Many programs or fitness classes refer to using plyos, which is short for plyometrics. Looking at the etiology of the word, ‘plyo’ (from pleio) is a pre-fix for “more” and metric refers to length; therefore, plyometric means “more length.” This describes the physiological affect of the involved muscles during jump training (the most common application for the lower body) or explosive movements such as medicine ball throws (often used for upper-body plyometric training).

Plyometric training was developed by Soviet sport scientists who originally referred to it as “shock training” because of the high forces experienced by the involved tissue. That’s why it’s important to perform only a few repetitions at a time to achieve the highest level of force output possible. Any program requiring participants to perform more than five or six rapid movements (i.e., jumps or explosive lifts) in a row can significantly increase the risk of injury by placing too much force on the involved tissue.