Immobilization, Tonic, Physical Activity
Conditions
Keywords
Immobilization, Angiogenesis, Skeletal muscle, Exercise training, Vascular function
Brief summary
The study includes healthy young habitually active subjects. All subjects are subjected to two weeks of immobilization of one leg followed by four weeks of training of both legs. The subjects are randomized to either one-leg training of the non-immobilized leg during the two-week immobilization period or to no training of the non-immobilized leg during the immobilization period. Measures include skeletal muscle morphology, markers of angiogenesis and apoptosis, muscle metabolic markers, vascular function, vascular proteins and performance.
Detailed description
One leg of young healthy subjects will be immoblized for two weeks. Changes in angiogenic proteins and markers of apoptosis in muscle tissue and muscle extracellular fluid will be determined in both legs and in parallel the functional consequences of immobilization will be assessed. Vascular function and vascular proteins will also be determined. In order to understand how the oxidative capacity of the muscle is altered in parallel with changes in capillarization, markers of mitochondria will be measured .Half of the subjects will be randomized to single-leg training during the immobilization period to assess whether simultaneous training reduces the loss of capillaries, muscle function and vascular function in the immobilized leg. After the immobilization period the study participants will train the immobilized leg and the control leg for four weeks by moderate to intense interval cycle training and the same parameteres as during immobilization will be assessed in both legs. The study will also include measurements of circulating compounds and platelets in blood.
Interventions
OTHERTraining with non immobilized leg
Exercise training will be conducted with the non-immobilized leg during the immobilization period of two weeks
OTHERExercise training with both legs
Exercise training will be conducted regularly on a cycle ergometer during a four week period
OTHERImmobilization
Full length cast of one leg R/L randomized
Sponsors
Johannes Gutenberg University Mainz
University of Leeds
Liverpool John Moores University
Radboud University Medical Center
University of Copenhagen
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
NONE
Intervention model description
Parallel randomized to training or no training of non-immobilized leg during immobilization of the other leg
Eligibility
Sex/Gender
ALL
Age
18 Years to 35 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy * BMI \<25 * Habitually/moderately physically active
Exclusion criteria
* Known chronic medical disorder * Smoking * Excessive alcohol intake * Known genetic/familial predisposition for thrombosis * Hormonal birth control * High level strength or endurance training on a regular basis
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Angiogenesis | Change from baseline to after 2 weeks of immobilization | Skeletal muscle capillarization-comparison between legs |
| Vascular function | Change from baseline to after 2 weeks of immobilization | Measurements of skeletal muscle blood flow by ultrasound doppler in response to infusion of vasodilators/constrictors-comparison between legs |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Knee extensor performance | Change from baseline to after 2 weeks of immobilization and from after immobilization to after 4 weeks of training | Measurements of maximal power and endurance-comparison between legs |
| Maximal oxygen uptake | Change from baseline to after 2 weeks of immobilization and from after immobilization to after 4 weeks of training | Measured by gas analysis during an incremental ergometer cycle protocol |
| Body composition | Change from baseline to after 2 weeks of immobilization and from after immobilization to after 4 weeks of training | Measurements by dual energy x-ray absorptiometry |
| Vascular and metabolic proteins | Change from baseline to after 2 weeks of immobilization and from after immobilization to after 4 weeks of training | Proteins of importance for vascular function and muscle metabolism measured in muscle biopsy samples, skeletal muscle interstitial fluid and plasma-comparison between legs |
| Markers of bone metabolism | Change from baseline to after 2 weeks of immobilization and from after immobilization to after 4 weeks of training | Measurements of bone markers in plasma |
| Markers of angiogenesis | Change from baseline to after 2 weeks of immobilization and from after immobilization to after 4 weeks of training | Measurement of angiogenic and apoptotic factors-comparison between legs |
| Vascular function-non-invasive | Change from baseline to after 2 weeks of immobilization and from after immobilization to after 4 weeks of training | Measurements of skeletal muscle blood flow at rest, during passive movement, during exercise, after five min of occlusion and during infusion of vasodilators and constrictors-comparison between legs |
| Skin microcirculation | Change from baseline to after 2 weeks of immobilization and from after immobilization to after 4 weeks of training | Measurements of skin blood flow and morphology and relevant proteins in skin biopsies |
| Arterial blood pressure | Change from baseline to after 2 weeks of immobilization and from after immobilization to after 4 weeks of training | Measured by sphygmomanometer and intra-arterially |
Countries
Denmark
Outcome results
None listed