Holliday A, et al. - An inquiry was performed of the outcomes of acute bouts of high-intensity aerobic exercise of varying durations on subjective appetite, food intake and appetite-associated hormones in endurance-trained males. No suppression was noted in the subjective appetite or affect absolute food intake via high-intensity aerobic cycling lasting up to 45 minutes. However, it reduced the relative energy intake, in well-trained endurance athletes. The role of appetite hormones in regulating subjective appetite in the acute post-exercise period was interrogated through the data.

Methods

• The enrollment comprised of 12 endurance-trained males (age=21±2 years; BMI=21.0±1.6 kg m^-2; VO₂max=61.6±6.0 mL. kg^-1. min^-1).
• They completed four trials, within a maximum 28-day period, in a counterbalanced order: resting (REST); 15-minutes exercise bout (15-MIN); 30-minute exercise bout (30-MIN) and 45-minute exercise bout (45-MIN).
• The exercise completion took place on a cycle ergometer at an intensity of ∼76% VO₂max.
• The enrollees consumed an ad libitum meal, 60 minutes post-exercise.
• The estimates were collected of subjective appetite and blood samples throughout the morning, with plasma analysed for acylated ghrelin, total polypeptide tyrosine-tyrosine (PYY) and total glucagon-like peptide 1 (GLP-1) concentrations.

Results

• The subjective appetite and absolute food intake did not vary between trials.
• Relative energy intake (intake - expenditure) appeared to be markedly greater after REST (2641±1616 kJ) compared with both 30-MIN (1039±1520 kJ) and 45-MIN (260±1731 kJ).
• It was notably greater after 15-MIN (2699±1239 kJ) compared with 45-MIN (condition main effect, p<0.001).
• An increased GLP-1 concentration was found immediately post-exercise in 30-MIN and 45-MIN, respectively (condition-x-time interaction, p<0.001).
• Acylated ghrelin was transiently suppressed in all exercise trials (condition-x-time interaction, p=0.011).
• The greatest, most enduring suppression was observed in 45-MIN.
• PYY concentration did not alter with exercise.