Fitness & Nutrition Tips
Journal of the International Society of Sports Nutrition 2008
In this study we assessed whether a liquid carbohydrate-protein (C+P) supplement (0.8g/kg C; 0.4g/kg P) ingested early during recovery from a cycling time trial could enhance a subsequent 60 min effort on the same day vs. an isoenergetic liquid carbohydrate (CHO) supplement (1.2g/kg).
Two hours after a standardized breakfast, 15 trained male cyclists completed a time trial in which they cycled as far as they could in 60 min (AMex) using a Computrainer indoor trainer. Following AMex, subjects ingested either C+P, or CHO at 10, 60 and 120 min, followed by a standardized meal at 4h post exercise. At 6 h post AMex subjects repeated the time trial (PMex).
There was a significant reduction in performance for both groups in PMex versus AMex. However, performance and power decreases between PMex and AMex were significantly greater (p<0.05) with CHO (-1.05+0.44 km and -16.50+6.74 W) vs C+P (-0.30+0.50 km and -3.86+6.47 W). Fat oxidation estimated from RER values was significantly greater (p<0.05) in the C+P vs CHO during the PMex, despite a higher average workload in the C+P group.
Under these experimental conditions, liquid C+P ingestion immediately after exercise increases fat oxidation, increases recovery, and improves subsequent same day, 60 min efforts relative to isoenergetic CHO ingestion.