The aim of the present study was to investigate the effect of protein and carbohydrate ingestion during early recovery from exhaustive exercise on performance after 18-h recovery. Eight elite cyclists (V̇o2max: 74.0 ± 1.6 ml·kg-1·min-1) completed two exercise and diet interventions in a double-blinded, randomized, crossover design. Participants cycled first at 73% of V̇o2max (W73%) followed by 1-min intervals at 90% of V̇o2max until exhaustion. During the first 2 h of recovery, participants ingested either 1.2 g carbohydrate·kg-1·h-1 (CHO) or 0.8 g carbohydrate + 0.4 g protein·kg-1·h-1 (CHO + PROT). The diet during the remaining recovery period was similar for both interventions and adjusted to body weight. After an 18-h recovery, cycling performance was assessed with a 10-s sprint test, 30 min of cycling at W73%, and a cycling time trial (TT). The TT was 8.5% faster (41:53 ± 1:51 vs. 45:26 ± 1:32 min; P < 0.03) after CHO + PROT compared with CHO. Mean power output during the sprints was 3.7% higher in CHO + PROT compared with CHO (1,063 ± 54 vs. 1,026 ± 53 W; P = 0.01). Nitrogen balance in the recovery period was negative in CHO and neutral in CHO + PROT (-82.4 ± 11.5 vs. 7.0 ± 15.4 mg/kg; P < 0.01). In conclusion, TT and sprint performances were improved 18 h after exhaustive cycling by CHO + PROT supplementation during the first 2 h of recovery compared with isoenergetic CHO supplementation. Our results indicate that intake of carbohydrate plus protein after exhaustive endurance exercise more rapidly converts the body from a catabolic to an anabolic state than carbohydrate alone, thus speeding recovery and improving subsequent cycling performance.NEW & NOTEWORTHY Prolonged high intensity endurance exercise depends on glycogen utilization and high oxidative capacity. Still, exhaustion develops and effective recovery strategies are required to compete in multiday stage races. We show that coingestion of protein and carbohydrate during the first 2 h of recovery is superior to isoenergetic intake of carbohydrate to stimulate recovery, and improves both endurance time-trial and 10-s sprint performance the following day in elite cyclists.
Keywords: branched-chain amino acids; diet; glucose; nitrogen balance; sprint.