Myostatin: Medical Breakthrough May Lead Athletes Astray

Any serious athlete knows that good results take time: dedication to training, proper nutrition, adequate rest, all of these things are strong contributors to any successful outcome. Some athletes choose to add a variety of natural supplements to their training regimen; yet even with this boost, there is no single “magic pill“ that can instantly transform the physique. Or is there?

Several years ago, researchers began experimenting with a naturally-occurring substance in the body known as myostatin. In its most elemental form, myostatin is a muscle-specific member of the transforming growth factor- (TGF- ) superfamily that plays an essential role in the negative regulation of muscle growth. In research labs, purposeful genetic deletion of myostatin has been shown to result in excessive growth of skeletal muscle. In 1997, a team of scientists led by McPherron and Lee at Johns Hopkins University was investigating a group of proteins that regulate cell growth and differentiation. During their investigations, they discovered the gene that may be responsible for the phenomenon of increased muscle mass, also called “double-muscling“. Myostatin is the protein for which that gene encodes. By knocking out the gene for myostatin in mice, these scientists were able to show that the transgenic mice developed two to three times more muscle than mice exhibiting the same gene intact. Lee commented that the myostatin gene knockout mice “look like Schwarzenegger mice.“

As it turns out, this phenomenon is not limited to the murine model. Experimentation of genes present in skeletal muscle of cattle led to the discovery of two breeds of double-muscled cattle, Belgian Blue and Piedmontese, both of which manifested mutations in the gene that codes for myostatin. The double-muscling trait discovered in both the mice and the cattle seems to indicate that myostatin performs the same biological function in these two species. Apparently, this substance may actually inhibit the growth of skeletal muscle.

Armed with this knowledge, the next reasonable step would be to question whether this adaptation is possible in humans. Many authors of the myostatin studies have speculated that such manipulation in humans may reverse muscle wasting commonly associated with muscular dystrophy, AIDS and end-stage cancer. Current research is underway to investigate such potential. The notion of an antibody vaccine for the myostatin protein is probably not too far from reality, considering the incredible benefits such a breakthrough would have on patients suffering from the aforementioned diseases.

But medical research, the goal of which is to improve the quality of life for individuals with cachexic conditions, is a far cry from purposeful manipulation of our bodies’ genetic protein simply for the sake of increased athleticism. Yet this is exactly what has been recently observed. A few supplement companies advertise that they have found a way to create products that claim to significantly reduce the amount of serum myostatin circulating in the body, thereby enabling greater growth of lean muscle mass. Serious bodybuilders, looking for any edge in today’s highly competitive field, are buying into this, despite the fact that further research is needed in order to ascertain the long-term effects to other bodily systems. Whether or not the companies’ claims are factual, the question remains: at what point has an athlete crossed over from “supplementation“ to “inappropriate genetic manipulation“? While it is exciting to entertain the possibility of a simple way to eradicate what might be the biggest obstacle in one’s ability to gain muscle, at what cost/health risk should an athlete engage in such activity?

Fortunately, at least for now, there seems to be a good deal of hesitancy among the masses in terms of jumping on any anti-myostatin bandwagon for the sake of enhancing one’s ability to add lean muscle tissue. More prudent athletes seem to be carefully considering the research at hand. Certainly there will always be supplements available for sports performance enhancement, whether they are natural or steroid-based, as well as competitors who are willing to exploit scientific research for personal gain. But perhaps the results of further medical experimentation in the myostatin realm should be limited to helping those suffering from debilitating diseases, while true athleticism is allowed to return to its roots, that being the quest for optimal performance of the body with which we are born.


1.Johns Hopkins Magazine, June 1997
2.McPherron, AC, AM Lawler, SJ Lee. Regulation of skeletal muscle mass in mice by a new TGF-b superfamily member. Nature 1997, 387:83.
3.McPherron, AC, SJ Lee. Double muscling in cattle due to mutations in the myostatin gene. Proc Natl Acad Sci USA 1997, 94:12457
4. Kunihiro Tsuchida The role of myostatin and bone morphogenetic proteins in muscular disorders. Sumary, Expert Opinion on Biological Therapy, February 2006, Vol. 6, No. 2, Pages 147-154.
5. Wagner, KR. Muscle regeneration through myostatin inhibition. Curr Opin Rheumatol., 2005 Nov; 17(6):720=4
6. James F. Tobin and Anthony J. Celeste. Myostatin, a negative regulator of muscle mass: implications for muscle degenerative diseases. Current Opinion in Pharmacology, Volume 5, Issue 3, June 2005, Pages 328-332

About the Author

Cathleen Kronemer is an AFAA-Certified Group Exercise Instructor, NSCA-Certified Personal Trainer, competitive bodybuilder and freelance writer. She is employed at the Jewish Community Center in St. Louis, MO. Cathleen has been involved in the fitness industry for 22 years. Look for her on

She welcomes your feedback and your comments!


These resources are for the purpose of personal trainer growth and development through Continuing Education which advances the knowledge of fitness professionals. This article is written for NFPT Certified Personal Trainers to receive Continuing Education Credit (CEC). Please contact NFPT at 800.729.6378 or [email protected] with questions or for more information.
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