Something that is isometric maintains the same length or size regardless of its position. Isometric exercises are therefore exercises in which the muscles contract against a force, but there is no movement of the joint(s) that the muscle crosses. There may be increasing muscle tension as the load is increased, but still no movement. Isometric exercises are normally undertaken by progressively pushing or pulling steadily harder against an immovable object.
(Last modified: 7th Oct 2014)