Volunteers Who Can do Moderate Physical Activity
Conditions
Brief summary
The recent appearance of ergocycles that can be used for eccentric pedaling (Cyclus type) has aroused a growing interest in the field of rehabilitation. The mechanical, metabolic, and cardiorespiratory characteristics of eccentric exercises make them an exercise of choice when the goal is to improve locomotor muscle function and exercise capacity. Despite its potential advantages, the optimal modalities of eccentric pedaling, in particular the choice of pedaling frequency, are still poorly understood, especially its effects on the neuromuscular system. Indeed, most training protocols impose a fixed pedaling power but with highly variable pedaling rates, ranging from 15 to 60 rpm (Besson et al., 2013; MacMillan et al., 2017). For a given pedaling power level (P), the choice of pedaling frequency (F) directly impacts the force torque (C) and thus the force applied to the pedals, since power is equal to the product of pedaling frequency and force torque (P = F.C). For frequencies varying from 15 to 60 rpm, the level of muscular tension during pedaling therefore varies from single to quadruple. These very large variations in force can influence the neuromuscular adaptations induced during a prolonged training period. For example, the use of low pedaling frequencies corresponding to high muscle tension could favor peripheral muscular adaptations (e.g. contractility) whereas higher pedaling frequencies could favor central (i.e. nervous) adaptations. A better understanding of the neuromuscular adaptations induced by a period of eccentric pedaling at different cadences will allow for a more precise definition of training protocols for populations likely to undergo this type of training (e.g. elderly people, patients with heart failure).
Interventions
Before and after training. Muscle function: * voluntary maximal isometric force of the knee extensors * evoked force in the knee extensors by double percutaneous electrical stimulation at 100 and 10 Hz * level of voluntary activation * voluntary maximum force in concentric and eccentric mode at an angular speed of 60°.s-1 * squat jump and counter-movement jump
Before and after training. Cardiovascular-respiratory function: * Oxygen consumption during the incremental concentric pedaling test conducted to high effort perception. * heart rate during pedaling tasks Muscle architecture: \- Pennation angle and thickness of vastus lateralis, rectus femoris, gastrocnemius medialis and lateralis muscles, before and after training. Familiarization with eccentric pedaling
3 training sessions per week for 6 weeks
Maintain usual physical activity and diet for a period of 6 weeks.
3 sessions per week of training for 6 weeks
Sponsors
Study design
Eligibility
Inclusion criteria
* Person who has given oral consent * Subject capable of understanding simple commands and giving consent * Subject (male or female) between 18 and 40 years of age. * Subject able to do moderate physical activity
Exclusion criteria
* Person not affiliated to national health insurance. * Physical disabilities affecting the lower limbs or the pelvis, and which may hinder or prevent the practice of exercise on an ergocycle, whether neurological (central or peripheral), arterial (in particular, arterial disease of the lower limbs with a systolic index \< 0.6) or orthopedic (degenerative or inflammatory rheumatism). * Person under legal protection (curatorship, guardianship) * Person under court order (sauvegarde de justice) * Pregnant, parturient or breastfeeding women * Major unable to express consent * Minor
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Maximum isometric force developed in the quadriceps | 6 weeks of training |
Countries
France