The purpose of this study was to compare heart rate peak in obese (n = 43) and normal weight (n = 45) female youth. Heart rate (HR) peak was significantly lower (p < or = 0.05) in the obese group as compared to the normal weight group (192.3 +/- 9.3, 203.4 +/- 7.6), and VO2 (L x min(-1)) peak similar between groups (1.77 +/- 0.53, 1.97 +/- 0.60). Bivariate correlations for heart rate peak with body weight, percent fat, and body mass index yielded the following: -0.53, -0.54, and -0.57. These findings agree with the adult data indicating low HR peak in obese individuals. Further research is needed to explore physiologic factors that may lead to reduced HR peak in obese female youth.