Validation of an incremental field test for the direct assessment of peak oxygen uptake in wheelchair-dependent athletes.

The aim of this study was to validate an incremental field test performed by wheelchair-dependent (WD) athletes. Nine male paraplegic subjects (mean age 28.9 +/- 4.2 years) performed an incremental field test (FT) and a comparable laboratory test (LT) with their own usual wheelchairs. Both tests started with an initial speed of 4 km.hr(-1) and increased by increments of 1 km.hr(-1) every minute until volitional exhaustion. The FT was an adapted Léger and Boucher test (ALBT) and was conducted on a 400 m tartan field marked-off every 50 m with pylons. Ventilatory data were collected every 15 s using a portable telemetric system (Cosmed K2, JFB International, Italy). The LT was performed on an adapted treadmill (Sopur, Germany) and ventilatory data were collected every minute using a breath-by-breath automated system (CPX, Medical Graphics, MN, USA). The LT and the FT were not significantly different for duration (8 min 50 +/- 1 min 24 vs 9 min 55 +/- 29 s), percentage of maximal heart rate (HR, 86.2 +/- 3.9 vs 89.7 +/- 5.3%), maximal minute ventilation (VE, 101.6 +/- 28.5 vs 96.8 +/- 28.2 1.min(-1)) and peak oxygen uptake (VO2 peak, 39.7 + 7.3 vs 36.1 + 5.8 ml.kg(-1).min(-1) assessed with the CPX and the K2, respectively. We concluded that the FT proposed in the present study is a valid test for direct VO2 peak assessment in wheelchair athletes using a portable VO2 telemetric system. Nonetheless, the Léger and Mercier model equation did not accurately predict VO2 max and further investigation is needed to determine a valid VO2 max prediction equation for these subjects during the FT.