Pulsatile properties of luteinizing hormone (LH) and growth hormone (GH) release were evaluated in 19 eumenorrheic untrained females [mean age 31.1 ± 1.1 yr, height 165.2 ± 1.4 cm, weight 64.8 ± 2.1 kg, peak oxygen uptake (V̇O2) 41.6 ± 1.4 (SE) ml · kg-1 · min-1] during the early follicular phase of the menstrual cycle (days 3-4 after the onset of menses). Each subject was studied during two consecutive menstrual cycles under each of two conditions in random order: 1) no formal exercise for 72 h (C) and 2) 12-24 h after two maximal exercise bouts (peak V̇O2/lactate threshold treadmill evaluation and a 3,200-m time-trial run or a maximal V̇O2 inclined treadmill test) performed on consecutive days (EX). Blood sampling was performed every 10 min for 12 h. LH and GH pulsatile parameters were identified and characterized by the Cluster pulse detection algorithm. No significant differences were noted in the number of peaks, peak amplitude, interpeak interval, peak increment, or 12-h integrated concentrations between C and EX for LH or GH. We conclude that maximal exercise protocols typically used for exercise evaluation do not have an effect on the pulsatile characteristics of LH or GH release in untrained women during the early follicular phase of the menstrual cycle if 12-24 h of recovery are allowed before evaluation of the pulsatile secretion of gonadotropins or GH.
- Neuroendocrine axes
- Reproductive hormones
- Sex steroids
ASJC Scopus subject areas
- Orthopedics and Sports Medicine
- Physical Therapy, Sports Therapy and Rehabilitation