Why Do Muscles Get Sore From Exercise?

Sore muscles post exercise is something that pretty much all of us have dealt with before. And although some of us dread the thought of being unable to walk properly for days, others crave this feeling because it provides reassurance that they pushed themselves hard enough in the gym. In this article, I am going to explain why our muscles get sore post exercise, and how you can induce it (or avoid inducing it) from a scientific perspective.

In the scientific community & fitness world, this phenomenon has been termed as Delayed Onset Muscle Soreness, or DOMS for short. Believe it or not DOMS is actually classified as a muscle strain; meaning it is similar to a pulled muscle. But instead of a substantial muscle pull or tear, DOMS is a result of many very tiny tears within the muscle called micro tears. These micro tears trigger the start of many different body processes such as protein synthesis, inflammation, myofibril repair, and fiber regeneration which promote healing to the region.

Once these kick in and your adrenaline high wears off after approximately 12-48 hours post workout, the DOMS makes its presence known on whatever muscles were targeted. DOMS typically sticks around anywhere from 2-7 days depending on the quantity & severity of the micro tears & how quickly your muscles are able to repair themselves. Knowing how this works is cool, but can you induce or suppress DOMS on your own?

In many cases, DOMS is triggered by intense, unfamiliar exercise. But your body is pretty good at adjusting to new exercises after just one exposure. Meaning that doing the same workout later probably won’t trigger the same result. The secret to regularly triggering DOMS is frequent eccentric muscle contraction. Eccentric muscle contraction represents the lengthening of muscle during a lift such as the down phase of a bicep curl, squat, deadlift or just about any other exercise you can think of. During eccentric movement, your muscle is still working and you can see for yourself the difference between lifting with and without it. Exercises such as downhill running, step ups and resistance cycling have been widely used by researchers to trigger DOMS in their test subjects.

To trigger muscle soreness, you need more eccentric muscle contraction in your workouts. You can do this many ways by including pause work, slow sets, or negatives.  Pretty much any way you intensify the eccentric portion of a lift will lead to that soreness you either crave (or detest).