Effects of HIIT and Concurrent HITT/Plyometric Training on Muscle-tendon Structure, Function and Metabolism in Pediatric Population With Obesity at Different Biological Maturation States (HIIT-PRO Kids).

"The HIIT plus plyometric training will perform two weeks of exercise adaptation involving 25 minutes of MICT at 65% of maximal heart rate (HRmax) and 5 minutes of jumps in place at 5 - 6 of the EPinfant scale of Perceived exertion. The HIIT plus plyometric training will perform 15 minutes of HIIT and 5 minutes of jumps each session. The HIIT phase will be performed in a work recovery intensity at 85 and 50% of the HRmax. The work phase of jumps will be performed all out, and the recovery phase will be performed at 5 - 6 of the EPinfant scale of perceived exertion. The work: recovery bouts will be progressed from 1:4 (15 seconds: 60 seconds) at weeks 3-6, to 1:3 (15 seconds: 45 seconds) at weeks 7-9, and to 1:3 (15 seconds: 30 seconds) at weeks 10-12. In all sessions, the rate of perceived exertion, heart rate, and exercise planning compliance will be measured."

The HIIT group will perform two weeks of exercise adaptation involving 30 minutes of moderate-intensity continuous training (MICT) at 65% of the maximal heart rate (HRmax) reached in the maximal oxygen consumption test. The HIIT group will perform 20 minutes of HIIT each session, with a work: recovery intensity at 85% and 50% of HRmax, respectively. The work: recovery bouts will be progressed from 1:4 (15 seconds:60 seconds) at weeks 3-6, to 1:3 (15 seconds:45 seconds) at weeks 7-9, and to 1:2 (15 seconds: 30 seconds) at weeks 10-12. In all sessions, the rate of perceived exertion, heart rate, and exercise planning compliance will be measured.