The effect of different sports beverages on recovery from endurance exercise.

The food and fluid provided during the post-exercise period plays an essential role in recovery and adaptation processes. There has been a considerable amount of research investigating the ideal quantity and quality of nutrients (e.g., carbohydrate, protein, electrolytes and water) for optimising the key recovery processes (i.e., repair, healing, growth, glycogen re-synthesis and rehydration) individually. This has lead to the development of recovery nutrition guidelines and recommendations, as well as commercially available recovery supplements. Considering dairy milk has similar nutritional properties to recovery nutrition guidelines and recommendations, there is emerging evidence suggesting that dairy milk has the potential to optimise recovery from prolonged exercise. Therefore, the aim of this study is to compare the effects of dairy milk to other sports recovery beverages, on aspects of recovery. Participants will complete any 2 out of the 4 trials in a randomised, repeated measures design, with 14 days washout between trials, such that participant numbers are equally distributed across all four trials. Prior to experimental trials, participants will perform an exhaustive exercise test on a treadmill to determine their VO2 maximal capacity. This test will also serve to familiarise participants with the laboratory. All experimental trials will involve a 2-hour exercise protocol, which is a modified version of the LIST test. After self paced warm-up (10min- not included in 2h), the participant will then run for 3 x 5min blocks (3min30sec jog at 55-60 percent VO¬2 max, 1min run at 70-75 percent VO2 max, and 30sec hard at 80-85 percent VO2 max) then perform 20 plyometric jumps (remaining time walking at 6km/h). This will be repeated until 2 hours (i.e. 6x20minute blocks). Ambient conditions will be 20-25 degrees celsius and 30-40 percent relative humidity. After exercise, participants will be given 1 of 4 recovery beverages (in randomised, double-blinded fashion) Trial 1: UHT tetra-pack chocolate flavoured dairy milk Trial 2: Commercially available protein recovery beverage Trial 3: Commercially available carbohydrate-electrolyte beverage Trial 4: Low carbohydrate high protein recovery beverage The beverage will be given in 3 equal boluses, every 10 minutes beginning immediately post-exercise. The volume will dependent on participant body-weight, to provide 1.2g of carbohydrate per kilogram bodyweight of the Trial 1 beverage. All other trial beverages will be matched for volume. Over the remaining recovery period, participants will be given additional water to provide a total volume of 35mL fluid per kilogram of bodyweight. Participants will be observed during the feeding period to ensure participants consume entire dose. The exercise protocol and beverage delivery will be administered by a dietitian. Trained researchers will closely monitor participants over a 4-hour recovery period. During this time, blood, breath and muscle biopsy samples and questionnaires will be collected to assess recovery from exercise. The following morning, participants will return to the lab to assess Psychophysiological parameters and exercise performance test. Throughout the intervention period (24 hours prior to testing through to performance testing) participants will be provided with standardised meals. Compliance will be assessed using food diaries and verbal confirmation.