Aerobic exercise training has demonstrated positive effects after brain injury. However, therapists express concern regarding the use of effortful exercise in individuals presenting with spasticity or involuntary muscle activity. This study aimed to address this concern and to evaluate whether an intervention of maximal intensity cycling exercise impaired an individual's ability to actively extend his hemiparetic elbow. Using a single case design, it was shown that active elbow extension improved during the period of this investigation, and was not impaired immediately following maximal cycling exercise.