Fig. 3.

Exercise responses in four different environmental conditions. CON temperate and sea level, HOT hot and sea level, HYP temperate and moderate altitude, H + H hot and moderate altitude. See text for details. At the onset of exercise, HR and Tskin were higher (P < 0.05) in warm conditions, whereas altitude exposure reduced SpO₂ and increased HR (both P < 0.05). Warm environments increased Tskin and HR at exhaustion (P < 0.05), whereas SpO₂ (P < 0.05) was lowered with altitude exposure. The rate of rise in Tcore, HR and RPE was speeded under warm conditions (P < 0.05), whereas the rate of HR and RPE increase and SpO₂ decrease was faster with altitude exposure (both P < 0.05). There was no interaction effect between temperature and altitude on either parameter