Influence of running and walking on hormonal regulators of appetite in women

Abstract

Nine female runners and ten walkers completed a 60 min moderate-intensity (70% VO(2)max) run or walk, or 60 min rest in counterbalanced order. Plasma concentrations of the orexogenic peptide ghrelin, anorexogenic peptides peptide YY (PYY), glucagon-like peptide-1 (GLP-1), and appetite ratings were measured at 30 min interval for 120 min, followed by a free-choice meal. Both orexogenic and anorexogenic peptides were elevated after running, but no changes were observed after walking. Relative energy intake (adjusted for cost of exercise/rest) was negative in the meal following running (-194 ± 206 kcal) versus walking (41 ± 196 kcal) (P = 0.015), although both were suppressed (P < 0.05) compared to rest (299 ± 308 and 284 ± 121 kcal, resp.). The average rate of change in PYY and GLP-1 over time predicted appetite in runners, but only the change in GLP-1 predicted hunger (P = 0.05) in walkers. Results provide evidence that exercise-induced alterations in appetite are likely driven by complex changes in appetite-regulating hormones rather than change in a single gut peptide.

Figure 1

Schematic of the counter-balanced cross-over study.

Figure 2

Average hematocrit for runners and walkers during exercise (solid grey) and rest (dashed black). “Pre” represents the time point just before exercise or rest. Vertical bars display the standard error of the mean hematocrit concentration at that time point.

Figure 3

Average change in ghrelin (pmol/L, upper left panel), ghrelin_acyl (pmol/L, upper right panel), PYY (pmol/L, lower left panel), and GLP-1 (pmol/L, lower right panel) for runners and walkers during exercise (solid grey) and rest (dashed black). “Pre” represents the time point just before exercise or rest. Vertical bars display the standard error of the mean concentration of gut peptide at that time point.

Figure 4

Average change in hunger (upper panel) and satiety (lower panel) for runners and walkers during exercise (solid grey) and rest (dashed black). “Pre” represents the time point just before exercise or rest. Vertical bars display the standard error of the mean for hunger and satiety at that time point. Data for fullness and desire to eat are not shown.

Figure 5

Absolute energy intake (AEI), relative energy intake (REI), and energy expenditure (EE) for exercise and rest in runners and walkers.