Weight and plyometric training: effects on eccentric and concentric force production.

The study was performed in an effort to gain greater insights into the adaptations invoked by plyometric and weight training. Forty-one previously trained males were randomly allocated in either a control, plyometric, or weight-training group. The experimental groups trained for 8 weeks, performing either heavy lifts or dynamic plyometric exercises. The following test items were performed prior to and at the completion of the training period: (a) vertical jump, (b) a series of isoinertial concentric and eccentric tests, (c) push-up tests, and (d) maximal bench press and squat lifts. Plyometric training significantly enhanced the rate of eccentric lower body force production. The weight-training group primarily enhanced concentric function. These results were attributed to the specific stresses imposed by the differing forms of training and are discussed with reference to methods of enhancing training induced adaptations and the types of movements such training would tend to facilitate.