No Effect of Menstrual Phase on Appetite-Regulatory Parameters After a Moderate-Intensity Exercise Session

INTRODUCTION: Exercise interventions are less effective in generating weight loss in females compared with males suggesting that the menstrual cycle may be important. Fluctuations in ovarian hormones are proposed to alter the appetite-regulatory response to exercise across the menstrual cycle and no study has assessed the response in all distinct hormonal phases. PURPOSE: To compare postexercise appetite-regulating parameters after a single bout of moderate-intensity continuous training (MICT) across three distinct menstrual phases. METHODS: Thirteen females (24 ± 4 y; 24.8 ± 5.4 kg·m -2 ) completed 30 min of MICT running in the follicular phase (FP), ovulatory phase (OP), and luteal phase (LP). Acylated ghrelin, active glucagon-like peptide-1 (GLP-1), plasma glucose, insulin, blood lactate, and appetite perceptions were measured preexercise, 0, 30, 60, and 120 min postexercise. Energy intake was recorded for a 3-d period (day before, of, and after each session). RESULTS: Acylated ghrelin was not different across phases ( P = 0.672, η p2 = 0.032) and only showed a main effect of time ( P = 0.006, η p2 = 0.757) increasing with time. Active GLP-1 was not different across phases ( P = 0.735, η p2 = 0.025) and had a main effect of time ( P < 0.001, η p2 = 0.569) decreasing with time. Appetite perceptions were not different across phases ( P = 0.577, η p2 = 0.045) and exhibited a main effect of time ( P < 0.001, η p2 = 0.786) increasing with time. There was no effect of phase for energy intake ( P = 0.544, η p2 = 0.065). Finally, there were no differences in plasma glucose, insulin, or blood lactate across phases ( P > 0.421, η p2 < 0.070). CONCLUSIONS: There were no divergent appetite responses after MICT running across three hormonally distinct phases (mid-FP, OP, mid-LP) of the menstrual cycle in young eumenorrheic females not using oral contraceptives.