myostatin decreases with training, increases with detraining

[Dr Pangloss]

the following study nicely demonstrates a suppression of myostatin mrna with training and a subsequent increase with detraining.

What does that mean? Training-related suppression of myostatin likely promotes muscle growth, while myostatin probably plays a direct role in reducing muscle in the detraining phase. IN fact, it may be associated specifically with atrophy of type II myofibers.

Scand J Med Sci Sports. 2009 Nov 9. [Epub ahead of print]
Myostatin expression during human muscle hypertrophy and subsequent atrophy: increased myostatin with detraining.

Jespersen JG, Nedergaard A, Andersen LL, Schjerling P, Andersen JL.
Institute of Sports Medicine Copenhagen, Bispebjerg Hospital, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
Myostatin is a potent negative regulator of skeletal muscle mass, but its role in human skeletal muscle hypertrophy and atrophy is sparsely described. Muscle biopsies were obtained from young male subjects before and after 30 and 90 days of resistance training as well as after 3, 10, 30, 60 and 90 days of subsequent detraining. Myostatin mRNA increased significantly with detraining. We observed a 28 kDa myostatin immunoreactive protein, which, however, was also present in myostatin knock out mice skeletal muscle. As a novel finding we consistently detected a 10 kDa band, which may represent a mature myostatin monomer under reducing conditions or a novel, unknown myostatin form. Further, we observed a significant increase in this 10 kDa band after 3 days of detraining preceding the rapid type II fiber atrophy, in which almost half of the acquired fiber area was lost after only 10 days of detraining. Accordingly, an increase in the level of the 10 kDa protein is associated with rapid type II fiber atrophy, suggesting myostatin-mediated specific type II fiber atrophy, which in combination with our mRNA data support a role for myostatin in the negative regulation of adult human skeletal muscle mass.

PMID: 19903317 [PubMed - as supplied by publisher]

[DocGabri]

Interesting.....

[heavyiron]

That is interesting, thank you!

[Strikerrjones]

So after just 3 days of detraining there might be a significant increase in myostatin?

[Dr Pangloss]

So after just 3 days of detraining there might be a significant increase in myostatin?

I'll give you a full report on the metes and bounds of this question tomorrow. i have the paper at work.

[Frosty]

So if you train more, is myostatin inhibited more?

[Dr Pangloss]

So if you train more, is myostatin inhibited more?

it certainly looks like it to within a reasonable degree. this study though fails to address a lot of questions like training intensity, frequency, highly trained indiividual effects.

they have a simple antibody assay for myostatin now, i'm sure there are plenty of guys asking all kinds of questions about how training effects this protein.

[heavyiron]

So if you train more, is myostatin inhibited more?

Man that is so counter intuitive. Weird.

I would also like to see the levels of myostatin on the various days of detraining.

[Frosty]

Man that is so counter intuitive. Weird.

I would also like to see the levels of myostatin on the various days of detraining.

The thought just occurred to me because of a type of training I've come to like where you basically train too much during a period and then take time off to recover and grow. If you train your ass off and suppress myostatin a lot with all that training, then you take time off and eat, the myostatin doesn't bounce back immediately, leaving a window of time open where you can really grow. Perhaps this is one factor in why this works.

[Dr Pangloss]

So after just 3 days of detraining there might be a significant increase in myostatin?

that's an increas in the 10 kd fragment of myostating. They really dont know for sure if this fragment (which would be a monomer; the usual protein is a dimer) has any function or what meaning to attribute to it. however, it does peak 3 days after.

mrna expression of myostatin, which is a more reliable measure here, only shows significant elevation after 10 days detraining.

Also, the subjects were initially untrained and the resistence program was 5-6 sets of 6-15 Repetition Maximums (RMs) of a variety of leg exercises. muscle biopsies were performed on the vastus lateralus.

So this is a beginner's program. And the most reliable thing you can say is that 10 days of detraining and mrna and 28kd (full size) myostatin was significantly elevated.

What's exciting here is that myostatin may be regulating muscle gains, and by studying the changes in myostatin levels with various types and frequencies of training, one could finally get at optimal training for muscle growth.

stay tuned...

[natron]

Good info Dr.P