T Nation

Muscle Hypertrophy


#1

Muscle hypertrophy is dependent on the ammount of ATP present in the muscle fibers. The higher the ATP levels, the better the environment for muscle growth.
Higher repetition Sets develop the numbers of mitochondria in muscle fibers which in turn can now produce higher levels of ATP - in effect increasing strength levels and promoting higher levels of hypertrophy.

When performing low repetition sets however, mitochondria levels dont increase, and might even decrease (correct me if Im wrong). This means sub-optimal levels of ATP produced by the muscle fiber. In this instance, where does the ATP come from? Since Growth is dependent upon levels of ATP present in the muscle fiber (along many other factors), it would be reasonable to say very low repetition exercise for PROLONGED periods of time would eventually stall muscle HYPERTROPHY (not necessarily strength).

Unless, there is a major flaw in my reasoning, or if muscle fibers with little mitochondria can get ATP from other sources, then the ideal recipe for continued muscle growth would by necessity have to incroporate periods of sarcoplasmic hypertrophy where mytochondria levels go up but Actin/Myosin hypertrophy is minimal, followed by low repetition work where Actin/Myosin hypertophy occurs - now in an environment where there is an abundance of ATP. Thus, alternating moderate-high repetition with low repetition training would be a necessity, not just a cool trick for maximal hypertrophy gains.

Just rambling, and all the pieces might be out of place. Please correct me if Im wrong - and Im sure Goldberg will have some interesting contributions.


#2

Don't forget about feeder satellite cells, which do exactly what their name means - feed the muscles. Also, via the mitochondria isn't the only way to produce energy, glycolysis being the other. Granted, there is 18x more energy being produced by electron transport in the mitochondria, so that is good. But in short, hard bursts, you have an anaerobic environment, which facilitates glycolysis.


#3

This just further strengthen's Mr. Waterbury's training protocols for maximal size (ABBH program). Good read.


#4

Thus, alternating moderate-high repetition with low repetition training would be a necessity, not just a cool trick for maximal hypertrophy gains.

I trained with exclusively low reps for several months and increased strength without increasing size--for the past 2-3 months I have been using 3-5 sets of 3-5 reps followed by 2 sets of 8-10 reps, but only on the major compound lifts (squat, deadlift, bench, chins, etc)

strength is still increasing (though slower) and size is starting to creep back up with higher calories (higher calories on low rep only lifting added more bf than muscle)

[NOTE: I train full-body, three days a week, using different lifts each day--your results may vary]

more experiential than scientific, but there it is

--Bill


#5

It it without a doubt true that muscles trained with lower repitition sets have fewer mitochondria than those trained with higher reps. This does not mean that there is less ATP present in the cell. ATP does contribute to muscle hypertrophy.

During lower rep sets muscles undergo aerobic cellular resperation, while in higher rep sets they undergo anaerobic cellular resperation.

During aerobic cellular resperation, 38 ATP molecules are produced from one glucose molecule (4 from substrate-level phosphorylation; 34 from oxidative phosphorylation). While 1 molecule of glucose can only produce two ATP molecules in anaerobic cellular resperation (they have to stop at pyruvate).

This would mean that muscles with trained with lower reps would only need 1/16th of the mitochondria that those trained with higher reps would need in order to produce the same amount of ATP (not really, but that is another story..they need a lot less though).

So, muscles trained with lower reps, that have less mitochondria still grow quite well.

Shawn


#6

I just realized that it seemed like I was saying glycolysis takes place in the mitochondria. What I was saying is that with aerobic glycolysis in the cytosol, there is less need for mitochondira.


#7

Unless, there is a major flaw in my reasoning... the ideal recipe for continued muscle growth would by necessity have to incroporate periods of sarcoplasmic hypertrophy where mytochondria levels go up but Actin/Myosin hypertrophy is minimal, followed by low repetition work where Actin/Myosin hypertophy occurs - now in an environment where there is an abundance of ATP. Thus, alternating moderate-high repetition with low repetition training would be a necessity, not just a cool trick for maximal hypertrophy gains.

In other words: Without periodization, your gains will stop.

Yes, this is true.


#8

What a revelation ... periodization works.

This is simply reinforces (not that it needs reinforcing) the need to alternate accumulation and intensificatin phases, ( which I personally hate doing, even if I know it works)

(one)


#9

"Muscle hypertrophy is dependent on the ammount of ATP present in the muscle fibers. The higher the ATP levels, the better the environment for muscle growth.
Higher repetition Sets develop the numbers of mitochondria in muscle fibers which in turn can now produce higher levels of ATP - in effect increasing strength levels and promoting higher levels of hypertrophy. "

Growth is not dependant to ATP levels in muscle fibers but There needs to be sufficient glycogen inside the muscle though. The growth stimulus and consequent elevated protein synthesis only lasts for about 48 hpours at the most and if glycogen repletion doesn't occur within this time frame not much will happen.

"When performing low repetition sets however, mitochondria levels dont increase, and might even decrease (correct me if Im wrong). This means sub-optimal levels of ATP produced by the muscle fiber. In this instance, where does the ATP come from? Since Growth is dependent upon levels of ATP present in the muscle fiber (along many other factors), it would be reasonable to say very low repetition exercise for PROLONGED periods of time would eventually stall muscle HYPERTROPHY (not necessarily strength). "

The reason why low rep training might eventually lead to impaired hypertrophic response is most likely due to reduced activity of a signaling protein called ERK 1/2, which is said to facilitate hypertrophy.

"Unless, there is a major flaw in my reasoning, or if muscle fibers with little mitochondria can get ATP from other sources, then the ideal recipe for continued muscle growth would by necessity have to incroporate periods of sarcoplasmic hypertrophy where mytochondria levels go up but Actin/Myosin hypertrophy is minimal, followed by low repetition work where Actin/Myosin hypertophy occurs - now in an environment where there is an abundance of ATP. Thus, alternating moderate-high repetition with low repetition training would be a necessity, not just a cool trick for maximal hypertrophy gains."

There's no scientific evidence at this points that suggest that you should train for one type of hypertrophy or the other. Load progression is mandatory and reps in themselves mean very little. The secret lies in beeing able to stay ahed what scientists labelled the repeated boot effect.


#10

All excellent contributions - thank you.

Restless, as soon as I have the time I will post references and quotes illustrating how muscle hypertrophy, by necessity, requires the presence of ATP in order to occur at all.

HVYWT78, you got it the other way around. Low Repetitions use anaerobic metabolism, whereas high repetitions use aerobic metabolism. Aerobic Glycolisis does provide far more energy than anaerobic glycolysis, which is why you can run for 50 minutes at a moderate pace without excessive effort.

Also, let me explain exactly the energy systems used by your body according to the length of your set:

0-30 seconds: first energy source tapped into is ATP and Creatine Phospate (to provide ATP). Glycolisis is very low in these first 30 seconds, and gradually increases.

30 seconds - 5 minutes : After 30 seconds Creatine stores are exhausted and cease to be used altogether. Anaerobic glycolisis is now the main source of energy used, and it peaks at 60 seconds into the exercise - after this point, anaerobic glycolisis slowly decreases.

5 mins> Anaerobic Glycolisis. Your body is now burning Glycogen through anaerobic glycolisis as its PRIMARY source of energy (anaerobic glycolisis continues to occur up to 15 minutes but in extremely small ammounts). This is MUCH MUCH more effective in terms of energy production than anaerobic glycolisis, as HYWT78 said.

As such you can see how important ATP stores will be for maximal performance in strength and explosive activities lasting under 30 seconds - such as maximal strength training, powerlifting, and so forth. Even if your set lasts 60-70 seconds, anaerobic glycolisis is very innefective in terms of energy production, which slows you down after creatine and ATP stores are depleted - thus the higherf your creatine stores, the better your performance will be. This is why creatine supplementation works.


#11

"Low Repetitions use anaerobic metabolism, whereas high repetitions use aerobic metabolism."

Just as a clarification, there really isn't any time that one energy system is used exclusively. In other words, you'll still use some anaerobic metabolism at the onset of a marathon.


#12

"Restless, as soon as I have the time I will post references and quotes illustrating how muscle hypertrophy, by necessity, requires the presence of ATP in order to occur at all. "

Thinking about it, if there's enough glycogen in the muscle it implies there probably wouldn't be any ATP shortage as well, so one thing kind of implies the other. Of course, if there's no ATP in the muscle but there's glycogen ATP will be replenished so the fundamental thing is glycogen, not ATP itself.


#13

Also, it's been shown that an untrained individual will need up to 3-5 minutes to fully restore Creatine Phosphate stores, whereas an aerobic trained athlete will need only 1-2 minutes to restore these same Creatine Phosphate stores.
This shows just how important and effective a larger number of larger Mytochondria, who can use more oxygen, is at expediting Energy store replenishment. The more mytochondria you have, and the larger these mytochondria are, the faster and effectively your body fully restores its energy stores, thus improving performance AND, since ATP levels directly influence supercompensation during recovery phase, the better the hypertophy gains should be later on during the lower rep phase.

Thus, a few weeks of higher repetition training with a few weekly bouts of interval training type running (90 seconds jogging, 30 seconds sprinting alternating), will significantly improve gains made by the subsequent strength/hypertrophy phases by :

a) speeding recovery between sets
b) speeding post workout recovery
c) improve performance and strength levels (more weight/reps = better gain potential)
d) lastly, though not related to strength gains, is sarcoplasmic hypertrophy through an increased number of mytochondria, which will also play a small part in size gains for those interested exclusively in size (i.e., bodybuilders). This is just a side benefit, since the real benefits are the improved strength/hypertrophy gains to follow during the subsequent strength/hypertrophy phases.

Recovery between sets consists of converting lactate into glycogen and store it as energy, and restoring creatine phosphate/ATP stores. Score of mytohondria are needed to accelerate this process.

Without this increased post workout recovery, mid-workout energy stores replenshiment, and improved ATP levels, hypertrophy is likely to be considerably lower and possibly stagnate after excessively long periods of strength/hypertrophy training.


#14

Eric Cressey, you are absolutely right.

At the onset of even an endurance activity, fast twitch fibers are still recruited, and creatine phosphate/atp, and anaerobic glycolysis still occurs to a very small degree. The key to remember is that the MAIN source of energy is aerobic during endurance activities, and anaerobic for those lasting under 5 minutes (especially those under 30 seconds of duration).


#15

Let me just emphasize that the main error in my reasoning - the one I suspect at least - could be the fact I assume fast twitch muscle fibers will not be able to replenish atp stores as effectively, fast, or to the same level as an individual who has high levels if mytochondria.

Another reason why my reasoning might not be entirely accurate is the fact that, as I look down on the book I have in front of me, there is a 90% increase in glycogen storage capacity, an increase of 70% in creatine phosphate storage capacity, and an increase of 50% in ATP storage capacity ALL stemming from STRENGTH training. The key point here is wether a large # of mytochondria is necessary to completely fill these increased stores, and wether low numbers increase reovery time between workouts.


#16

Let me point out that during recovery other muscle groups are involved in converting lactate into glycogen and possibly atp, for further use by the body. The heart is especially involved in this process, each heart muscle fiber containing an average of 10,000 mytochondria.
The faster these lactate levels come down and the faster glycogen and atp is restored, the faster the recovery between sets. As such, light activity between sets is recommended to help improve this process by involving the heart and other muscle groups to a higher degree (for example light jump rope, slow jogging, and so forth). The key here is LIGHT, as the central nervous system needs to fully recover as well (an under-recovered CNS will lead to weaker signals to the muscle which, much like a weak radio signal, will get a weaker response and fail t oeffectively recuit the muscle fibers to the same degree).


#17

Im not even going to attempt to tackle all of your points. But there is one i want to comment on. You said that subsequent cycles aimed at strength gain would be better if preceded by a phase where the trainee trained for more muscular endurance. This may sound good in theory but in the real world it doenst always happen that way. If i were to spend three weeks on higher repetitions working for strength endurance, i would spend the next three weeks trying to get my strength and size back that i had lost in the previous phase. This is why conjugate periodization is so much better than linear periodization. If i train for "strength" at the beginning of the session, i can end that session with high rep work which can accomplish much of what you wanted to with your higher reps phases without the subsequent loss in stength and mass.

Every single time i tried linear periodization i would lose what i had gained in the previous cycle. It was like taking two steps forward and two steps back over and over. I was too stupid to realize that my body was trying to tell me that it was wrong because everybody "in the know" said that linear periodization was the way to go.


#18

More or less neglecting ATP for a min..we also must realize(as I'm sure we all do) that fast twitch muscles have the most growth potential. Therefore training that works mainly those fibers will obviously lead to growth if your diet is dialed in. Duh!Also sarcomer hypertrophy seems to me to be of more value than sarcoplasmic hypertrophy. :wink:


#19

You guys are like books, I cant believe how much knowledge you guys have. Im 21 and am still learning about these things. I thought I knew about ATP and the main energy systems, but you guys take it to a whole new level. I hope to one day possess the knowledge the knowledge that some of you guys have. My main source of reference thus far has been Tudor Bompa and his periodization techniques, and I have just started reading up on Paul Chek and Charles Poliquins principles. Goldberg what is the difference between linear periodization and the other one you said. I feel the same way you do in that I go through my 3 week phases of muscular endurance and than am fighting to get my strength back. Thanks for all the info, you guys are amazing. I find myself reading the forums and the information for hours. This is a great website.


#20

ATP does not function alone. For a muscle contraction to occur ATP(Adenosine triphosphate) needs CP(Creatine phosphate) to replace the missing phosphate (in ATP)for further muscle contraction. IT goes something like this 2-3 second ATP muscular contraction , 3-9 secs CP muscle contraction...that is if i remember my shit correctly.