Fifteen male and 15 female subjects performed activities designated as purposeful and nonpurposeful that required the same muscle function. Subjects continued each activity to a predefined level of perceived exertion. The number of repetitions performed, the heart rate, and electromyogram (EMG) recordings were compared for the purposeful and nonpurposeful activities. Results showed a significantly greater number of repetitions performed on the purposeful activities (p = .001) recorded at equal levels of exertion. The hypothesis that individuals will be motivated to perform longer when the activity is purposeful was supported empirically, thereby substantiating a basic premise of occupational therapy.