The effect of exercise-induced muscle damage on isometric and dynamic knee extensor strength and vertical jump performance

J Sports Sci. 2002 May;20(5):417-25. doi: 10.1080/026404102317366672.


In this study, we assessed the effect of exercise-induced muscle damage on knee extensor muscle strength during isometric, concentric and eccentric actions at 1.57 rad x s(-1) and vertical jump performance under conditions of squat jump, countermovement jump and drop jump. The eight participants (5 males, 3 females) were aged 29.5+/-7.1 years (mean +/- s). These variables, together with plasma creatine kinase (CK), were measured before, 1 h after and 1, 2, 3, 4 and 7 days after a bout of muscle damaging exercise: 100 barbell squats (10 sets x 10 repetitions at 70% body mass load). Strength was reduced for 4 days (P< 0.05) but no significant differences (P> 0.05) were apparent in the magnitude or rate of recovery of strength between isometric, concentric and eccentric muscle actions. The overall decline in vertical jump performance was dependent on jump method: squat jump performance was affected to a greater extent than countermovement (91.6+/-1.1% vs 95.2+/-1.3% of pre-exercise values, P< 0.05) and drop jump (95.2+/-1.4%, P< 0.05) performance. Creatine kinase was elevated (P < 0.05) above baseline 1 h after exercise, peaked on day 1 and remained significantly elevated on days 2 and 3. Strength loss after exercise-induced muscle damage was independent of the muscle action being performed. However, the impairment of muscle function was attenuated when the stretch-shortening cycle was used in vertical jumping performance.

MeSH terms

  • Adult
  • Creatine Kinase / metabolism
  • Exercise / physiology*
  • Female
  • Humans
  • Isometric Contraction / physiology*
  • Knee Injuries / physiopathology*
  • Knee Joint / physiology
  • Male
  • Movement / physiology*
  • Muscle, Skeletal / injuries*
  • Muscle, Skeletal / physiopathology*
  • Recovery of Function / physiology
  • Task Performance and Analysis


  • Creatine Kinase