Flywheel-based Inertial Training to Prevent Muscle Weakness and Atrophy During 30 Days of One-Leg Unloading in Adults Aged 35 to 45

What this Trial Is About

Researchers are investigating how flywheel-based inertial training FIT, applied using velocity-based training VBT and high-intensity interval training HIIT, impacts physical decline caused by disuse. This includes examining muscle strength loss, aerobic capacity reduction, and balance problems. The study focuses on healthy adults aged 35 to 45 who will experience 30 days of unilateral lower limb suspension ULLS to simulate muscle disuse. Participants will wear a specially modified shoe and use crutches to unload one leg during daily activities. They will be randomly assigned to either a control group with no exercise or an exercise group performing FIT leg press and upright squats three times weekly. The FIT exercises use a flywheel device adjusted for specific movement speeds and include resistance training and high-intensity intervals. The study duration for the suspension and exercise intervention is 30 days. Throughout the study, participants will undergo multiple assessments before, during, and after the intervention. These include body composition measurements, balance testing with force platforms, aerobic capacity tests using cycling with gas exchange monitoring, muscle imaging with diffusion tensor imaging, and muscle strength evaluations. Researchers will measure muscle activation, twitch properties, motor unit behavior, muscle size, and physiological changes at baseline, day 13, and day 30. Secondary outcomes include heart rate, blood pressure, and postural sway. The entire participation lasts about one month with repeated testing sessions.

FIT Exercise in 30d of ULLS-induced Muscle Disuse