Related Experiment Videos
Strength gains following different combined concentric and eccentric exercise regimens
P C Hilliard-Robertson1, S M Schneider, S L Bishop
1University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA.
Aviation, Space, and Environmental Medicine
|April 12, 2003
Summary
Eccentric exercise, combined with concentric exercise, significantly boosts muscle strength more than concentric exercise alone. Emphasizing eccentric movements yields the greatest strength gains, crucial for spaceflight countermeasures.
Area of Science:
- Exercise physiology
- Space medicine
- Muscle physiology
Background:
- Spaceflight causes muscle weakness and atrophy, with current countermeasures being insufficient.
- Resistance training combining eccentric and concentric actions shows promise for muscle gains.
Purpose of the Study:
- To compare strength gains from combined concentric/eccentric exercise versus concentric exercise alone.
- To determine if an eccentrically biased regimen yields the greatest strength increase.
Main Methods:
- 31 subjects trained one leg using isokinetic exercise for 5 weeks.
- Groups: 75% concentric/25% eccentric (CON-ECC), 75% eccentric/25% concentric (ECC-CON), or 100% concentric (CON).
- Pre- and post-training strength tests and DEXA scans measured changes.
Main Results:
- All groups increased eccentric strength; the CON group showed the smallest gain (10.1%).
- Combination groups (CON-ECC, ECC-CON) had significantly larger gains (19.5%, 18.1%; p < 0.042).
- No significant changes in muscle mass were observed.
Conclusions:
- Resistance exercise including eccentric actions, especially emphasized, enhances strength gains more than concentric exercise alone.
- Eccentric exercise may be vital for astronaut resistance training protocols during long-duration spaceflight.
Keywords:
Non-programmatic