The aim of this study was to compare the effect of ad libitum intake of a milk-based liquid meal supplement against a carbohydrate-electrolyte sports drink following exercise induced fluid loss. Seven male participants (age 22.3 ± 3.4 years, height 179.3 ± 7.9 cm, body mass 74.3 ± 7.3 kg; mean ± SD) completed 4 separate trials and lost 1.89 ± 0.44% body mass through moderate intensity exercise in the laboratory. After exercise, participants consumed ad libitum over 2 h a milk-based liquid meal supplement (Sustagen Sport) on two of the trials (S1, S2) or a carbohydrate-electrolyte sports drink (Powerade) on two of the trials (P1, P2), with an additional 1 hr observational period. Measures of body mass, urine output, gastrointestinal tolerance and palatability were collected throughout the recovery period. Participants consumed significantly more Powerade than Sustagen Sport over the 2 h rehydration period (P1 = 2225 ± 888 ml, P2 = 2602 ± 1119 mL, S1 = 1375 ± 711 mL, S2 = 1447 ± 857 ml). Total urine output on both Sustagen trails was significantly lower than the second Powerade trial (P2 = 1447 ± 656 ml, S1 = 153 ± 62 ml, S2 = 182 ± 118 mL; p < .05) and trended toward being lower compared with the first Powerade trial (P1 = 1057 ± 699 ml vs. S1, p = .067 and vs. S2, p = .061). No significant differences in net fluid balance were observed between any of the drinks at the conclusion of each trial (P1 = −0.50 ±0. 46 kg, P2 = −0.40 ± 0.35 kg, S1 = −0.61 ± 0.74 kg, S2 = −0.45 ± 0.58 kg). Gastrointestinal tolerance and beverage palatability measures indicated Powerade to be preferred as a rehydration beverage. Ad libitum milk-based liquid meal supplement results in similar net fluid balance as a carbohydrate-electrolyte sports drink after exercise induced fluid loss.
Baguley, Leveritt, Zilujko are with the School of Human Movement and Nutrition Sciences, The University of Queensland, Queensland, Australia. Desbrow and Irvin are with the School of Allied Health Sciences and Menzies Health Institute Queensland, Griffith University, Australia.