Isometric training (also known as static strength training) involves muscular contractions in which the length of the muscle does not change and there is no visible movement in the joint.
The word ‘contraction’ signifies a change in length (shortening) of a muscle but this does not occur in static strength training so the preferred term is static action not static contraction. Isometric exercises can be performed with ‘sub maximal’ muscle actions – which hold a weight steady on to a side for example. Here the force is not maximal as this would lift the weight further causing movement, change in the muscle length and joint angle. However, isometric exercises can also be maximal such as pushing against an immoveable object (like a wall or heavy weight). Both of these types of isometric action can increase strength and induce muscular hypertrophy although in practice maximal exercises are used for strength and conditioning whereas sub maximal exercises are used for rehabilitation.
Many sports require isometric actions such as climbing, mountain biking, judo, wrestling, skiing, gymnastics and horse riding. But one must be made aware that isometric exercises aren’t the most dynamic actions (which most sports are – running and jumping) so do not increase the limbs maximal velocity and may only strengthen the muscle at the angle at which it is trained.
Isometric resistance in isometric exercises typically involves contractions of the muscle using the body’s own muscles (such as pressing palms together),
structural items like a wall or door, free weights, weights machines and elastic equipment where the weight is in a fixed position
and ressure plate equipment that can give a digital read out of the force, like the iGrip.
Isometric exercises can achieve maximum muscular contraction as opposed to isotonic exercise (weight training).
The workout is much faster. You can do each body part in as little as a minute (with a few seconds rest).
It can gain strength to the isolated areas you specifically trained.