Muscles are not just for bodybuilders; they’re a requirement for healthy living. Here is why: In brief, skeletal muscle tissue is chock full of mitochondria, insulin, and leptin receptors. As such, it’s the body’s fat-burning furnace and is a blood sugar sponge. Moreover, we owe much credit to the contribution muscles make to our resting metabolic rate.
One reason why we are seeing such a spike in obesity, diabetes, and cardiovascular disease rates is due to the development of sick muscle and muscle loss, medically known ectopic lipid deposition and sarcopenia, respectively. Various factors are to blame here, ranging from lack of stimulation—that is, sedentary activity—to increased cortisol (cortisol eats muscle for lunch) and age-related changes in anabolic hormones (growth hormone and testosterone).
— Mike Mutzel MSc (@MikeMutzel) January 25, 2015
The equation to healthy muscle is simple: increase muscle protein synthesis (MPS) and reduce muscle protein breakdown. Said another way, the goal is to increase anabolism and decrease catabolism. As we age, muscle protein synthesis declines a lot—studies show up to a 30 percent reduction in protein synthesis.
The cellular switch that can pivot your muscle out of breakdown mode and into growth mode is called mammalian target of rapamycin or mTOR. Physical activity in general, and resistance training in particular, activate mTOR. Additionally, many studies have reported that three grams of the essential amino acid leucine also activate mTOR, improving muscle protein synthesis and decreasing muscle protein breakdown. Omega-3 fatty acids similarly improve mTOR signaling and help combat age-related muscle loss.
High-Intensity Weight Training and High Protein Diets Increase Muscle Protein Synthesis (MPS)
One of the best ways to increase MPS, resting metabolic rate, and muscle mass is to ingest whey protein immediately after resistance training. (This post-workout window is a critical period.) Whey protein ingested immediately after resistance training also increases mTOR.
But post-workout is not the only important time to consume protein. Research shows that daily protein intake in the order of 1.9 to 2.7 grams/kg of body weight per day is needed to increase mTOR and MPS.
For many people, this means three solid meals that include 20 to 30 grams of protein and one to two protein shakes that contain either whey protein or high-leucine pea protein.
A simple way to increase your resting metabolic rate, fat burning potential, and blood sugar regulation is to increase muscle mass. Many age-related chronic diseases are linked to loss of muscle mass.
mTOR is a key signaling molecule involved in muscle protein synthesis (MPS) and preventing muscle protein breakdown. Consuming whey protein immediately after resistance training (weight training) and eating a high-protein diet are two key strategies for increasing the health of muscle tissue.
1) Breen, L., & Phillips, S. M. (2011). Skeletal muscle protein metabolism in the elderly: Interventions to counteract the “anabolic resistance” of ageing. Nutrition & Metabolism, 8(1), 68. doi:10.1186/1743-7075-8-68
2) KOOPMAN, R., Saris, W. H. M., WAGENMAKERS, A. J. M., & van Loon, L. J. C. (2007). Nutritional interventions to promote post-exercise muscle protein synthesis. Sports Medicine (Auckland, N.Z.), 37(10), 895–906.