Pedal Rate Influence on Oxygen Consumption in Eccentric

Study Overview
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Brief Summary
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Nowadays, ECC exercise can be realized using various modalities that target small or large muscle masses in a segmentary or dynamic way. The training program proposed in this study is realised on an handmade ergocycle which allows eccentric contractions. With this type of ergometer, O2 consumption (VO2) is three to five fold lower than during an exercise realised at the same power output with a concentric ergocycle. Due to this later propertie, which origins are not yet fully identified, there is an increasing interest to embed ECC in rehabilitation programs. The investigators hypothesis that a higher pedal rate will induce a lower oxygen consumption, with the same benefits. This study aims to compare oxygen consumption at two pedal rates : 50 and 80 rotation per minute (rpm). The ultimate goal is to assess efficacy and tolerance of eccentric training on ergocycle and to enhance comprehension of the physiological mecanisms involved in the lower O2 consumption observed.

Detailed Description
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The training program proposed in this study is realised on an handmade ergocycle which allows almost pur eccentric contractions. Fifteen healthy volunteers realize a incremental test until exertion on a concentric ergometer. If the minimal power output of 200W is reached, the volunteers are familiarized with eccentric exercise during several bouts of exercise. This habituation session allows avoiding the secondary muscular effects of high intensity eccentric exercise. Then, volunteers could take part in a two-stepped eccentric protocol: 1) an incremental test consisting in 3 stages. Each stage lasts 4 minutes. 2) A constant-load test realized at 320W during 6 minutes. Each test is realized twice: at 50 and 80 rpm and sequence is randomly assigned. [One step (incremental or constant load) = two tests (50 and 80 rpm)] During each step, oxygen consumption is continuously measured, as well as cardiac output and muscular activity and intramuscular oxygen kinetic.

Official Title
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Pedal Rate Influence on Oxygen Consumption in Eccentric

Conditions
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Healthy

Intervention / Treatment
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* Procedure: pedal rate on 50 RPM
* Procedure: pedal rate on 80 RPM


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: - Males IMC <30 physically active Pmax concentric > 200W Pmax > Pmax théo sédentaire Exclusion Criteria: cardio pulmonary, osteo articulary or muscular diseases Eccentric based physical activities or sports (weight liftering, alpine skiing)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 55 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: pedal rate ON 50 RPM<br> | Procedure: pedal rate on 50 RPM<br>* All measurements are performed in two pedalling situations. The two frequencies used will be 50 and 80 RPM. For each subject the running order (50 and 80, 80 and 50) is randomly determined<br>|
| Experimental: pedal rate on 80 RPM<br> | Procedure: pedal rate on 80 RPM<br>* All measurements are performed in two pedalling situations. The two frequencies used will be 50 and 80 RPM. For each subject the running order (50 and 80, 80 and 50) is randomly determined<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Oxygen consumption (VO2 ml/min) | Oxygen consumption (VO2) is continuously assesse during exercises at 50 and 80 rpm. | at day 1 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cardiac output( l/min) |  | at day 1 | 
| muscular oxygen kinetic (arbitrary unit and %) |  | at day 1 | 
| Muscular activity (mV) | Muscular activity is measured during one and half minute, at the end of each stage | at day 1 during one and half minute (1min30s) | 
| VO2 (ml/min) | VO2 is continously assessed during the constant-load exercise | at day 1 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Eccentric, Ergometer, Pedal rate, Oxygen consumption, Only health volunteers