Criterion validity of a field-based assessment of aerobic capacity in wheelchair rugby athletes

Purpose: To confirm whether peak aerobic capacity determined during laboratory testing could be replicated during an on-court field-based test in wheelchair rugby (WR) players. Methods: Sixteen WR players performed an incremental speed-based peak oxygen uptake (V̇O_2peak) test on a motorised treadmill (TM) and completed a Multi-stage Fitness Test (MFT) on a basketball court in a counter-balanced order while spirometric data were recorded. A paired t-test was performed to check for systematic error between tests. A Bland-Altman plot for V̇O_2peak illustrated the agreement between the TM and MFT results and how this related to the boundaries of practical equivalence. Results: No significant differences between mean V̇O_2peak were reported (TM:1.85±0.63 vs. MFT: 1.81±0.63 L.min^-1; p=0.33). Bland-Altman plot for V̇O_2peak suggests that the mean values are in good agreement at the group level; i.e., the exact 95% confidence limits for the ratio systematic error (0.95 to 1.02) are within the boundaries of practical equivalence (0.88 to 1.13) showing the group average TM and MFT values are interchangeable. However, consideration of the data at the level of the individual athlete suggests the TM and MFT results were not interchangeable because the 95% ratio limits of agreement either coincide with the boundaries of practical equivalence (upper limit) or fall outside (lower limit). Conclusions: Results suggest that the MFT provides a suitable test at a group level with this cohort of WR players for the assessment of V̇O_2peak (range 0.97 – 3.64 L∙min^-1), yet caution is noted for interchangeable use of values between tests for individual players.