title: Salivary cortisol and testosterone responses to resistance and plyometric exercise in 12- to 14-year-old boys.
abstract: This study examined changes in salivary testosterone and cortisol following resistance and plyometric exercise protocols in active boys. In a crossover experimental design, 26 peri-pubertal (12- to 14-year-old) soccer players performed 2 exercise trials in random order, on separate evenings, 1 week apart. Each trial included a 30 min control session followed by 30 min of either resistance or plyometric exercise. Saliva was collected at baseline, post-control (i.e., pre-exercise), and 5 and 30 min post-exercise. There were no significant differences in the baseline hormone concentrations between trials or between weeks (p > 0.05). A significant effect for time was found for testosterone (p = 0.02, [Formula: see text] = 0.14), which increased from pre-exercise to 5 min post-exercise in both the resistance (27% ± 5%) and plyometric (12% ± 6%) protocols. Cortisol decreased to a similar extent in both trials (p = 0.009, [Formula: see text] = 0.19) from baseline to post-control and then to 5 min post-exercise, following its typical circadian decrease in the evening hours. However, a significant protocol-by-time interaction was observed for cortisol, which increased 30 min after the plyometrics (+31% ± 12%) but continued to decrease following the resistance protocol (-21% ± 5%). Our results suggest that in young male athletes, multiple modes of exercise can lead to a transient anabolic state, thus maximizing the beneficial effects on growth and development, when exercise is performed in the evening hours.
authors.affiliation: a Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada.
authors.forename: Panagiota
authors.initials: P
authors.lastname: Klentrou
authors.affiliation: a Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada.
authors.forename: Angeliki
authors.initials: A
authors.lastname: Giannopoulou
authors.affiliation: a Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada.
authors.forename: Brandon J
authors.initials: BJ
authors.lastname: McKinlay
authors.affiliation: a Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada.
authors.forename: Phillip
authors.initials: P
authors.lastname: Wallace
authors.affiliation: b Department of Psychology, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada.
authors.forename: Cameron
authors.initials: C
authors.lastname: Muir
authors.affiliation: a Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada.
authors.forename: Bareket
authors.initials: B
authors.lastname: Falk
authors.affiliation: a Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada.
authors.forename: Diane
authors.initials: D
authors.lastname: Mack
mesh_terms: D000293:Adolescent; D056352:Athletes; D015992:Body Mass Index; D002648:Child; D018592:Cross-Over Studies; D006801:Humans; D006854:Hydrocortisone / Q000737:chemistry*; D008297:Male; D059385:Plyometric Exercise; D055070:Resistance Training; D012463:Saliva / Q000737:chemistry*; D012916:Soccer; D013739:Testosterone / Q000737:chemistry*
chemical_list: D013739:Testosterone; D006854:Hydrocortisone
keywords: anabolic response; catabolic response; children; enfants; exercice contre résistance; pliométrie; plyometrics; resistance exercise; réponse anabolique; réponse catabolique