Sex differences in the response of total PYY and GLP-1 to moderate-intensity continuous and sprint interval cycling exercise.
BACKGROUND
Exercise interventions are often less effective at improving body composition for females than males, potentially due to post-exercise hormonal responses that increase energy intake in females. Recently, sprint interval training was shown to effectively reduce body fat in females despite being relatively low during exercise energy expenditure.


OBJECTIVE
To determine whether any sex difference in total PYY, GLP-1 or perceived hunger exists following moderate-intensity continuous exercise (MICT) and sprint interval exercise (SIT) METHODS: Twenty-one active participants (11 females) participated in three sessions in a randomized crossover design: (1) MICT, 30-min cycling at 65% VO2max; (2) SIT, 6 × 30 s "all-out" sprints with 4-min recovery periods; (3) control (CTRL; no exercise). Blood samples were collected pre-exercise, immediately and 90 min post-exercise for the measurement of total PYY and GLP-1. Subjective perceptions of hunger were assessed using a visual analogue scale pre-breakfast and before all blood samples.


RESULTS
Concentrations of total PYY and GLP-1 were greater during MICT (P = 0.05) and SIT (P = 0.005) compared to CTRL. Total PYY increased more immediately post-exercise in males than females (P = 0.030). GLP-1 only increased in females following MICT (P = 0.034) and SIT (P = 0.024) compared to CTRL. Perceived hunger was lower immediately post-MICT (P = 0.016) and SIT (P = 0.006) compared to CTRL.


CONCLUSIONS
These results suggest that total PYY and GLP-1 respond differently to exercise in males and females over 90 min following various exercise intensities. The observed post-exercise hormonal response would not be expected to create a compensatory increase in energy intake in females.
Department of Kinesiology and Physical Education, Wilfrid Laurier University, Waterloo, ON, N2L 3C5, Canada. thazell@wlu.ca.
Tom J
http://orcid.org/0000-0002-8135-4518
TJ
Hazell
Department of Kinesiology and Physical Education, Wilfrid Laurier University, Waterloo, ON, N2L 3C5, Canada.
Logan K
LK
Townsend
Department of Kinesiology and Physical Education, University of Lethbridge, Lethbridge, AB, T1K 3M4, Canada.
Jillian R
JR
Hallworth
Department of Kinesiology and Physical Education, University of Lethbridge, Lethbridge, AB, T1K 3M4, Canada.
Jon
J
Doan
Department of Kinesiology and Physical Education, University of Lethbridge, Lethbridge, AB, T1K 3M4, Canada.
Jennifer L
JL
Copeland
D000328:Adult; D001066:Appetite; D005260:Female; D052216:Glucagon-Like Peptide 1 / Q000097:blood*; D000072696:High-Intensity Interval Training; D006801:Humans; D008297:Male; D019894:Peptide YY / Q000097:blood*; D011897:Random Allocation; D012737:Sex Factors
D019894:Peptide YY; D052216:Glucagon-Like Peptide 1
Aerobic exercise; Anorexigenic; Appetite regulation; High-intensity interval training; Satiety