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The Fall of The Greatest Theory of Muscle Growth
Beginner | 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:
Exercise induced muscle growth is primarily due to an acute increase in these hormones.
Hence workouts should mainly use multi joint exercises with short rest periods to raise the hormone levels.
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
Reference 1
The Fall of the Greatest Theory of
Muscle Growth - Part 2
BEGINNER | May 22 2011
If you haven?t read the first part of the article and is not aware of the debate, please read the The Fall of the Greatest Theory of Muscle Growth. Recently, another study was conducted by a different group of authors and concluded that the acute hormone elevations may help. Now let?s take a closer look at the study titled
hysiological elevation of endogenous hormones results in superior strength training adaptation.
What was the design of the study?
Nine untrained men performed four single joint biceps exercise per week for 11 weeks.
For two training sessions, 3 leg exercises(leg press, leg extensions and leg curls) were performed before the bicep exercises for one of the arms (hormone Group).
For the other two training sessions, the same protocol was performed for the other arm without the leg exercise (NO hormone group).
This type of within-subject design ensures that motivation levels and genetics do not affect the results.
The same design was employed in the previous study too, but the big difference was that the leg exercises were performed after the arm exercises But in the current study the leg exercises were performed before the arm exercises.
What were the results of the study?
Both group increased muscle CSA, 1RM strength, peak power and muscle volume.
Only the hormone group obtained significant increase in muscle CSA at the part of the arm with ht e largest cross sectional area.
Only the hormone group showed a significant improvement in 1RM strength in biceps.
My Comments
One of my concerns is the design of the study. The design of having them do leg exercises before arm exercises is not ideal. The acute increase in catecholamine and the neural drive after leg exercises makes you feel stronger which can be evident especially in smaller muscle exercises.
The % strength increase for the no hormone group is 14% (12lbs) and 21% (18lbs) for the hormone group. In the previous study, they saw a 24% increase in strength for the no hormone group and they did only 3-4 sets compared to 6 sets in this study. That is almost twice more than what they got here!
Though the results are statistically significant, the difference of only 5-6 lbs in 11 weeks in beginners is not really impressive.
The muscle cross sectional area (CSA) increase was significant in all sections for both the groups except section 8 & 9 (circled in red in the figure) for the no hormone group. But the author for some reason only mentions the significant increase in section 8 of the hormone group in the abstract. In the previous study, all sections in both groups had a significant increase in CSA.
The CSA increased more in one group, but the muscle volume inexplicably remained the same for both groups.
Practical Applications
Even after doing 6 sets of biceps exercise after leg exercise for 11 weeks, the increase in biceps strength was only 5-6 lbs in rank beginners in the hormone group. Hence the benefits of such a training protocol for trained individuals is dubious.
Based on this study, performing just leg exercises and increasing hormones will not make your biceps grow. You have to perform sets of bicep exercises and make sure they are done ?right? after the leg exercises.
Considering that this is the only study which gives a causative role for the hormone theory, the evidence is still weak for a theory which is still the most popular theory of muscle growth.
Beginner | 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:
Exercise induced muscle growth is primarily due to an acute increase in these hormones.
Hence workouts should mainly use multi joint exercises with short rest periods to raise the hormone levels.
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
Reference 1
The Fall of the Greatest Theory of
Muscle Growth - Part 2
BEGINNER | May 22 2011
If you haven?t read the first part of the article and is not aware of the debate, please read the The Fall of the Greatest Theory of Muscle Growth. Recently, another study was conducted by a different group of authors and concluded that the acute hormone elevations may help. Now let?s take a closer look at the study titled
hysiological elevation of endogenous hormones results in superior strength training adaptation.What was the design of the study?
Nine untrained men performed four single joint biceps exercise per week for 11 weeks.
For two training sessions, 3 leg exercises(leg press, leg extensions and leg curls) were performed before the bicep exercises for one of the arms (hormone Group).
For the other two training sessions, the same protocol was performed for the other arm without the leg exercise (NO hormone group).
This type of within-subject design ensures that motivation levels and genetics do not affect the results.
The same design was employed in the previous study too, but the big difference was that the leg exercises were performed after the arm exercises But in the current study the leg exercises were performed before the arm exercises.
What were the results of the study?
Both group increased muscle CSA, 1RM strength, peak power and muscle volume.
Only the hormone group obtained significant increase in muscle CSA at the part of the arm with ht e largest cross sectional area.
Only the hormone group showed a significant improvement in 1RM strength in biceps.
My Comments
One of my concerns is the design of the study. The design of having them do leg exercises before arm exercises is not ideal. The acute increase in catecholamine and the neural drive after leg exercises makes you feel stronger which can be evident especially in smaller muscle exercises.
The % strength increase for the no hormone group is 14% (12lbs) and 21% (18lbs) for the hormone group. In the previous study, they saw a 24% increase in strength for the no hormone group and they did only 3-4 sets compared to 6 sets in this study. That is almost twice more than what they got here!
Though the results are statistically significant, the difference of only 5-6 lbs in 11 weeks in beginners is not really impressive.
The muscle cross sectional area (CSA) increase was significant in all sections for both the groups except section 8 & 9 (circled in red in the figure) for the no hormone group. But the author for some reason only mentions the significant increase in section 8 of the hormone group in the abstract. In the previous study, all sections in both groups had a significant increase in CSA.
The CSA increased more in one group, but the muscle volume inexplicably remained the same for both groups.
Practical Applications
Even after doing 6 sets of biceps exercise after leg exercise for 11 weeks, the increase in biceps strength was only 5-6 lbs in rank beginners in the hormone group. Hence the benefits of such a training protocol for trained individuals is dubious.
Based on this study, performing just leg exercises and increasing hormones will not make your biceps grow. You have to perform sets of bicep exercises and make sure they are done ?right? after the leg exercises.
Considering that this is the only study which gives a causative role for the hormone theory, the evidence is still weak for a theory which is still the most popular theory of muscle growth.
