Endocrine responses to resistance exercise.

The purpose of this brief review is to examine resistance training responses of selected hormones related to acute stress and growth promoting actions. Hormonal mechanisms appear to be involved with both short-term homeostatic control and long-term cellular adaptations. Few studies have modeled the exercise stimulus in resistance training to determine the role of different exercise variables to the hormonal response. A variety of resistance exercise protocols result in increases in peripheral hormonal concentrations. It appears that single factor variables such as the intensity (% of RM) of exercise and amount of muscle mass utilized in the exercise protocol are important determinants of hormonal responses. The volume (sets x repetitions x intensity) of exercise also appears to be an important determinant of hormonal response. Still, little is known with regard to other single and multiple factor variables (e.g., rest period length) and their relationships to peripheral hormonal alterations. Collectively, such information will allow greater understanding concerning the nature of the exercise stimulus and its relationship to training adaptations resulting from heavy resistance exercise.