Purpose: To investigate the association between the heart rate (HR) at maximal fat oxidation (MFO) and the HR at the aerobic threshold (AerT) in adolescent boys and girls, and to identify sex differences in the intensity that elicits MFO (Fat_max) as a percentage of HR peak (HR_peak). Methods: Fifty-eight healthy adolescents participated in this study (29 boys and 29 girls). Participants performed a cardiopulmonary exercise test on a cycle ergometer. MFO was calculated using a stoichiometric equation, and the AerT was identified using gas exchange parameters. Results: A strong correlation between HR at Fat_max and HR at AerT was found in both boys and girls (r = .96 and .94, respectively). Fat_max as a percentage of HR_peak occurred at 61.0% (4.9%) of HR_peak and 66.8% (6.9%) of HR_peak in adolescent boys and girls (P = .001, F = 13.6), respectively. MFO was higher in boys compared with girls (324 [150] and 240 [95] mg/min, respectively), and no sex differences were observed in the relative contribution of fat to energy expenditure at Fat_max. Conclusions: HR at Fat_max and HR at AerT were highly correlated in adolescent boys and girls. Girls obtained Fat_max at a higher percentage of HR_peak than boys.

目的:研究青春期男孩和女孩最大脂肪氧化 (MFO) 时的心率 (HR) 与有氧阈值 (AerT) 时的心率 (HR) 之间的关系，并确定引发 MFO (Fat _max)强度的性别差异。) 作为 HR 峰值 (HR _peak )的百分比。方法： 58名健康青少年（29名男孩和29名女孩）参加了这项研究。参与者在自行车测力计上进行了心肺运动测试。MFO 使用化学计量方程计算，AerT 使用气体交换参数确定。结果:在男孩和女孩中发现Fat _{max 的}HR 和 AerT 的 HR之间存在很强的相关性(r  = .96 和 .94，分别）。脂肪_最大的人力资源的百分比_的峰值发生在HR的61.0％（4.9％）_的峰值和人力资源的66.8％（6.9％）_的峰值在青春期男孩和女孩（P  = 0.001，˚F 分别为13.6 =）。与女孩相比，男孩的 MFO 更高（分别为 324 [150] 和 240 [95] mg/min），并且在 Fat _{max 时}脂肪对能量消耗的相对贡献没有观察到性别差异。结论：在青春期男孩和女孩中，Fat _{max 的}HR 和 AerT 的 HR 高度相关。女孩在 HR_峰值的百分比更高时获得了_最大脂肪 比男孩。