Evaluation of wheelchair users in the field and in laboratory: Feasibility of progressive tests and critical velocity tests

The feasibility and relevance of three field tests previously studied in running - Montreal progressive Track Test (MTT), critical velocity test (V-c)and maximal velocity with lactate steady state (V-ch)- were investigated for wheelchair exercises performed on a 400 m outdoor track. Ten wheelchair athletes from the Handisport Federation of Senegal participated in this field study. The MTT consisted of a progressive exercise with a 1 km h(-l) velocity increment every 2 mins. The velocity at the last stage of the MTT (maximal aerobic speed, MAS) was 14 +/- 1 km h (-1). The critical velocity (V-c) was calculated as equal to the slope of the linear relationship between exhaustion time and the distance covered during three exercises at constant velocities until exhaustion (85, 90 and 95% of the MAS). The V-c was equal to 11.9 +/- 0.9 km h(-l). The maximal velocity with lactate steady state (V-ch) was calculated from the lactate slope during two exercises at 65 and 75% of the MAS. Whereas the MTT and the critical velocity rest were feasibile, the measurements of V-ch could not be used because of many absurd results. A second study in laboratory, which was carried out on 13 wheelchair users, showed that the concept of critical velocity and critical power can be used in wheelchair testing on a treadmill (TM) or in arm cranking (AC). This study also showed that the maximal oxygen uptake (V-o2max) and the heart rate (HR) at the end of an incremental exercise were similar with TM and AC.