Muscles that can be controlled at will are referred to as voluntary muscles. Those that are not under the control of the will (volition) are called involuntary muscles. Smooth muscles are involuntary muscles.

Involuntary muscles are not under our conscious control which means we can't make them contract when we think about it. Voluntary muscles are under our conscious control so we can move these muscles when we want to. These are the muscles we use to make all the movements needed in physical activity and sport.

Voluntary muscles are skeletal muscles that contract and relax under conscious control. These muscles attach to bones and regulate movement of the body. Involuntary muscles, on the other hand, are not under conscious control.