Table 1.

Subjects description and plasma osmolarity

	50 km		80 km
	Before	After	Before	After
n	31	29	31	16
Age, years	19 ± 1
Weight, kg	81  ± 1.2	80  ± 1.2	83  ± 1.3	82  ± 1.3
Height, cm	181  ± 1
Plasma osmolarity, mmol/kg	293  ± 1.5	285  ± 2	287  ± 1.6	282  ± 1.9

The group was on a regular training process. They were monitored before and after each of two extensive marches of 50 and 80 km for body weight and plasma osmolarity. Data are given as values ± SE.