eccentric

Examples of eccentric in the following topics:

• Exercise-Induced Muscle Damage

  • Exercise damages muscles due to eccentric and concentric muscle loading and often results in delayed onset muscle soreness (DOMS).
  • Exercise damages muscles due to eccentric and concentric muscle loading.
  • Resistance training, and particularly high loading during eccentric contractions, results in delayed onset muscle soreness (DOMS).
  • Acute inflammation of the muscle cells, as understood in exercise physiology, can result after induced eccentric and concentric muscle training.
  • Participation in eccentric training and conditioning, including resistance training and activities that emphasize eccentric lengthening of the muscle including downhill running on a moderate to high incline can result in considerable soreness within 24 to 48 hours, even though blood lactate levels, previously thought to cause muscle soreness, were much higher with level running.

• Types of Muscle Contractions: Isotonic and Isometric

  • Isotonic muscle contractions can be either concentric or eccentric.
  • An eccentric contraction results in the elongation of a muscle while the muscle is still generating force; in effect, resistance is greater than force generated.
  • For example, a voluntary eccentric contraction would be the controlled lowering of the heavy weight raised during the above concentric contraction.
  • An involuntary eccentric contraction may occur when a weight is too great for a muscle to bear and so it is slowly lowered while under tension.
  • An isotonic concentric contraction results in the muscle shortening, an isotonic eccentric contraction results in the muscle lengthening.

• Impacts of Exercise on Muscles

  • Muscle soreness, once thought to be due to lactic acid accumulation, has more recently been attributed to small tearing, or micro-trauma, of the muscles fibers caused by eccentric contraction.
  • With repeated cycles of eccentric contraction this soreness will be reduced.

• Creatine Supplementation

  • Exercise resulting in eccentric contractions at high loading can cause muscle soreness, indicative of muscle tearing, and reduced or impaired muscle function.
  • This is specifically caused by eccentric exercise altering muscle ultrastructure and sarcoplasmic reticulum functioning.

• Shin Splint Syndrome

  • With repetitive stress, the impact forces eccentrically fatigue the soleus and create repeated tibial bending or bowing; thus, contributing to MTSS.