Physiological Performance Determinants of a 22-km Handbiking Time Trial

To investigate physiological performance determinants of the partial laps and an overall 22-km handbiking (HB) time trial in athletes with high paraplegia. Seven male HB athletes with spinal cord injury (lesion levels thoracic 2-8) performed a laboratory maximal incremental test under cardiorespiratory-mechanical monitoring including respiratory-exchange ratio (RER), oxygen uptake (VO2), and mechanical power output (PO). Individual first and second ventilatory thresholds (VO 2VT1 and VO 2VT2), VO 2peak, and PO peak were posteriorly identified. Athletes also performed a simulated HB time trial along a 4-lap bike circuit under cardiorespiratory measurement. Overall metabolic cost (C) and %VO 2peak (ratio of VO2 to VO 2peak) were calculated from race data. Race performance was defined as mean race velocity (v). athletes completed the 22-km HB time trial in 45 ± 6 min, at 29.9 ± 3.6 km/h, with %VO 2peak = 0.86 ± 0.10 and RER = 1.07 ± 0.17. VO 2peak (r = .89, P = .01), POpeak (r = .85, P = .02), VO 2VT1 (r = .96, P = .001), VO 2VT2 (r = .92, P = .003), and C (2nd lap, r = .78; 3rd lap, r = .80; and 4th lap, r = .80) were significantly (P < .05) positively correlated with race performance. Within-subjects correlation coefficient revealed a large and significant (r = .68, P < .001) relationship between %VO 2peak and v. VO 2peak, PO peak, ventilatory thresholds, %VO 2peak, and C appeared to be important physiological performance determinants of HB time trial.