Abstract

The effect of resistance on sprint power and the relationship between sprint and aerobic power production in wheelchair propulsion was evaluated. Six able-bodied subjects performed nine 20-s sprint tests on a wheelchair ergometer and an aerobic maximum wheelchair exercise test to study both anaerobic and aerobic power production. Ergometer data were analyzed unilaterally. Of all power and torque parameters, only maximal power output was independent of resisting load. Mean sprint power output over 20s increased from 21 W to 87 W. The highest power output, P5, calculated over a period of 5s (unilateral) increased from 24 W to 101 W. The Pmean and P5 reached more or less constant values at the final two levels of resistance. The observed increase in power output with increasing load is the result of a greater increase in torque compared to the decrease in velocity. Mean maximal power in the maximal aerobic exercise test (n=5) was 79 W, respresenting 42% of mean power (averaged over the nine sprint tests) and 37% of P5. In contrast to Pmean and P5, Pmax showed a significant association with peak aerobic power production and peak oxygen uptake. This may indicate that Pmax is an indicator of overall performance capacity, whereas Pmean and P5 are much more sprint related. The methodology of wheelchair exercise testing requires further detailed study with respect to the physiology and biomechanics of arm work, the functionality of the subject population, the reliability and validity of procedures and techniques. Verf.-Referat (gekuerzt)