Muscle growth is a common aim for millions of athletes, so understanding the science behind the processes that trigger it is essential for anyone working in sports nutrition.
If you ask a biologist exactly how muscles get bigger and stronger, expect them to talk about mTOR, which stands for “Mammalian Target of Rapamycin.” mTOR is a protein critically involved in the signalling mechanisms that tell your muscles when it’s time to grow. Although it’s only one letter away from “motor”, it’s more like the digital ignition system that tells the motor it’s got work to do – it is the central controller of cellular growth in the muscles.
Three key factors stimulate mTOR. The first is mechanical stress: during a heavy workout, the muscles use mTOR to send a cellular message that they need help. The second are growth factors – such as growth hormones. And the third is nutrition – mTOR is highly dependent on the following dietary factors:
A surplus of calories – when you’re eating well, your body uses mTOR to tell your muscles, it’s a good time to grow.
Protein – you need to be getting enough protein to ensure your muscles have the amino acids they need for growth and recovery
Lipids – fats support the production and function of hormones that activate mTOR pathways
Three key factors stimulate mTOR
Any supplement that is promoted to increase the size and strength of muscles should in some way stimulate mTOR, and some of the most impressive results with supplementation have been achieved with members of the phospholipid family.
Phospholipids, including phosphatidylserine (PS), are a major component of cell membranes and play an important role in the body as biological messengers. Experts have speculated that they have the power to “send the body’s cells a louder message to ‘grow’!”
Phosphatidylserine, of which Sharp•PS® is a leading brand, is already well known insports nutrition for the range of potential benefits offered. Studies have shown that intake of PS leads to improved performance, reduced recovery time, less muscle soreness, and reduced levels of cortisol (Kingsley, M. I., Wadsworth, D., Kilduff, L. P., McEneny, J. & Benton, D. Effects of phosphatidylserine on oxidative stress following intermittent running. Medicine and science in sports and exercise 37, 1300-1306 (2005); Starks, M. A., Starks, S. L., Kingsley, M., Purpura, M. & Jager, R. The effects of phosphatidylserine on endocrine response to moderate intensity exercise. J Int Soc Sports Nutr 5, 11, (2008);
There is also increasing evidence that PS plays a significant role in mTOR signaling. In key studies, researchers found that: PS can “stimulate a robust increase in mTOR signalling” (Joy et al, Nutrition & metabolism. 2014); and. PS from soy was “sufficient to induce an increase in mTOR signaling” (Gundermann et al, Journal of the International Society of Sports Nutrition, 2013).
These data suggest that PS supplementation supports mTOR signaling, which in turn supports muscle growth.