Metabolic reaction after concentric and eccentric endurance-exercise of the knee and ankle

Med Sci Sports Exerc. 2001 May;33(5):791-5. doi: 10.1097/00005768-200105000-00018.


Purpose: Power training plays an essential part in many sport disciplines. The importance of eccentric power training remains a matter of controversial discussion. The objective of this study was therefore to investigate the difference in metabolic reaction between eccentric and concentric stress in comparable work.

Methods: Sixty-four men between 22 and 60 yr of age performed maximum isokinetic 1-min endurance tests of the knee and ankle each in concentric (180 degrees.s-1) and eccentric (60 degrees.s-1) modes with comparable total area of contraction-time curve (NS). Higher strength values (mean peak torque, P < 0.01), lower fatigue (fatigue index, P < 0.001), lower increase in lactate (P < 0.01), and lower ammonia production (P < 0.01) were found in eccentric than in concentric exercise, independent of the joint. The eccentric form of stress showed lower decrease and thus age-dependence in maximum strength and in fatigue than the concentric form.

Results: The results permit the conclusion that eccentric exercise leads to less fatigue and lower lactate and ammonia reaction than concentric exercise in comparable work levels. Variable visco-elastic properties of the muscle fibers themselves with additive passive strength in eccentric mode is considered as the cause.

Conclusions: It remains uncertain whether the lower metabolic stress might be useful during the training process. A greater scope of training and increased number of training stimuli might be applied in primarily eccentric forms of exercise.

MeSH terms

  • Adaptation, Physiological
  • Adult
  • Ammonia / metabolism
  • Humans
  • Lactic Acid / blood*
  • Male
  • Middle Aged
  • Muscle Fatigue / physiology*
  • Weight Lifting / physiology*


  • Lactic Acid
  • Ammonia