Anabolic hormones are chemicals produced within the human body that help facilitate muscle recovery after physical exertion like aerobic exercise or resistance training. Physical training, nutrition and the time of day trigger the release of anabolic hormones such as testosterone, insulin, growth hormone and IGF-1.
Testosterone
Testosterone is a powerful anabolic hormone that is important for muscle growth and protein synthesis. Testosterone levels rise in reaction to exercise. According to bodybuilding magazine “Muscle and Fitness,” taking certain nutritional supplements before and after workouts can boost testosterone production or enhance the effects of testosterone. Supplements that may support testosterone’s effects on muscle growth include amino acids such as acetyl-L-carnitine and supplements containing protein and carbohydrates. A 2007 study published in "International Journal of Sport Nutrition and Exercise Metabolism" found that subjects who took protein supplements after intense workouts experienced a boost in testosterone levels in the several hours that followed supplementation.
Insulin
Insulin is also crucial for muscle recovery after exercise. Insulin sensitivity increases during exercise, which facilitates the delivery of glucose to muscles. Heightened insulin levels and increased insulin sensitivity during and after exercise also aid recovery by enhancing the transport of amino acids to muscles and facilitating protein synthesis. According to a scholarly paper by the University of New Mexico's Associate Professor of Exercise Science, Dr. Len Kravitz, Ph.D., and Ashley Chambers, M.S., during the 45 minutes after exercise, anabolic hormones start working to repair muscles, and muscle cells are particularly sensitive to insulin. Due to the body's heightened sensitivity to insulin in the 45-minute post-exercise period, eating carbohydrates during this time helps supply muscles with glucose, which facilitates the recovery process, say Kravitz and Chambers.
Growth Hormone and IGF-1
Growth hormone is an anabolic hormone that increases protein synthesis and triggers the release of another anabolic hormone called insulin-like growth factor I, or IGF-1. lGF-1 causes immature muscle cells to develop into growing muscle cells and, eventually, into developed muscle fibers. As with other anabolic hormones, nutrition may also affect levels of growth hormone and IGF-1. A 1994 study published in the "Journal of Applied Physiology" found that athletes who took supplements of carbohydrates and protein after a weight-training workout had increased levels of growth hormone in their blood compared to a control group. The study's authors concluded that dietary supplements after weight training may produce a hormonal environment that favors muscle recovery. According to “Muscle and Fitness,” taking the amino acid argine also stimulates the production of growth hormone.
References
- University of New Mexico: Nutrient Timing--The New Frontier in Fitness Performance
- "Muscle and Fitness": Blow Up Your Size
- "Journal of Applied Physiology": Dietary Supplements Affect the Anabolic Hormones After Weight-Training Exercise
- "International Journal of Sport Nutrition and Exercise Metabolism": Effect of Protein-rich Feeding on Recovery After Intense Exercise
