Reliability of a 60-min treadmill running protocol in the heat: The journal Temperature toolbox

摘要

We determined the reliability of a 60-min treadmill protocol in the heat when spaced >4 weeks apart, longer than the test-retest duration of 1 week found in the literature. Nine unacclimated, trained males (age: 31 ± 8 y; VO2peak: 60 ± 6 ml-kg~(-1)-min~(-1)) undertook a 15 min self-paced time-trial pre-loaded with 45 min of running at 70 of individual ventilatory threshold (11.2 ± 0.3 km-h~(-1)) in 30 ± 1°C (53 ± 5 relative humidity). They repeated this following 40 ± 14 and 76 ± 26 days, with pre-trial standardization of diet and exercise for 48 h. When considering trial 1 as a familiarization, change in _(CORE) temperature (AT_(CORE)) during the first 45 min (A2.0 ± 0.2°C) between trials 2 and 3 yielded bias and 95 limits of agreement(LoA) of -0.10 ± 0.43°C, standard error of measurement (SEM) of 0.13°C and intraclass correlation coefficient (ICC) of 0.75, more reliable than measures of baseline T_(CORE) (36.9 ± 0.2°C; LoA: -0.23 ± 0.90°C; SEM: 0.22°C; ICC: 0.03) and T_(CORE) at 45 min during exercise (38.9 ± 0.4°C; LoA: 0.32 ± 1.12°C; SEM: 0.28°C; ICC: 0.15). The coefficient of variation (CV) between trials 2 and 3 for distance run during the 15 min time-trial was 2.1 ± 2.0 with LoA of 0.001 ± 0.253 km and SEM of 0.037 km. This protocol is reliable spaced ~5 weeks apart when considering the most commonly accepted limit of <5 CV for performance, reinforced by reliability of the AT_(CORE) being 0.1 ± 0.4°C.