What is Eccentric Training?
Eccentric training involves muscle actions where the muscle lengthens while generating force, typically functioning as a braking or decelerating movement against resistance, such as lowering a weight 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. 1 The key distinguishing features include:
- Higher force-generating capacity compared to concentric (shortening) contractions, allowing muscles to produce greater tension during the lengthening phase 1, 2
- Lower energy requirements, typically 4-5 times lower metabolic cost than concentric muscle work when measured at similar mechanical power output 2
- Enhanced shock absorption capacity, enabling muscles to decelerate during landing tasks or precisely manage high external loading 3
Primary Training Methods
Traditional Eccentric Exercises
- Tempo eccentric training uses controlled lowering phases during standard resistance exercises (e.g., slowly lowering a barbell during bench press) 4
- Accentuated eccentric loading involves adding extra resistance during the lowering phase compared to the lifting phase 4, 3
- Plyometric training incorporates rapid eccentric loading followed immediately by concentric actions (e.g., depth jumps) 4
Specialized Equipment-Based Methods
Flywheel resistance training represents a distinct approach where you pull a strap to initiate rotation of a flywheel disc (concentric phase), then apply braking force to decelerate the spinning flywheel as the strap rewinds (eccentric phase). 5, 1 This method allows variable loading within each repetition and can achieve eccentric overload when performed with appropriate technique and effort. 5
Eccentric cycle ergometry involves pedaling backward against motorized resistance where the legs lengthen under load, offering a low-impact option for large muscle mass training. 1, 2
Isokinetic eccentric training uses specialized equipment that controls movement speed while the muscle lengthens against resistance. 1
Critical Distinction: Eccentric Overload
A common misconception is that all eccentric training automatically produces "eccentric overload." 5 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 exercises, users, or training loads achieve this—it depends on user effort, training experience, moment of inertia selected, and device characteristics. 5
Training Adaptations
Eccentric training produces distinct physiological adaptations:
- Muscle hypertrophy: Increases in muscle cross-sectional area, particularly type II fibers, with significant growth (≥5%) possible in 4-8 weeks 6, 3
- Strength gains: Enhanced maximal force production and improved muscle coordination during eccentric tasks 3
- Architectural changes: Increased fascicle length and greater number of sarcomeres in series, optimizing muscle length for tension development at greater extension 3
- Functional improvements: Enhanced performance during stretch-shortening cycles critical for sprinting, jumping, and throwing 3
Recommended Training Parameters
- Frequency: Train 2-3 days per week for optimal strength gains, allowing adequate recovery between sessions 1, 7
- Duration: Continue for minimum 4-6 weeks to generate meaningful strength improvements 1, 7
- Cardiovascular intensity: Eccentric training can be performed at relatively low heart rate (approximately 64% of maximum), making it suitable for populations with limited exercise capacity 2, 8
Important Caveats
Combining eccentric exercises with plyometric training produces superior functional outcomes for balance, functional activities, and subjective function compared to either method alone. 1, 7 Do not rely solely on eccentric training in isolation. 7
The term "flywheel resistance training" should be used instead of "eccentric overload training" when describing this modality, as eccentric overload is not guaranteed with all flywheel exercises. 5