2007, Piran, Slovenia

Environmental Ergonomics XII
Igor B. Mekjavic, Stelios N. Kounalakis & Nigel A.S. Taylor (Eds.), © BIOMED, Ljubljana 2007
Data were analysed using linear regression, unpaired t-test, and one- to three-way ANOVAs
(α=0.05) due to one between-subjects factor (Fitness) and two within-subjects factors
(Hydration, Time). Post hoc t-tests were Bonferroni corrected. Data are reported as means
±SE unless otherwise stated.
RESULTS
During pre-exercise resting in EUH, the Trained and Untrained groups had equivalent body
mass (c.f. baseline: 0.2 ±0.3 vs 0.5 ±0.8%, respectively, P=0.43), plasma osmolality (Figure
1, P=0.21), plasma [Na + ] (both 137 ±1 mmol·L -1 ), plasma [AVP] (Figure 1, P=0.94), and
thirst ratings (2.6 ±0.8 vs 1.8 ±0.3, P=0.36), but the Trained group had lower USG (1.009
±0.003 vs 1.016 +/- 0.002 g·cm -3 , P=0.04). In contrast, HYPO was initiated with a 1.8 ±0.1%
body mass deficit in both groups, and all measures were equivalent (P>0.05) between groups.
As shown in Figure 1 (left panel), not only was plasma [AVP] higher in HYPO than EUH
(P