High intensity interval training (HIIT) is now a very exercise attention by society, scholars from all over the world have to look into the training methods. At present, most studies on HIIT in the market compare it with moderate intensity continuous aerobic exercise. From another perspective, this study compares HIIT training with typical Repetition Training (RT) in strength training to study the changes of cardiopulmonary function indicators in adolescents. The aim is to find out a more suitable and efficient way for youth sports training, so as to improve their physical fitness level.