The Efficacy of Chocolate Milk as a Recovery Aid

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Sport nutritionists recommend that endurance athletes performing two workouts a day ingest carbohydrates immediately following the first training session to rapidly replenish muscle glycogen. To meet this need, many nutritional products have been marketed as carbohydrate replacement drinks (CR) or fluid replacement drinks (FR) containing less carbohydrate. Since chocolate milk has a similar carbohydrate content to that of many CR, it may be an effective means of recovery from exhausting exercise. PURPOSE: To test the efficacy of chocolate milk (CM) as a recovery aid following exhausting exercise. METHODS: Nine male, endurance-trained cyclists (22.1 ± 2.0 yrs, VO₂max 65.0 ± 9.0 mL.kg^-1.min^-1) performed an interval workout to deplete muscle glycogen (Kuipers et al., 1987), followed by four hours of recovery, and an endurance performance trial to exhaustion at 70% VO₂max (Fallowfield & Williams, 1997), on each of three days. Immediately after the first exercise and at two hours of recovery, subjects were given isovolumic amounts (based on body mass) of CM, FR, or CR, in a single-blind, randomized design. The carbohydrate content (1 g.kg^-1 body mass) was equivalent for CM and CR. Blood lactate concentration, body mass, and total body water (TBW) were measured pre- and post-exercise. Time to exhaustion (TTE), average heart rate (HR), rating of perceived exertion (RPE), and total work (WT) for the endurance exercise were compared between trials using a oneway, repeated measures ANOVA. RESULTS: TTE (40.0 ± 14.7 min; 41.3 ± 15.0 min; 26.8 ± 10.3 min) and WT (626.5 ± 262.7 kJ; 590.5 ± 218.7 kJ; 398.6 ± 185.0 kJ) were different (p<0.05) (CM, FR, and CR trials, resp). There were no differences in exercise HR (169 ± 13 bts.min^-1; 172 ± 5 bts.min^-1;172 ± 13 bts.min^-1), end-exercise RPE (16.2 ± 2.3; 16.8 ± 1.4; 17.2 ± 1.5), or post-exercise blood lactate (3.9 ± 3.3 mmol.L^-1; 2.9 ± 1.3 mmol.L^-1; 2.6 ± 0.7 mmol.L^-1) (CM, FR, and CR trials, resp). TBW did not differ across treatments or within trials. CONCLUSION: As compared to the commercial products tested, chocolate milk is an effective recovery aid following exhausting exercise.

Supported, in part, by a grant from the Dairy and Nutrition Council, Inc.