Time under contraction is not directly measured in a typical weight training program. Most people really don't even think about the number of seconds a given muscle is forced to work. Indirectly, ...

Boost muscle contraction with isolation exercises. Target your CNS and recruit more muscle fibers for strength and growth.

A certified trainer shares 5 chair exercises that firm inner thigh looseness after 55 better than squats—seated, joint-friendly moves.