T6 Burn Survivors Can Perform Mild/moderate-intensity Exercise in Thermoneutral Conditions Without a Risk of Excessive Elevations in Core Body Temperature

Abstract

Abstract Introduction Burned skin excision and subsequent grafting removes sweat glands, which impairs thermoregulation. Consequently, exercise prescribed for rehabilitation may expose individuals with burn injuries to a greater risk of hyperthermia, depending on exercise duration, intensity, and environmental temperature. Little is known regarding the risk of hyperthermia in adult burn survivors performing mild/moderate-intensity exercise under thermoneutral environmental conditions, i.e. conditions similar to the rehabilitation clinic and/or the gym. This project tested the hypothesis that burn survivors, across a wide range of percent total body surface area (%TBSA) burned, can participate in mild/moderate-intensity exercise in a thermoneutral environment without excessive elevations in core body temperature. Methods Twenty-eight well-healed burn survivors with low (23±5%TBSA; N=10), moderate (42±7%TBSA; N=9), and high (60±8%TBSA; N=9) sized burn injuries performed 60 minutes of cycle ergometry exercise (72±15 Watts, oxygen uptake rate of 1.25±0.21 L/min equivalent to 4.5±0.2 METs) in a 25°C and 23% relative humidity environment. Absolute gastrointestinal temperatures (Tcore) and changes in gastrointestinal temperatures (ΔTcore) were obtained at 15-minute increments throughout the exercise bout. A participant with an absolute Tcore of greater than 38.5°C, and/or a ΔTcore of >1.5°C, at any time point during the trial was categorized as being at risk for hyperthermia. Results Sixty minutes of exercise increased Tcore in all groups (Low: 0.72±0.21°C; Moderate: 0.42±0.22°C; High: 0.77±0.25°C, all P< 0.01 from pre-exercise baseline), resulting in similar absolute Tcore values of upon exercise termination (Low: 37.87±0.24°C; Moderate: 37.56±0.34°C; High: 37.76±0.47°C, P=0.19). Importantly, no participant was categorized as being at risk for hyperthermia, based upon the aforementioned criteria. Conclusions These data indicate that individuals with substantial %TBSA burned can exercise at a mild/moderate intensity for 60 minutes in thermoneutral environmental conditions without a risk of excessive elevations in body core temperature.