EXERCISE INDUCED MUSCLE DAMAGE

Delayed onset muscle soreness (DOMS) is the most common and probably the most noticeable symptom of EIMD that an athlete will incur. Post exercise muscle soreness can be as delayed as 24 hours to commence and can then last up to 4 or 5 days in some severe cases with the peak pain generally coming between 24 and 48 hours (Clarkson, Nosaka, & Braun, 1992; Jones, Newham, & Torgan, 1989). DOMS will often radiate out of the main area of work to surrounding muscles and even completely different body parts where not much work was being done. However DOMS is not a good measurement of EIMD severity as it has a different time frame of starting, time to peak and finishing than the symptoms strength loss and visible tissue damage. DOMS has also been found to have no affect on performance (Jones, Newham, Round, & Tolfree, 1986; Prasartwuth, Taylor, & Gandevia, 2005).

 

Swelling and reduced flexibility will undoubtedly occur after tissue damage and the inflammatory response has begun. Although not a good measurement of the severity of EIMD the reduction in movement will have an effect on performance even if just an increase in warm up is needed.

 

Increase in creatine kinase (CK) is a measurable indicator of EIMD. As stated earlier blood protein levels increase due to the inflammatory response and so not only are a symptom but a way to judge EIMD severity. The most commonly measured blood protein is CK with peak levels usually seen between 24 and 48 hours. Although in some instances a delayed response has been found with CK levels peaking between 4 and 5 days after exercise (Davies, 2010) lowering its efficacy as an indicator of EIMD.

 

REDUCED STRENGTH is the most effective way to assess the impact EIMD has had on the bodies function. Studies have shown no difference in the effect EIMD has between the 3 types of muscle contraction so a simple isometric strength test will be fine although a test of any contraction type will suffice (Warren, Lowe, & Armstrong, 1999). A loss of up to 50% of force when compared to pre exercise values has been found in some cases with a typical loss in force being between 10% and 30% (Byrne & Eston, 2002; Sanchis Moysi et al., 2005; Saxton et al., 1995).The greatest loss of force will generally be found immediately after EIMD has been induced with a linear recovery, the loss of force can last up to 1 week in extreme cases (Byrne & Eston, 2002; Sanchis Moysi et al., 2005; Saxton et al., 1995).