Assessing the Repeatability of a Running Heat Tolerance Assessment in Trained and Untrained Populations

• There is a growing need to develop measures for assessing performance and health status under heat stress, as heat-related health risks increase with global warming.
• The ACSM recommends that a tailored heat tolerance assessment (HTA), based upon participants’ fitness levels, should be applied for individual’s affected by heat related illness.
• Aerobically-trained athletes show features of heat adaptation at baseline and, in our experience, a standardised HTA to provide robust heat stress and challenge fitter individuals is lacking.
• We designed a progressive HTA to be performed in uncompensable conditions, in order to minimise differences attributable to variation in body size and increase comparability.