Eccentric
An eccentric muscle action happens when an active muscle lengthens as it resists a load.
Eccentric: a practical example
For example, your elbow flexors work eccentrically as you lower a dumbbell during a curl.
Use it in your log
When you log your workout, keep this in mind: eccentric describes the muscle action. It is often the lowering part of a lift, but context matters.
Next, use the workout log to keep names, weights and reps in one place. Then check your progress across sessions.
Related terms
These examples explain terms. They do not tell you what to lift. If you need help with a plan, ask a qualified trainer.
Updated October 22, 2026. For more context, read the ACSM training guide (2009). However, terms can vary by plan.