Teenagers: Impact of Eccentric eXercise Training on Overweight and Obesity

Study Overview
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Brief Summary
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Nowadays, eccentric exercise can be realized in a dynamic way with an ergocycle which permits eccentric (ECC) lower limbs contractions at a defined power output. With this type of ergometer, O2 consumption (VO2) in ECC is three fold lower than in concentric (CON) for the same power output. Consequently, ECC program could be used in chronic disorders with limited capacities, such as obesity. The investigators hypothesis that an eccentric training program, as it will induce higher mechanical constraints, would improve body composition, especially by reducing fat mass. This effect could be explained by an increased rest energy expenditure and a better improvement in biological parameters (particularly lipid profile and insulin-resistance) after ECC training (versus CON training). This study aims to compare the modification of fat mass after an ECC program versus a CON program at the same VO2.. The secondary goal is to assess the physiological mechanisms involved in the modification of body composition.

Detailed Description
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40 obese adolescents will be randomized into 2 groups: CON or EXC. The patients of ECC group will follow habituation sessions (2 weeks) to avoid the secondary muscular effects of high intensity eccentric exercise. The training program will last 12 weeks for the two groups. Before and after, each subjects will participate to the following measurements: total and segmental body composition (DXA), aerobic capacities (maximal incremental exercise test, VO2max), muscular lower limbs strength (isometric and isokinetic dynamometer), rest energy expenditure (indirect calorimetry), biological parameters (lipid profile, insulin-resistance), physical activity (actimetry), food intakes and quality of life (questionnaires).

Official Title
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Impact of Muscular Training Program on Body Composition of Overweight and Obese Teenagers: classi201c Cycling Exercise in Concentric Versus Eccentric

Conditions
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Adolescents (12 to 17 Years Old), Obese (BMI>90th Percentile)

Intervention / Treatment
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* Other: Cycling exercises


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adolescent (12 to 17 years old) BMI>90th percentile Post puberty (Tanner 3 to 5) Inactive (<10 METS/h/week) No other chronic disease (cardio pulmonary, osteo articulary or muscular diseases), no surgery during the last 3 months, no genetic obesity and no contraindication to physical activity Exclusion Criteria: -

Ages Eligible for Study
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Minimum Age: 12 Years
Maximum Age: 17 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Concentric cycling exercise (CON)<br>40 obese adolescents will be randomized into 2 groups: CON or EXC | Other: Cycling exercises<br>* All measurements are performed before and after the training program (12 weeks)<br>|
| Experimental: eccentric cycling exercise (EXC)<br>40 obese adolescents will be randomized into 2 groups: CON or EXC | Other: Cycling exercises<br>* All measurements are performed before and after the training program (12 weeks)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| change in total body fat mass (Dual X ray Absorptiometry) |  | before and after the 12 weeks training program | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| aerobic capacities (VO2max) |  | before and after the 12 weeks training program | 
| isometric muscular lower limbs strength |  | before and after the 12 weeks training program | 
| isokinetic muscular lower limbs strength |  | before and after the 12 weeks training program | 
| rest energy expenditure (indirect calorimetry) |  | before and after the 12 weeks training program | 
| biological parameters (plasma lipid profile and insulin-resistance ) |  | before and after the 12 weeks training program | 
| physical activity (actimetry and questionnaires) |  | before and after the 12 weeks training program | 
| food intakes (measurements and questionnaires) |  | before and after the 12 weeks training program | 
| quality of life (questionnaires) |  | before and after the 12 weeks training program | 
| segmental body composition (segmental fat and fat free mass, Dual X-ray Absorptiometry) |  | before and after the 12 weeks training program | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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pediatric obesity, eccentric exercise, body composition, training program