title: Reliability of a high-intensity endurance cycling test.
abstract: This study assessed the reproducibility of performance and selected metabolic variables during a variable high-intensity endurance cycling test. 8 trained male cyclists (age: 35.9 ± 7.7 years, maximal oxygen uptake: 54.3 ± 3.9 mL·kg - 1·min - 1) completed 4 high-intensity cycling tests, performed in consecutive weeks. The protocol comprised: 20 min of progressive incremental exercise, where the power output was increased by 5% maximal workload (Wmax) every 5 min from 70% Wmax to 85% Wmax; ten 90 s bouts at 90% Wmax, separated by 180 s at 55% Wmax; 90% Wmax until volitional exhaustion. Blood samples were drawn and heart rate was monitored throughout the protocol. There was no significant order effect between trials for time to exhaustion (mean: 4 113.0 ± 60.8 s) or total distance covered (mean: 4 6126.2 ± 1 968.7 m). Total time to exhaustion and total distance covered showed very high reliability with a mean coefficient of variation (CV) of 1.6% (95% Confidence Intervals (CI) 0.0 ± 124.3 s) and CV of 2.2% (95% CI 0.0 ± 1904.9 m), respectively. Variability in plasma glucose concentrations across the time points was very small (CV 0.46-4.3%, mean 95% CI 0.0 ± 0.33 to 0.0 ± 0.94 mmol·L - 1). Plasma lactate concentrations showed no test order effect. The reliability of performance and metabolic variables makes this protocol a valid test to evaluate nutritional interventions in endurance cycling.
authors.affiliation: Leeds Metropolitan University, Carnegie Research Institute, Carnegie Faculty, Leeds, United Kingdom. j.ohara@leedsmet.ac.uk
authors.forename: J P
authors.initials: JP
authors.lastname: O'Hara
authors.forename: A
authors.initials: A
authors.lastname: Thomas
authors.forename: A
authors.initials: A
authors.lastname: Seims
authors.forename: C B
authors.initials: CB
authors.lastname: Cooke
authors.forename: R F G J
authors.initials: RF
authors.lastname: King
mesh_terms: D000328:Adult; D056352:Athletes; D054874:Athletic Performance / Q000502:physiology*; D001642:Bicycling / Q000502:physiology*; D001786:Blood Glucose / Q000378:metabolism; D005080:Exercise Test / Q000379:methods*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D010807:Physical Endurance / Q000502:physiology*; D015203:Reproducibility of Results; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D019344:Lactic Acid