Local vs. Systemic Factors for Muscle Growth

[Donald Lee]

I know Lyle's written about this issue, but I liked how organized and simple this article was in explaining it:

http://www.exercisebiology.com/index.php/site/articles/the_fall_of_the_greatest_theory_of_muscle_growth/

The Fall of The Greatest Theory of Muscle GrowthBeginner | May 09 2010

The recent study was the final nail in the coffin for one of the greatest theories of muscle growth-the hormone theory - proposed by the prominent researcher William J Kramer.

What is the hormone theory of muscle growth?
Growth & Development: Hormones like testosterone, growth hormone, & IGF-1 are important for growth & development.

Injection of hormones: Injection of hormone,s especially testosterone has shown increase strength and muscle mass while suppression of testosterone has shown to decrease in muscle mass & strength.

Acute Increase after exercise: These same hormones are elevated acutely after resistance training. The magnitude of increase depends on rest times between sets, the weight used and so on.

For example, the large rises in these hormones are observed after high intensity exercises with short rest periods using big muscle groups (multi-joint exercises).

Based on the above hormone hypothesis , it is assumed that

1. Exercise induced muscle growth is primarily due to an acute increase in these hormones.
2. Hence workouts should mainly use multi joint exercises with short rest periods to raise the hormone levels.
3. Small exercising muscle groups (e.g., biceps), which are incapable of causing large increases in anabolic hormones when used in isolation, should be trained concurrently with large exercising muscle masses like squats or leg press that can elevate testosterone and GH.

The fall of the hormone hypothesis
Local factors in muscle growth: The recent discovery of local factors like MGF,muscle IGF-1 showed that it is local factors that are mainly responsible for muscle growth and not systemic hormones.

The discovery of these local factors, which are found inside the muscle, showed why muscle growth is specific to the exercised muscle. If systemic hormone were indeed responsible, you would have seen an increase in muscle growth in the non-exercised muscle too.

No effect of GH administration: Injection of high doses growth hormone to raise resting levels resulted in little increase in muscle growth or strength.

So the benefits of these tiny spikes in GH after exercise which do not even change the resting levels are questionable.

Unilateral exercises: Increase in muscle growth has been observed with unilateral exercises like biceps curl without any increases in systemic hormones.

For example, unilateral exercise like biceps curl and leg extensions which do not cause a spike in systemic hormones have shown to increase muscle growth and strength.

No Increase in protein synthesis: There was no significant increase in protein synthesis due to an acute increase in systemic hormones after the workout.

BUT the question can these spikes in systemic hormones play a small role if not a major role in muscle growth which might have been overlooked in the above studies . All the above were indirect studies until the recent study.

What was the study design?
•Twelve healthy untrained young men trained their biceps independently for 15 wk on separate days.
•In one training condition, participants performed isolated biceps curl exercise designed to maintain basal hormone levels.
•In the other training condition, participants performed identical biceps curls followed immediately by a high volume of leg resistance exercise to elicit a large increase in these hormones .
•If the hormone hypothesis were true, the biceps curl plus leg pres group should see greater muscle growth & strength, right.

What were the results of the study
Unfortunately, at the end of 15 weeks there was no significant difference between groups in strength, muscle cross sectional area, & Type 1 or Type 2 fiber area.

Simply put, the increase in testosterone, growth hormone or IGF-1after your workout do not help in muscle growth/strength.This study was the final nail in the coffin and clearly drops the curtain on one of the best known theories of muscle growth .

Practical Applications
•Don’t perform multi-joint exercise like deadlifts, squats, 20 resp squats or leg press for the sake of increasing hormones.
•Don’t keep rest times short or perform high intensity workouts for the purpose of raising hormone levels.
•If your trainer says the program works by increasing hormones, send this article to him

[Michael Hartman]

Thanks for sharing. I agree that too much is made over the acute changes in hormone concentrations during and immediately following strength training. Performance Menu (04/30/10) (http://www.performancemenu.com/wod/index.php?show=wod&dailyID=1172)

That said:

One research study with 12-untrained subjects is never enough evidence to "drop the curtain" on any theory.

The differentiation between the local / systemic and autocrine / paracrine growth factors has been established for well over 10-years.

Never take exercise advice from someone who questions the effectiveness of deadlifts and squats.

[Steven Low]

It would be more interesting if they tracked local and systemic hormonal changes for 0-72 hours after training... not just a couple hours after training. Especially during sleep when most of the repair and tissue regeneration is going to occur...

But of course most body adaptations are going to be specificity driven.

[Donald Lee]

Thanks for sharing. I agree that too much is made over the acute changes in hormone concentrations during and immediately following strength training. Performance Menu (04/30/10) (http://www.performancemenu.com/wod/index.php?show=wod&dailyID=1172)

That said:

One research study with 12-untrained subjects is never enough evidence to "drop the curtain" on any theory.

The differentiation between the local / systemic and autocrine / paracrine growth factors has been established for well over 10-years.

Never take exercise advice from someone who questions the effectiveness of deadlifts and squats.

Your name sounded very familiar, but I eventually realized I was thinking of Dr. J. Hartmann.

I read the article you linked. Do you still think HGH plays a major role in muscle growth?

[Michael Hartman]

GH definitely has a role in muscle growth...long term.

The benefit of using rest short periods, and the associated increase in GH during/following exercise, has more to do with increased lipolysis.

[Donald Lee]

Isn't GH's muscle growing properties mostly mediated through it's conversion to IGF-1?

I've been reading the same thing about GH and lipolysis.

[Steven Low]

Yeah, GH has downstream effects on a couple growth factors including IGF-1, and a lot of the body's organs.

[Dave Van Skike]

Now I know this argument is more logic based than a deep understandign of endocronology but the question is settled for me by talking with training around people who take superaphysiological doses of Test, IGF-1 and GH.

The effects of their doses are nowhere near dramatic as the high intensity crowd claims for the mythological 72 hour hormone bump you're supposed to get from HIIT.

[Steven Low]

Now I know this argument is more logic based than a deep understandign of endocronology but the question is settled for me by talking with training around people who take superaphysiological doses of Test, IGF-1 and GH.

The effects of their doses are nowhere near dramatic as the high intensity crowd claims for the mythological 72 hour hormone bump you're supposed to get from HIIT.
Well, I do think it's more overblown than it really is. Most people think steroids or other hormones are magical substances that let you train 2x harder and move 2x faster. No.

They do allow you to improve your recovery rates, but only slightly. You're not going to be able to increase your volume or intensity or frequency to insane levels.

Over time, of course, things add up. The cumulative effects are likely best seen over a period of months or even years in some cases rather than a couple workouts.

However, there is something to be said for working out intensely via SAID principle -- specific adaptation to implied demand. Your body is going to adapt more strongly to exercise of greater intensity (albeit obviously easier to burn out at higher intensity).

[Dave Van Skike]

Over time, of course, things add up. The cumulative effects are likely best seen over a period of months or even years in some cases rather than a couple workouts.




I understand all of the rest of what you said but this.

Am I to understand that engaging in activities that are alleged to raise GH temporarily will have an effect...as long as you engage in these activites for months/years?

Again. first hand looking at what people have done, GH in particular, takes several months for any notable effect. This is at doses well above "replacement" therapy.

It doesn't make any sense at all. There has to be something else at work...Here's a softball....maybe it's appetite and diet. Not saying that HIIT is a waste of time for conditoning and body comp...but it ain't the hormones at work.

[Alex Bond]

Article doesn't use the phrase "alter your hormonal milieu" and as a result, fails to attract my attention.

[Steven Low]

I understand all of the rest of what you said but this.

Am I to understand that engaging in activities that are alleged to raise GH temporarily will have an effect...as long as you engage in these activites for months/years?

Again. first hand looking at what people have done, GH in particular, takes several months for any notable effect. This is at doses well above "replacement" therapy.

It doesn't make any sense at all. There has to be something else at work...Here's a softball....maybe it's appetite and diet. Not saying that HIIT is a waste of time for conditoning and body comp...but it ain't the hormones at work.
No, I meant the cumulative effects of using PEDs vs. not using them.

Like most things the efficacy of training methods or PEDs or whatever you're going to compare is best seen over a larger stretch of time than days or weeks.

[Gant Grimes]

Article doesn't use the phrase "alter your hormonal milieu" and as a result, fails to attract my attention.

:)

Not saying that HIIT is a waste of time for conditoning and body comp...but it ain't the hormones at work.

You're a liar. When I stopped doing CF-type metcons, I had to take HCG just to get right.

Fran>DBol.

[Dave Van Skike]

ya caught me......

the couch ain't drunk...he's just bloated...too much Grace and you got aromatization problems.

Tommorow's WOD as RX'd

~one arm cattleball thrusters. 20 min each arm
~500 pushups, two or three at a time to save time.
~chinese split L-sit to failure
~.5 mg of arimidex..

[Donald Lee]

With regards to some of what Dave has been saying, I know Lyle uses intervals in two of his stubborn fat protocols to mobilize stubborn fat. He follows the intervals with low intensity steady state cardio though to burn the mobilized fat. I reckon this means that the elevated GH, adrenaline, noradenaline, etc. is largely temporary.

[Anoop Balachandran]

One research study with 12-untrained subjects is never enough evidence to "drop the curtain" on any theory.

There are multiple lines to evidence which questioned the validity of the hormone hypothesis. In fact, this was the 3rd study from Phillips lab, apart from other studies from other labs, which questioned the validity of the hypothesis and came out against it.

here is something related: http://www.exercisebiology.com/index.php/site/articles/can_workouts_designed_to_increase_testosterone_inc rease_muscle_mass_strengt/

It is a within subject design which eliminates a lot of variables. So the control group was the subject themselves. And Phillips is one of the prominent researchers and I do think they are smart enough to do a power analysis to find the right sample size before the study.


Never take exercise advice from someone who questions the effectiveness of deadlifts and squats.

Can you show me where I question the effectiveness of squats and deadlifts. Please re-read the conclusion again.

[Anoop Balachandran]

Thanks Donald for the comments. I usually try to keep it short and to the point and expect to write comments if people have more questions.

[Justin Arnold]

dang....