Combined effect of coffee ingestion and repeated bouts of low-intensity exercise on fat oxidation

We investigated the effect of the combination of coffee ingestion and repeated bouts of low-intensity exercise on fat oxidation. Subjects were seven young, healthy male adults. They performed four trials: a single 30-min bout of exercise following ingestion of plain hot water (WS) or coffee (CS); a trial with three 10-min bouts of exercise separated by 10-min periods of rest following ingestion of plain hot water (WR) or coffee (CR). The coffee contained 5 mg kg⁻¹ of caffeine. All trials were performed on a cycle ergometer at 40% maximal oxygen uptake for each subject an hour after beverage ingestion. Oxygen uptake in the CS and CR trials was higher compared with the WS and WR trials at 90 min after exercise (P<0·05). Respiratory exchange ratio (RER) in the CS and CR trials was decreased during the whole recovery period compared with baseline (P<0·05), whereas no significant decreases were observed in either the WS or WR trials. Moreover, RER was significantly lower at 30 min after exercise in the CR trial than in either the WS or WR trials (P<0·05 each). Similarly, it is notable that fat oxidation rate in the CR trial was significantly higher at 30 min after exercise compared to that in the WS and WR trials (P<0·05). These results suggest that the combination of coffee intake and repeated bouts of low-intensity exercise enhances fat oxidation in the period after exercise.