Question: Should hormonal response be considered in program design?
The endocrine system mediates the breakdown and repair of muscle protein, which is necessary for an overall training effect to occur (1). Because of the role the endocrine system plays on the development of protein metabolism and muscle growth (1-3) one might think the hormonal response to exercise is of high importance in program design. However, due to conflicting evidence (1,4), hormonal response should not be the main focus of an exercise program. Many variables are considered when designing an exercise program, but the weight of each variable differs based on the desired outcome for each individual and on the information gathered during the needs analysis. Such information includes, but is not limited to age, sex, training status, training goals, and etc., each accounting for variances in hormone production and hormone requirements of the individual. Based on the needs analysis, hormonal response may need to be considered, but the main focus when designing a training program should be on the training scheme and metabolic response.
Kraemer & Ratamess (2) suggest that training programs with high volume, moderate to high intensity, short rest intervals, and lifts focusing on large muscle mass require the greatest muscle fiber recruitment, which will increase the hormone-tissue interactions, thus producing a greater anabolic effect. The high volume and intensity of the programs yield the greatest release of testosterone (TST) and growth hormone (GH; 1-4). However, such lifting schemes, and others properly designed for hypertrophy or dynamic power may elicit enough metabolic stress and contraction-mediated hypertrophy, especially in the presence of a carbohydrate/protein supplement, that the slight increases in the anabolic hormones are not necessary for strength gains and muscle development (3). Furthermore, it is difficult to measure hormonal concentrations because they are influenced by the natural circadian rhythms of the body, menstrual cycles, and by the processes of the liver, pancreas, and other organs (2,6). Thus, designing a program specifically for hormonal response would be unrealistic.
However, an important consideration in regards to hormonal response to exercise programming is the increase and influence of cortisol (COR), the primary catabolic hormone produced in response to stress and over-training (1,2). Elevated COR can decrease protein synthesis and increase protein degradation, which may lead to decreased TST and GH (1). Hypertrophy and dynamic power training schemes, while resulting in the desired effect of increased TST and GH, also increase COR, which may invoke an unfavorable TST-COR ratio (1,2). Elevated COR and other stress hormones may result in depression, anxiety, injury, etc. Thus, it is important to be mindful of the potential for elevated cortisol when designing training programs, but as previously stated, it would be unrealistic to design a program with full consideration of hormonal responses.
- Crewther, B., Keogh, J., Cronin, J., & Cook, C. (2006). Possible stimuli for strength and power adaptation: Acute hormonal responses. Sports Medicine (Auckland, N.Z.), 36(3), 215-238.
- Kraemer, W. J., & Ratamess, N. A. (2005). Hormonal responses and adaptations to resistance exercise and training. Sports Medicine (Auckland, N.Z.), 35(4), 339-361.
- Durand, R. J., Castracane, V. D., Hollander, D. B., Tryniecki, J. L., Bamman, M. M., O’Neal, S., … Kraemer, R. R. (2003). Hormonal responses from concentric and eccentric muscle contractions. Medicine and Science in Sports and Exercise, 35(6), 937-943.
- Schroeder, E. T., Villanueva, M., West, D. D., & Phillips, S. M. (2013). Are acute post-resistance exercise increases in testosterone, growth hormone, and IGF-1 Necessary to stimulate skeletal muscle anabolism and hypertrophy? Medicine and Science in Sports and Exercise, 45(11), 2044-2051.
- Kraemer, W. J., Gorden, S. E., Fleck, S. J., Marchitelli, L. J., Mello, R., Dziados, J. E., … Fry, A. C. (1991). Endogenous anabolic hormonal and growth factor responses to heavy resistance exerices in males and females. International Journal of Sports Medicine, 12(2), 228-235.
- Borst, S. E., DeHoyos, D. V., Garzarella, L., Vincent, K., Pollock, B. H., Lowenthal, D. T., & Pollock, M. L. (2001). Effects of resistance training on insulin-like growth factor-1 and IGF binding proteins. Medicine and Science in Sports and Exercise, 33(4), 648-653.