Lower head temperature does not affect children's self-paced running velocity

To test if the use of a peaked cap protects children against sun radiation, allowing increased exercise performance, nineteen healthy children (10.3 ± 0.8 years old, 146.2 ± 6.9 cm, 36.8 ± 5.5 kg, 1.2 ± 0.1 m2 and 44.1 ± 2.8 mL.kg-1.min-1) took part in 4 experimental situations: 2 initial familiarization runs and 2 self-paced 6km runs (4 × 1.5 km exercise bouts with 3min rest intervals) one of them wearing a peaked cap (CAP) and another situation without the cap (NOCAP). The CAP and NOCAP situations were randomized. Exercise was performed outdoors 3-7 days apart. Environmental variables were measured every 10min, and physiological variables were measured before and after each run and during the rest intervals. Running velocity did not differ between CAP and NOCAP situations. The mean head temperature was reduced by 1.1 °C in the CAP situation (p < .05). Average skin temperature, mean heart rate, rate of perceived exertion and wet bulb and globe temperature did not differ between CAP and NOCAP. The decrease in the mean head temperature was not sufficient to alter running velocity.