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Decellularization-Based Quantification of Skeletal Muscle Fatty Infiltration
Published on: June 9, 2023
Triceps brachii strength and regional body composition changes after detraining quantified by MRI
Jelena Z Popadic Gacesa1, Dusko B Kozic, Kozic B Dusko
1Laboratory for Functional Diagnostics, Department of Physiology, Medical School, University of Novi Sad, Serbia. jpopadic@uns.ac.rs
Journal of Magnetic Resonance Imaging : JMRI
|April 22, 2011
Summary
Twelve months of detraining significantly decreased triceps brachii endurance strength and increased intermuscular adipose tissue (IMAT). Muscle volume returned to baseline, but IMAT accumulation exceeded pretraining levels due to reduced muscle activity.
Area of Science:
- Exercise physiology
- Muscle adaptation
- Body composition analysis
Background:
- Resistance training induces muscle hypertrophy and strength gains.
- Detraining leads to the loss of these adaptations.
- Understanding long-term detraining effects on muscle composition is crucial.
Purpose of the Study:
- To investigate functional adaptations of the triceps brachii muscle after 12 months of detraining.
- To assess regional body composition changes, specifically intermuscular adipose tissue (IMAT), in the upper arm following prolonged detraining.
Main Methods:
- Seventeen healthy young men underwent 12 months of detraining after a 12-week resistance exercise program.
- Triceps brachii strength and endurance were measured using isoacceleration dynamometry.
- Muscle volume and adipose tissue (subcutaneous and intermuscular) were quantified using MRI.
Main Results:
- Endurance strength decreased by 17% and fatigue rate by 19% after detraining.
- Maximal muscle strength showed a non-significant 4% decrease.
- Triceps brachii muscle volume returned to pretraining levels, while IMAT significantly increased by 14%.
Conclusions:
- Long-term detraining results in decreased muscle endurance and a return of muscle volume to baseline.
- Significant accumulation of intermuscular adipose tissue (IMAT) occurs after 12 months of detraining.
- Increased IMAT levels post-detraining indicate a negative adaptation linked to reduced muscle activity.
