Eccentric movement refers to a type of muscle action where the muscle lengthens under load, typically during the lowering phase of a movement. It is one of the three main types of muscle actions, alongside concentric (shortening) and isometric (no movement) actions. Eccentric movements are often emphasized in resistance training because they can significantly contribute to muscle strength, hypertrophy, and overall athletic performance.
### Key Characteristics of Eccentric Movement:
1. **Lengthening Under Load**: The muscle fibers elongate while resisting an external force, such as when lowering a weight during a bicep curl or squat.
2. **High Force Production**: Eccentric movements can generate greater forces than concentric movements because the muscle is decelerating the movement.
3. **Muscle Damage and Hypertrophy**: Eccentric exercises are known to cause micro-tears in muscle fibers, which can lead to muscle growth and strength gains when properly recovered.
4. **Injury Rehabilitation**: Eccentric training is often used in physical therapy to strengthen muscles and tendons, particularly in the rehabilitation of injuries like tendinitis or muscle strains.
### Examples of Eccentric Movements:
– **Squat**: The lowering phase of a squat is an eccentric movement for the quadriceps and hamstrings.
– **Bicep Curl**: The lowering phase of a bicep curl is an eccentric movement for the biceps.
– **Lunges**: The backward motion of a lunge is an eccentric movement for the quadriceps and glutes.
– **Deadlift**: The lowering phase of a deadlift is an eccentric movement for the hamstrings, glutes, and lower back.
### Training Techniques That Emphasize Eccentric Movement:
1. **Eccentric-Only Training**: This involves focusing solely on the lowering phase of an exercise, often with the help of a partner or equipment to lift the weight back up.
2. **Negative Reps**: Similar to eccentric-only training, where the lifter focuses on the lowering phase, often using a weight that is heavier than their concentric capacity.
3. **Tempo Training**: Using a specific time under tension for the eccentric phase, such as lowering a weight over 3-5 seconds, to increase the time the muscle spends under load.
4. **Isometric Holds**: Incorporating pauses during the eccentric phase to further challenge the muscle.
### Benefits of Eccentric Training:
– **Increased Strength**: Eccentric training can improve both concentric and eccentric strength.
– **Muscle Hypertrophy**: The damage caused by eccentric movements can stimulate muscle growth.
– **Improved Muscle Endurance**: Eccentric training can enhance the muscle’s ability to sustain activity over time.
– **Injury Prevention**: Strengthening muscles and tendons through eccentric training can reduce the risk of injury, particularly in sports and activities that involve repetitive movements.
### Considerations:
– **Muscle Soreness**: Eccentric training can lead to delayed onset muscle soreness (DOMS), especially in individuals who are new to such training.
– **Progressive Overload**: Gradually increasing the load or time under tension during eccentric movements is crucial for continued progress.
– **Form and Control**: Maintaining proper form during eccentric movements is essential to avoid injury and maximize benefits.
In summary, eccentric movement is a powerful tool for building strength, muscle size, and functional capacity, and it should be a component of any well-rounded training program.
