Musclin: The New Exercise Hormone

Jennifer O'Donnell-Giles | March 8, 2016

It is known that exercise does wonders for the body. Athletes want to train harder and for longer periods of time to improve their performances. People with slightly sedentary lifestyles want to be able to tolerate longer workouts. Either way, the discovery of a new hormone that promotes physical endurance brings great news to exercisers and non-exercisers alike!

In a study conducted on mice at the University of Iowa, scientists found a peptide called musclin, which is a hormone-like substance made by skeletal muscles and released into the bloodstreams in response to physical activities. They concluded that this "exercise factor" is responsible for building the muscle’s capacity for energy production and, therefore, may help increase endurance. That means people would be able to exercise for longer periods of time and, for athletes, at greater levels of intensity.

Scientists found that when supplemented with musclin, the mice began exercising on their own and behaving like those with naturally-occurring musclin. After a week, they actually started exercising for longer periods of time and at a higher intensity than the placebo mice. Researchers went on to say that the musclin signaled increased production of mitochondria, the power production center of the cell, improving muscle performance and increasing the aerobic capacity in the mice.

While the research is still ongoing, it’s exciting to know that exercising could be easier. Athletes and sedentary individuals could potentially benefit greatly from further investigation into musclin. Although knowledge of this peptide would not replace exercise, it could make exercising more enjoyable and sustainable for those who find it challenging. And if working out felt easier, people would no doubt be encouraged to exercise more, ultimately taking better control of their health.


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Jennifer O'Donnell-Giles

Jenn Giles, R.D., C.S.S.D. is all about health and wellness. She has over 15 years’ experience, including a dual master’s degree in Nutrition and Exercise Physiology from Columbia University. She is a Registered Dietitian (RD) and a Board Certified Specialist in Sports Dietetics (CSSD). She supplements all of this with her spin instructor certification and USATriathlon Level I Coach Certification.

Jennifer is passionate about (actually, obsessed with) the sport of triathlon. She has been personally participating in triathlons since 2000 and running road races since 1992. She is a two-time Ironman finisher and has completed countless numerous marathons. She has been a member of Power Bar Team Elite since 2006 and competed as a member of the 2006 Aquaphor/Active.com Sponsored Athlete Team. She was ranked as USAT All American Honorable mention in 2006 and 2011. Jennifer does all of this along side of her husband, Patrick, who is an equally accomplished triathlete and runner. They try as hard as they can to do all of their training and racing together.

She will tell you, however, that her most important, most rewarding and most challenging job is as a mother of four. She knows first hand the challenges of maintaining optimal fitness, overall good health and achieving goals while raising a family - of which good nutrition is the cornerstone.

Most importantly, she knows how to motivate, inspire and challenge athletes based on their own abilities, strengths and everyday lifestyles. She believes there is an athlete in everyone - no matter what their abilities are – and if those abilities are manifold, then there is an even better athlete in there!

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