Strength of muscle work-Muscle contraction

Question

To raise strength of the muscle work is the muscle contraction intensely raised?

Answer 1

Raise in strength of muscle work is not accomplished by raise in the intensity of stimulation of each muscle fiber. Muscle fiber obeys an all-or-nothing rule, that is, its contraction strength is only one and can’t be raised.

When the body requires raise the strength of muscle work a phenomenon recognized as spatial summation takes place: new muscle fibers are recruited in addition to fibers already in action. So strength of muscle contraction rises only when the number of the active muscle cells raises.