Authors: Crewther, BT et al (2011).

Sports Medicine 41(2) p 103-123

Commentary by Leo Thornley

Understanding the hormonal response to training has led us to refine the design of a given workout and indeed the structure for the wider training program. While the body responds to a training stimulus with a milieu of different hormones two of the more commonly discussed by athletes, coaches and sport science staff are steroid hormones testosterone and cortisol.

This review paper by Crewther et al looks at the research from both a short term effect on the neuromuscular system and the dose (training) response relationship. This paper highlights that as our understanding of a topic evolves some concepts may become more complex.

Crewther et al remind us that workout design, nutrition, genetics as well as training status and training type all contribute to the testosterone and cortisol response; which in turn play a large role in regulating muscle growth and therefore performance.

Planning the workout with the stimulus in mind and using the hormone response to get the most out of the workout is good practice. The idea that utilizing hypertrophy workouts in order to stimulate a large testosterone response and over time enhance muscle form and function is common practice. This paper suggests that the notion that these hormones have little short term effects may be too simplistic. In the more acute sense these hormones may have beneficial effects on neuromuscular signaling and activation as well as contractile properties of the muscle. These more acute benefits may enhance subsequent strength and power exercises. While early gains in strength training may be mostly attributed to neural factors the elevated testosterone and cortisol may play a permissive role in these adaptations, their role being perhaps wider than previously considered.

Crewther et al highlight that individual differences particularly when looking at an athlete’s career point or training status may require us to measure the these hormonal response factors in order to determine the best workout design and indeed the trainability of an athlete.

This paper is a good read for anyone prescribing strength training workouts. It is clear that more research is required on elite athletes in particular to better understand the multifactorial contributions these hormones play in the athletic training environment.