Concentric
A concentric muscle action happens when an active muscle shortens as it produces force.
Concentric: a practical example
For example, your elbow flexors act concentrically as you lift a dumbbell in a curl.
Use it in your log
When you log your workout, keep this in mind: the concentric phase is a movement phase, not a separate kind of exercise you must log.
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.