Comparison of Peak Oxygen Uptake Between Upper-Body Exercise Modes: A Systematic Literature Review and Meta-Analysis

Purpose: To compare peak oxygen uptake (VO_2peak) between the asynchronous arm crank ergometry (ACE), and synchronous wheelchair ergometry (WERG), wheelchair treadmill (WTR), and upper-body poling (UBP) mode. Methods: PubMed, Scopus, CINAHL, and SPORTDiscus™ were systematically searched, and identified studies screened based on title, abstract, and thereafter full-text. Studies comparing VO_2peak between ≥2 of the modes were included. A meta-analysis was performed by pooling the differences in VO_2peak between upper-body exercise modes. The quality of the included studies was assessed and the level of evidence (LoE) established for each mode comparison. Meta-regression analyses investigated the effect of total body mass and participant-related characteristics (% of able-bodied participants, % of participants with tetraplegia and % of participants who are wheelchair athletes) on differences in VO_2peak between modes. Results: Of the 19 studies included in this review, 14 studies investigated the difference in absolute and body-mass normalized VO_2peak between ACE and WERG, and 5 studies examined the differences between ACE and WTR. No significant difference in absolute or body-mass normalized VO_2peak was found between ACE and WERG (overall effect ±95% CI: 0.01 ± 0.06 L·min^-1 and 0.06 ± 1.2 ml·kg^-1·min^-1, both p > 0.75; LoE: strong). No significant difference in absolute or body-mass normalized VO_2peak was found between ACE and WTR (overall effect ±95% CI: -0.10 ± 0.18 L·min^-1 and -1.8 ± 2.5 ml·kg^-1·min^-1, both p > 0.14; LoE: moderate). Absolute and/or body-mass normalized VO_2peak did not differ between WERG and WTR in one study with 13 participants (LoE: limited) and between ACE and UBP in one study with 18 participants (LoE: moderate). In the meta-regression analyses, there was no significant effect of the investigated factors on differences in VO_2peak. Conclusions: The differences between the asynchronous ACE and synchronous WERG propulsion, including possible differences in trunk involvement, do not seem to influence VO_2peak. Therefore, ACE and WERG can be used interchangeably to test VO_2peak. Possible differences in VO_2peak in all other mode comparisons remain unclear due to the wide CIs and limited to moderate LoE.