Developing the ability to activate a muscle group through controlled eccentric movements may take several weeks to months, and should eventually be integrated with concentric and isometric contractions.

“Keep down that path and eventually work that into a progression where you can do the concentric, eccentric, and isometric portions and get activation. So that that may take you six weeks, may take you six months, but that's generally a pretty good strategy for learning how to activate a muscle group.”