Responses of obese and non-obese boys cycling in the heat.

This study compared rectal temperature (T re ), heat sensation and sweating between obese and non-obese boys during cycling in the heat. Participants (aged 12–15 years) were 17 obese and 16 non-obese (BMI=29.4±4.3 and 16.8±1.7 kg · m  − 2 , respectively) boys. They cycled for 30-min (50–55% VO 2peak ) in a climatic chamber (35°C, 45% RH) and T re , heat sensation and sweat volume were monitored. From the start to the end of cycling, T re was similar between the obese (37.4±0.3–37.8±0.3°C) and non-obese (37.3±0.2–37.9±0.2°C) groups. Heat sensation was higher in the obese group from the start (3.6±2.7 vs. 1.3±1.4 cm; P=0.008) to the end (7.6±2 vs. 5.2±2.2 cm; P=0.003) of cycling. Sweat volume corrected by body surface area was similar between the obese (200±123 mL · m  − 2 ) and non-obese (212±80 mL · m  − 2 ) groups. Initial and final HR were similar in both groups, and RPE was higher in the obese group at 25 th (P=0.040) and 30 th (P=0.019) min. In conclusion, the obese pubescent participants presented similar T re and sweating volume, but higher heat sensation while cycling in the heat.