Influence of post-exercise nutrient intake on recovery and subsequent exercise performance in youth cyclists

Purpose: The purpose of this study was to determine if chocolate milk (CM) consumption after high-intensity cycling exercise affects post-exercise recovery and subsequent exercise performance in youth cyclists, compared to a carbohydrate-only (CHO) and a placebo (PL) beverage. Methods: Eight youth cyclists (15-18 y, VO2peak = 61.8 ± 7.7 mL·kg-1·min-1) performed an exercise/recovery protocol consisting of 2 bouts of exercise, on 3 separate occasions, in a randomly counterbalanced crossover design. The first exercise bout (EX1) consisted of 30 min of constant-load cycling (40-60% Wmax), and 60 min of high-intensity intervals (alternating 2 min at 70-90% Wmax, 2 min at 50% Wmax). Subjects consumed a recovery beverage (PL, CHO or CM) immediately following EX1 and again 2 h after EX1. EX2 consisted of 30 min of constant-load cycling (60% Wmax) followed by a simulated 30 km time trial (TT). Ratings of muscle soreness and mental and physical energy/fatigue were obtained prior to EX1, 4 h post-EX1, and pre-EX2. Results: Changes in muscle soreness ratings over time were not significantly different between treatments. However, within the PL trial, soreness was significantly elevated from pre-EX1 to 4 h post-EX1 and pre-EX2 (pre-EX1, 4h-post, pre-EX2 = 44.1 ± 23.1, 67.4 ± 22.2, 68.3 ± 19.6 mm, respectively. Physical fatigue ratings increased significantly from pre-EX1 to pre-EX2 in PL. In addition, changes in physical fatigue 4 h following EX1 were greater in CHO than CM, with no other significant within- or between-treatment effects in energy/fatigue ratings. Average power during the TT was not significantly different between treatment trials (PL: 181 ± 27, CHO: 197 ± 39, CM: 195 ± 38 W) (p = 0.23 CHO vs. PL; 0.19 CM vs. PL). Conclusion: CM ingestion after exercise may confer some recovery benefits in youth cyclists, as demonstrated by the absence of elevated post-exercise muscle soreness and energy/fatigue ratings in the CM trials. CM ingestion did not significantly improve subsequent cycling performance when compared to CHO or PL beverages. Subsequent research should utilize larger sample sizes to provide more conclusive evidence to enhance the knowledge regarding the impact of CM as a recovery method for youth cyclist