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).

Universidad Nacional Andres Bello40 enrolled

Overview

The randomized controlled trial will compare the effects of a High-intensity interval training (HIIT) protocol versus a HIIT plus plyometric training in the muscle-tendon structure function and metabolism of the pediatric population with obesity at different biological maturational stages (pre-to-age peak velocity \[APHV\] and post-APHV). Both groups perform baseline evaluations of the main and secondary outcomes and receive the intervention for twelve weeks, three times per week. Once the interventions are completed, the participants undergo the same evaluations they performed at baseline.

The prevalence of pediatric obesity increased 4.2-fold between 1976 and 2022, and it's expected to continue increasing toward 2030. Pediatric obesity is a public health problem due to its multiple metabolic comorbidities. Moreover, body weight and fat infiltration due to pediatric obesity negatively affect muscle-tendon structure, function, and metabolism, negatively impacting physical activity levels, active play, functional performance (e.g., jumping capacity), and quality of life. As a solution, HIIT protocols could decrease body weight and fat percentage and increase muscle oxidative capacity. The addition of plyometric training to HIIT protocols could generate the same effects as the HIIT protocol alone, with an additional enhancement in functional performance. However, the influence of biological maturation stages in the adaptations to training in pediatric population with obesity has been scarcely reported. Thus, throughout different biological maturation stages, such as pre-to-age peak velocity (APHV) (early stage of biological maturation) to post-APHV (final stage of biological maturation stage), an increase in testosterone, growth factors, and glycolytic metabolism capacity occurs. Therefore, the differences in the anabolic milieu and glycolytic metabolism between the pre-APHV and post-APHV could produce a differential capacity of training stimuli to modify the muscle-tendon, structure, function, and metabolism in these pediatric population with obesity. Therefore, this study aims to determine the effects of HIIT and concurrent HIIT and plyometric training in the muscle-tendon structure, function, and metabolism of the pediatric population with obesity in different maturation stages. The study will be a parallel-group randomized controlled trial that compares the effects of HIIT versus HIIT plus plyometric training on muscle-tendon structure, function, and metabolism in the pediatric population pre-APHV and post-APHV with obesity in a public health setting. The primary outcome will be the Achilles tendon mechanical properties. We estimate a sample size of 10 participants per group and 40 in total. The investigators aim to demonstrate the beneficial effects of HIIT plus plyometric training on the muscle-tendon structure and metabolism of the pediatric obesity population. Moreover, the researchers expected a difference in the adaptations provided by the training protocol between the pre-APHV and post-APHV groups.

Interventions

HIIT plus plyometric trainingBEHAVIORAL

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.

HIITBEHAVIORAL

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.

Outcomes

Primary Outcomes

Achilles Tendon Stiffnes (N/mm)

The stiffness will be estimated as the slope of the linear tendon elongation-force relationship above 50% of each participant's maximum attained force.