title: Acute hormonal responses to heavy resistance exercise in younger and older men.
abstract: The purpose of this investigation was to examine the acute responses of several hormones [total and free testosterone (TT and FT, respectively), adrenocorticotropic hormone (ACTH), cortisol (C), growth hormone (GH), and insulin (INS)] to a single bout of heavy resistance exercise (HRE). Eight younger [30-year (30y) group] and nine older [62-year (62y) group] men matched for general physical characteristics and activity levels performed four sets of ten repetitions maximum (RM) squats with 90 s rest between sets. Blood samples were obtained from each subject via an indwelling cannula with a saline lock pre-exercise, immediately post-exercise (IP), and 5, 15 and 30 min post-exercise. Levels of TT, FT, ACTH, C and lactate significantly increased after HRE for both groups. Pre-HRE pairwise differences between groups were noted only for FT, while post-HRE pairwise differences were found for TT, FT, GH, glucose and lactate. Area under the curve analysis showed that the 30y group had a significantly higher magnitude of increase over the entire recovery period (IP, 5, 15, and 30 min post-exercise) for TT, FT, ACTH and GH. Few changes occurred in the INS response with the only change being that the 62y group demonstrated a decrease IP. Lactate remained elevated at 30 min post-HRE. This investigation demonstrates that age-related differences occur in the endocrine response to HRE, and the most striking changes appear evident in the FT response to HRE in physically active young and older men.
authors.affiliation: Noll Physiological Research Center and Laboratory for Sports Medicine, Pennsylvania State University, University Park 16802, USA.
authors.forename: W J
authors.initials: WJ
authors.lastname: Kraemer
authors.forename: K
authors.initials: K
authors.lastname: Häkkinen
authors.forename: R U
authors.initials: RU
authors.lastname: Newton
authors.forename: M
authors.initials: M
authors.lastname: McCormick
authors.forename: B C
authors.initials: BC
authors.lastname: Nindl
authors.forename: J S
authors.initials: JS
authors.lastname: Volek
authors.forename: L A
authors.initials: LA
authors.lastname: Gotshalk
authors.forename: S J
authors.initials: SJ
authors.lastname: Fleck
authors.forename: W W
authors.initials: WW
authors.lastname: Campbell
authors.forename: S E
authors.initials: SE
authors.lastname: Gordon
authors.forename: P A
authors.initials: PA
authors.lastname: Farrell
authors.forename: W J
authors.initials: WJ
authors.lastname: Evans
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000097:blood; D000328:Adult; D000375:Aging / Q000502:physiology*; D001786:Blood Glucose / Q000378:metabolism; D006728:Hormones / Q000097:blood*; D019382:Human Growth Hormone / Q000097:blood; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007328:Insulin / Q000097:blood; D019344:Lactic Acid / Q000097:blood; D008297:Male; D008875:Middle Aged; D013739:Testosterone / Q000097:blood; D014891:Weight Lifting / Q000502:physiology*
chemical_list: D001786:Blood Glucose; D006728:Hormones; D007328:Insulin; D019382:Human Growth Hormone; D019344:Lactic Acid; D013739:Testosterone; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone