Eccentric movement is when a muscle contracts while lengthening under load — the downward phase of a pull-up, lowering a barbell in a squat, or the landing phase of a jump. Eccentric loading produces more muscle damage than concentric (shortening) contractions and is the primary driver of DOMS. Research shows emphasising the eccentric phase (slow 3-5 second lowering) increases hypertrophy stimulus. Nordic hamstring curls, the most evidence-backed injury prevention exercise, are purely eccentric. The body can handle greater loads eccentrically than concentrically — hence assisted reps (going up with a spotter, lowering alone) for building eccentric strength.
Key points
- Muscle lengthening under load (lowering phase)
- Primary driver of DOMS
- Greater hypertrophy stimulus than concentric alone
- Body handles more load eccentrically than concentrically