In brief: Nine male racquetball players were monitored during matches with Opponents of equal, stronger, and weaker ability, and heart rate response and intensity of play were determined. The highest heart rate and percent intensity occurred when the monitored player was weaker than his opponent and the lowest occurred when he was stronger than the opponent. Matches Were significantly longer when the Players were of equal ability. The author suggests that when racquetball is recommended to develop and maintain cardiovascular fitness, the participant should be advised to select a partner of similar skill and fitness level.