Effects of Sex and Menstrual Cycle Phase on Post-Exercise Appetite Regulation.

Abstract

Introduction: Moderate-intensity exercise interventions for weight loss are less effective in females, suggesting biological sex and fluctuations in menstrual cycle hormones may be involved. To date, no study has explored the post-exercise appetite response between males, females in the follicular phase (FP) and females in the luteal phase (LP).

Purpose: To examine differences in appetite regulation in response to an acute bout of moderate-intensity continuous training (MICT) between males, females in the FP, and females in the LP.

Methods: Males, FP, and LP females (n=14 per group; n=42 total) completed a single bout of MICT (30 min, 70% V̇O₂max). Acylated ghrelin, active glucagon-like peptide-1 (GLP-1), and subjective appetite perceptions were measured pre-exercise and 0-, 30-, 60- and 120-min post-exercise. Energy intake was assessed for a 3-day period (day before, of, after).

Results: There were no between-group differences in acylated ghrelin (P=0.388, η²ₚ=0.047) or active GLP-1 (P=0.413, η²ₚ=0.044). Subjective appetite was lower pre-exercise in males compared to both females in the FP (P=0.087, d=0.85) and LP (P=0.013, d=0.65) with no other between-group differences. Absolute energy intake was greater in males compared to females in the LP only (P=0.032, η²ₚ=0.111), however when analyzed relative to body mass there were no between-group differences (P=0.306, η²ₚ=0.062).

Conclusion: There were no differences in the response to MICT for appetite-regulating hormones, subjective appetite, or energy intake between males or females in either phase. Further work should consider exploring appetite following high-intensity exercise to thoroughly investigate if sex differences on hormonal and subjective appetite regulation are present.