title: Reliability of Time to Exhaustion Treadmill Running as a Measure of Human Endurance Capacity.
abstract: Little if any research has examined the variability in time to exhaustion (TTE) during submaximal treadmill running. This study investigated the test-retest reliability of submaximal treadmill TTE as a measure of endurance capacity. 16 endurance-trained males (n=14) and females (n=2) completed a run to exhaustion at 70% V̇O2max (T1) and repeated the same run 3 weeks later (T2). At 30-min intervals during each run, expired gas, heart rate (HR) and ratings of perceived exertion (RPE) were collected. Mean ± SD TTE was 96 ± 20 min in T1 vs. 101 ± 29 min in T2 (P=0.3). The mean ± 95% confidence intervals (CI) of the coefficient of variance (CV) was 5.4% (1.4-9.6). The average intraclass correlation coefficient (± 95% CI) was 0.88 (0.67-0.96) between trials. The respiratory-exchange ratio was not different between trials, T1: 0.87 ± 0.1 and T2: 0.89 ± 0.1 (P>0.05) and neither was total whole-body carbohydrate oxidation (2.1 ± 0.4 g·min(-1) and 2.3 ± 0.6 g·min(-1)), fat oxidation (0.6 ± 0.2 g·min(-1)), HR (178 ± 8 and 175 ± 7 beats·min(-1)) or RPE (17 ± 3 and 16 ± 3). These results suggest that use of prolonged treadmill-based TTE can be a reliable research tool to assess human endurance capacity in aerobically-trained men and women.
authors.affiliation: Department for Health, University of Bath, Bath, United Kingdom.
authors.forename: A F
authors.initials: AF
authors.lastname: Alghannam
authors.affiliation: Department for Health, University of Bath, Bath, United Kingdom.
authors.forename: D
authors.initials: D
authors.lastname: Jedrzejewski
authors.affiliation: Department for Health, University of Bath, Bath, United Kingdom.
authors.forename: M
authors.initials: M
authors.lastname: Tweddle
authors.affiliation: Department for Health, University of Bath, Bath, United Kingdom.
authors.forename: H
authors.initials: H
authors.lastname: Gribble
authors.affiliation: Department for Health, University of Bath, Bath, United Kingdom.
authors.forename: J L J
authors.initials: JL
authors.lastname: Bilzon
authors.affiliation: Department for Health, University of Bath, Bath, United Kingdom.
authors.forename: J A
authors.initials: JA
authors.lastname: Betts
mesh_terms: D000293:Adolescent; D000328:Adult; D056352:Athletes; D005080:Exercise Test / Q000379:methods*; D005221:Fatigue; D005260:Female; D006801:Humans; D008297:Male; D010101:Oxygen Consumption; D010807:Physical Endurance / Q000502:physiology*; D015203:Reproducibility of Results; D012420:Running / Q000502:physiology*; D055815:Young Adult