This study compared health-related fitness variables of high school students (14 to 19-years-old; 120 males, 67 females) participating in physical education (PE) and school-sponsored sports (SSS) to students participating solely in PE. Cardiovascular fitness, the primary variable of interest, was measured using the 20-Meter Shuttle Run (number of completed laps, 20OMST). Secondary analysis compared upper body strength (90 degrees push-ups), flexibility (sit and reach), and body mass index (BMI kg/m2). Comparisons were made between students participating in 1-2 SSS and > or = 3 SSS for males and 1 SSS and > or = 2 for females to students participating solely in PE. Males participating in 1-2 SSS (mean (+/- SD) 20MST 63.80 +/- 25.61) and > or = 3 SSS (81.13 28.26) completed significantly (p < .001) more laps than males participating solely in PE (44.18 +/- 19.09). Females participating in 1 SSS (37.33 +/- 15.53) and > or = 2 SSS (49.48 +/- 19.83) completed significantly (p = .02) more laps than females participating solely in PE (23.50 +/- 7.96). Significant differences in number of 90 degrees push-ups was observed between males participating in > or = 3 SSS (49.41 +/- 12.90) and males participating solely in PE (37.63 +/- 11.79, p = .006). No significant differences existed for males on BMI (p = .223) or the sit and reach (p = .145), and for females on 90 degrees push-ups (p = .79), sit and reach (p = .579), and BMI (p = . 122). As the number of SSS increase, significant increases are observed in cardiovascular fitness, with youth participating solely in PE exhibiting the lowest levels of cardiovascular fitness in comparison to youth participating in PE and SSS.