STRETCH-SHORTENING CYCLE FATIGUE DECREASES PERFORMANCE BUT INCREASES PERFORMANCE AT THE END OF RECOVERY
Cheilleachair, N. N., & Harrison, A. (2010). The acute effects of maximal fatigue on the subsequent performance of endurance trained athletes. Presentation 700 at the 2010 Annual Meeting of the American College of Sports Medicine, Baltimore, Maryland; June 2-5.
This study investigated the acute effects of maximal stretch-shortening cycle fatigue on the subsequent performance of endurance trained athletes (N = 9) and the pattern of recovery. Ss performed four initial sets of drop and rebound jumps on a sledge and force plate apparatus in order to establish baseline performances. A maximal stretch-shortening cycle fatigue protocol was then performed; consisting of consecutive rebound jumps to a height of 90% of maximum baseline jump until the target on three consecutive jumps could not be reached. This was followed immediately by one set of drop and rebound jumps at 15, 45, 120, 300, and 600 seconds post-fatigue. Measurements of peak ground reaction force, ground contact time, jump height, reactive strength index, and leg spring stiffness were calculated for each drop jump and rebound jump. All recovery interval jumps were analyzed and Sís minimum and maximum post-fatigue jumps were further analyzed.
The fatigue protocol resulted in a significant reduction in jump height and reactive strength index in the drop jump and a significant reduction in ground reaction force, jump height, and reactive strength index in the rebound jump. The maximal fatigue workout also resulted in performance potentiation. During the latter recovery intervals, after fatigue had subsided, there was a significant improvement in performance in leg spring stiffness in the drop jump and in ground reaction force and leg spring stiffness in the rebound jump. This response was individual and occurred at either 300 or 600 seconds post-fatigue.
Implication. Exhausting stretch-shortening cycle exercise induces a clear and immediate decrease in jumping performance and the biomechanical process of the jumps in endurance trained athletes. However, maximal stretch-shortening cycle fatigue can also result in a potentiation affect in endurance athletes in the latter stages of recovery. [This is one reason not to participate in highly fatiguing land exercises before training for endurance events such as swimming.]
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