Isometric exercise

The term "isometric" combines the Greek words isos (equal) and -metria (measuring), meaning that in these exercises the length of the muscle and the angle of the joint do not change, though contraction strength may be varied.

Considered as an action, isometric presses are also of fundamental importance to the body's ability to prepare itself to perform immediately subsequent power movements.

For example, in a bench press set-up the barbell can be held in a fixed position and neither pushed upwards nor allowed to descend.

In addition, when a subject performs a dynamic movement, supportive muscle groups can work isometrically.

Whilst this may be considered to be an isometric hold, there is also an amount of dynamic movement as the skier alters how deep the crouch is during their travel.

As the bent legs resist the downward force upon them in equal measure, an isometric press is generated.

[3] The employment of isometric presses in order to aid explosive power movements is also found in sports such as boxing.

The boxer then throws a lead hook from this position and the forces from the isometric press are channelled into the punch and help to increase its overall power.

[4] Such a channelling of force fundamentally represents the purpose of an isometric preload: which is as a preparatory action to aid a subsequent power movement.

In the 1950s, German scientists Dr. Erich Albert Müller[6] and Theodor Hettinger[7] "observed that contractions involving less than about one third of maximum strength do not train the muscle.

[11] Isometric exercises were first brought to the modern American public's attention in the early days of physical culture, the precursor to bodybuilding.

[15] NASA has researched the use of isometrics in preventing muscle atrophy experienced by astronauts as a result of living in a zero gravity environment.