The purpose of this study was to examine selected physiological characteristics and pushing performance over a distance of five kilometres (5 km) in twelve wheelchair athletes (10 paraplegics and 2 tetraplegics). The physiological tests and 5 km wheelchair time trials were performed on a motorised treadmill adapted for use by wheelchairs. The maximum oxygen uptake (VO2 max) and %VO2 max utilised at a fixed speed equivalent to a blood lactate concentration of 4 mmol.l-1, identified as being of importance in successful able-bodied endurance performance, were also found to correlate highly with 5 km performance in wheelchair athletes. Low correlations were found between performance and mean %VO2 max utilised over the whole distance and between performance and oxygen uptake at a standard speed. The results also showed that the tetraplegics had lower physiological reserves than the paraplegics, with a much reduced maximum heart rate and ventilation. The findings indicate that a combination of physiological characteristics influence pushing performance in wheelchair athletes.