A preliminary V02max test utilizing a modified walking exercise protocol with a
set speed of 3.5 mph and increases in grade 2% every three minutes was performed by
each participant to establish 50% of their maximum cardiorespiratory workload. This
workload was used to standardize workloads in the four test trials. Environmental
conditions within the chamber were set at 35°C and 45-55% relative humidity. Heat trials
were terminated if participant's core temperature exceeded 38.7°C, heart rate exceeded
95% of max heart rate, nausea or dizziness occurred, or the participant requested for the
test to be terminated.
Once the baseline workload was established, the participants participated in four
hot treadmill exercise trials. Participants were placed in the environmental chamber
connected to the ISO Thermex electronic thermometer and put on an exercise treadmill.
The participants exercised at a workload of 50% of their V02max until their core
temperature reached 38.7°C. Core temperature and heart rate was collected every five
minutes with the ISO Thermex electronic thermometer using rectal probes and Polar
heart monitoring system. Thermal sensation responses were acquired by utilizing the
OTSS and the RTS at five minute intervals once the test began. OTSS and RTS trial
administration was counterbalanced to minimize the impacts of ordering effects.
Participants were blind to the scale until the workload began. There was no set time limit
for the trials since workload and fitness levels varied for each participant.