The Movement Doctor

Concentric or eccentric training?

Maybe the better question is: do coaches actually understand that muscles almost never function as purely concentric or purely eccentric in real movement?

In the weight room, those terms are useful for teaching tempo or describing a lift. But in authentic movement, tissue has a three-dimensional responsibility. A muscle can be lengthening in one plane, shortening in another, and stabilizing or decelerating in a third — all at the same time.

That is why the Gray Institute concept of econcentric function matters.

The body does not think, “I’m doing an eccentric rep now.” It reacts to gravity, ground reaction force, momentum, mass, and task demand. Muscles are turned on by motion. They load to explode. They decelerate one segment to accelerate another. That happens through the whole chain, not in isolated muscle actions.

So when coaches only chase “eccentric training” or “concentric power,” they may be missing the bigger truth:

The body trains in transformational zones, not textbook contractions.

A lunge, cut, throw, jump, sprint, or change of direction is not simply eccentric then concentric. It is tri-plane loading and unloading. The tissue is constantly managing sagittal, frontal, and transverse plane motion simultaneously.

So yes, eccentric and concentric language has value. But if a coach does not understand econcentric, chain-reactive, task-specific function, they are probably training muscles more like parts on a machine than tissues inside a living, reacting human being.