The physiological responses of heart rate, oxygen consumption, sweat loss, rectal temperature and mean skin temperature were monitored as eight well-conditioned young adult males were exposed to effective temperatures of 70°F, 80°F and 90°F. The body fat contents of the subjects ranged from 11.3% to 34%. The subjects pedalled a 300 kilopond meters/minute load on a bicycle ergometer for 25 minutes. Results indicate that body fat or the percent of body fat squared have a statistically significant effect on the dependent variables of oxygen consumption/lean body weight, change in heart rate, core-skin temperature gradient, and oxygen consumption/maximum oxygen consumption.
Heart rate variability tests in healthy young adult males and females