Postexercise muscle glycogen recovery enhanced with a carbohydrate-protein supplement.

ABSTRACT

PURPOSE: This study assessed whether liquid carbohydrate-protein (C+P) supplements, ingested early during recovery, enhance muscle glycogen resynthesis versus isoenergetic liquid carbohydrate (CHO) supplements, given early or an isoenergetic solid meal given later during recovery (PLB). METHODS: Two hours after breakfast (7.0 kcal.kg; 0.3 g.kg P, 1.2 g.kg C, 0.1 g.kg F), six male cyclists performed a 60-min time trial (AMex). Pre- and postexercise, vastus lateralis glycogen concentrations were determined using nMRS. Immediately, 1 h, and 2 h postexercise, participants ingested C+P (4.8 kcal.kg; 0.8 g.kg C, 0.4 g.kg P), CHO (4.8 kcal.kg; 1.2 g.kg C), or PLB (no energy). Four hours postexercise, a solid meal was ingested. At that time, C+P and CHO received a meal identical to breakfast, whereas PLB received 21 kcal.kg (1 g.kg P, 3.6 g.kg C, 0.3 g.kg F); energy intake during 6 h of recovery was identical among treatments. After 6 h of recovery, measurement and cycling protocols (PMex) were repeated. RESULTS: Absolute muscle glycogen utilization was 18% greater (P muscle glycogen resynthesis was greater in C+P (+ 28.62+/-2.10 mmol.L) versus CHO (+ 22.20+/-1.19 mmol.L, P treatments during both AMex (C+P 37.61+/-0.63 km; CHO 37.03+/-0.60 km; PLB 37.24+/-0.34 km) and PMex (C+P 36.31+/-0.83 km; CHO 36.38+/-0.80 km; PLB 35.34+/-0.45 km).

CONCLUSIONS:

C+P supplements, given early after exercise, enhance glycogen resynthesis relative to CHO and PLB. However, this does not influence performance in this type of exercise bout.