Postexercise substrate oxidation is environmental temperature dependent before and after short‐term exercise training in obese women

Abstract

AbstractSubstrate oxidation can be altered by both environmental temperature and exercise training. It is unclear whether environmental temperatures before and after short‐term exercise training influence substrate oxidation rates and energy expenditure (EE) during postexercise recovery. The purpose of this paper is to study the effects of hot and thermoneutral environments on substrate oxidation and EE during postexercise recovery before and after a 1‐month exercise training in obese women. Sixteen overweight or obese women underwent a 1‐month exercise training. Before and after training, each participant completed metabolic testing during postexercise recovery at either hot (31°C–32°C) or thermoneutral (22°C–23°C) environments in a randomized crossover fashion with a washout period of 2–4 days between the two tests. The substrate oxidation and EE determined by indirect calorimetry during the 60‐min postexercise recovery of the hot and thermoneutral environments were compared. Following exercise training, fat oxidation during recovery was significantly greater at thermoneutral than at hot environments (thermoneutral, 56.0 ± 24.6 mg/kg/h vs. hot, 39.7 ± 27.5 mg/kg/h; p < 0.001). Conversely, carbohydrate oxidation during the recovery was significantly greater at hot than at thermoneutral environments, and the total EE at both temperatures did not significantly differ (hot, 70.5 ± 19.6 kcal/h vs. thermoneutral, 71.3 ± 13.7 kcal/h; p = 0.846). The results were the same as those before exercise training. After an acute bout of exercise, recovery in a thermoneutral environment increases fat oxidation; however, environmental temperatures produce no effect on the total EE. The same results were obtained before and after exercise training, suggesting that energy and substrate metabolism during postexercise recovery are more influenced by the environmental temperature than exercise training.