Table 1.

Cross-over experimental design, in which tests are performed on six groups of two people at 1-week intervals under three hydration conditions (I—isotonic drinks, W—water, NH—no hydration), with a balanced number of interventions in each of the six possible sequences.

Group	Number of Participants	Hydration in Individual Tests
		Test 1	Test 2	Test 3
I-W-NH	2	I	W	NH
W-NH-I	2	W	NH	I
NH-I-W	2	NH	I	W
I-NH-W	2	I	NH	W
W-I-NH	2	W	I	NH
NH-W-I	2	NH	W	I