The Effect of Eccentric Training on Anthropometrics, Physical Fitness and Bone Strength in Overweight Children

recent studies have shown that similarly to regular exercise, aerobic ECcentric Contraction (ECC) exercise induces changes in the musculoskeletal system while using lower energy consumption, due to the fact that eccentric training creates greater force in the muscle.

most of the studies in this subject were done on healthy or overweight adults. therefore, the effect of aerobic eccentric training on children is still unknown. this study wants to test the impact of eccentric training on overweight and obese children.

this study will include approximately 100 overweight and obese children (boys and girls), aged 5-18 years. participants will be recruited from the population of overweight children from children sports medical center 'Meir' in Kfar Saba, Israel. participants will be randomly divided into two groups (intervention and control). Participants and their parents will sign a consent form before entering the study.

Each participant will undergo a series of tests including: anthropometrics (height, weight, bmi, body composition by BIA), fitness tests (Maximal distance achieved in a 12min outdoor run\walk, Vertical jump, Standing long jump, 4X10 meter sprint run), quadriceps and hamstrings strength test (hand-held dynamometer MicroFet2), bone strength (bone sonometer), ankle and tibial kinematic(accelerometers+ video of foot strike).

Intervention group will then perform an 8 week (16 sessions) ECC training program on a decline treadmill, the program will include two weeks of habituation to lower as possible DOMS (delayed onset muscle soreness) and possible injuries, training length and intensity will be gradually increasing over the time of the program, maximal negative gradient will be -15% at the end of the program.