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.