Document Type

Thesis

Degree Name

Master of Kinesiology (MKin)

Department

Kinesiology and Physical Education

Faculty/School

Faculty of Science

First Advisor

Dr. Tom J. Hazell

Advisor Role

Supervisor

Abstract

Appetite regulation has exclusively been examined during the follicular phase (FP) of the menstrual cycle, and it remains unclear whether the greater levels of estradiol (E2) and progesterone (P4) in the luteal phase (LP) affect this process. Thus, the purpose of this study was to utilize vigorous-intensity continuous training (VICT) as a method to modulate plasma concentrations of E2 and P4 and examine their associations with post-exercise alterations in acylated ghrelin, peptide tyrosine-tyrosine3-36 (PYY3-36), active glucagon like peptide-1 (GLP-1), subjective appetite perceptions, and energy intake across the menstrual cycle. Eleven women completed 30 min of VICT (80% O2max) in both the FP and LP in a randomized order. E2, P4, acylated ghrelin, PYY3-36,active GLP-1, and appetite perceptions were measured pre-, immediately, 30, and 90 min post-exercise, and energy intake was recorded for a 3-day period beginning the day prior to each experimental session. E2 concentrations increased immediately post-exercise (P=0.041) with no differences in P4 (P=0.078). Acylated ghrelin was significantly lower in the FP compared to the LP (P=0.029), and active GLP-1 was elevated at 30 min post-exercise compared to 90 min post-exercise (P=0.016). There were no observable effects of exercise or menstrual cycle phase on PYY3-36 (P=0.305), overall appetite (P=0.616), or free-living energy intake (P=0.244). These findings suggest the typical post-exercise suppression of acylated ghrelin may be blunted in the presence of elevated sex hormones in the LP, though sex hormones do not appear to play a role in the anorexigenic hormone response to acute exercise. Future work should focus on the reproducibility of our findings to further elucidate the influence of sex hormones on appetite regulation across the menstrual cycle.

Convocation Year

2019

Convocation Season

Fall

Available for download on Thursday, September 29, 2022

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