Effects of body mass-based squat training in adolescent boy

The purpose of this study was to determine the effects of body mass-based squat training on body composition,muscular strength and motor fitness in adolescent boys. ninety-four boys (13.7 ± 0.6 yrs,1.60 ± 0.09 m,50.2 ± 9.6 kg) participated in this study and were randomly assigned to training (n = 36) or control (n = 58) groups. the training group completed body mass-based squat exercise training (100 reps/day,45 sessions) for 8 weeks. body composition and muscle thickness at the thigh anterior were determined by a bioelectrical impedance analyzer and ultrasound apparatus,respectively. maximal voluntary knee extension strength and sprint velocity were measured using static myometer and non-motorized treadmill,respectively. jump height was calculated using flight time during jumping,which was measured by a matswitch system. the 8-wk body mass-based squat training significantly decreased percent body fat (4.2%) and significantly increased the lean body mass (2.7%),muscle thickness (3.2%) and strength of the knee extensors (16.0%),compared to control group. the vertical jump height was also significantly improved by 3.4% through the intervention. the current results indicate that body mass-based squat training for 8 weeks is a feasible and effective method for improving body composition and muscular strength of the knee extensors,and jump performance in adolescent boys. © journal of sports science and medicine.