title: Validity of 3 protocols for verifying VO2 max.
abstract: The verification bout has emerged as a technique for confirming 'true' VO2 max; however, validity during a single visit is unknown. We evaluated 3 different GXT durations with severe intensity verification bouts. On 3 separate days, in counterbalanced order, 12 recreational-trained men completed short (9±1 min), middle (11±1 min), and long (13±2 min) duration GXTs followed by exhaustive, sine wave verification bouts during the same visit. Intensities for verification were set at speeds equivalent to 2-stages minus end-GXT speed. No differences (p<0.05) in VO2 max (mL/kg/min) were observed between short (49.1), middle (48.2), and long (48.8) protocols. In addition, no differences in verification bout duration occurred between protocols (3±1 min). Validity of VO2 max was strongest for the middle duration protocol (ICC α=0.97; typical error=1 mL/kg/min; CV=2%). A small, but significantly higher HR (max) (∼1-2 bpm) was observed for the long protocol. Maximum respiratory exchange ratios were inconsistent (ICC α ranged 0.58-0.68). Our findings indicate GXT-verification bout testing during a single visit is a valid means of measuring 'true' VO2 max. The 10 min target for GXT duration was the optimum.
authors.affiliation: Department of Human Performance, Minnesota State University, Mankato, Mankato, MN 56001, United States.
authors.forename: J M
authors.initials: JM
authors.lastname: Kirkeberg
authors.forename: L C
authors.initials: LC
authors.lastname: Dalleck
authors.forename: C S
authors.initials: CS
authors.lastname: Kamphoff
authors.forename: R W
authors.initials: RW
authors.lastname: Pettitt
mesh_terms: D000328:Adult; D005080:Exercise Test / Q000379:methods*; D006801:Humans; D008297:Male; D010101:Oxygen Consumption; D010807:Physical Endurance / Q000502:physiology; D005082:Physical Exertion / Q000502:physiology; D012420:Running / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult