title: The slope of the VO2 slow component is associated with exercise intolerance during severe-intensity exercise.
abstract: The aim of this study was to analyze the relationship between the slope of the VO2 slow component (VO2sc) and exercise tolerance (tlim) during constant-work-rate (CWR) exercise performed within the severe intensity domain. Fifteen active subjects (VO2max = 41.2 ± 5.1 ml.kg-1.min-1) performed the following tests: 1) an incremental test to determine the VO2max and the work rate associated with the VO2max (IVO2max) and; 2) two CWR transitions at 95% of the IVO2max to determine the slope of the VO2 slow component and the tlim. Three tlims were obtained: tlim1 = CWR1; tlim2 = CWR2; and tlim1+2 = (CWR1 + CWR2) / 2. There was no significant difference between the VO2max (3271.7 ± 410.7 mL·min-1) and VO2peak obtained during the CWR tests (CWR1 = 3356.3 ± 448.8 mL·min-1, CWR2 = 3362.2 ± 393.4 mL·min-1, p > 0.05). Significant correlations (p < 0.05) were found among the VO2sc kinetics and tlim1 (r = -0.53), tlim2 (r = -0.49) and tlim1+2 (r = -0.55). Thus, exercise tolerance during CWR performed within the severe intensity domain is partially explained by the slope of the VO2 slow component.
authors.affiliation: UNESP - Rio Claro Human Performance Laboratory Av. 24A, 1515 - Bela Vista 13506-900 Rio Claro SP Brazil.
authors.forename: L F
authors.initials: LF
authors.lastname: Barbosa
authors.affiliation: UNESP - Rio Claro Human Performance Laboratory Av. 24A, 1515 - Bela Vista 13506-900 Rio Claro SP Brazil.
authors.forename: C C
authors.initials: CC
authors.lastname: Greco
authors.affiliation: UNESP - Rio Claro Human Performance Laboratory Av. 24A, 1515 - Bela Vista 13506-900 Rio Claro SP Brazil.
authors.forename: Benedito Sérgio
authors.initials: BS
authors.lastname: Denadai
mesh_terms: D000328:Adult; D015444:Exercise; D005080:Exercise Test; D017079:Exercise Tolerance; D006801:Humans; D008297:Male; D009119:Muscle Contraction; D018763:Muscle Fatigue; D018482:Muscle, Skeletal / Q000378:metabolism*; D010101:Oxygen Consumption; D010807:Physical Endurance; D013997:Time Factors; D055815:Young Adult
keywords: cycling; endurance; exercise performance; fatigue; oxygen kinetics