Why Do Muscles Get Sore After Exercise?
Unaccustomed, strenuous exercise commonly causes muscle pain or soreness. When a high demand is put on the muscle for long periods of time, the strain becomes too much for the individual muscle cells and they can become damaged. Small fibers within the cells can be pulled out of place and the membrane surrounding each cell can tear. Once this damage occurs, the body must act to repair it. An immune response mounts, increasing circulation and inflammatory cells to the damage to clean out the non-working cells and stimulate growth. This process is what causes muscle soreness for hours to days after a difficult workout, often called delayed onset muscle soreness (DOMS).
