While many hormones that your body produces contribute to muscle growth, testosterone contributes more than any other. Often referred to as the primary anabolic hormone, testosterone contributes to both recovery from exercise and your ability to build lean muscle mass. Low testosterone levels will limit your ability to reap the rewards exercise. Consult your physician before beginning any exercise program, or if you suspect you may have low testosterone levels.
Testosterone
Testosterone is produced in the gonads in men and the adrenal glands in women. Men produce far more testosterone than women, and this is one of the primary reasons for the differences in both lean muscle mass and strength levels between genders. Testosterone is what is known as a steroidal hormone, and like all steroidal hormones its production is governed by your endocrine system. Regardless of where you produce testosterone, this hormone directly affects your ability to respond to resistance training.
Response to Training
When you train with sufficient intensity, your endocrine system responds in many ways, and producing testosterone is one of them. Intense resistance training with short rest periods will increase your production of testosterone, according to a 1991 study in the "International Journal of Sports Medicine." While this response has been observed in both men and women, depending on exercise selection and intensity, the response is not as great in women, according to a 2005 study published in the "Journal of Strength and Conditioning Research."
Maximizing Training
Intensity and amount of muscle mass stimulated are critical factors in maximizing your anabolic response. Training small muscles with light weights, such as endless sets of curls with little dumbbells, is not exactly a stress that your endocrine system will rush to respond to. Heavy squats, deadlifts, and other exercises that use multiple joints and muscle groups generate far more of a response, according to a review of multiple studies published in "Sports Medicine" in 2005.
Diet
While you produce testosterone, dietary deficiencies can limit this. If your goal is to build muscle, you need a modest amount of fat in your diet. This does not mean you should load up on bacon, butter and lard, but dietary sterols, commonly found in fats, are compounds that your body converts to testosterone. Get the majority of your fats from healthy sources. Oily fish are a good source, as they are high in omega-3 fatty acids which help improve your ability to build muscle. Other good sources include olives and olive oils, nuts and seeds. If you are currently eating a low-fat diet, you may wish to increase your fat intake slightly, which can have a positive effect on your training and recovery.
References
- "Journal of Applied Physiology"; Successive Time Courses of Strength Development and Steroid Hormone Responses to Heavy-resistance Training; R.C. Hickson, et al.; February 1994
- "International Journal of Sports Medicine"; Endogenous Anabolic Hormonal and Growth Factor Responses to Heavy Resistance Exercise in Males and Females; W.J. Kraemer, et al.; April 1991
- "Journal of Strength and Conditioning Research"; Acute Hormonal Responses to Submaximal and Maximal Heavy Resistance and Explosive Exercises in Men and Women; V. Linnamo, et al.; August 2005
- "Sports Medicine"; Hormonal Responses and Adaptations to Resistance Exercise and Training; W.J. Kraemer, et al.; 2005
- "Journal of Steroid Biochemistry"; Decrease of Serum Total and Free Testosterone During a Low-fat High-fibre Diet; E.K. Hamalainen, et al.; March 1983
- "American Journal of Clincial Nutrition"; Dietary Omega-3 Fatty Acid Supplementation Increases the Rate of Muscle Protein Synthesis in Older Adults: a Randomized Controlled Trial; G.I. Smith, et al.; February 2011
