Background: Research suggests participation in sports is an important contributor to overall adolescent physical activity (PA). Sports play has become increasingly important in physical education (PE) classes as a means for promoting healthful and enjoyable PA. Research is needed that investigates physiological and perceptual responses to sport play. Methods: We studied 101 (55 males; 46 females, age 11-14) students who participated in flag football (FF), basketball (BB), and flag rugby (FR). Activity counts were collected using accelerometers. Perceived competence and enjoyment were measured using the intrinsic motivation inventory. Results: Each sport activity produced acceptable levels of activity and positive perceptual responses, but differences among sports were noted. Accelerometry data indicated that FR and BB were more intense than FF (p <?0.001). Perceptual data indicated participation in FR elicited higher perceptions of competence and greater enjoyment when compared to FF and BB (p <?0.001). Conclusions: Participation in sport activity within middle school PE classes provides excellent opportunities for energy expenditure and positive perceptual responses. Most importantly, FR provides an activity stimulus that has potential benefits both physiologically and psychologically.