Exercising in Warm Environment is More Stressing As Measured by Cortisol And TNFα
As Hosick et.al. found ( Hosick, 2010 ) the exaggerated core temperature response to exercise in warm water environment triggers a significant increase in cortisol and TNFα , both parameters of increased metabolic stress in the 8 male subjects (men age 24y) who participated in "two 40 min trials of cycle ergometry at 65% of VO 2 peak immersed to chest level in cool (25 °C) and warm (38.5 °C) water". Cortisol & TNF-alpha values for subjects before and after 40min exercise immersed in cool or warm water ( Hosick, 2010 ) With a score of 16 (warm ) vs. 16 (cool) the rating of perceived exertion (Borg scale 6-20) was also significantly elevated and correlated with the heart rate (180BPM, warm vs. 144BPM, cool) of the subjects. The researchers conclude that: "[...] this finding is of importance to individuals, coaches, and fitness professionals attempting to understand ideal training load and design in warm or hot environments." ( Hosick, 2010 ) Just another...