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Currently, the effect of passive heat acclimation on aerobic performance is still controversial. Therefore, this study aimed to observe the effect of passive and intervallic exposure to high temperatures (100 ± 2 °C) in untrained males. Forty healthy untrained men participated in this investigation. They were randomised into a Control Group (CG; n = 18) and an Experimental Group (EG; n = 22). Both groups performed maximum incremental tests until exhaustion in normothermia (GXT1; 22 ± 2 °C), and 48h afterwards, in hyperthermia (GXT2; 42 ± 2 °C). The EG performed 9 sessions of intervallic exposure to heat (100 ± 2 °C) over 3 weeks. Subsequently, both groups performed two maximal incremental trials in normothermia (GXT3; 22 ± 2 °C) and 48h later, in hyperthermia (GXT4; 42 ± 2 °C). In each test, the maximal ergospirometric parameters and the aerobic (VT1), anaerobic (VT2) and recovery ventilatory thresholds were recorded. The Wilcoxon Test was used for intra-group comparisons and the Mann-Whitney U for inter-group comparisons. There were improvements in absolute VO 2 max (p = 0.049), W (p = 0.005) and O 2 pulse (p = 0.006) in hyperthermia. In VT1 there was an increase in W (p = 0.046), in VO 2 in absolute (p = 0.025) and relative (p = 0.013) values, O 2 pulse (p = 0.006) and VE (p = 0.028) in hyperthermia. While W increased in hyperthermia (p = 0.022) at VT2. The results suggest that passive and intervallic acclimation at high temperatures improves performance in hyperthermia. This protocol could be implemented in athletes when they have to compete in hot environments. • Passive heat acclimation at high temperature improves aerobic performance in hyperthermia. • This heat acclimation protocol could improve ventilatory thresholds during exercise performance. • Passive heat acclimation makes performance in hyperthermia equal to that in normothermia in 3 weeks. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effect of the performance of an incremental exercise test until exhaustion in normothermic and hyperthermic conditions on serum, erythrocyte and urine concentrations of Iron (Fe), Copper (Cu), Selenium (Se) and Zinc (Zn). Nineteen adult males (age: 22.58 ± 1.06 years) performed two maximum incremental exercise tests on a cycloergometer in normothermia (22 ± 2 °C) and hyperthermia (42±2 °C) separated by 48 h. Urine, serum and erythrocyte samples were collected before and after each test. Serum Se (p < 0.01) and Cu (p < 0.05) levels were altered after each test, but the significance disappeared with the correction for haematocrit. The rest of the values did not undergo alterations in either condition. It seems that a higher stimulus is necessary to obtain changes in these minerals. The study reveals the need to correct serum concentrations concerning possible changes in these volumes after an acute effort. • The link between iron, selenium, copper and zinc metabolism in exercise and hyperthermia is new. • It seems that these elements suffer changes after exercise, but not after applying the correction for hemoconcentration. • It has been observed that heat stress affects the body metabolism of these elements. • The changes of these elements in hyperthermia need to be deepened. [ABSTRACT FROM AUTHOR]