The DOMS or Delayed Onset Muscle Soreness explained!
DOMS is caused by localised micro trauma to the muscles fibres, owing to the increased use of the muscles, and so tiny microscopic tears occur in the muscle fibres plus the connective tissue that binds all our muscle fibres together is broken down. So the muscle fibres need to heal and the body’s first response to start the healing process is inflammation, which causes heat, redness, swelling and then this is followed by an increase in circulatory and fluid activity. All of these together put pressure on our pain receptors and so this is the ache/soreness that we feel. The healing process starts of slowly in the first 24 hours and is at full pelt from day 2 onwards so this is why we may feel more achy/ sore 1-2 days after exercise.
Interestingly, it is scientifically proven that DOMS is felt more where there is an increase in muscle tension by lengthening the muscle (this is called an eccentric movement) and for example occurs in the calves or hamstrings when we are running (in the push off phase as we leave the ground) or the quadriceps slowing us down as we run downhill, or rising from a squat, lowering a dumbbell after a bicep curl or controlling the lowering after a dead lift.
DOMS and building Muscle Strength - this is also a key part of our healing process after exercise, our body reacts to the increased load and stress the muscles have been put through by activating the release of growth factors involved in muscle development. So this is a growth response to increased activity and this is how our muscles build strength. Our body responds and adapts by strengthening the ability of our muscles to withstand future muscle damage. (Please note though that causing muscle soreness to the point where we can’t even lift our arm, or walk, is too much!!!!! and this can actually be detrimental to muscle growth, causing strains and tears etc. which take longer to heal).