What Constitutes Eccentric Exercises
Eccentric exercises are muscle actions where the muscle lengthens while generating force, typically functioning as a braking or decelerating movement against resistance. This occurs when you resist or control a load during the lengthening phase of movement, such as lowering a weight, decelerating during landing, or controlling body position against gravity 1.
Core Mechanical Characteristics
Eccentric muscle contractions involve the muscle-tendon unit lengthening while under tension, producing force to decelerate or control movement. Key features include:
- Higher force-generating capacity: Muscles can produce greater force during eccentric actions compared to concentric (shortening) contractions at the same metabolic cost 2, 3
- Lower energy requirements: Eccentric work requires approximately 4-5 times less metabolic energy than concentric exercise at similar mechanical power output 4, 2
- Shock absorption function: Eccentric contractions decelerate movements during landing tasks and control high external loads 3
Common Eccentric Exercise Modalities
Traditional Resistance Training
- Tempo eccentric training: Deliberately slowing the lowering phase of conventional exercises (e.g., taking 3-5 seconds to lower a weight) 5
- Body weight exercises: Controlled lowering movements using gravity as resistance 2
Specialized Equipment-Based Methods
Flywheel resistance training represents a distinct eccentric training approach where the concentric action initiates rotation of a flywheel disc, and the eccentric action applies braking force to decelerate the spinning flywheel 1. This method:
- Allows variable loading within each repetition 1
- Can achieve eccentric overload (higher mechanical output during eccentric vs. concentric phase) when performed with appropriate technique 1
- Generates significant strength and hypertrophic adaptations in 4-8 weeks 6
Eccentric cycle ergometry involves pedaling backward against motorized resistance, where the legs lengthen under load 7, 4. Training should:
- Begin at 3 weeks post-injury rather than delaying to 12 weeks for superior strength gains and muscle hypertrophy 7, 8
- Ramp loads progressively over 3 weeks to prevent muscle damage 4
- Reach final training loads of 400-500W in rehabilitation settings 4
Isokinetic eccentric training uses specialized equipment that controls movement speed while the muscle lengthens against resistance 7
Plyometric Training
Drop jumps and similar exercises impose very high eccentric loads (several thousand Watts) on muscles and tendons during the landing phase, representing the highest intensity form of eccentric training 4, 5
Important Distinction: Eccentric Overload vs. Eccentric Exercise
A critical misconception is that all eccentric exercises automatically produce "eccentric overload"—this is incorrect. Eccentric overload specifically means higher mechanical output (force, power, or speed) during the eccentric phase compared to the concentric phase, with an eccentric:concentric ratio >1 1.
Not all eccentric exercises achieve this:
- Exercise type, resistance level, training experience, and braking technique all influence whether eccentric overload occurs 1
- Practitioners must confirm eccentric overload numerically by measuring parameters like power, speed, or force 1
Training Parameters for Eccentric Exercise
Perform eccentric training 2-3 days per week for optimal strength gains, allowing recovery between sessions 7, 8. Training should:
- Progress loads gradually over initial 3-week period to minimize muscle damage and delayed onset muscle soreness 4
- Continue for 4-6 weeks minimum to generate strength improvements 7
- Involve sessions of 20-30 minutes duration 4
Critical Pitfall to Avoid
Do not rely solely on eccentric training in isolation. Combining eccentric exercises with plyometric training produces superior functional outcomes for balance, functional activities, and subjective function compared to either method alone 7, 8. This combined approach is more effective than eccentric training by itself for comprehensive neuromuscular development.