Effects of whey protein in carbohydrate-electrolyte drinks on post-exercise rehydration

Abstract

The purpose of this study was to examine the effects of different amounts of whey protein in carbohydrate–electrolyte (CE) drinks on post-exercise rehydration. Ten males completed 5 trials in a randomised cross-over design. A 4-h recovery was applied after a 60-min run at 65% VO_2peak in each trial. During recovery, the participants ingested a high-carbohydrate CE drink (CE-H), a low-carbohydrate CE drink (CE-L), a high-whey-protein (33 g·L⁻¹) CE drink (CW-H), a medium-whey-protein (22 g·L⁻¹) CE drink (CW-M) or a low-whey-protein (15 g·L⁻¹) CE drink (CW-L) in a volume equivalent to 150% of their body mass (BM) loss. The drinks were provided in six equal boluses and consumed by the participants within 150 min in each trial. After exercise, a BM loss of 2.15% ± 0.05% was achieved. Urine production was less in the CW-M and CW-H trials during recovery, which induced a greater fluid retention in the CW-M (51.0% ± 5.7%) and CW-H (55.4% ± 3.8%) trials than in any other trial (p < .05). The plasma albumin content was higher in the CW-H trial than in the CE-H and CE-L trials at 2 h (p < .05) and 3 h (p < .01) during recovery. The aldosterone concentration was lower in the CE-H trial than in the CW-M and CW-H trials after recovery (p < .05). It is concluded that the rehydration was improved when whey protein was co-ingested with CE drinks during a 4-h recovery after a 60-min run. However, this additive effect was only observed when whey protein concentration was at least 22 g·L⁻¹ in the current study.

Keywords:

• Whey protein
• fluid retention
• plasma albumin
• aldosterone

Acknowledgements

The authors would like to thank all the courageous participants for their enthusiasm and persistence in this challenging experiment.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplemental data

Supplemental data for this article can be accessed here (https://doi.org/10.1080/17461391.2018.1442499).