Specificity Principle

The Specificity Principle is a principle that states that exercising a certain body part, component of the body, or particular skill primarily develops that part or skill. In relation to the body, in order for one to train the pectorals, for example, one must use exercises which activate the pectorals; performing squats in this instance will be ineffective.

In relation to skill, the Principle of Specificity implies that, to become better at a particular exercise or skill, one should perform that exercise or skill. For example, a runner should run to improve running performance. For a runner, exercises like swimming or cycling may have mixed effects: they may help by improving general cardiovascular endurance and burning off fat, but it may also harm performance by increasing the size and weight of muscles which aren't crucial to running.

other possible sites that may be useful for you to read are

• SAID Principle
• General Adaptation Principle