title: Self-pacing increases critical power and improves performance during severe-intensity exercise.
abstract: The parameters of the power-duration relationship for severe-intensity exercise (i.e., the critical power (CP) and the curvature constant (W')) are related to the kinetics of pulmonary O2 uptake, which may be altered by pacing strategy. We tested the hypothesis that the CP would be higher when derived from a series of self-paced time-trials (TT) than when derived from the conventional series of constant work-rate (CWR) exercise tests. Ten male subjects (age, 21.5 ± 1.9 years; mass, 75.2 ± 11.5 kg) completed 3-4 CWR and 3-4 TT prediction trial protocols on a cycle ergometer for the determination of the CP and W'. The CP derived from the TT protocol (265 ± 44 W) was greater (P < 0.05) than the CP derived from the CWR protocol (250 ± 47 W), while the W' was not different between protocols (TT: 18.1 ± 5.7 kJ, CWR: 20.6 ± 7.4 kJ, P > 0.05). The mean response time of pulmonary O2 uptake was shorter during the TTs than the CWR trials (TT: 34 ± 16, CWR: 39 ± 19 s, P < 0.05). The CP was correlated with the total O2 consumed in the first 60 s across both protocols (r = 0.88, P < 0.05, n = 20). These results suggest that in comparison with the conventional CWR exercise protocol, a self-selected pacing strategy enhances CP and improves severe-intensity exercise performance. The greater CP during TT compared with CWR exercise has important implications for performance prediction, suggesting that TT completion times may be overestimated by CP and W' parameters derived from CWR protocols.
authors.affiliation: Sport and Health Sciences, College of Life and Environmental Sciences, St. Luke's Campus, University of Exeter, Heavitree Road, Exeter, EX1 2LU, UK.|Sport and Health Sciences, College of Life and Environmental Sciences, St. Luke's Campus, University of Exeter, Heavitree Road, Exeter, EX1 2LU, UK.
authors.forename: Matthew I
authors.initials: MI
authors.lastname: Black
authors.affiliation: Sport and Health Sciences, College of Life and Environmental Sciences, St. Luke's Campus, University of Exeter, Heavitree Road, Exeter, EX1 2LU, UK.|Sport and Health Sciences, College of Life and Environmental Sciences, St. Luke's Campus, University of Exeter, Heavitree Road, Exeter, EX1 2LU, UK.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Jones
authors.affiliation: Sport and Health Sciences, College of Life and Environmental Sciences, St. Luke's Campus, University of Exeter, Heavitree Road, Exeter, EX1 2LU, UK.|Sport and Health Sciences, College of Life and Environmental Sciences, St. Luke's Campus, University of Exeter, Heavitree Road, Exeter, EX1 2LU, UK.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Bailey
authors.affiliation: Sport and Health Sciences, College of Life and Environmental Sciences, St. Luke's Campus, University of Exeter, Heavitree Road, Exeter, EX1 2LU, UK.|Sport and Health Sciences, College of Life and Environmental Sciences, St. Luke's Campus, University of Exeter, Heavitree Road, Exeter, EX1 2LU, UK.
authors.forename: Anni
authors.initials: A
authors.lastname: Vanhatalo
mesh_terms: D000328:Adult; D001642:Bicycling / Q000502:physiology*; D016552:Ergometry / Q000706:statistics & numerical data; D005080:Exercise Test / Q000706:statistics & numerical data*; D006801:Humans; D008168:Lung / Q000502:physiology*; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D011930:Reaction Time; D015203:Reproducibility of Results; D013997:Time Factors; D055815:Young Adult
keywords: V̇O2 mean response time; W′; contre-la-montre; critical power; exercice d’intensité très élevée; power-duration relationship; puissance critique; relation puissance-durée; severe-intensity exercise; temps de réponse moyen du V̇O2; time trial