title: The Decremental Protocol as an Alternative Protocol to Measure Maximal Oxygen Consumption in Athletes.
abstract: OBJECTIVE
  To determine whether a decremental protocol could elicit a higher maximal oxygen consumption (VO2max) than an incremental protocol in trained participants. A secondary aim was to examine whether cardiac-output (Q) and stroke-volume (SV) responses differed between decremental and incremental protocols in this sample.
  
  
  METHODS
  Nineteen runners/triathletes were randomized to either the decremental or incremental group. All participants completed an initial incremental VO2max test on a treadmill, followed by a verification phase. The incremental group completed 2 further incremental tests. The decremental group completed a second VO2max test using the decremental protocol, based on their verification phase. The decremental group then completed a final incremental test. During each test, VO2, ventilation, and heart rate were measured, and cardiac variables were estimated with thoracic bioimpedance. Repeated-measures analysis of variance was conducted with an alpha level set at .05.
  
  
  RESULTS
  There were no significant main effects for group (P = .37) or interaction (P = .10) over time (P = .45). VO2max was similar between the incremental (57.29 ± 8.94 mL · kg-1· min-1) and decremental (60.82 ± 8.49 mL · kg-1· min-1) groups over time. Furthermore, Q and SV were similar between the incremental (Q 22.72 ± 5.85 L/min, SV 119.64 ± 33.02 mL/beat) and decremental groups (Q 20.36 ± 4.59 L/min, SV 109.03 ± 24.27 mL/beat) across all 3 trials.
  
  
  CONCLUSIONS
  The findings suggest that the decremental protocol does not elicit higher VO2max than an incremental protocol but may be used as an alternative protocol to measure VO2max in runners and triathletes.
authors.forename: Katrina
authors.initials: K
authors.lastname: Taylor
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Seegmiller
authors.forename: Chantal A
authors.initials: CA
authors.lastname: Vella
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D056352:Athletes; D001642:Bicycling; D002302:Cardiac Output; D002307:Cardiography, Impedance; D000072599:Cardiorespiratory Fitness; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D009043:Motor Activity; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000378:metabolism*; D010101:Oxygen Consumption; D015203:Reproducibility of Results; D012420:Running; D013550:Swimming; D013997:Time Factors; D055815:Young Adult
keywords: cardiac output; oxygen uptake; runners