Poor physical fitness of wheelchair-dependent individuals may result in excessive cardiorespiratory responses during locomotion. The purpose of this study was to develop and implement an interval training program (ITP) incorporating wheelchair ergometer (WERG) exercise to improve fitness for wheelchair activity. Of thirteen able-bodied female volunteers, seven were selected to participate in a 5-week ITP, while the remainder served as sedentary controls. Both the exercise training (ET) group and the sedentary control (SC) group completed a standardized fitness test on the WERG before (pre-test) and after (post-test) the 5-week period. Following the ITP, submaximal heart rate, pulmonary ventilation and oxygen uptake responses of the ET group were generally found to be significantly lower during the post-test. These improvements in WERG exercise performance were not observed in the SC group. The ITP may have contributed to adaptations of upper body muscles, improved cardiorespiratory function, and/or a higher level of skill for wheelchair propulsion. We conclude that applying the concepts of interval training to wheelchair exercise may substantially improve the performance and fitness characteristics of wheelchair users. This could reduce the relative stresses of wheelchair locomotion and lead to a higher level of rehabilitation.