One of my client asked me another day, why her muscles feel sore day or couple day after training, why not immediately? Simple answer is because it DOMS, but in the reality what is DOMS or what cause it?

DOMS means Delayed onset muscle soreness, it normally appears 24 to 72 hours after exercise. You might notice how your muscles feel sore, and sitting down or climbing the stairs feel difficult, day after the exercise. This basically DOMS.

My muscles are sore, so they are building more muscles, right? Actually no, DOMS can improve muscle growth, but not to a large extent. Muscle hypertrophy mechanism increases muscle, its most central mechanisms are mechanical tension, metabolic stress and muscle damage. Although DOMS causes muscle damages, it can also be disadvantageous, as tired and sore muscles cannot produce enough strength which interfere performance, which, in turn, slows down the muscle development.

What cause DOMS?
DOMS is caused by microtrauma which occur during exercise, the most DOMS cause eccentric training (lengthening). During eccentric exercise, the actin and myosin cross-bridges are distinguished, which causes greater tension for the active motor units. This leads to enlargement and degradation of the sarcomere, resulting in microtrauma in the muscle tissue, which leads the feel of pain.
“Enzyme efflux” is another theory that would cause DOMS. Accordingly, calcium would be stuck in microtraums, which would cause proteases and phospholipids break down and degeneration of muscle protein.
Also isometric training (static) cause much less DOMS.

What does not cause DOMS?
Concentric exercise (shortening) doesn’t cause DOMS.
Lactic acid does not cause DOMS, although in the past it was though so, but lactic acid levels return to the normal level much faster normally within hour.

What you can do?
Increasing training load slowly decrease DOMS possibility. DOMS often disappear within 72 hours, so you do not have to do anything. Sauna, massage, hot bath, low intensity exercise or anything where your blood flow increase might help with recovery.