Physiological Correlates of Simulated Wheelchair Racing in Trained Quadriplegics

Abstract

This study examined the physiological responses during a 7.5-km simulated wheelchair race (SR) performed on rollers by 8 male quadriplegic marathon racers and analyzed the factors associated with SR time. Cardiac output (Q) was estimated during the SR using carbon dioxide rebreathing, from which stroke volume (SV) and [Formula: see text] were calculated. Subjects raced at 90 and 93% of peak oxygen uptake [Formula: see text] and peak heart rate, respectively. SR time was inversely related (p < 0.05) to peak [Formula: see text], and [Formula: see text], Q, and SV during the SR, but not [Formula: see text], age, and lesion level. Multiple regression analysis included only absolute SR [Formula: see text] in the equation to predict SR time: Y = −29.7X + 65.9; SE = 5.8. SR [Formula: see text] was significantly (p < 0.05) related to Q and SV but not to [Formula: see text]. These descriptive data suggest that SR performance in trained male quadriplegics might be limited by central, as opposed to peripheral, factors that determine [Formula: see text]. Key words: oxygen uptake, cardiac output, spinal cord injury