title: Repeatability of a running heat tolerance test.
abstract: At present there is no standardised heat tolerance test (HTT) procedure adopting a running mode of exercise. Current HTTs may misdiagnose a runner's susceptibility to a hyperthermic state due to differences in exercise intensity. The current study aimed to establish the repeatability of a practical running test to evaluate individual's ability to tolerate exercise heat stress. Sixteen (8M, 8F) participants performed the running HTT (RHTT) (30 min, 9 km h(-1), 2% elevation) on two separate occasions in a hot environment (40 °C and 40% relative humidity). There were no differences in peak rectal temperature (RHTT1: 38.82 ± 0.47 °C, RHTT2: 38.86 ± 0.49 °C, Intra-class correlation coefficient (ICC)=0.93, typical error of measure (TEM) = 0.13 °C), peak skin temperature (RHTT1: 38.12 ± 0.45, RHTT2: 38.11 ± 0.45 °C, ICC = 0.79, TEM = 0.30 °C), peak heart rate (RHTT1: 182 ± 15 beats min(-1), RHTT2: 183 ± 15 beats min(-1), ICC = 0.99, TEM = 2 beats min(-1)), nor sweat rate (1721 ± 675 g h(-1), 1716 ± 745 g h(-1), ICC = 0.95, TEM = 162 g h(-1)) between RHTT1 and RHTT2 (p>0.05). Results demonstrate good agreement, strong correlations and small differences between repeated trials, and the TEM values suggest low within-participant variability. The RHTT was effective in differentiating between individuals physiological responses; supporting a heat tolerance continuum. The findings suggest the RHTT is a repeatable measure of physiological strain in the heat and may be used to assess the effectiveness of acute and chronic heat alleviating procedures.
authors.affiliation: Exercise in Extreme Environments Research Group, University of Brighton, Welkin Human Performance Laboratories, Denton Road, Eastbourne BN20 7SR, UK. Electronic address: J.Mee@brighton.ac.uk.
authors.forename: Jessica A
authors.initials: JA
authors.lastname: Mee
authors.affiliation: Exercise in Extreme Environments Research Group, University of Brighton, Welkin Human Performance Laboratories, Denton Road, Eastbourne BN20 7SR, UK.
authors.forename: Jo
authors.initials: J
authors.lastname: Doust
authors.affiliation: Exercise in Extreme Environments Research Group, University of Brighton, Welkin Human Performance Laboratories, Denton Road, Eastbourne BN20 7SR, UK.
authors.forename: Neil S
authors.initials: NS
authors.lastname: Maxwell
mesh_terms: D000328:Adult; D001831:Body Temperature; D001833:Body Temperature Regulation; D005080:Exercise Test; D005260:Female; D006339:Heart Rate; D006358:Hot Temperature; D006801:Humans; D008297:Male; D005082:Physical Exertion; D015203:Reproducibility of Results; D012420:Running / Q000502:physiology*; D012881:Skin Temperature; D013312:Stress, Physiological; D055815:Young Adult
keywords: Continuum; Heat illness; Heat tolerance; Reliability; Thermoregulatory strain