Effects of 8-weeks of training conducted at two ambient temperatures on basic physiological characteristicsand heat stress levels in young, non-training men

Abstract

Background: Adaptive changes to work in a warm environment are manifested by greater sweat secretion, a reduction in the time required to trigger this response, and a smaller volume of droplet sweat flowing down the skin, much of which is not evaporated. The aim of this study was to determine the effects of aerobic physical training at two different ambient temperatures of 210.50C and 310.50C on the level of exercise physiological responses of the body in young, non-trained men.Material and Methods: Basic anthropometric measurements were taken, as well as baseline exercise tests to assess aerobic capacity and the efficiency of the body’s exercise thermoregulatory mechanisms. After the 8-week training cycle completion, anthropometric and physiological tests were repeated. During the training cycle, at the first, middle and last workout, changes in rectal temperature and heart rate during training were assessed, as well as the assessment of its nuisance in Borg’s scale. The efficiency of exercise-induced thermoregulatory mechanisms was assessed by the Kubica test. Two indices were used to examine the effect of heat stress: the Physical Strain Index and the Cumulative Heat Strain Index.Results and Conclusions: Training at ambient temperatures of 21C and 31C did not significantly change the body’s aerobic capacity (VO2max), resulted in a significant and similar increase in the body’s endurance level as demonstrated by an increase in the work time in the graded test; the time to reach the anaerobic threshold and an increase in maximal aerobic power; contributed to a higher level of efficiency of the body’s thermoregulatory mechanisms. The repetitive physical stimuli at different ambient temperatures had a significant effect demonstrated by a decrease in the subjective feeling of the strenuousness of the work performed in the graded test, on each segment of the exercise load.