Delayed-onset muscle soreness

It is common for people to experience some form of muscular pain or discomfort about 16-24 hours after an intense workout. This phenomenon is called delayed-onset muscle soreness (DOMS) and it usually peaks about 24-48 hours post-exercise before starting to diminish. The severity depends on fitness level of individuals and workout intensity. Though normally it will disappear within 72 hours, it may last several days in cases of more severe damage.

The main cause of DOMS is muscle fibre damage that may include tension-induced disruption of the sacromeres and sarcolemma, and increased intracellular calcium. Eccentric contractions are much more likely to cause DOMS than static or concentric muscle contractions. DOMS is often associated with resistance exercises but endurance-type exercises with a significant eccentric component (for example, running downhill) can cause DOMs as well. So for strength athletes looking into using resistance exercises for their cardio workout but would rather not induce further muscle damage, they could consider eccentric-less exercises such as sled pushing/pulling and medicine ball throws.

The most effective means of reducing DOMS is to exercise regularly. This repeated bout effect explains that even a single bout of exercise has a significant protective effect against DOMS during subsequent bouts of similar exercise. Therefore, it is important to engage in regular exercise as well as active recovery in-between sessions. Apart from working out regularly and avoiding long breaks (more than 1-2 weeks), I would go for a swim or play basketball at an easy-moderate pace on my rest days as part of my recovery.

Non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin and muscle cream/rub reduce the pain associated with DOMS but longer-term use may be counter-effective. It would be advisable to avoid regular use of such drugs.

References:

Antonio, J., Kalman, D., Stout, J. R., Greenwood, M., Willoughby, D. S., & Haff, G. G. (Eds.). (2008). Skeletal Muscle Plasticity. In A. Chromiak, J.A. and Antonio, J (Eds.), Essentials of sports nutrition and supplements (pp. 40-41). Chapter Humana Press.