The exercise-induced suppression of acylated ghrelin is blunted in the luteal phase of the menstrual cycle compared to the follicular phase following vigorous-intensity exercise

Limited work examining woman's appetite-regulatory response to exercise has been focused on the follicular phase (FP) of the menstrual cycle. This is an important limitation as estradiol (E2) and progesterone (P4) fluctuate across phases with greater concentrations in the luteal phase (LP). Objective: To examine the appetite-regulatory response to vigorous-intensity continuous exercise (VICT) in the FP and LP. Methods: Twelve women completed 30 min of VICT at 80% VO2 max in the FP and LP. E2, P4, acylated ghrelin, active peptide tyrosine-tyrosine (PYY), active glucagon-like peptide-1 (GLP-1), and appetite perceptions were measured pre-exercise, 0-, 30-, and 90-min post-exercise. Energy intake was recorded for a 2-day period (day before and of each session). A series of twoway repeated measure ANOVA were used to compare all dependent variables. Results: Pre-exercise E2 (P = 0.005, d = 1.00) and P4 (P < 0.001, d = 1.41) concentrations were greater in the LP than the FP and exercise increased both at 0-and 30-min post-exercise (E2: P < 0.009; P4: P < 0.001, d = 0.63). Acylated ghrelin was lower in the FP versus LP at pre-exercise as well as 0-min (P = 0.006, d = 0.97) and 90-min (P = 0.029, d = 0.72) post-exercise. There were no differences of menstrual phase on PYY (P = 0.359, eta 2p = 0.092), GLP-1 (P = 0.226, eta 2p = 0.130), or overall appetite (P = 0.514, eta 2p = 0.066). Energy intake was greater on the day of in the LP versus the FP (P = 0.003, d = 1.2). Conclusion: Acylated ghrelin was lower in the FP compared to the LP and though there were no differences in anorexigenic hormones or subjective appetite, energy intake was greater on the day of the session in the LP suggesting important differences across the menstrual cycle where greater concentrations of ovarian hormones in the LP may blunt the exercise response.