title: Testosterone and cortisol in relationship to dietary nutrients and resistance exercise.
abstract: Manipulation of resistance exercise variables (i.e., intensity, volume, and rest periods) affects the endocrine response to exercise; however, the influence of dietary nutrients on basal and exercise-induced concentrations of hormones is less understood. The present study examined the relationship between dietary nutrients and resting and exercise-induced blood concentrations of testosterone (T) and cortisol (C). Twelve men performed a bench press exercise protocol (5 sets to failure using a 10-repetitions maximum load) and a jump squat protocol (5 sets of 10 repetitions using 30% of each subject's 1-repetition maximum squat) with 2 min of rest between all sets. A blood sample was obtained at preexercise and 5 min postexercise for determination of serum T and C. Subjects also completed detailed dietary food records for a total of 17 days. There was a significant (P < or = 0.05) increase in postexercise T compared with preexercise values for both the bench press (7.4%) and jump squat (15.1%) protocols; however, C was not significantly different from preexercise concentrations. Significant correlations were observed between preexercise T and percent energy protein (r = -0.71), percent energy fat (r = 0.72), saturated fatty acids (g.1,000 kcal-1.day-1; r = 0.77), monounsaturated fatty acids (g.1,000 kcal-1.day-1; r = 0.79, the polyunsaturated fat-to-saturated fat ratio (r = -0.63), and the protein-to-carbohydrate ratio (r = -0.59). There were no significant correlations observed between any nutritional variables and preexercise C or the absolute increase in T and C after exercise. These data confirm that high-intensity resistance exercise results in elevated postexercise T concentrations. A more impressive finding was that dietary nutrients may be capable of modulating resting concentrations of T.
authors.affiliation: Department of Kinesiology, Pennsylvania State University, University Park 16802, USA.
authors.forename: J S
authors.initials: JS
authors.lastname: Volek
authors.forename: W J
authors.initials: WJ
authors.lastname: Kraemer
authors.forename: J A
authors.initials: JA
authors.lastname: Bush
authors.forename: T
authors.initials: T
authors.lastname: Incledon
authors.forename: M
authors.initials: M
authors.lastname: Boetes
mesh_terms: D000328:Adult; D004040:Dietary Carbohydrates / Q000494:pharmacology*; D004041:Dietary Fats / Q000494:pharmacology*; D004044:Dietary Proteins / Q000494:pharmacology*; D004734:Energy Metabolism / Q000187:drug effects; D015444:Exercise / Q000502:physiology*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D008297:Male; D013739:Testosterone / Q000097:blood*
chemical_list: D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins; D013739:Testosterone; D006854:Hydrocortisone