AN EXAMINATION OF THE SLOW AND FAST STRETCH SHORTENING CYCLE IN CROSS COUNTRY RUNNERS AND SKIERS

Performance in fast and slow stretch shortening cycle (SSC) activity was examined. 13 NCAA Div. I cross country skiers and runners performed a countermovement jump (CMJ) and a drop jump (DJ) on a force platform. These jumping actions were classified as slow and fast SSC activities respectively based on ground contact times. In the slow SSC subjects achieved significantly greater jump heights while in the fast SSC subjects produced greater peak ground reaction force and measured higher on the reactive strength index. A weak correlation was found between slow SSC and fast SSC ability suggesting that training in slow SSC tasks might not accrue benefit in fast SSC ability and vice versa. Consideration to ground contact duration and the principle of specificity should be given when using the CMJ or the DJ as a testing tool or as a training exercis