Effect of exhausting stretch-shortening cycle exercise on the time course of mechanical behaviour in the drop jump: possible role of muscle damage

Abstract

The purpose of the present study was to investigate the effect of stretch-shortening-cycle-induced muscle damage on the time course of mechanical behaviour in the drop jump. Ten healthy male subjects performed submaximal stretch-shortening cycle (SSC) exercise on a special sledge apparatus. Exhaustion occurred on average within 3 min. A drop jump (DJ) test from a 50-cm height was performed before and immediately after the sledge exercise as well as 2 h, 2 days and 4 days later. The fatigue exercise showed relatively high blood lactate concentration [12.5 (SD 2.6) mmol x l(-1)] and an increase of serum creatine kinase (CK) activity delayed by 2 days [540 (SD 407) U x l(-1)]. The initial decline in the jump performance (before - immediately after) was related negatively to the early recovery in performance (immediately after 2 h) (P < 0.05). The early recovery of the knee joint moment at the end of stretch showed a negative correlation to the delayed decrease in DJ performance (2 h 2 days) (P < 0.01). Thus, the DJ performance showed an initial decline followed by an early recovery and a secondary decline. Both the initial decline and early recovery in the knee joint moment at the end of stretch were related to the corresponding initial (after 2 h) (P < 0.05) and secondary increases (2 h - 2 days) (P < 0.01) in CK. It is suggested that the early recovery as well as the initial decline in the knee joint function could depend on the degree of muscle damage. Delayed decrease in initial stiffness (2 h - 2 days) was negatively related to the corresponding changes in the knee joint angle at touch down in DJ (P < 0.001). These interactions would imply that the decrease in the stiffness regulation and the modulation of the prelanding motor control might be attributable to secondary muscle damage during 2 days after the SSC exercise. Therefore, it may be suggested that the changes in the DJ performance after the exhausting SSC exercise accompany the progress of muscle damage observed by the corresponding increase in serum CK concentration and the corresponding deterioration of stiffness regulation and motor control in DJ.

An Investigation Into the Recovery Process of a Maximum Stretch-Shortening Cycle Fatigue Protocol on Drop and Rebound Jumps

“…Aspects of the bimodal trend for recovery after a fatigue workout, as indicated by Horita et al (27) and Komi (29), are evident in this study. The initial dramatic decline in DJ and RBJ performances was followed by a gradual improvement in performance at the subsequent recovery intervals up to the point where some variables were enhanced at the 300-second interval.…”

“…Horita et al (27) reported an early recovery 2 hours postfatigue, but no potentiation effect was reported for the DJ. Horita et al (25) again examined the effect of a repeated exhaustive submaximal SSC fatigue protocol on DJs that were performed 20 minutes and 2 and 4 days after the workout.…”

“…Avela and Komi (4), Gollhoffer et al (20,19), and Horita et al (25) reported a reduction in CT postfatigue. Avela and Komi (4), Hortia et al (26,27), and Nicol and Komi (33) indicated that because of submaximal SSC fatigue, the muscle mechanics and joint and muscle stiffness control are hampered. A reduction in force production has been reported by Gollhofer et al (20,19) and Nicol and Komi (33).…”

“…These and other research studies examining SSC fatigue in long distance running (29), have indicated that longer duration of fatiguing exercise often results in a reversible muscle damage process, which has considerable influence on muscle mechanisms, stretch reflex sensitivity (29), and joint and muscle stiffness (21). Various studies (19,20,25,27,30) induced fatigue by repeated submaximal SSC movements to exhaustion on a sledge and force platform ergometer and found that fatigue caused immediate reductions in SSC performance or longer term losses because of muscle damage.…”

Altered neuromuscular control of leg stiffness following soccer-specific exercise

“…For participants who decreased stiffness following exercise this would suggest more of a yielding action during the ground contact phase. Horita et al (1999) demonstrated that short duration exhaustive SSC exercise (3 min) reduced stiffness, increased joint extension at touchdown, thus enabling a greater yielding action. The authors speculated that the observed changes in stiffness were the result of altered prelanding motor commands, which is substantiated by the relationship between changes in feedforward activity and stiffness observed in the present study.…”