PHYSIOLOGICAL CORRELATES OF SIMULATED WHEELCHAIR RACING IN TRAINED QUADRIPLEGICS

This study examined the physiological I responses during a 7.5-km simu lated wheelchair race (SR) performed on rollers by 8 male quadriplegic marathon racers and analyzed the factors associated with SR time. Car diac output (Q) was estimated during the SR using carbon dioxide rebre athing, from which stroke volume (SV) and (a-(v) over bar O-2 diff wer e calculated. Subjects raced at 90 and 93% of peak oxygen uptake (VO2) and peak heart rate, respectively. SR rime was inversely related (p < 0.05) to peak VO2, and VO2, Q, and SV during the SR, but not (a-(v) o ver bar)O-2 diff, age, and lesion level. Multiple regression analysis included only absolute SR VO2 in the equation to predict SR time: Y = -29.7X +65.9; SE = 5.8: SR VO2 was significantly (p < 0.05) related to Q and SV but not to (a-(v) over bar)O-2 diff. These descriptive data suggest that SR performance in trained male quadriplegics might be lim ited by central, as opposed to peripheral, factors that determine VO2.