Experimental procedure
BLOOD, APPENDIX
Participants attended the laboratory for four experimental trial days, each separated by 7-days. All trials were conducted in the morning after an overnight fast (> 8 h). Participants ingested 500 ml of still water (Highland SpringWater, energy, macronutrient, sodium, and potassium content of tested beveragesApart from water, test beverages were selected to provide similar carbohydrate (CHO) content, but with differing protein and electrolyte compositionImmediately at the end of the 60-min beverage ingestion period, participants were asked to empty their bladder, and subsequently each hour for the next 3 h to monitor urine volume. Participants could urinate at any time they required but they were also asked to empty their bladder completely every 60-min to track hourly urine production. If volunteers needed to urinate before the 60-min period, the urine was collected and added to the urine produced at the next 60-min time point. Urine mass was recorded to determine cumulative urine mass every 60-min and a 5 ml aliquot was retained for analysis. Blood samples were drawn immediately after the drinking period, and every 60-min for the next 3 h. All blood samples were drawn from participants after they had remained in a seated position for at least 15-min (Supplementary Appendix 1).