Sport-specific performance assessment with oxygen uptake measurements in time trials and critical power tests.

This study investigated the added value of peak oxygen uptake ([Formula: see text]O) measurements during a 4-min time trial (4TT) or a 3-min all-out test (3MT) as compared to a ramp cycling test to enhance sport-specific performance assessment. Data from two cross-sectional studies were analysed. In study 1, 18 male and 13 female recreational cyclists performed two ramp tests and two 4TT on different days. In study 2, 23 male and 17 female CrossFit athletes performed one ramp test followed by a 3MT with an intervening 20-min recovery. The tolerance limits for ∆[Formula: see text]O between the two exercise tests was set to ± 0.13 L·min, reflecting common day-to-day variation in [Formula: see text]O. In study 1, comparing the first ramp test with the first 4TT and comparing the second ramp test with the second 4TT showed mean differences of 0.02 L·min (p = 0.930) and 0.03 L·min (p = 0.873), respectively. However, the tolerance limits were - 0.35-0.31 L·min and - 0.36-0.42 L·min, respectively. In study 2, the mean difference and tolerance limits were 0.08 L·min (p = 0.637) and - 0.42-0.58 L·min. Although the 4TT and 3MT show limited agreement with ramp tests for [Formula: see text]O, the lack of systematic deviations supports their value for sport-specific performance assessment.