t made some noticeable im-provement, it’s time for a change.

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The big-gest mistake you can make is to faithfullystick to a program that’s not giving you goodresults.These suggestions to “take inven-tory” and “look for improvement” lead di-rectly to the second major concept, which isthat you need to be scientific about analyz-ing your progress. You cannot achieve great-ness in any field by guesswork, includingbodybuilding. You need to have some spe-cific, objective goals and keep records to de-termine if you’re making progress towardachieving them. The basic goals for body-builders are to increase muscle mass, to de-crease body fat, to increase strength in thebasic lifts, and to improve overall size, shapeand symmetry. To know if you are makingprogress toward increasing muscle mass orlosing body fat, you need to periodicallymeasure your body composition and keeprecords. To monitor your gains in strength,you need to keep a training journal andrecord your performance on basic lifts likesquats, deadlifts, bench presses, shoulderpresses, and rows. Set some specific goals,such as to gain a pound of muscle per weekfor the next 12 weeks, or to reach an all-timepersonal low body fat percentage, or to geta new personal best in the bench press. Ifyou don’t have specific goals, and if youdon’t monitor your progress toward reach-ing those goals, then it’s hard to know ifyou’re really making any progress or not.

Most people in the gym don’t ever bother toformulate specific goals, don’t keep a train-ing journal, and don’t measure their bodycomposition. They’re the ones who lift thesame weight month after month and whosebodies never change. One of the best waysto set a goal is to pick a date six to twelveweeks in the future and to plan for a certainbody weight and fat percentage at that time.For example, “By next I want to weigh 220pounds at 6% body fat. This means that byMay I need to gain 10 pounds of muscle andlose 8 pounds of fat.” This gives you somespecific goals to shoot for, and a timetableto monitor your progress. Of course, youcan’t do it without measuring your bodycomposition. The Parrillo Performance BodyStat Kit was made just for this reason, andincludes a manual with detailed instructionson how to modify your program to keep mak-ing progress.Bodybuilding is not really all thatcomplicated. If you’re not making goodprogress you need to make some kind of achange, and the two places to makes thesechanges are in your training or your nutri-tion. Don’t be afraid to change one or bothof these. Let’s consider the muscle gainingplateau first. The most common problem hereis with nutrition – people just don’t eatenough calories to sustain further musclegrowth. Consider this: your body’s dailyenergy expenditure – the number of caloriesyou burn in a day – is determined by yourmuscle mass, among other factors (1,2).Muscle is metabolically active tissue – apound of muscle requires 25-30 calories aday to maintain and up to 100 calories tobuild.

This means that as your muscle massincreases your daily calorie requirement in-creases at the same time. As an example,let’s consider a hypothetical 180 poundbodybuilder whose maintenance energy re-quirement is 2500 calories a day. This meansthat during an average day, his body burns2500 calories total. If he consistently con-sumes less than 2500 calories a day he’lllose weight, and if he consistently consumesmore than 2500 calories a day he’ll gainweight. If he consumes 2500 calories a day,his present body weight will  be maintained,and that’s why we call this his “maintenanceenergy requirement.” Now let’s say he wantsto pack on some mass, so he starts eating2800 calories a day. For several weeks he willgain at about a pound a week, but then thegains stop. Why? Well, if each pound of newmuscle burns 30 calories a day just for main-tenance purposes, and he gained 10 pounds,that’s 300 more calories he burns every dayjust to maintain his body. That means hisnew maintenance energy requirement is now2800 calories a day, not 2500 like it used tobe. So for awhile he was making good gainson 2800 calories, but the added muscle hasincreased his metabolic rate so that now heneeds 2800 calories a day just to maintainhis new weight. So the gains stop. To add the next 10 pounds of muscle he would haveto increase calories again.

This is pretty basic stuff, but you’dbe surprised how often it’s overlooked. Formany people, gaining more muscle is assimple as eating more calories. Many body-builders are afraid to try it because they’reafraid they’ll gain fat. The key is to eat clean,lean bodybuilding foods. The Parrillo Nutri-tion Manual describes how to increase yourcalories from foods which are more prone tohelp you build muscle and which are diffi-cult for your body to store as fat. What’s thebest way to increase calories to gain moremuscle?Generally speaking, an increase in complexcarbohydrates is the best way to go. Youalso need to increase your protein intake asyou gain weight, so that you’re getting atleast one to one-and-a-half grams or more ofcomplete protein per pound of body weighteach day, but the bulk of your calories shouldbe derived from carbohydrates. By increas-ing your carbohydrate intake, this will in-crease your ratio of insulin to glucagon andincrease the anabolic drive to build moremuscle (3). Increasing your carbohydrateintake actually provides a more potentgrowth stimulus than increasing protein.Remember this as a general rule: as yourbody weight increases, increase your pro-tein. As your energy requirement increases,increase your carbs.

A growth plateau gen-erally means you need more calories, notmore protein (as long as you’re meeting yourone to one-and-a-half grams or more perpound per day requirement). And those calo-ries are best supplied as carbohydrates. Besure to use complex carbs and stay awayfrom sugar or refined carbs, which are easilyconverted to fat.A brief word on supplements here:provided your protein requirement is beingsatisfied, the most potent supplements forgaining weight are probably Pro-Carb Pow-der™ and CapTri®. A couple scoops of Pro-Carb® taken with or between meals will initself be enough to help most people packon several pounds of lean muscle. If youfind that you’re putting on fat, consider us-ing CapTri® instead. It supplies calories in away which is almost impossible for yourbody to convert to fat (4,5). And if you don’ttolerate carbs too well, CapTri® can give youthe added calories and help maintain a morefavorable glucagon/insulin ratio.As you continue to gain lean mass,your metabolic rate will increase, so you’llhave to gradually increase your caloric in-take to support further weight gain. It’s notuncommon for big bodybuilders to eat 6,000calories a day or more.

Don’t make the mis-take of increasing calories too fast, however.You might be tempted to say that you wantto gain 40 pounds, and try to do it all at onceby upping your calories by several thou-sand. If you do that all at once, you’ll gain alot of fat along with the muscle. You can onlybuild muscle so fast, and if you push yourcalories up too fast you’ll get fat. On theParrillo Performance Program, we recommendgaining at a rate of about a pound a week.That way, you know you’re adding solidmuscle mass, instead of possibly packingon fat. It’s best to increase your calo-ries in increments of300-500 a day.Although ittakes around 30calories a day tomaintain a poundof muscle, it takesmuch more to actu-ally build thatmuscle. That’s whyyou can’t just add 30extra calories a dayand expect to gain apound of muscle in aweek. Just doesn’t hap-pen that way. And as your maintenance levelchanges, so will the number of calories youneed. Your body just doesn’t gain ten poundson 300 to 500 extra calories then stop, wait-ing for that next 300-500 calorie increase.Your growth and caloric needs are constantlychanging.As you eat more you provide yourbody with the nutrients to gain more muscle,and as you gain more muscle, you’ll need toincrease your calories to maintain the muscleyou’ve already gained plus the extra calo-ries your body needs to make new muscle.

That’s why it’s so important to record whatyou’re eating on Diet Trac Sheets and checkyour body composition regularly using theBodyStat Kit. A lot of people think this toolis used only during the pre-contest period.But in actuality, the BodyStat Kit can tellyou a lot about your lean mass and body fatand how these percentages change accord-ing to your diet and training.The other possible problem if youhit a plateau could be in the area of training.Within this category, you could be under-training, over-training, or not training in-tensely enough. Just as your nutritionalneeds change as you gain more muscle mass,you will find that periodic variation in yourtraining will help you break through plateaus.Although it’s hard to make generalizationsabout this, probably the most common mis-take here is not training intensely enough.Intensity is the key to productive weighttraining exercise. Increasing or decreasingthe volume of exercise you do won’t makemuch difference if the exercise you’re doingis not intense enough to stimulate musclegrowth in the first place.

The key principlehere is progressive resistance—you have to lift heavier weight if youwant to get bigger and stronger. This is whykeeping a training journal is so important.On a monthly basis you should be gettingstronger on the basic lifts. Certainly now youshould be benching, squatting, and press-ing more weight than you were this time lastyear. If you’re not, you need to make achange. Every workout you should try to lifta heavier weight than you did the last time,or else do more reps with the same weight. Itmay not be realistic for an advanced body-builder to increase the weight at everyworkout, but if a month or two goes bywith no improvement, that’s a sign it’s timefor a change.What do you change? The vari-ables to play with here are endless, butthe bottom line is that you want to increaseyour strength on the basic lifts. This meanslifting more weight on squats, bench press,shoulder press, rows, and deadlifts. Train-ing for strength and training for size arenot the same, but they do go together. Thebest way to train for strength is to lift veryheavy weights in the 3-6 rep range andkeep the volume fairly low. To train formuscle size it’s better to do 8-12 repeti-tions and to do a higher volume of exer-cise. It’s important to train to positivemuscle failure, so that you can’t performanother repetition.

When training for size,it’s also very important to emphasize the ec-centric phase of the muscle contraction. Thatmeans you need to resist the weight as youlower it while the muscle is lengthening.When you can perform 12 repetitions in goodform, it’s time to increase the load. This iswhere many people fail in the gym. They dothe same 3 sets of 10 reps with the sameweight every week and never increase theload. They never get any stronger and theirmuscles don’t grow. You have to continu-ally push yourself. You have to continuallychallenge yourself with heavier weights.Regarding the issue of whether youshould train in the 3-6 rep range or the 8-12rep range, I think you should do both. In lastmonth’s article I suggested a program whereyou do “powerlifting-style” training (3-6 reprange) for one month, then “bodybuilding-style” training (8-12 rep range) the nextmonth. Alternatively you can do low repsone week and moderate reps the next week,or even incorporate both into each workout.Any of these approaches will work, just soyou remember to try and increase the load orthe number of reps as often as possible.

Isuggest making some alterations in yourtraining program every 4-6 weeks to presentyour muscles with a fresh stimulus. Yourmuscles seem to adapt to a given trainingregimen after about a month.Regarding the questions of specific trainingroutines, training volume, and training fre-quency, I would have to write an entire bookto cover these issues. (Actually, I wrote threebooks about that – The Parrillo PerformanceTraining Manual, John Parrillo’s Fifty Work-out Secrets, and High Performance Body-building.) What I can tell you here are justsome basic concepts. Everyone seems to besearching for the “ultimate” workout routine,as if it were some sort of holy grail. The truthis, there is no single ultimate routine, al-though some are better than others. The keyconcepts are to emphasize the basic exer-cises, train hard, train to failure, continuallylift heavier weight, and periodically alter yourworkout to get some variety. Many body-builders rotate their body parts five or sixdays a week, training only one muscle groupat each workout. Others do better on a threeor four day rotation and training two or threemuscle groups at each workout. Experimentwith a six day split, training six days a week,one body part per workout, versus a threeday split, training two body parts per work-out. See what works best for you. The onlymistake you can make is to stick with a pro-No Limits: How To Break Through Plateaus, Part Igram that’s not working. Check out my train-ing books if you want more details on de-signing routines and on exercise perfor-mance.

References

1. McArdle WD, Katch FI, and Katch VL.Exercise Physiology: Energy, Nutrition, andHuman Performance. Lea & Febiger, Phila-delphia, 1991.

2. Wilmore JH and Costill DL. Physiologyof Exercise and Sport. Human Kinetics,Champaign, IL, 1994.

3. Westphal SA, Gannon MC, and NuttallFQ. Metabolic response to glucose in-gested with various amounts of protein.Am. J. Clin. Nutr. 52: 267-272, 1990.

4. Baba N, Bracco EF, and Hashim SA. En-hanced thermogenesis and diminisheddeposition of fat in response to overfeed-ing with diet containing medium chain trig-lyceride. Am. J. Clin. Nutr. 35: 678-682, 1982.

5. Bach AC and Babayan VK. Medium chaintriglycerides: an update. Am. J. Clin. Nutr.36: 950-962, 1982.

6. Maughan RJ. Creatine supplementationand exercise performance. International Jour-nal of Sport Nutrition 5: 94-101, 1995.

7. Greenhaff PL. Creatine and its applicationas an ergogenic aid. International Journal ofSport Nutrition 5: S100-S110, 1995.

Bulletin #32 – Parrillo Performance Guide to Muscle, Part 5

In the previous bulletin I introducedthe “all or nothing” principle of musclecontraction, which states that a givenmotor unit either contracts maximally ornot at all. I also explained the pattern ofmuscle fiber recruitment. For low inten-sity activities, such as fine finger move-ments or precise movement of the eyes,small motor units are recruited. Smallmotor units allow precise muscular con-trol and are primarily composed of slowtwitch fibers, which generate low forcesand are fatigue resistant. As progressivelymore force is required for an activity, morefast twitch motor units are called into play.These have more muscle fibers connectedto each nerve cell (that is, they are largermotor units) and are capable or generat-ing high forces although they fatigue moreeasily.

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In this bulletin I would like to talk aboutdifferent types of muscle contraction, andwhy these are important in bodybuilding.Concentric muscle actions occur when amuscle is shortening. This happens whenforce generated within the muscle is suf-ficient to overcome the resistance toshortening (1).  An example is the liftingphase of a biceps dumbbell curl.  Duringthis phase of contraction, action poten-tials are arriving at the neuromuscularjunction, causing a release of the neu-rotransmitter acetylcholine at the synap-tic cleft.  This causes an influx of cal-cium into the muscle cell, as well as arelease of calcium from the sarcoplasmicreticulum.  (Review previous articles inthis series in these concepts are fuzzy.)The rising calcium concentration sets offa series of events resulting in activationof the actin-myosin cross-bridges.  ATPis consumed as the sarcomeres shorten,bringing the Z lines at the ends of the sar-comere closer together.  

Thus when amuscle fiber contracts, each of the indi-vidual sarcomeres contract, and ATP isconsumed.  Concentric muscle actions arereally the only true muscular contractions,because contraction literally means “toshorten.”Isometric muscle actions refer to thesituation where the force generated by themuscle is sufficient to exactly balance theresistance.  An example is at the top of abiceps curl at the moment of peak con-traction, or any time when you pause dur-ing the curl and the weight remains sta-tionary.  “Isometric” means “the samelength,” and thus describes any time amuscle is working but is not changing inlength.  Eccentric muscle actions refer tosituations when the muscle is generatingforce but that force is less than the resis-tance on the muscle.  An example is thelowering phase of a biceps curl.  Here,the muscle is still working and generatingforce, but the muscle is actually gettinglonger.  Gravity is the force pulling thedumbbell downward, and this force istransmitted to the forearm and then to thebiceps tendon.  If this force is greater thanthe internal force generated by the bicepsmuscle, then the muscle will lengthen in-stead of contracting, even though it is stillworking and generating force.“Isokinetic” means “the same velocity” anddescribes muscle actions that occur atconstant velocity.  

An isokinetic contrac-tion is simply a concentric muscle actionthat occurs at constant velocity.It is important to realize that duringisometric and eccentric muscle actions westill have nerve impulses (action poten-tials) arriving at the muscle, triggeringcalcium release and activation of the ac-tin-myosin cross-bridges, just like we doduring concentric actions.  The differenceis that the force generated by the muscleis no longer sufficient to overcome theresistance.  During isometric actions thesarcomeres remain the same length, andduring eccentric actions the sarcomeresactually get longer.  During eccentric ac-tions the actin-myosin cross-bridges arestill trying to pull the Z lines together toshorten the sarcomere, but they’re justnot strong enough.  As you might imag-ine, this causes quite a bit of damage tothe cross-bridges and to the whole sar-comere.  The sarcomere is working tocontract, but is being overcome by ex-ternal forces which are forcing it tolengthen while it is trying to contract.This is the main source of microtrauma(microscopic damage) to the muscle thatoccurs when you work out.

 If you takea muscle biopsy (a small tissue sample)from a muscle after a workout and lookat it in the electron microscope, you willsee that the normal structure of the musclehas been disrupted.  The amount of dam-age to the muscle is far greater followingeccentric actions than for concentric orisometric actions, as you might guess.  Inconcentric actions under heavy resistance,the microscopic structures of the musclefiber literally get ripped apart as the musclefiber is forced to lengthen while it is try-ing to contract.Following intense training sessions wesee a phenomenon called “Z band steam-ing,” which describes the Z band struc-ture being disrupted and myofilamentsstreaming out from the normal sarcom-ere structure.  Under extreme conditionsyou can even see rupture (breakage) the sarcoplasmic membrane (the cell mem-brane of muscle cells) and leakage of cel-lular contents from the cell.  Some of thesecan be measured in routine lab tests in ahospital.  Creatine phosphokinase (CPK)is an enzyme in muscle cells which formscreatine phosphate, the short-term energyreserve in muscle cells which is respon-sible for immediately replenishing ATP(refer back to our series on cellular en-ergy metabolism).  When muscle cells aredamaged and the cell membrane startsleaking, CPK is released into the blood andcan be measured in the laboratory.  Inhospitals CPK levels are used as an initialscreen to tell if someone has had a heartattack or not, since during a heart attacksome of the heart muscle cells die andrelease CPK.  

Skeletal muscle cells alsorelease CPK when they are damaged.Using tests like muscle biopsy and CPK,scientists have determined that mostmuscle damage occurs during eccentricmuscle actions, when external forces ripthe myofibers apart.  This is also the maincause of muscle soreness 24-48 hoursafter a workout, and is called “delayedonset muscle soreness,” or DOMS.  Trya few sets of heavy forced negativessometime to prove it to yourself.  It iswell known to bodybuilders that negativescause the most muscle soreness, and nowyou know why.Why is all of this important to body-builders?  Because it is at the very heartof muscle growth.  You see, the micro-scopic tissue damage that occurs afterweight training serves as the stimulus forinflammation.  Inflammation is a processthat occurs in damaged or infected tis-sues that signals the immune system tocome into play.  White blood cells, mainlylymphocytes, neutrophils, and macroph-ages, are called in to clean up the mess ofthe damaged and leaking muscle cells.  Thewhite blood cells release immune media-tors such as histamine, bradykinin,cytokines, and interleukins, which helpbring about the repair process.  Bradyki-nin is one of the immune mediators that isparticularly famous for causing pain, andimmune mediators like bradykinin andprostaglandins are the reason muscles getsore after a workout.  

During the inflam-mation process, damaged cells and re-paired and the tissue is returned to its origi-nal state.  The body doesn’t like this in-flammation and repair process however,and overcompensates a bit during the re-pair process.  The body makes the musclesa little bit bigger and stronger than theywere before the workout, so that nexttime you hit the weights hopefully themuscles can take it and not get damaged.The body’s ability to overcompensate isvery limited however, and estimates arethat with each good workout yourmuscles increase in size only about 0.1%.This is why it takes years of consistenttraining to get really big muscles.There are two basic principles of body-building training that are more importantthan all the others put together.  The firstis the principle of intensity.  A workoutmust exceed some threshold of intensityin order to stimulate growth.  The secondis the principle of progressive resistance.This means that as you get stronger, youhave to keep progressively increasing theresistance to overload the muscle.  In otherwords, as the muscle gets stronger theintensity threshold required to stimulatefurther growth increases.  

This is a directconsequence of the over-compensationprocess I described above.  During theinflammation and repair process, tissueremodeling occurs to help the muscleadapt to the stresses imposed on it.  Ini-tially, a 30 pound dumbbell curl maybe intense enough to cause muscledamage and set into play the pro-cess of muscle growth.  Musclegrowth is really just an adaptiveresponse that occurs so that thenext time you curl a 30 pounddumbbell it doesn’t cause somuch damage to the muscle.After a while, you will be able tocurl the 30 pound dumbbell eas-ily, without much strain or dam-age to the muscle.  At that point,the muscle and it’s associatedconnective structures have ad-equately adapted to the stressimposed by a 30 pound dumb-bell.  You can keep workingout with 30 pound dumbbells for the restof your life and little, if any, additionalgrowth will occur.  The muscle has grownand adapted to that level of stress.  If youstick to the 30 pound dumbbells you willfind that over time you will be able to domore and more reps with 30 pounds, butthat will do little to increase muscle size.Any time you’re doing more than 12-15reps with a weight you’re primarily train-ing muscle endurance, not musclestrength.  

Training for muscle enduranceis just fine, but does very little to increasemuscle size.  To increase muscle size youhave to increase strength, which meanslifting a heavier weight.  So you go up tothe 35 pound dumbbells and get maybe 6reps before your biceps fails.  This repre-sents a new level of stress, a higher levelof intensity, and the adaptation processbegins again.  After a few weeks ormonths you will be able to curl the 35pound dumbbells for 12 reps and yourbiceps will be bigger and stronger than itwas when you could only curl 30 poundsfor 12 reps.  This is the principle of pro-gressive resistance.For maximal gains in strength, youwant to train with a heavy weight at lowreps, say 3-6 reps.  For maximal gains inmuscle size, you want to train with aweight you can handle for 6-10 reps.  Asthe muscle adapts and gets stronger, youwill need to increase the weight in smallincrements (about 5-10% per jump) tokeep yourself in the proper rep range.  Themost effective training strategies over thelong haul involve some work in the 3-6rep range and some work in the 6-10 reprange.  This helps train the nervous sys-tem and well as the muscle and helps en-sure the high threshold pathways are re-cruited.  For purposes of increasingmuscle size and strength, by the time youcan perform 12 reps with a given weightthis means it’s time to increase the load.Just how does this process of musclegrowth and adaptation occur?  There aretwo basic mechanisms that come into play:hypertrophy and hyperplasia.  

Musclehypertrophy means that an individualmuscle cell gets bigger.  This occurs as itbuilds more myofibrils by adding moreactin and myosin (and other associatedstructures).  In other words, an individualmuscle cell builds more contractile pro-teins inside it, making it increase in diam-eter.  This of course also makes it stron-ger and able to generate more force whenit contracts.  Muscle hyperplasia describesthe situation of adding more muscle cells.Hypertrophy is an increase in muscle cellsize, and hyperplasia is an increase inmuscle cell number.  The overwhelmingbody of scientific evidence indicates thatmost muscle growth is the result of hy-pertrophy (2,3).  If you take biopsysamples of muscle before and after a train-ing program, you will see that after train-ing there are still about the same numberof muscle fibers (muscle cells), but thateach muscle fiber is bigger in diameter.This indicates that hypertrophy is a moreimportant adaptive response to exercisetraining that is hyperplasia.  Several stud-ies with bodybuilders do indicate howeverthat muscle hyperplasia can occur.  Inthese studies it was found that bodybuild-ers had more muscle fibers (cells) percross-sectional area than untrained con-trols (2,3).  

One experiment with catsdemonstrated a 9% increase in fiber num-ber following 101 weeks of resistance legtraining (2,3).  To reconcile these obser-vations with the body of data suggestingthat most muscle growth occurs by fiberhypertrophy, it was suggested that in or-der for muscle cell hyperplasia to occurthe training stimulus must be of high in-tensity, with heavy resistance and lowrepetitions (2,3).  Most studies in exer-cise physiology use untrained subjects,with moderate to low resistance and higherrepetitions.  While both growth mecha-nisms are probably at play in bodybuild-ers, most experts agree that most musclegrowth occurs by hypertrophy of exist-ing muscle fibers.When muscle cells do undergo hyper-plasia, what is the source of the newmuscle cells and the stimulus for theirgrowth?  This question is of course ofgreat interest to bodybuilders, since it isthe door to almost unlimited musclegrowth.  New muscle cells are believedto derive from differentiation and prolif-eration of satellite cells.  Satellite cells arelittle tiny cells not much bigger than nu-clei, and are found along the periphery ofmuscle fibers.  Satellite cells seem to bemost active during the growth of the fe-tus, while it is rapidly forming new muscletissue.  During adult life, satellite cells canbe induced to turn into new muscle cellsby factors released from damaged musclecells (4).  

When satellite cells were placedin culture dishes it was found that theycould be induced to differentiate (turn intonew muscle cells) by adding an extractfrom minced or ground up muscle tissue(4).  An extract from undamaged muscleor from some other tissue could not dothe trick.  Thus it appears that muscle cellscontain some substance that can leak outwhen the cell membrane is damaged, andthis substance acts as a signal to causethe satellite cells to grow.  The idea is thatsatellite cells represent a reserve sourceof precursor cells that can be called uponfollowing muscle damage, to make newmuscle cells and repair the damagedmuscle.This all makes sense if you think aboutit.  We know that most muscle cell hy-perplasia comes about as a result of highresistance training with heavy weight (2).We also now that high resistance train-ing, especially the eccentric phase of themuscle action, results in the most muscledamage (1,2,3).  Finally, we also knowthat high resistance training is the mosteffective stimulus for increasing musclesize and strength (1,2,3).  So it all fitstogether.  And this is why it’s vitally im-portant for bodybuilders to pay specialattention to the lowering phase of eachrep – it’s the most important part of therep for stimulating muscle growth.  Youshould always lower the weight slowlyand resist the weight on the way down.

This type of training will make you sore,but it’s the best stimulus for musclegrowth.  I don’t recommend negative-onlytraining, however.  You still need the posi-tive (lifting) part of the rep to fully workthe muscle and to exhaust its ATP stores.Since the muscle requires ATP to relax aswell as to contract, if you use up the ATPin the positive phase of the movement,this will result in greater microtraumaduring the eccentric phase.  And this, pre-sumably, will trigger a greater adaptiveresponse and more muscle growth.The Parrillo program is founded on thebasics to help this process work at peakefficiency.  I’m sorry, but there really areno tricks or secrets.  It takes dedication,consistency, and hard work.  What do youdo?  First, you have to make every work-out count.  Every workout must be in-tense enough to stimulate muscle growth,or you’re just wasting your time in thegym.  You have to attack each workout.Think of the weights as enemies to beconquered – to be slaughtered.  Walk intothe gym with a feeling of overwhelmingpower.  The weights simply are not strongenough to resist you.  You WILL lift heavyweights today.  Get in there, kill theweights, and get out.  

That’s your job.Second, supply your body with morethan adequate amounts of every nutrientit needs to build muscle.  Protein, carbo-hydrate, vitamins, minerals, branchedchain amino acids – and most importantly, a foundation of solid nutritious food.  Startwith a solid bodybuilding diet and addsupplements to boost cellular nutrient lev-els even higher.  Don’t compromise onnutrition.  Can you imagine going to allthat work of busting your butt in the gymand then not growing because of sub-op-timal nutrition?  The optimal bodybuild-ing diet is laid out in detail in the ParrilloPerformance Nutrition Manual.  Whichfoods to eat ,which foods to avoid, howmuch protein, carbs, and fat, how manycalories, how many meals, and everythingelse you need to know.  It even comeswith a food scale and a food compositionguide, so you can precisely structure eachmeal for optimal results.  After the foun-dation is laid with the right foods, thenadd in supplements to boost nutrient lev-els even higher.  Start with the basics: Hi-Protein Powder™, Pro-Carb™, , Vitamins,and Minerals.  Add in Muscle Amino™,  forextra branched chain amino acids — theprimary structural amino acids in muscleprotein.  If you’re a hard gainer or wantfaster results, add in CapTri®.  

CapTri®supplies calories which are preferentiallyused for energy, sparing amino acids sothey can be used to build protein insteadof being burned as fuel.  The special thingabout CapTri® is that excess calories fromCapTri® are readily burned as body heatinstead of being converted to body fat.This makes CapTri® THE BEST way toadd calories to your diet in a way that willminimize body fat.  It’s a hard gainer’sdream come true.Third, get adequate rest to allowmuscles to recover between workouts.This is a must.  Remember, muscles don’tgrow in the gym – they get damaged inthe gym.  The growth phase occurs dur-ing the next couple of days following aworkout while the muscles are recover-ing.  You have to get adequate rest forthis recovery process to occur optimally.There’s no simple answer to the questionsof how often should you train eachmuscle, or how many days a week shouldyou train.  Trainers and muscle physiolo-gists have been studying this for years,and still don’t know the answer.  The rea-son is that the optimal training protocol isdifferent for different people.  Hard gain-ers do better with less work and moretime for recovery – say, training three daysa week on a one on — one off schedule.People who are naturally muscular andgain muscle easily often can train more,three on and one off, for example.  Somepeople even do well training every day,training one muscle group each day.  Someprofessionals train twice a day.  

The opti-mal schedule for you depends or your ownbody’s recovery ability as well as howmany other stressors you have in yourlife.  If you work 60 hours a week, forexample, this takes a big toll on your re-covery ability, and you probably won’t beable to recover from daily workouts.  Pro-fessional bodybuilders don’t have anyother job to worry about, so they are atan advantage in terms of recovery.  Youwill have to experiment to find the bestroutine for your body.  There are somebasics however, that are true for every-body.  You have to train hard.  You haveto give each workout everything you’vegot.  You have to keep slowly increasingthe resistance and getting stronger.  TheParrillo Performance Training Manualdescribes all the best exercises for body-builders, with descriptions of proper ex-ercise performance and sample routines.There’s enough in there to take you fromthe beginning level all the way through theprofessional ranks.Start off with the Nutrition and Train-ing Manuals, which are where you get theinformation you need to reach your body-building goals.  At any time, feel free tocall or write with questions or for per-sonal counseling.  We support our pro-gram all the way – we don’t just sell yousomething and then turn you loose.  Whatsets us apart is that Parrillo is a compre-hensive package, a total program of train-ing and nutrition, which is supported allthe way.  We supply information, not justsupplements.

 We actually teach you whatyou need to know to become the best youcan be.  Who else does that?  Who elsesends out a free magazine to customerswith scientific information about body-building endocrinology, cellular energymetabolism, and muscle physiology justParrillo Performace Guide to Muscle, Part Vto educate customers so they can get themost out of the workouts?  Nobody else.A lot of people sell supplements, but no-body else does what we do.  We’re forreal.  We’re here for the few people outthere who are really serious about reach-ing their goals.  We believe that peoplewho are dedicated and work hard in thegym deserve results.  When you buysupplements from somebody else, that’sall you get.  But when you buy supple-ments or a manual from Parrillo, that’sjust the beginning of a relationship.  That’sour commitment to you.  To supply notonly the products, but more importantlythe support and information you need toget results.  That’s why the serious peopleend up with Parrillo.

References

1. Baechle TR. Essentials of StrengthTraining and Conditioning. Human Kinet-ics, Champaign, IL, 1994.

2. Wilmore JH and Costill DL. Physi-ology of Sport and Exercise. Human Ki-netics, Champaign, IL, 1994.

3. McArdle WD, Katch FI, and KatchVL. Exercise Physiology – Energy, Nutri-tion, and Human Performance. Lea &Febiger, Malvern, PA, 1991.

4. Lieber RL. Skeletal Muscle Structureand Function. Williams and Wilkins,Baltimore, MD, 1992.

Bulletin #31 – Parrillo Performance Guide to Muscle, Part 4

In this bulletin we continue our super-feature on muscle and will discuss somekey concepts of muscle physiology. Sofar we’ve covered muscle anatomy, ul-trastructure and biochemistry, as well ascontrol of muscle tissue by the nervoussystem. In final three parts of this serieswe’ll discuss metabolic adaptations ofmuscle to exercise and how to design ef-fective training strategies to achieve yourgoals.  Please refer back to your old is-sues of the Parrillo Performance Press forour articles about hormones and cellularenergy metabolism, as these tie in directlyto muscle metabolism and physiology.In Part 2 I introduced the concept ofthe motor unit: a lower motor neuron(nerve cell) in the spinal cord plus themuscle fibers that it controls.  I said thata motor unit fires according to the all-or-nothing principle.  That means it eitherfires at full power or not at all.  There’sno such thing as partially contracting amuscle fiber, or it contracting at mediumintensity.  What determines the strengthof a muscular contraction is then howmany motor units are recruited to fire(contract).  

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This month we will extendthis concept to the next level, and talkabout patterns of muscle fiber recruit-ment.Nerve impulses traveling down theaxon of a motor neuron (nerve fiber) to amuscle cell travel in discrete bundles calledaction potentials.  An action potential isan electrical signal that is carried alongnerves that stimulates muscle fibers tocontract by triggering the release of cal-cium from the sarcoplasmic reticulum.Rather than being like the continuous flowof electricity that is delivered from a bat-tery, an action potential is a short burst orpulse of electricity, like flipping a switchon and then quickly off again.  An ex-ample you may be familiar with is an EKGtracing of the heart – this is the actionpotential of the heart muscle.Each action potential results in a shortperiod of activation of the muscle fiber,and is referred to as a twitch (1).  Thecalcium released during a twitch is suffi-cient to allow optimal activation of actinand myosin, and therefore maximal forcedevelopment by the muscle fiber (1).

However, as the contracting muscle fi-bers begin to pull on the tendons and “takeup the slack,” pumps begin pumping thecalcium back into the sarcoplasmicreticulum.  Thus the muscle fibers beginto relax before the muscle has time togenerate maximal force on the tendons.So while a twitch stimulates a muscle fi-ber to contract maximally, it begins to re-lax before maximal force is generated bythe muscle (1).  If a second action poten-tial (nerve impulse) arrives at the musclefiber and causes another twitch before thefiber has completely relaxed, the forcefrom the two twitches summates (addstogether) to generate a greater force thanfrom a single twitch (1).  As we increasethe frequency of action potentials we willdecrease the rest period between twitches,and the summation of force increases (1).At a high enough frequency of stimula-tion the twitches fuse (that is, there’s notime for the fibers to relax), and forceproduction reaches a plateau called tetany.This is the highest force that a motor unitcan produce (1).A given muscle is composed of sev-eral different fiber types.  There are manyclassification schemes for describing dif-ferent muscle fiber types.  The first ap-proach is to classify muscle fibers accord-ing to twitch time.  

You’ve probably heardof slow-twitch versus fast-twitch fibers.A fast twitch fiber (also termed type 2)develops force rapidly and has a shorttwitch time (1).  A slow twitch fiber (alsotermed type 1) develops force slowly andhas a long twitch time (1).  This results indifferent abilities to develop force and re-sist fatigue.  Slow twitch fibers generallyare fatigue resistant and have a high ca-pacity for aerobic energy production (re-fer back to our series on cellular energymetabolism).  This makes them ideal forlow energy activities that you need to beable to sustain for a long time, like walk-ing or standing or keeping the spine erectwhile sitting.  Fast twitch fibers, in con-trast, are easily fatigued, are relativelypoor at aerobic energy production, but areable to generate tremendous forces veryrapidly.  Fast twitch fibers are further sub-divided into two subtypes, 2a and 2b, ac-cording to differences in ATPase activity(2).Perhaps the oldest classificationscheme is based on gross appearance.  Inthe early 1800’s it was noticed thatmuscles range in color from deep red topale white (2).  This is most easily ob-served when looking at the muscles ofbirds, where the differences are the great-est.  It is now understood that somemuscles are red because they containgreater capillary density and more myo-globin (an oxygen storing molecule likethe hemoglobin found in red blood cells)and mitochondria (the little furnaces in-side cells where food molecules areburned to produce energy).  

These prop-erties (more capillaries, myoglobin, andmitochondria) make red muscle fibersbetter at aerobic energy production.White muscle fibers have less myoglobinand mitochondria but more stored glyco-gen, making them better at anaerobic en-ergy production.  The difference is easilyseen when comparing a chicken breast toa chicken thigh.  A chicken breast is whitemeat (white muscle fibers) and a thigh isdark meat (red muscle fibers).  These dif-ferences make sense if you think about it.The breast of a bird is involved in beatingthe wings during flight, which requires ahigh level of force production.  The thighs,however, are involved in weight supportand walking, requiring a lower level of force production.Another classification scheme is basedon metabolic and histochemical (micro-scopic staining) properties of musclecells.  This is basically an extension ofthe fast twitch/slow twitch scheme, butalso takes into account fuel types preferredby different fiber types.  According to thisscheme, fibers may be either slow oxida-tive (SO), fast glycolytic (FG), or fastoxidative glycolytic (FOG) (2).  Thisscheme is based on microscopic analysisof fibers looking at various enzyme sub-types (such as subtypes of ATPases) andit gets real technical real fast.

For thoseof you interested in greater detail, the bestdiscussion of muscle fibers types is foundin Lieber, Skeletal Muscle Structure andFunction, pages 70-89 (2).In summary:  Within any given muscledifferent fiber types exist for performingdifferent functions.  There are many waysto classify the different fiber types.  Theseinclude twitch time, muscle color, fuelsources, enzyme subtypes, fatigability, andcombinations of the above.  A compari-son of different classification schemes ispresented in the table.In general, slow twitch (ST) fibershave a high level of aerobic endurance (3).ST fibers are thus very efficient at pro-ducing ATP from the oxidation of carbo-hydrate and fat (3).  As long as oxygenand fuel are available, ST fibers can con-tinue to produce ATP and thus the energyto contract.  ST fibers are therefore pref-erentially recruited for low intensity ac-tivities like walking, jogging, or biking.Fast twitch (FT) fibers, on the other hand,are better suited for anaerobic energy pro-duction.  This is largely through the con-version of stored muscle glycogen to lac-tic acid via glycolysis.  

FT motor unitscan generate considerably more force andpower (work per unit time) than ST mo-tor units because their rate of force pro-duction is not limited by the rate of oxy-gen delivery.  Furthermore, FT motor unitsare generally larger (contain more musclefibers) than ST units.  FT motor unitsfatigue easily however, because they ex-haust their fuel supply (and other inter-mediates) and build up lactic acid.  Whenthe acid level builds up too high in the cell,this shunts down the cellular enzymes thatproduce energy, so contraction comes toa halt.  FT fibers are thus best suited forbrief, high intensity activities such assprinting.  During extremely high inten-sity exercise, such as weight lifting, bothST and FT units are recruited to maxi-mize force production.Remember that force production withina muscle is increased by increasing thefrequency of action potentials arriving atthe muscle, and thus the frequency oftwitches, and by increasing the numberof motor units participating in the con-traction.  When only a little force isneeded, only a few motor units are re-cruited.  Recall also that FT motor unitscontain more fibers than ST units.  There-fore, when only a little force is needed,small motor units, which are primarily theST type, are recruited (3).  As exerciseintensity increases, FT type 2a (corre-sponding roughly to FOG type fibers) arealso recruited.  At maximal intensity, FTtype 2b (or  FG) fibers are called in.This gets us back to the concept ofintensity threshold that we talked about inthe first article of our muscle series.  

Ex-ercise must provide a high intensity stimu-lus in order to recruit all of the fibers.  Ilike to refer to these as the “high thresh-old nerve pathways.”  It is of great im-portance to realize that the fast twitch fi-bers are the ones with the greatest poten-tial for hypertrophy (growth).  In orderto stimulate these fibers to grow we mustrecruit them to contract, and to do thatwe must apply a high intensity stimulus.This is why you have to lift big weightsto get big muscles.  Curling 5 pounddumbbells all day will never give you bigbiceps.So for maximal muscular growth abodybuilder has to perform at least fourdistinct types of training: 1. Drop sets toensure that nearly 100% of muscle fibersare recruited. 2. Heavy sets around 1-3rep maximum to recruit the high thresh-old nerve pathways. 3. High intensityaerobics (around 30 minutes 3 times aweek) to increase capillary supply ofmuscles. 4. Standard “bodybuilding sets”carried to failure at 8-10 reps.  I’ll explainmore about this in the future, but the ba-sic function of these is to induce local tis-sue trauma which serves as a stimulusfor inflammation and remodeling.  In themedium rep work (8-10 rep range), spe-cial attention must be paid to going to fail-ure and to resisting the weight during theeccentric (lowering) phase of the contrac-tion.

References

1. Baechle TR. Essentials of StrengthTraining and Conditioning. Human Kinet-ics, Champaign, IL, 1994.

2. Lieber RL. Skeletal Muscle Struc-ture and Function. Williams and Wilkins,Baltimore, MD, 1992.

3. Wilmore JH and Costill DL. Physiol-ogy of Sport and Exercise. HumanKinetics, Champaign, IL, 1994.

Bulletin #30 – Parrillo Performance Guide to Muscle, Part 3

In Part 3 of our series about musclewe are going to take a microscopic lookat exactly what happens inside a musclecell when you lift weights. First, let’s re-view some basics about how muscles arecontrolled by the central nervous system.The first thing that happens is thatyou decide to lift a weight.  This happensin the frontal lobe of the brain, where con-scious thought occurs.  The frontal lobesends a signal to the prefrontal gyrus, ormotor strip, of the brain.  You see, eachmuscle cell is controlled by a chain of twoneurons, or nerve cells.  The first one isin the brain, in the motor strip, and is calledthe upper motor neuron.  The second isin the spinal cord, and is called the lowermotor neuron.  The upper mo-tor neuron is a very long cell,and sends a cellular process (along extension) called an axoninto the spinal cord.  There itmakes a contact called a syn-apse with the lower motor neu-ron.  

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The upper motor neuronreleases a chemical called a neu-rotransmitter into the synapticspace, which then binds to a re-ceptor on the lower motor neu-ron.  Neurotransmitters can ei-ther be inhibitory or excitatory.The balance of inhibitory andexcitatory neurotransmitters is what de-termines if the lower motor neuron firesor not.  If the lower motor neuron re-ceives the signal to fire from the brain, itin turn sends a signal out to the musclecell.  Lower motor neurons are also verylong cells—sometimes over three feetlong!  The body of the lower motor neu-ron is in the spinal cord, and its axon iscalled a peripheral nerve.  Muscles in yourfeet are thus controlled by a chain of twonerve cells, one that has its body in thebrain and sends its axon all the way to thelower spinal cord, and the second whichhas its body in the lower spinal cord andsends its axon all the way to the foot.Before a message is sent out from themotor strip in the brain, other parts of thebrain are also contacted to help performthe computations necessary for goodmuscular control.  

The motor strip con-tacts the basal ganglia, which helps themuscle contract in a smooth, controlledfashion.  This part of the brain helps getjust the right balance of excitatory andinhibitory nerve impulses, so the weightmoves smoothly and under control.  With-out the basal ganglia, the muscle wouldsometimes contract too hard and some-times not hard enough, and the weightwould jerk up and down.  People withParkinson’s disease have a problem in thebasal ganglia, and have tremors when theyuse their muscles.  The frontal gyrus alsocontacts the cerebellum, which helpsmaintain balance and coordination.  With-out the cerebellum, you would lose yourbalance and fall over if you picked up a50 pound dumbbell with one hand.  Soafter you decide to lift a weight in the fron-tal cortex, the motor strip has a telecon-ference with the basal ganglia and the cer-ebellum to help do the calculations so thatthe weight is lifted under control in asmooth fashion and you don’t lose yourbalance.  After all the computations aredone, which happens almost instanta-neously, the motor strip sends its signalto the lower motor neuron.One lower motor neuron can controlanywhere from one to several hundredmuscle cells.  Some muscles, like thosecontrolling the fingers and the eye, areunder very fine control, so that each lowermotor cell controls only one or a fewmuscle cells.  

Other muscles, like thosein the quadriceps or glutes, don’t requiresuch fine control and each lower motorcell may control hundreds of these musclecells.  A lower motor neuron and themuscle cells under its control is called aMOTOR UNIT.  This is a very importantconcept, not just for muscle physiologistsbut for bodybuilders too.  When a motorunit fires, it is an all or nothing phenom-enon.  This means that either all or themuscle cells controlled by thatmotor neuron fire, or none ofthem do, depending on the bal-ance of excitatory and inhibi-tory impulses arriving at thatnerve cell.  There’s no suchthing as a muscle cell partlycontracting, or contracting atmoderate intensity.  It eithercontracts completely, at fullpower, or not at all.You will recall that a givenmuscle, like the biceps of thearm for example, is made ofhundreds of individual musclefibers, or muscle cells.  The strength of amuscle is defined by the maximum weightyou can lift for one repetition, the one repmaximum (1RM).  The strength of yourbiceps is determined by a combination offour general parameters: 1. The numberof muscle fibers in the muscle. 2. Thesize of each individual muscle fiber. 3. Thenumber of muscle fibers you can stimu-late to fire (contract) at once.

4. Lever-age factors, such as the length of yourbones and the points of insertion of themuscle tendons onto the bones.  You can’tdo anything about the leverage factors,this is purely genetics.  All other thingsbeing equal, someone with better lever age factors will be stronger.  Genetics isvery important in athletics, includingpowerlifting, for this reason.You can, however, address the otherthree factors by using specific trainingtechniques.  The strength of your bicepsis determined not only by the size of themuscle itself, but by how many of themuscle fibers you can make contract atthe same time.  Remember, each musclefiber either contracts completely or not atall.  Let’s say for example thatyour single rep maximum in thedumbbell curl is 50 pounds.  Nowyou pick up a 5 pound dumbbelland begin curling.  Only about10% of the muscle fibers in yourbiceps are contracting, and theother 90% are just along for theride.  If you keep curling longenough, the 10% of the fibersyou started with will eventuallyfatigue and no longer be able tocarry on.  Then a different set ofmuscle fibers will take over thework while the first set rests.  Bythe time you go through all of themuscle fibers, the first set is wellrested and is ready to go again.This is why you can maintain lowintensity work for a very longtime.  Now let’s pick up a 25pound dumbbell and do a set ofcurls.  Here, we have to fire about50% of the fibers to lift the weight.  Aftera few reps these fibers are tired, and theothers take over.  

After about 15 or 20reps all of the fibers are tired and you can’tget any more reps.  The first set of fibersto fire didn’t get enough time to rest andaren’t ready to go again yet.  This is whyyou can’t get as many reps as you couldwith the lighter weight.  Now let’s con-sider curling a 50 pound dumbbell, yoursingle rep maximum in this example.  Yourecruit 100% of the fibers to fire, so theyall get “spent” after one rep.  There areno other fibers left to recruit, which wouldallow the tired ones to rest, so the set isdone after one rep.  Read on, becausehere’s where it gets interesting.You should realize that the above ex-ample is not quite accurate.  Here’s why:very few people, if any, actually have theability to contract all of their muscle fi-bers to fire at once.  The best estimatesare that a typical person only has the abil-ity to fire about 50% of his muscle fibersat once, and that with training this mayincrease to about 70%.  This is kind of asafety mechanism to make sure you al-ways have some strength left, even if it’sonly a little.  (It also helps prevent youfrom ripping the tendons off of the bones!)Everyone knows after going to failure ona heavy set it’s still possible to crank outa few more reps with a lighter weight.This means that there must be a few fi-bers left.  

This is the physiologic basisfor drop sets, or strip sets.  Start with aheavy weight where you can get about 5reps and go to failure.  Then pick up amoderate weight that will allow you to getabout 10 more reps and go to failure again.Finally pick up a very light weight and goto failure at about 15-20 reps.  By the timeyou’ve finished a triple drop set you willhave recruited virtually 100% of the fi-bers in that muscle.  There’s really noother way to do it.  Don’t rest at all be-tween sets, because that would allow thefibers to recover.  The point here is toNOT allow the first set of fibers to re-cover, which FORCES the muscle to re-cruit the other fibers that haven’t fired yet.Drop sets are a very effective way to in-crease both size and strength and shouldbe a part of every bodybuilder’s andpowerlifter’s program.You see, when you lift weights you’renot only training your muscles, you’re alsotraining your nervous system.  With prac-tice you can learn to recruit more musclefibers to fire at once, thus increasingstrength.  This is a key differ-ence between bodybuilding andpowerlifting.  As we mentionedbefore, bodybuilders generallyhave bigger muscles butpowerlifters can usually liftmore weight.  Powerlifters aregenerally stronger because theywere born with better leveragefactors and because they havetrained their nervous systems’to recruit more motor units tofire simultaneously.  The wayyou do this is by practice.  Lift-ing very heavy weights, in the1-3 rep maximum range, forcesyour body to fire more musclefibers at once.  

This makes youstronger.  And this is why lowrep work forms the basis forpowerlifting-style training.Powerlifters train with explosivemovements using very heavyweights, and often don’t care about thenegative portion of the exercise.  (Youmight see a powerlifter virtually throw theweight on the floor after completing aheavy snatch, for example.)  This is notthe most effective training style for in-creasing muscular size however.  To un-derstand the basis for training to increasemuscle size, you need to know a little moreabout muscle physiology first.You will recall from a previous ar-ticle that each muscle fiber is made up ofhundreds to thousands of smaller unitscalled myofibrils.  These are the contrac-tile units of skeletal muscle (1).  Myo-fibrils are long chains of still smaller sub-units called sarcomeres.  Sarcomeres havea striped, or striated, appearance when vi-sualized in a microscope, and this is why skeletal muscle is sometimes called stri-ated muscle.  Sarcomeres are made of al-ternating light regions, called I bands, anddark regions, called A bands.  In the middleof each I band is a dark line called the Zdisk (1).  A sarcomere spans from Z diskto Z disk.  A myofibril is thus a long chainof sarcomeres joined end to end atthe Z disks.  

As we discussed in aprevious article, the two main pro-teins in muscle are actin and myo-sin.  Actin is a thin protein filament,while myosin is a thick protein fi-ber.  The light I band is the regionof the sarcomere that contains onlythin actin filaments.  The A band,in the middle of the sarcomere, isa region containing both thin andthick filaments organized in anoverlapping arrangement.  Whenthe muscle is fully relaxed, a re-gion in the middle of the A bandcalled the H zone becomes appar-ent, called that because it containsonly heavy, thick filaments(1,2,3,4).Each actin molecule has oneend anchored in the Z disk, and theother end extending toward themiddle of the sarcomere where itinterdigitates with the thick myo-sin molecules.  Each myosin mol-ecule is composed of two proteinstrands twisted around each other(1,2,3,4).  One end of the myosin mol-ecule forms a globular structure called themyosin head, which is attached to themyosin chain by a cross bridge.  Eachmyosin molecule contains several heads,which protrude from the surface of themyosin fiber to interact with special siteson the actin molecules.  Each actin fila-ment is actually composed of three pro-teins: actin, tropomyosin, and troponin(1,2,3,4).The basic idea of what’s happeninghere is that muscle is mainly composedof two types of protein strands, actin andmyosin.  These strands are lying parallelto each other and are overlapping.  Whena muscle contracts, the fibers slide pasteach other to make the muscle shorter.Each sarcomere acts as a single unit sowhen it contracts its fibers slide past eachother to pull the Z disks closer together.Each sarcomere is only microscopic insize, so when it contracts it only gets alittle shorter.  

But since each myofibril ismade up of thousands of sarcomeresjoined end to end, when they contract thewhole muscle gets shorter.  How does thishappen?When a nerve impulse arrives at amuscle, the electrical signal is spreadacross the muscle cell membrane and isconducted to the interior of the cell bythe T tubule system (discussed last time).The T tubule system carries the impulseto the sarcoplasmic reticulum (SR) andcauses the SR to release a bunch of cal-cium ions.  In a muscle’s resting state,tropomyosin molecules lie on top of theactive sites of actin, blocking their inter-action with myosin (1).  When calcium isreleased, it binds to troponin, causing theprotein molecule to change shape (1).This in turn pushes tropomyosin off ofthe active site of actin.  Actin is now freeto bind to the myosin head groups.  Whena myosin cross bridge attaches to an ac-tin chain, it undergoes a conformationalchange (a change in molecular shape)which causes the two filaments to slidepast one another.  This is referred to asthe power stroke (1).  

Immediately afterthe myosin head tilts, it breaks away fromactin, rotates back to its original position,and attaches to a new active site onactin.  Repeated cycles of attachmentsand power strokes cause the filamentsto slide past each other in ratchet-likefashion, giving rise to the term “slidingfilament theory” (1,2,3,4).You know from pervious articlesthat the energy that drives this processcomes from ATP.  So, how does ATPtie in here?  Each myosin head grouphas an enzyme called an ATPase, whichcan break down ATP to release its en-ergy.  The energy released from ATP isused to bind the myosin head to the actinfilament (1,2,3,4).  The muscle is thus“primed” and ready to contract.  It’sjust waiting for calcium to bind tropo-nin and push tropomyosin out of theway.  So the energy comes from ATP,the immediate signal to contract comesfrom calcium, and the calcium releaseis triggered by neurotransmitters re-leased from the peripheral nerve.Simple, eh?

References

1. Wilmore JH and Costill DL. Physi-ology of Sport and Exercise. Human Ki-netics, Champaign, IL, 1994.

2. McArdle WD, Katch FI, and KatchVL. Exercise Physiology – Energy, Nutri-tion, and Human Performance. Lea &Febiger, Malvern, PA, 1991.

3. Lieber RL. Skeletal Muscle Struc-ture and Function. Williams and Wilkins,Baltimore, MD, 1992.

4. Baechle TR. Essentials of StrengthTraining and Conditioning. Human Kinet-ics, Champaign, IL, 1994.

Bulletin #26 – Activating Muscular Growth: Part III

Last month I left you ready to startyour last set of the belt squat workout —the dreaded 100 rep set. This set pushes bothaerobic and anaerobic energy producingsystems in their absolute limits. It elicits andadaptive response in your cardiovascularsystem to strengthen your heart and in-crease capillary density in muscle. This in-creases cardiovascular reserve and anaero-bic threshold and improve nutrient and oxy-gen delivery to the muscle.A cell contains enough ATP tosupply energy to last for about two seconds(1). So you would use this up during yourfirst rep. Obviously you have to immediatelyand constantly replenish you ATP supply.Within about 1.2 seconds of maximum con-traction, 80% of the ATP is being derivedfrom CP — creatine phosphate (1). CP is theother phosphagen compound, along withATP, which supplies energy very rapidly. Thephosphagen system is always the first en-ergy pathway called into action. Since themachinery of the cell needs ATP for power,it begins by using ATP, and then other en-ergy sources are used to replenish the ATP.CP acts like a buffer to maintain relativelyuniform levels of ATP within the cell. As ATPis broken down to release his energy, one ofits phosphate groups is split off to form amolecule of ADP (adenosine diphosphate)and a free phosphate group. CP is able todonate its phosphate group to the newlyformed ADP to regenerate ATP. The phos-phagen system able to supply energy in rapidbursts, immediately on demand, but it doesn’tlast very long (about six seconds at maximalpower output).

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This is why a typical set withheavy weights doesn’t last very long — yourun low on ATP and can’t make it fast enoughto continue.Within 2.5 seconds of maximal con-traction, 50% of ATP is being supplied bythe lactic acid system, also known as theglycolytic pathway (1). Anaerobic glycoly-sis is the pathway used to make ATP fromcarbohydrates in the absence of oxygen.This is the second energy producing sys-tem called into play and is used to meet short-term energy de-mands. When the in-tensity of exercise istoo great and thebody can’t supplyoxygen fast enough,carbs can be par-tially broken down toyield energy withoutoxygen. The advan-tage is this is a veryrapid way to pro-duce energy, but thedisadvantage is thatit’s not as efficient asaerobic energy pro-duction.After sixseconds of maximalcontraction CP lev-els have fallen toaround 65% of theirresting level andpower output beginsto decline. Continuing beyond six secondsof maximal contraction, ATP and CP levelsbegin to fall and lactic acid begins to accu-mulate. These factors severely hinder poweroutput (1). So we can see that after just  afew reps we’re using both of our anaerobicpathways: the phosphagen system and thelactic acid system.Back to our belt squats: during thesecond 20 reps you will need some help. ATPlevels may be depleted by as much as 60%of initial values (1). CP levels are nearly ex-hausted after about 40 seconds of maximalintensity exercise (1). At this point glycoly-sis is going full speed, but is unable to gen-erate enough ATP to keep up with the de-mand.

Lactic acid production is maximal dur-ing exercise of intensity that can be main-tained for 1-3 minutes. So one minute intothe set lactic acid levels are soaring and yourmuscles are burning like crazy.The third energy producing sys-tem — the aerobic pathway — begins to kickin after about 20 seconds into the set, andbecomes the major energy producer afterabout 90 seconds (see figure). Notice thatthere is considerable overlap, with all threeenergy systems being utilized at the sametime. It’s not like you use up one energysource, turn off that system, then turn onthe next system. They all blend in together,with different systems playing the major roledepending on the intensity and duration ofthe exercise. If we were talking about lowintensity exercise like walking instead ofbelt squats, the aerobic system could pro-duce energy fast enough to fuel the ac-tivity, and the lactic acid system wouldnever be called in.The aerobic pathway is able to sup-ply energy for long-term demands — evenfor hours. Activities like weight lifting drawmainly from the phosphagen and lactic acidsystems, while things like running and bik-ing are fueled mostly by the aerobic system.The advantage of the aerobic system is thatit can supply energy for a very long periodof time, but the disadvantage is that it can-not produce energy very quickly. For weightlifting you need to supply a tremendous amount of energy immediately, but for en-durance activities you need a lower energylevel for a longer period of time.In the aerobic pathway, carbohy-drates and fat are burned — combined withoxygen — to release energy.

The rate of en-ergy production by this pathway is limitedby your vascular supply (which limits oxy-gen delivery) and by the size and number ofmitochondria inside cells. Mitochondria areorganelles in cells where aerobic metabolismis carried out. Notably, fat can only be usedfor energy via the aerobic pathway. Fat can-not undergo anaerobic glycolysis, as cancarbs. Therefore, aerobic activity is the onlyway to burn fat. This is another reason tomake aerobic exercise a part of your program,in addition to strengthening your heart andblood vessels.Now, back to our set: after 50 repsthe phosphagen system is long gone, andthe glycolysis is pretty much shot too. Youhave continued to expend energy faster thanyour cells can replace it, and consequentlybuild up an “oxygen debt.” This describes asituation we are all familiar with. You knowhow you breathe real hard for a few minutesafter a set? This extra oxygen is being usedto replenish the ATP, CP and glycogen youspend anaerobically during the exercise. Theoxygen debt is the difference between theamount oxygen actually consumed and theamount that would have been consumed ifthe exercise had been fueled entirely aerobi-cally from the beginning (2). By the time theoxygen debt builds up to 3-4 liters of oxy-gen, you enter a severe level of ATP deple-tion. Exercise will only continue on a “payas you go” basis wherein ATP is being con-tinually replenished by aerobic metabolism(2). Power output decreases and your heartand lungs are working at absolute maximum.You will be sweating profusely.

All energysystems are either maxed out or have alreadyfailed.By 60 reps you will beg to quit. Atthis point you will be beyond positive fail-ure and it will be difficult even to resist theweight on the way down. From here on outyour life is in the spotter’s hands. By 70 repsyou get that adrenaline rush that comes fromthe fear of eminent death. By 80 reps youcan’t feel your legs anymore and your mindenters a strange trance-like state. You kindof lose touch for a while. You probably won’thave much energy left to groan or screamand your body gets limp. By 90 reps you’rejust along for the ride, with the spotters do-ing almost all the work.The universal reaction after thisexperience is to lay down on the floor. Somepeople have to throw up. Loss of conscious-ness may occur as the result of acute meta-bolic acidosis — the lactic acid builds upand acidifies the blood. This corrects itselfin a few minutes after you blow off somecarbon dioxide. Most people lie down forfive minutes or so before pulling themselvesover to a bench. You’ll be breathing hardand sweating for about 20 minutes after this.One other energy system deserves mention,but probably doesn’t play much of a role inbelt squats. That’s the glucose-alanine cycle(2). During long term aerobic exercise afterblood glucose and glycogen are depleted,the body begins to break down muscle tis-sue into free amino acids.

The amino groupsare removed from the amino acids and addedto pyruvate to form alanine. Alanine is trans-ported by the bloodstream to the liver whereit can be converted to glucose. The glucoseis carried back to the muscle to be used asfuel (2). In addition, the branched chainamino acids (BCAA’s) leucine, isoleucineand valine can be used directly as fuel bythe muscles. So in ultra-endurance activities,such as a marathon, muscle is actually bro-ken down and used as fuel. This is one rea-son why endurance athletes have smallmuscles and one reason why bodybuildersdon’t run marathons. Amino acids may sup-ply 15% of energy used in endurance activi-ties (2).In summary, we find that the beltsquat boosts energy producing capabilitiesof the entire body. Cardiovascular reserveand anaerobic threshold are increased.Training at this level of intensity carries overinto your other exercises and allows you toperform them more intensely also. Belt squatstax all three major energy producing systemsat maximal levels. While ultra-endurance ac-tivities like marathon running are counter-productive for bodybuilders, a certainamount of high intensity aerobic exerciseseems to allow increased muscular growth.This may result from increased vascular sup-ply to muscles which may stimulate growthby providing increased nutrient delivery (1-3).Everybody has a dream. Every-body wants to get to that next level. That’swhat Parrillo Performance is all about.

References

1. Hatfield FC. Hardcore Bodybuilding — AScientific Approach. Contemporary Books,Inc., Chicago, 1991.

2. McArdle WD, Katch FI, and Katch VL.Exercise Physiology — Energy, Nutrition,and Human Performance. Lea & Feiberger,Malvern PA, 1991.

3. Lieber RL. Skeletal Muscle Structure andFunction. Williams and Wilkins, Baltimore,1992.

Bulletin #25 – Activating Muscular Growth: Part II

Conventional wisdom has it thatstrength training and endurance trainingare incompatible, since they elicit differ-ent adaptive responses that compete witheach other (1-3). This is true, at least inthe short term. Last month I introducedthe concept that at some point in themuscle’s growth it may become “perfu-sion limited,” meaning that any furthergrowth is limited by the muscle’s bloodsupply. Increasing the vascular supply toa muscle will allow for greater delivery ofnutrients and oxygen and greater removalof wastes. Ideally, a bodybuilder wouldlike the benefit of increased capillary den-sity in muscle which accrues from high-intensity aerobic exercise without the cata-bolic effect that comes from running amarathon. The belt squat is probably thebest way to achieve this.The amazing thing about the beltsquat is not that it makes your legs grow— everybody expects that. The amazingthing is the overall effect it has on yourwhole body’s ability to produce energyand perform high intensity exercise. Ifyour strength and muscular developmentare at a plateau, the belt squat is a greatway to blast through it — no matter whatmuscle group you’re having trouble with.The belt squat increases your cardiovas-cular reserve and your anaerobic thresh-old.

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Cardiovascular reserve is the abilityof your cardiovascular system to deliver“extra” oxygen above what you normallyneed. In other words, it’s your ability toincrease oxygen delivery to muscles dur-ing times of intense exercise. Anaerobicthreshold is the maximum intensity of ex-ercise (power output, which is work perunit of time) your body can perform aero-bically, before the anaerobic pathways kickin. Simply put, the partner-assisted beltsquat is the most intense exercise you’llever do. Acquiring the ability to exercisethat intensely will carry over into yourother exercises.I think the key point about thebelt squat is that it pushes all three of yourenergy producing systems to their limit.Let me explain. Your body has three mainenergy producing pathways that are usedduring exercise. These are the phosph-agen system, the lactic acid system andthe aerobic system. All work performedby the body, including muscular contrac-tions, is directly fueled by a molecule calledATP, adenosine triphosphate. ATP is a“meta-stable” chemical compound whichis made inside all cells of the body andpowers their every function. ATP has a“high energy phosphate bond,” whichmeans that when ATP is broken down alot of energy is released.

This energy isthen used to power muscular contrac-tions, maintain ion gradients transmit nerveimpulses, synthesize proteins, and provideenergy for everything a cell needs to doto live and grow. While fat and glycogenrepresent energy storage molecules withinthe body, ATP represents and energy trans-fer molecule, acting as a molecular bridgebetween the energy contained in food andthe energy used by the cell. To summa-rize, the energy released when foodburned is used to make ATP, and the sub-sequent breakdown of ATP is the directenergy source for cells.A typical belt squat workout be-gins with some leg curls for a warm-up.This gets blood flowing into the musclesand warms up the joints. Two sets of eachare enough, for about 10-12 reps with amoderate weight. Be sure and hold thecontraction at the top. Next, two or threesets of leg presses are used to furtherwarm up the legs and to prepare you forthe squats. Start of light for about 15-20reps, then do a moderate set around tenreps, and finish with a fairly heavy setaround six reps. Be sure to go all the waydown on the leg press. You may evenwant to briefly pause at the bottom to geta good stretch. You don’t want to wearyourself out during the warm-up, but youdo want to get things flowing and loos-ened up. Next, stretch your quads andhamstrings, and walk around the gym fora few minutes to rest. Don’t get a drinkof water because you don’t want any-thing in your stomach. This is a good timeto pray and make sure all your importantpapers are in order.

We intentionally placeour belt squat by the back door of thegym. If this is not the case in your gym,get a trash can and put it by the belt squat.The belt squat is strictly a part-ner-assisted exercise. We like to have agroup of four people on the belt squat days.This allows for three spotters, which youwill need to take it to the absolute limit (atleast one spotter is required). We usuallydo four sets each, taking turns. You de-velop pretty good friendships with yourbelt squat partners. I honestly think I canremember every belt squat workout I’veever done.The first thing you do is put onthe harness. Adjust the shoulder straps tofit your body and make sure the belt istight. Load the weight onto the weightcarriage and sit on it. Your partner willattach the straps through the hole in theplates, so that the weight is suspended bythe harness. Grab the handle and stand up, and your partner will remove theweight carriage, so that the plates arehanging between your legs. When usinga heavy weight, your partners will helpyou stand up. Removing the weight car-riage exposes “the pit” — a large slot inthe platform where the plates will travelas you squat. Place your feet slightly widerthan shoulder width with your toes angledout and your heels placed directly under-neath your shoulders.

Grasp the handlesecurely and keep your arms straight. Youwant to keep your arms locked out so youdon’t lose balance. If you maintain thisstance and keep your arms straight, youwon’t get injured. The worst thing thatcan happen is you lose the weight, whichjust means you sit down on it in the pit.The beauty of the belt squat is that it’s sointense and yet so safe. The harness takesthe strain off your lower back so you canmaximally overload your legs without fearof injuring your back. This is an extremelysafe exercise.We usually start with one plate,which is 100 pounds (we have special highdensity plates made up for the belt squat).Do this for about 20 reps. This is anotherwarm-up set, to getthe feel of the exer-cise. You will prob-ably need no helpfrom your partneron this set. Rackthe plate back on thecarriage, take off theharness, and give itto the next person.Next, stretch yourlegs, using one ofthe fascial stretchingexercises in theParrillo TrainingManual. You’re be-ginning to get apump, and it feelsgood — so far.After your trainingpartners their turns,it’s back to youagain.

This time wego up to 200 poundsfor about 15 reps.This is somewhat harder, but much easierthan squatting 200 for 15 reps on the con-ventional squat because your lower backis taken out of the movement. On yournext set you can either go for your heavyset or continue pyramiding by doing 300pounds for 10-12 reps. Have a spotterstand directly behind you on the platform.He will have his arms around you and holdthe belt in the center in the front. The spot-ter goes up and down with squatter, per-forming the exercise in parallel. The spot-ter provides just enough help to get youthrough any sticking points. On yourheavy set, you will be able to go at least100 to 200 pounds heavier than your maxwhen you didn’t have a spotter — ormaybe more. Five hundred pounds for abig guy is not uncommon. Take yourheavy set to complete positive failure. Youwill still be able to resist the weight on theway down, but you will need your spot-ters to get you up out of the hole. Onespotter behind you and one on each sideworks the best.The heavy set done to positive failure ataround 8-12 reps will stimulate your legsActivating Muscular Growth, Part IIThe Belt Squat Machine looks innocent enough.But once you’re on the platform with the harnessstrapped on, you’ll wish you had scheduled thatdentist appointment that you’ve been putting offfor the last two years.to grow. The next set is the hardest and isthe one that will really stimulates your car-diovascular system. In this set we do 100reps with 100 to 200 pounds. This is es-pecially hard since you just went to fail-ure on your last set. We rotate spotterson this set because they go to failure too.Change spotters after every 20 reps.Next month, I’ll take you through a 100rep set of belt squats and explain the en-ergy producing systems involved.

References

1. McArdle WD, Katch FI, and Katch VL.Exercise Physiology – Energy, Nutritionand Human Performance. Lea &Feiberger, Malvern, PA, 1991.

2. Hatfield FC. Hardcore Bodybuilding -A Scientific Approach. ContemporaryBooks, Inc., Chicago, 1991.

3. Lieber RL. Skeletal Muscle Structureand Function. Williams and Wilkins, Bal-timore, 1992.

Bulletin #24 – Activating Muscular Growth

Mention the words “Belt Squat”to anyone’s who’s trained at the ParrilloPerformance Gym in Cincinnati, and you’llget a reaction that’s a mixture of fear andnausea. The mere thought of belt squatsis enough to make most people need to sitdown. There’s really nothing quite like it.Anyone’s who’s done it will agree that itis the most mentally and physically de-manding exercise ever developed. The beltsquat will take you to a new level of in-tensity.At this time, the Parrillo Perfor-mance Gym is a private gym, not open tothe public. It’s really more of a researchfacility than a gym.

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We experiment withnew equipment and new techniques, de-veloping the next generation of bodybuild-ers. We work with a lot of top competi-tive amateurs trying to make it to the nextlevel and break into the professional ranks.We also deal with a lot of professionalcompetitors, all the way up to peopletraining for the Olympia.I guess you could say that’s ourspecialty — taking people to the next level.That’s really what brings me the most sat-isfaction and is my biggest reward —helping people realize their dreams. Andthis applies to everyone from the over-weight 45-year-old mother of three to thenext Mr. Olympia. Everybody wants tolook good, feel good and have more en-ergy. Everybody has a dream. What keepsme going are the people who call in to tellme they’re in the best shape of their lives.I get just as excited whether it’s someonewho’s used our program to lose those 30extra pounds they’ve been struggling withfor years, or someone who’s just won hisfirst contest.Among conventional bodybuild-ing exercises, most people would agreethat a set of squats taken to complete fail-ure is the most demanding.

I developedthe belt squat to take people to the nextlevel of intensity — it’s probably the ulti-mate plateau-buster. The belt squat is aspecial machinewhere the traineewears a harnesswhich suspendsthe weight be-tween his legs.This arrangementtakes the stress offthe lower back, al-lowing you tomaximally over-load the legs. It’sthe same move-ment as the con-ventional squats,except you can usea lot more weightfor a lot more reps.Of courseyour legs willgrow. This will bethe highest inten-sity exercise yourlegs will ever expe-rience. But theamazing thing about the belt squat is theoverall effect it has on your entire body.It allows you to take your whole body tofailure, including all of your energy pro-ducing systems. You will be breathing ashard as you can, your heart will be pump-ing as hard as it can, and every cell inyour body will be trying to produce en-ergy as fast as it can. Adding belt squatsto your routine will strengthen your car-diovascular system and improve oxygendelivery to your muscles.

The belt squatis unique among resistance training exer-cises in that it truly combines extremesof intensity in both anaerobic and aerobicwork. It is well-documented that high-in-tensity aerobic training increases capillarydensity in muscles, as well as the numberand size of mitochondria (1). It also in-creases the level of enzyme systems in-volved in energy production (1). Thesefactors act to increase the anaerobicthreshold — the maximum intensity ofpower production you can achieve aero-bically (1).No doubt you’ve heard thatanaerobic training and aerobic trainingelicit different adaptive responses which,to some extent, work against each other(2). In other words, strength training andendurance training are not completelycompatible, and if you want to maximizeyour results in one form of training, youshould avoid the other form. Everybody’sfavorite example is to compare the phy-siques of a marathon runner with a body-builder. To be sure, endurance trainingimproves your endurance and strength-ens your respiratory and cardiovascularsystems, but marathon runners don’t havebig muscles — not even in their legs.Marathon runners don’t want bigmuscles, because too much weight wouldactually slow them down. For them, it’sthe ratio of strength to weight that’s im-portant. All they care about is how far and how fast they can run. So for whatthey want, their training style is appropri-ate.

All bodybuilders care about, on theother hand, is getting big muscles. So theylift weights a lot and don’t run much. Toomuch running can actually cause yourbody to break down muscle tissue to sup-ply amino acids to burn as fuel. This wouldbe a disaster for a bodybuilder. So youdon’t find too many endurance athleteswho can squat 405, and you don’t findtoo many bodybuilders who can run amarathon. This is all well and good —decide what your goals are and train ap-propriately to attain those goals.Here’s what’s going on: All formsof exercise of sufficient intensity repre-sent a stress on the body. The body re-sponds by adapting to that particularform of stress, so it can tolerate it betterthe next time around. Strength training(resistance training, weight training) rep-resents a severe stress on the muscle fi-bers that make up your muscles, andthey respond by building bigger, stron-ger fibers (1,2,3). This, of course, re-sults in bigger, stronger muscles.

Endur-ance training (running, biking, etc.) rep-resents a stress on the aerobic energyproducing capabilities of the body, andthe body responds by increasing its abil-ity to produce aerobic energy. To run amarathon, you don’t need extremelystrong legs, but you need to be able toproduce a lot of energy sustained over along period of time. It’s not easy. Aerobicexercise training therefore results in astronger heart and more blood vessels todeliver more oxygen to muscles. It in-creases mitochondria number and size inmuscles. Remember that mitochondria arethe furnaces inside cells where foods areburned (combined with oxygen) to pro-duce energy. Increasing capillary and mi-tochondrial density in muscle increases itsability to produce energy.So to a large extent, the dogmayou’ve heard about the “incompatibility”of strength and endurance training is true.One form of training results in biggermuscles, and the other form results inhigher energy producing ability. If yourbody’s adaptive reserve is split trying toachieve both goals, your progress on ei-ther will be compromised compared to ifyou were performing only one type oftraining. And at this point in the argumentmost people think they’ve reached theconclusion and stop thinking about it, andtherefor miss and important point.Consider the following: Let’s talkabout a bodybuilder who’s been traininghard and eating right for a few years andhas put on 50 pounds of muscle. Althoughhe’s very happy with this achievement,lately he’s seen his progress slow downand he really hasn’t changed much in thelast year. He believes he has probablyreached his “genetic limit.” He has basi-cally gone as far as conventional trainingand dietary strategies can take him.

Feel-ing that it’s genetically impossible to in-crease size much more, he shifts his em-phasis on “refining” his physique and per-fecting his symmetry. Many professionalbodybuilders are at exactly this level andstay there for the rest of their careers.The smart ones come to Parrillo Perfor-mance at this point. If there is a geneticlimit, we haven’t found it yet.Now let’s take a microscopic lookat his muscles. We see huge muscle bel-lies with huge, hypertrophied muscle fi-bers. Crammed wall to wall with contrac-tile proteins — actin and myosin. Hismuscles have reached a “steady state” —a term from thermodynamics which de-scribes a system where flow of matterand energy into the system is balanced byflow of matter and energy out of the sys-tem. Here, protein anabolism (building up)is balanced by protein catabolism (tearingdown). Flow of amino acids into themuscle equals flow of amino acids out ofthe muscle, so his muscles stay the samesize. Now think about what would hap-pen if we could somehow double the cap-illary supply to his muscle. Blood supplydoubles, the flow of amino acids and glu-cose into his muscle doubles and his abil-ity to carry waste products away fromhis muscle doubles. Is it possible that ifwe could increase the supply of nutrientsand energy to his muscle that we couldget it to grow again? Could it be that whena muscle gets very large, maybe the rea-son it stops growing is it becomes lim-ited by its supply of nutrients and oxy-gen? Of course may factors are involved,but we believe this is one of them.So while strength training andaerobic training do represent differentadaptive responses and interfere witheach other in the short term, there comesa point in muscular development whereincreasing blood supply to a muscle mayhelp overcome a growth plateau. Doesthis mean I recommend bodybuilders be-gin running marathons? Of course not.I’m just saying that a certain amount ofhigh-intensity aerobics may increase nu-trient and oxygen supply to a muscle andhelp it grow better. You think you’vereached your genetic limit? I think not. Afew weeks of belt squat training, andyou’ll be growing again.

References

1. McArdle WD, Katch VL. ExercisePhysiology – Energy, Nutrition andHuman Performance. Lea & Febiger,Malvrn PA, 1991

2. Hatfield FC. Hardcore Bodybuilding -A Scientific Approach. Contemporybooks, Inc., Chicago, 1991.

3. Lieber RL. Skeletal Muscle Structureand Function. Williams and Wilkins,Baltimore, 1992

Bulletin #18 – Growth Hormone: The Ultimate Weapon

In this bulletin we’re pulling out theultimate weapon — growth hormone. Thisis the most important hormone for body-builders, acting as a powerful stimulus formuscle growth and fat loss. Many of theeffects of exercise in increasing musclemass and decreasing body fat are medi-ated by growth hormone. The most ef-fective training strategies are those whichmaximize growth hormone release. ParrilloPerformance knows exactly how to eatand how to train to maximize this mostimportant controller of nutrient partition-ing. And like always, we’re here to showyou how. If you’re willing to train hardenough, we’ll help you reach the stars.Every athlete who has struggled tobuild muscle is painfully aware of the factthat you have to lift weights to do it. Infact, you have to lift weights very in-tensely and consistently over a period ofsome time (months to years) to accumu-late significant increases in muscle mass.Since muscles are made from nutrients inthe food we eat, you may logically askwhy can’t we build muscle just by eatingthe right foods?

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The answer to this ques-tion takes us back to the theme of thisseries: hormones.Hormones are ultimately responsiblefor the process of tissue remodeling —that is, the process of laying down newmuscle tissue. Although you can exertgreat control over some hormones by dietalone (refer back to the previous bulletinsin this series), exercise is required to gen-erate the complete hormonal spectrumwhich will result in muscle gain and fatloss (1,2). Furthermore, the damage tomuscle tissue which results from exer-cise training (especially the eccentric, orlowering phase of muscle contraction)serves as a stimulus to the muscles moreresponsive to the growth-promoting ef-fects of anabolic hormones (1).Growth hormone (GH) is the mostanabolic substance in the human body(3,4). In a study of old men (whosegrowth hormone levels are diminished),it was found that GH administration pro-moted an increase in muscle mass and adecrease in body fat even in the absenceof exercise training (3,4). Growth hor-mone is anabolic, meaning that it acts topromote incorporation of nutrients intonew body tissues. This includes increas-ing protein synthesis in the muscle tissue(5,6). Part of this effect is believed to bedue to GH promoting transport of certainamino acids inside muscle cells (5). No-tably, insulin also acts to transport a dif-ferent set of essential amino acids, so youneed adequate amounts of GH an insulinpresent at the same time to stimulatemuscle growth (5). GH also has a lipoly-tic effect, which means it mobilizes bodyfat from adipose depots and increases theuse of fat for energy (5,6). This in turnspares carbohydrates so glycogen storesare preserved (5,6). GH is probably themost important hormone for bodybuild-ing since it has powerful actions in build-ing muscle and burning fat.The most important role of growthhormone is in promoting growth duringchildhood. Without GH, normal adult stat-ure will not be achieved (5,6). Growthhormone acts to promote growth of alltissues of the body except the nervoussystem. GH levels reach maximal levelsin the late teens and gradually decline withage.

The high levels of GH and testoster-one in young adult males explain why mostbodybuilders make their best gains dur-ing their late teens and twenties. This againunderscores the central role of hormonesin bodybuilding.Although I’ve discussed this before,it is so important as to bare repeating: thecentral reason behind all of your body-building activity, including both diet andtraining, is to manipulate your hormonelevels so as to promote muscle gain andfat loss. Your body’s level of muscle massand body fat are determined by hormonesand by the set point of your hypothala-mus. By following the guidelines in thisseries and in the Parrillo Nutrition andTraining Manuals you will adopt a lifestylewhich optimizes anabolic drive and setsup the proper hormonal environment forachieving a top physique.During the next couple of  bulletins Iwill explain in detail the physiology ofgrowth hormone, including its mecha-nisms of release, its actions and what youcan do to control your GH levels for maxi-mum results. As you know by now, hor-mones do not work alone in the body. Itis the combined interaction of all the hor-mones which generates the physiologicaladaptations to exercise. Therefore, I willdiscuss growth hormone in the contextof the other hormones with which itsynergizes to produce its effects. I havedecided to organize this discussion aroundsome of the most basic and importantquestions about growth hormone. If thediscussion sounds a little medical inplaces, bear with me. You will come awaywith a thorough understanding of growth hormone and how to control it. Get readyto annihilate the competition.1. Exactly what is growth, and whatis the difference between lineargrowth, mass increase and obesity?The common feature of growth is anincrease in mass (body weight). The com-mon definition of growth refers to theorganized addition of new tissue that oc-curs normally in development from infancyto adulthood (6). Bodybuilders are a bitunusual in that they continue to grow af-ter reaching adulthood. This is largely dueto the effects of intense exercise in in-creasing growth hormone. Normal growthinvolves both linear growth (increase inbody length or height) and mass increase(increase in body weight). Obesity spe-cifically refers to growth of fat stores outof proportion to the rest of the body. Quan-titatively, anything above 30% body fat iscommonly considered obese. Growth isnormal and healthy; obesity is not. Ab-normal growth can becaused by an excess ordeficiency in growth hor-mone.

GH causes parti-tioning of nutrients to thelean compartment andaway from fat stores. Ad-ministration of GH will in-crease muscle mass anddecrease body fat, and adeficiency of GH will re-sult in excess fat accumu-lation.2. What are the main stages ofnormal growth and the hormones thatstimulate growth in each?Prenatal: Hormonal control duringprenatal development is largely unknown,but insulin is believed to be important (6).Human placental lactogen, hPL, is prob-ably also involved.Infantile (0-1 years): Insulin is re-quired and possibly other unknown hor-mones as well (6). Interestingly, GH andT3 (thyroid hormone) are not requiredduring prenatal and infantile growth (6).Juvenile (1-12 years): GH is the mostimportant, but there is also a strict require-ment for T3 and insulin (5,6). Vitamin Dis also required.Adolescent (age 10-14 for females,12-16 for males): The sex steroids areresponsible for the adolescent growthspurt, closure of the epiphyseal plate (seebelow) and attainment of final adult height.GH, T3, vitamin D and insulin are still re-quired for normal growth during this time.Glucocorticoids are also required in nor-mal levels for normal growth but its ac-tion is mainly permissive (6). Permissiveactions of hormones describe effects ofhormones on enzyme systems so as toallow other hormones to exert their regu-latory effects. The permissive hormonesdo not stimulate growth directly, but ratherallow other growth-promoting hormonesto be active.3. What is the difference betweengrowth-regulating hormones and localgrowth factors?Hormones are released into the blood-stream to exert their effects on target tis-sues throughout the body, while growthfactors act mainly locally (as autocrinesor paracrines) to stimulate growth. Themost important growth-regulating hor-mones are GH, T3, insulin and the sexsteroids. Most growth factors act as regu-lators of local processes such as woundhealing, tissue repair, regeneration or or-dinary replacement of aged cells, but someare found in the circulation and may func-tion as true hormones. IGF1 (somatome-din C) is especially important in this re-gard in mediating many of the actions ofGH. See the below for more informationon IGF1.4. What are the other require-ments for normal growth in additionto hormones and growth factors? Proper nutrition (including energy,amino acids, vitamins, minerals and es-sential fatty acids) rest, and a good psy-chosocial environment are all requirementsfor growth (6). Mental state (emotionalstate) can directly influence normalgrowth in humans. No doubt this effectis mediated by the hypothalamus, since itconnects the endocrine system to themind. If you’re eating and training right,but are totally stressed out about work orsome personal problem, you’re probablynot going to make very good gains. Themind in very important to bodybuilding.You must maintain a positive and aggres-sive attitude and not be distracted by out-side stresses.5. What are catch-up growth andcompensatory growth?Catch-up growth is a period ofgrowth at greater than the normal rate torecover from a time when growth wasretarded, as during illness. Notably, in-creased levels of hormones (includingGH) are NOT required during catch-upgrowth. Compensatory growth is growthof an organ to compensate for damage tothat organ or its pair.

For example, if onekidney is removed, the remaining kidneywill grow larger. Increased hormone lev-els are probably not needed for compen-sation by the liver and kidney, althoughIGF1 may be increased. Compensatorygrowth of the adrenal gland is accompa-nied by increased levels of ACTH (6).Many athletes who are over-trained orunder-nourished experience a growthspurt when they correct the problem. Inthe case of over-training, the problem islikely due to elevated cortisol levels, whichare catabolic.6. What are the roles of insulin,glucocorticoids, sex steroids and thy-roid hormone in normal growth? Howdo these relate to growth hormone?Insulin: Optimal concentrations ofinsulin are required for normal growthduring postnatal life. Insulin stimulatesprotein synthesis and inhibits proteinbreakdown. Without insulin, normal re-sponses to GH are not seen and protein breakdown is severe. Insulin promotesgrowth primarily by shuttling nutrients(glucose and some amino acids) insidecells, providing energy and the buildingblocks for protein synthesis. Note thatinsulin and GH must both be present atthe same time for normal growth to oc-cur. Guyton (5) suggests that this is be-cause insulin and GH each shuttle a DIF-FERENT compliment of essential aminoacids inside cells, and of course all of theessential amino acids must be present atthe same time for protein synthesis (andthus growth) to occur. Neither insulin norGH alone is sufficient to supportnormal growth — it takes optimallevels of all the body’s hormonesto produce optimal health and opti-mal gains. As noted in a previousbulletin, excess insulin cannot cre-ate muscle mass, but it will pro-mote fat storage. It’s not the calo-ries in sugar that make you fat —it’s the insulin response (7,8).Glucocorticoids: Glucocorti-coids (primarily cortisol) promoteoptimal function of a wide varietyof organ systems, but do not havedirect growth promoting actions.Excess GC’s inhibit growth by thecatabolic effects of cortisol (in-creased protein breakdown). Nor-mal levels of GC’s seem to be needed topermit optimal function of the other hor-mones. The concept here is that gluco-corticoids act to stimulate (or maintain)optimal levels (amounts) of metabolic en-zymes, whose activities in turn are regu-lated by the other hormones. GC’s sortof set the stage and make sure all of themachinery is in place. Cortisol functionsto make sure the key regulatory enzymesare present in sufficient amounts to allowallosteric regulation (enzyme regulation viasmall effector molecules such as meta-bolic intermediates) and enzyme regula-tion by other hormones.

Also, cortisol isimportant in maintenance of glucose lev-els and resistance to stress, which intu-itively would seem important for normalgrowth.Sex Steroids:Androgens: Androgens (such as tes-tosterone) are potent stimulators of lineargrowth in children whose epiphyses (thegrowing ends of bones) have not yetclosed. Androgens can promote somegrowth in the absence of GH, but com-bined treatment with androgens and GHtogether promote more rapid growth thanthe sum of the two hormones alone. Thisis an example of the synergistic action ofcertain hormones. Much of the growth-promoting action of androgen appears tobe mediated by increased GH secretion(6). Androgens increase the frequencyand amplitude of GH secretory pulses (6).In addition to promoting linear growth,androgens also stimulate growth ofmuscle, and this can occur in the absenceof GH or T3. Androgens bind to nuclearreceptors and the hormone-receptor com-plex in turn binds to chromosomes andactivates transcription of specific genes.Estrogens: In normal girls, theadolesent growth spurt usually occurs be-fore estrogen secretion is sufficient to ini-tiate breast development and is probablyattributable to very low concentrations ofestrogens (6). Paradoxically, concentra-tions of estrogen sufficient to promotebreast development actually inhibit growth(6). Stranger still is the fact the concen-trations of estrogens which inhibit growthincrease GH secretion. What is the basisfor the complex interaction between es-trogen and GH? High concentrations es-trogens appear to inhibit growth by inter-fering with the actions of GH (6). Estro-gens also antagonize the effects of GH onnitrogen retention. Of course, estrogen isalso responsible for the characteristic fe-male fat distribution. The differential ef-fects of estrogen and testosterone, as wellas their different interactions with GH, ex-plain why males on average contain 50%more muscle mass than females and whyfemales have a higher body fat percent-age.At the same time thatgonadal steroids stimulatelinear growth, they also ac-celerate closure of the epi-physes (the sites at the endsof the bones where boneelongation occurs) andtherefore limit the finalheight that can be attained.This is why linear growthstops a few years after pu-berty. GH and the sex ste-roids are still present andactive, but the ends of bonesare permanently sealed andcannot grow anymore. Flatbones, such as the bone inyour forehead, can still in-crease in thickness, however. People whoabuse growth hormone experience thiscondition, known as acromegaly.Thyroid Hormone: Thyroid hormoneis present in two forms, known as T3 andT4. Most of the circulating hormone is inthe form of T4 which is converted to themore active T3 form inside target cells.Thyroidectomy (removal of the thyroidgland) has nearly as devastating an effecton growth as does hypophysectomy (re-moval of the pituitary gland — the body’ssource of GH). Restoration of T3 and T4promptly reinitiates growth. T3 and T4have little if any growth promoting effectin the absence of GH however. T3 acts topromote the actions of GH at three levels:GH synthesis, GH secretion and GH ac-tion. Plasma concentrations of GH arevery low in the absence of T3 or T4. This action is independent of GHRH (growthhormone releasing hormone) and appearsto be exerted directly at the level of genetranscription. In addition to its permissiveeffects on GH synthesis, T3 maintainsnormal responsiveness of somatotropes(the cells that make GH) to GHRH. Fail-ure of growth in thyroid deficient indi-viduals is largely due to GH deficiency.However, even large amounts of GH can-not sustain normal growth in thyroidec-tomized animals unless thyroid hormoneis also given. Thyroxin decreases theamount of GH needed to stimulate growth(increases sensitivity) and exaggerates themagnitude of the response (increases ef-ficacy). T3 and T4 seem to potentiate theeffects of GH on long bones and to in-crease its effects on protein synthesis inmuscle and liver.In summary, GH interacts withinsulin, the sex steroids and thyroidhormones directly to stimulategrowth. These actions are not onlycrucial to growth during childhoodbut are also at the very core of theadaptations which occur in responseto exercise.

Thyroid hormone is re-quired for optimal GH release andfunction. Glucocorticoids (cortisol)are also required in normal levels toplay a supporting role. Cortisol en-sures that the metabolic enzymes arepresent in sufficient amounts so thatGH, insulin and testosterone can ex-ert their effects. If cortisol is too low,optimal growth cannot occur be-cause enzyme levels are too low, and ifcortisol is too high you will actually losemass because high cortisol levels are cata-bolic and promote protein breakdown.Epinephrine is released during exercise andis the most potent stimulus for fat break-down. It is the interplay of these hormonesin the proper balance that makes a greatbodybuilder. These hormones controlmuscle and fat metabolism, and the strat-egy behind a bodybuilding diet and train-ing is to control them to produce a lean,muscular body.7. What exactly is the molecularstructure of human growth hormone?GH is a protein. Ninety percent of GHproduced by somatotropes (cells of thepituitary gland where growth hormone ismade) is comprised of 191 amino acidsand has a molecular weight (MW) of about22,000 daltons (6). The other 10% has aMW of 20,000 and lacks 15 amino acidscorresponding to residues 32 to 46 of the22,000 MW form. Both forms are prod-ucts of the same gene and arise from dif-ferential RNA splicing. Both forms aresecreted and have similar growth-promot-ing activity, although the metabolic effectsof the 20K form are reduced. GH is storedin the anterior pituitary and is the mostabundant of the anterior pituitary hor-mones. As much as half of the GH inplasma protein and a substantial fractionis in the form of dimers or oligomerswhich are inactive. hGH used for therapytoday is produced in bacteria from thecloned gene.8. Describe the major effects ofGH on growth (linear and mass) andmetabolism of carbohydrate, proteinand fat.Linear growth: Linear growth is aconsequence of elongation of the skeleton,especially the spine and leg bones. Prolif-eration of chondrocytes (cartilage cells)at the epiphyseal border of the growthplate is balanced by cellular degenerationat the diaphyseal end, so in the normallygrowing individual the thickness of thegrowth plate remains constant as the asthe epiphyses are pushed farther apart bythe elongating shaft of the bone (6). Inthe absence of GH there is severe atro-phy of the epiphyseal plates, which be-come narrower as proliferation of carti-lage progenitor cells slows markedly. Con-versely, after GH is given to a hypopitu-itary subject, resumption of cellular pro-liferation causes columns of chondrocytesto elongate and the epiphyseal plates towiden. Bone growth is also accompaniedby an increase in diameter, which involvesbone remodeling. Treatment with GH of-ten induces a transient increase in urinecalcium and phosphorus excretion, re-flecting stimulation bone remodeling.Mass: GH increases lean body massby stimulating protein synthesis and in-creasing nitrogen retention.

GH-deficientindividuals have a relatively high propor-tion of body fat. Treatment with GHcauses a decrease in body fat accompa-nied by an increase in body protein,mostly muscle.Carbohydrate Metabolism:Sometimes, particularly after a pe-riod of glucose deprivation, GH hasan insulin-like effect in increasingglucose uptake and utilization. Thisanomalous effect disappears quicklyand its physiological significance isa mystery. After about two hours,glucose metabolism is inhibited inmuscle and adipose tissue. There isa decrease in glucose uptake andmuscle glycogen stores are pre-served.Fat Metabolism: In adipose tis-sue GH promotes breakdown ofstored triglyceride (body fat) whichincreases plasma free fatty acids(FFA). Since glucose uptake is sup-pressed by GH, fat synthesis is also sup-pressed. These effects, combined resultis a net loss of body fat.Protein Metabolism: As already dis-cussed, GH promotes nitrogen retentionand increases protein synthesis, mainly asmuscle. Part of this effect may be due toGH’s role in transport of certain aminoacids inside cells (5). Immediately afterGH injection, plasma amino acid concen-trations decrease as a result of rapid up-take and conversion of protein.The thing to remember is GH de-creases glucose uptake and utilization andspares glycogen, it increases use of fatfor energy by mobilizing fat stores and it increases protein synthesis. The net ef-fect is to make the body leaner and moremuscular. Many of the effects of exer-cise in making the body leaner and moremuscular are mediated by an exercise-in-duced increase in growth hormone (1,2).9. How do bones grow and how doesGH affect this process? Growth of long bones occurs by aprocess of called endochondrial ossifica-tion, in which proliferating cartilage is re-placed by bone. Proliferation ofchondrocytes (cartilage cells) occurs atthe epiphyseal plate — the ends of thebones where growth occurs. Frequent di-vision of small cells in the germinal zoneat the distal end of the growth plate pro-vides for continual elongation of the col-umns of chondrocytes. GH stimulatesproliferation of chondrocytes, and thusbone elongation. GH also stimulates os-teoblastic progenitor cells to proliferatecausing bone remodeling and an in-crease in bone diameter. Lack of GHgreatly retards bone growth, and with-out GH normal height cannot beachieved.10. How are the effects of GHmediated at the cellular level? Whatis the “somatomedin hypothesis”and the “dual effector hypothesis?”The SOMATOMEDIN HYPOTH-ESIS explains the observation that GHalone is not sufficient to stimulate pro-liferation of cartilage progenitor cells,or protein synthesis by cartilage cells,in vitro.

To study the cellular effects ofGH, cartilage cells are isolated andgrown in culture dishes. When normalblood plasma was added to the mixture,or plasma from a hypophysectomizedrat which had been treated with GH, therewas a sharp increase in protein synthesis,DNA synthesis and bone matrix forma-tion. These effects could not be stimu-lated by adding plasma from a hypophy-sectomized rat which was not treated withGH. These experiments demonstrate thatGH requires a factor from plasma to beactive, and this factor itself is induced byGH. Thus, GH may not directly promotegrowth itself, but rather stimulates the liverto produce and intermediate blood-bornesubstance that stimulates chondrogenesisand perhaps other processes as well. Thissubstance was originally called somatome-din C (somatotropin mediator C). Its in-sulin-like effects on glucose and its mo-lecular resemblance to proinsulin gave riseto the name insulin-like growth factor(IGF). Now, two IGFs are known: IGF-I (somatomedin C) and IGF-II. IGF-I isa small peptide (MW 7500) produced pri-marily by the liver. It is tightly bound tospecific carrier proteins in the plasma.IGF-I can cause hypophysectomized ratsto grow in the absence of GH, indicatingmany of the actions of GH are mediatedby IGF-I.The DUAL EFFECTOR HYPOTH-ESIS explains the observation that injec-tion of GH into epiphyseal cartilage of oneleg of a hypophysectomized rat producesgrowth in only that leg. This means thatthings are a little more complicated thanexplained by the original somatomedinhypothesis. Studies with cultured fibro-blasts which can differentiate intoadipocytes in a manner which is absolutelywhich is absolutely dependent on GH mayact directly on precursor cells to initiatedifferentiation. According to the dual ef-fector hypothesis, cartilage progenitor cellsin the epiphyseal plates differentiate in re-sponse to GH and then undergo clonalexpansion (cell division) in response toIGF-I, whose production is also triggeredby GH. Chondrocytes and other cells cansynthesize and secrete GH when stimu-lated by GH. IGF-I may then act as anautocrine to stimulate cell division. Thuswe have two effectors, one to stimulatedifferentiation (GH), and one to stimulatecell division (IGF-I). IGF-I may act lo-cally in processes such as wound healingand compensatory growth.Apparently eccentric (lowering) mus-cular contractions result in tearing of myo-fibrils (muscle fibers) and this in someway causes local release of IGF-I whichacts as a paracrine to stimulate differ-entiation of satellite cells into newmyocytes (muscle cells). Exercise is re-quired to induce a GH response (whichin turn induces hepatic IGF-I produc-tion) and to produce the micro-traumawhich serves as the stimulus for tissueremodeling.11. How is GH secretion regulatedin humans?GH secretion is stimulated by sleep,stress, low blood glucose, an increasein certain amino acids (especially argin-ine, leucine, valine and ornithine) andexercise. Normally GH is secreted in anepisodic fashion with maximal secretionoccurring during deep sleep. GH is syn-thesized and stored in the anterior pitu-itary, and its plasma level is controlledvia its rate of secretion. Its rate of se-cretion is controlled by two hormonesin the hypothalamus: GHRH (growthhormone releasing hormone) and soma-tostatin (which inhibits GH release). GHsecretion is thus under minute-by-minutecontrol by the nervous system. GH se-cretion is also controlled by negative feed-back, mediated by IGF-I. IGF-I appearsto increase release of somatostatin by thehypothalamus and to reduce the respon-siveness of the pituitary to GHRH. In ad-dition to direct regulation by the hypothala-mus, GH release is indirectly regulated bythyroid hormone. T3 stimulates GH re-lease by maintaining sensitivity tosomatotropes to GHRH.

T3 enhancesGH’s actions by decreasing the amount of GH needed to stimulate growth (in-creases sensitivity) and exaggerating themagnitude of the response (increases ef-ficacy). T3 and T4 seem to potentiate theeffects of GH on long bones and to in-crease its effects on protein synthesis inmuscle and liver.12. How does the integrated GHconcentration change with age?GH secretion is most active duringthe adolescent growth spurt and persiststhroughout life, long after the epiphyseshave closed. GH secretion gradually de-creases in both men and women betweenages 20-40.13. What are the effects of excessGH in humans before and after the endof adolescent growth?Overproduction of GH in childrenproduces giantism — and adult height ofover eight feet may be achieved. Over-production of GH in adulthood resultingfrom a pituitary tumor, or abuse of GH,produces acromegaly. This condition ischaracterized by thickening of the craniumand mandible and enlargement of the bonesof the hands and feet. There is also ab-normal growth of the ribs, liver and spleenand thickening of the skin. You never haveto worry about acromegaly resulting fromnaturally increasing your body’s own pro-duction of GH. You can naturally increaseGH enough to dramatically increasemuscle mass and decrease body fat, butnot enough to experience the side effectsof acromegaly. Acromegaly only resultsfrom pituitary disease or abuse of exog-enous GH.14. What are the effects of diet andexercise on GH?What should I do to naturally increaseGH levels? There are several things youcan do as a bodybuilder to naturally in-crease your GH levels (9). First, eat anadequate diet containing at least one gramof protein per pound of body weight. Ahigh protein meal increases GH release.Also remember our previous bulletin aboutdialing in your protein to carbohydrateratio to optimize insulin and glucagon lev-els. Second, supplement your diet withMax GH Formula containing the most ef-fective combination of amino acids for GHrelease ever produced (10). Use Max GHFormula before bed and before training.Always take it on an empty stomach. Gly-cine is also a potent GH stimulator (3) andthis may explain the well-known anaboliceffects of glycine. Parrillo PerformanceHi-Protein Powder and Pro-Carb Formulaare fortified with significant amounts ofglycine. This combination of supplements,along with the right diet, has proven overthe years to be incredibly anabolic. Third,make sure you get enough sleep. Maxi-mal GH release occurs during deep sleep.Take a nap during the afternoon if pos-sible. Fourth, train smart.

Heavy, low-repwork is known to be effective in increas-ing strength. This is probably due to anincrease in testosterone levels and a train-ing effect on the nervous system. High-rep work with moderate weights is moreeffective in stimulating GH release (1,2,9).It’s a huge mistake to leave out the high-rep part of your training. While low-repwork is more effective in increasingmuscle strength, high-rep work is veryeffective in increasing muscle size. TheGH release resulting from high volumetraining also serves as a potent stimulusfor fat loss.Of course, you need both high-repand low-rep work to make continuingprogress. Don’t get the idea that youdon’t have to lift heavy weights any-more. If you want to get biggermuscles, you will always have to liftheavy weights — but you also have toincorporate high-rep work for maximumdevelopment. There are several strate-gies for doing this. You can incorporateboth heavy and light work into the sametraining session using a pyramid tech-nique. Start with one or two warm upsets around 15 reps. Use a light weightwhen warming up and do not go to fail-ure. Then pick a weight you can handlein good form for ten reps. Continue in-creasing the weight and do sets of eight,six and four reps. Take all working setsto positive failure. Then decrease theweight and do a set of 20 reps to fail-ure. This helps pump the blood into themuscle and stimulates GH release.Lower the weight slowly, emphasizingthe eccentric part of the contraction.This is especially important at the endof a set when ATP is the muscle is de-pleted. ATP is required for muscle re-laxation as well as muscle contraction.When a muscle runs out of ATP it “locksup” in the contracted state and cannotrelax properly. This state is known as“ischemic rigor.” When the muscle isin rigor and your are lowering a weightfrom the contracted position, the fiberscannot relax and literally get torn as themuscle elongates. If this sounds pain-ful, it is. Most people stop a set just asthis starts to happen because the paingets unbearable. The ones who fightthrough the pain and crank out a fewmore reps are the ones who get bigmuscles. Sorry, but that’s the way it is.Another way to incorporate high repwork is to train in the four-to-eight reprange one week and the 12-to-20 reprange the next week. Finally, somepeople do a “powerlifting cycle” involv-ing heavy, low-rep work for four-to-sixweeks followed by a “bodybuildingcycle” with moderate weights and higherreps for the next four-to-six weeks.Most advanced bodybuilders have ex-perimented with all three strategies atsome point. The key is to find whatworks best for you. If you’re at a pla-teau, it’s probably time for a change.To break out of a plateau, increasecalories and try training less frequentlyby with heavier weights. If you haven’tbeen doing any high-rep work, doingsome will probably stimulate a growthspurt. Of course, there are many rea-sons for reaching a training plateau, butthey usually relate to over-training, un-der-training, under-nutrition or notenough rest. Constant fatigue, loss oflibido and failure to recover from work-outs are signs of over-training and notenough rest. If you neglect any part ofthe program — high-rep training, low-rep training, aerobics, stretching rest,nutrition, or supplementation — your re-sults will definitely suffer. The ParrilloProgram is a balanced approach cover-ing every facet of bodybuilding. Yousupply the hard work, consistency anddedication, and we’ll supply the winningstrategy.  

References

1. Kraemer WJ. Influence of the en-docrine system on resistance training ad-aptations. Nat’l Strength and Condition-ing J. 14: 47-54, 1992.

2. Kraemer RR, Kilgore JL, KraemerGR and Castracane VD. Growth hor-mone, IGF-I and testosterone responsesto resistive exercise. Med. Sci. SportsExerc. 24: 1346-1352, 1992.

3. Colgan M. Optimum Sports Nutri-tion. Advanced Research Press, NewYork, 1993.

4. Rudman D, et al. Effects of Hu-man Growth Hormone in Men over sixtyyears old. N Engl. J. Med. 323: 1, 1990.

5. Guyton AC. Textbook of MedicalPhysiology. W.B. Saunders, 1991.

6. Johnson, LR. Essential MedicalPhysiology. Raven Press, New York,1992.

7. de Castro JM, Paullin SK, andDeLugas GM. Insulin and glucagon asdeterminants of body weight set point andmicroregulation in rats. J. Comp. Physiol.Psychol. 92: 571-579, 1978.

8. Remington DW, Fisher AG, andParent EA. How to Lower your Fat Ther-mostat. Vitality House International,Provo, 1983.

9. Crist DM. Growth Hormone Syn-ergism. DMC Health Sciences, Albuquer-que, 1991.

10. Isidori A, Lo Monaco A, andCappa M. A study of growth hormonerelease in man after oral administration ofamino acids. Current Medical Researchand Opinion. 7: 475-481, 1981.

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