Exercising causes your body to respond by increasing the production of various hormones. Some of them are beneficial, others are not. The primary hormones affected by training are testosterone, cortisol, insulin and growth hormone. Each has multiple functions within your body, and with proper diet and exercise you can get the most, or least, out of each. Consult your physician before beginning any diet or exercise program.
Testosterone is a steroidal hormone that is primarily responsible for muscle growth. Even though testosterone is often referred to as a "male hormone," both sexes produce it. Testosterone is called the primary anabolic hormone because it is most responsible for recovery from exercise and the growth of muscle tissue. This production of testosterone is primarily triggered by intense exercise, which means engaging in heavy, compound exercises with at least 75 percent of what you can lift for a single repetition of each exercise.
Growth hormone is produced by your pituitary gland and is responsible for multiple bodily functions. Growth hormone can assist in recovery, muscle repair and growth and the strength of your connective tissues. Your production of growth hormone can be increased with exercise, but again only with heavy exercise. Rest periods play a larger role in the stimulation of growth hormone, so by keeping your volume and intensity high and your rest periods under 90 seconds, you can increase your production of this hormone.
Insulin is a hormone produced by your pancreas and is primarily responsible for the regulation of blood sugar or glycogen levels. Following heavy resistance exercise, the release of insulin will stimulate your ability to synthesize protein, recover from training and rebuild muscle tissue. Insulin is powerful enough that your ability to synthesize protein may increase up to 100 percent following intense resistance training exercise. When combined with increased protein and carbohydrate intake following a workout, your ability to build muscle mass may be increased.
Exercise is a stress, and cortisol, often called the "stress hormone" is produced in response to stress. The longer you exercise, the more cortisol you produce, and the production is increased the longer you rest between exercises. Keeping your rest periods short can limit your body's ability to produce cortisol. One of the functions of cortisol is to break down proteins for amino acids, and large concentrations of cortisol will scavenge muscle tissue for any amino acids your body may require.
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- "Williams Textbook of Endocrinology"; Henry M. Kronenberg MD, et al., 2007
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This article reflects the views of the writer and does not necessarily reflect the views of Jillian Michaels or JillianMichaels.com.