The effects of exercise in the cold on ghrelin, PYY and food intake in overweight adults

Purpose Exercise in cold water has been shown to simulate postexercise energy intake (EI) in normal-weight individuals. However, the effect of cold exercise on EI in overweight individuals has yet to be examined. The present study investigated the effect of brisk walking in a cold (8°C) and neutral (20°C) environment on postexercise EI and appetite hormone responses. Methods Sixteen overweight participants (10 men and six women; age, 50.1 ± 11.6 yr; body mass index, 28.9 ± 4.2 kg·m−2) completed a 45-min treadmill walk at 8°C and 20°C in a randomized counterbalanced design. Participants were presented with an ad libitum buffet meal 45 min after exercise, and EI was covertly measured. Skin and rectal temperature were monitored throughout exercise and for 30 min after exercise, and concentrations of the appetite hormones total ghrelin, acylated ghrelin, and total peptide YY were assessed before and after exercise and before and after meal. Results EI was significantly greater after exercise in the cold (1299 ± 657 kcal (mean ± SD)) compared with that after exercise in the neutral environment (1172 ± 537 kcal (mean ± SD)) (P < 0.05). The change in the acylated ghrelin concentrations and the acylated ghrelin AUC values were significantly greater during walking in the cold versus those during walking in the neutral condition (P < 0.05). Conclusions These findings show that in overweight individuals, exercise in the cold stimulates postexercise EI to a greater extent than exercise in a neutral environment.