Although Title IX has now been in effect for 30 years, a fair amount of controversy still exists regarding whether co-educational or gender segregated classes provide the best setting for males and females at the secondary level. This study compared the physical activity levels of males and females in co-educational and gender segregated physical education classes. The subjects were 48 sixth grade students from an urban elementary school. Using a mixed model factorial anova, the subjects were studied in both a controlled (co-ed) and an experimental (gender segregated) setting. The subjects wore Polar heart rate monitors for six days of game play in an Ultimate Frisbee unit. Three days were in co-ed classes and three days were in gender segregated classes. In every class, the subjects recorded starting, middle, and ending heart rates. The heart rate data was compared for the two settings in order to determine which setting solicited the greatest amount of physical activity. Results of the study indicated that heart rates for males were higher than those for females at the beginning, middle, and end of the class in both coeducational and segregated settings. Females spent approximately 5.8 minutes in the target heart rate zone in the segregated setting and 6.2 minutes in the coeducational setting; males spent 8.3 minutes in the target heart rate zone in the segregated setting and 7.9 minutes in the coeducational setting. This indicates that although the coeducational setting may provide higher levels of physical activity for females, the segregated setting seems to provide more physical activity for males. Although both the males and females were working in their target heart rate zones during both the segregated and coeducational settings, they were doing so for a relatively short duration (5-8 minutes). The study concluded that the use of heart rate monitors is an effective way of determining levels of physical activity in children but further investigation is needed to study whether segregated or coeducational classes are physically more beneficial for males or females.