Assessment of the OmiusTM cooling headband during a 70-minute submaximal running effort followed by a 5-km time-trial in hot/humid conditions

Exercise performed under hot/humid conditions can hinder endurance performance. The OmiusTM headband (OH) is purported to reduce the perception of heat and improve performance. We examined the impact of OH on selected thermal and cardiovascular functions, subjective perceptions and running performance. Using a randomized crossover protocol, 10 trained male athletes (28 ± 4 years) completed two trials (OH and sham headband (SH), 35.0 ± 0.3ºC, 56 ± 3% relative humidity) comprising 70 min of running (60%O2max) followed by a 5-km running time-trial (TT). Heart rate, perceived exertion and whole-body thermal comfort did not significantly differ between conditions during the submaximal running effort and TT. Rectal temperature was lower with SH (− 0.11 ± 0.16ºC, p = 0.052) than OH prior to the submaximal running effort; this difference slightly accentuated (− 0.14 ± 0.20ºC, p = 0.043) during the submaximal running effort.Rectal temperature did not differ significantly between conditions during the TT. Forehead temperature was significantly lower with OH than SH during the submaximal running effort, but no significant difference was observed at the end of the TT. Scores of perceived forehead thermal comfort was only significantly lower with OH than SH during the submaximal running effort. TT performance did not significantly differ between OH (19.8 ± 1.2 min) and SH (20.2 ± 1.0 min). In conclusion, OH reduces forehead temperature and forehead thermal comfort but not rectal temperature, heart rate and perceived exertion during, nor 5-km TT performance following, 70 min of submaximal running in the heat.