Why Do You Feel Sore After Exercising?

If you’re a regular at your local gym, then you’ve likely figured out the ins and outs of exercise, as well as how to do it safely without hurting yourself. Even so, when you try to push yourself particularly hard during a given workout session, you know that you’re “going to feel that in the morning.”

This is even more true for people who infrequently work out and decide to eagerly jump in before their bodies have become accustomed to the rigors of exercise.

Whether you’re an expert or a novice, it’s not uncommon for your muscles to be sore following an intense workout, which is called Delayed Onset Muscle Soreness (DOMS). However, don’t worry too much, as it’s an important part of the process of muscle growth and improvement!

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The Definition of DOMS

First of all, DOMS is not the temporary pain/tiredness you experience during and directly after a workout. In fact, DOMS mainly affects the body 24-72 hours after your workout is finished.

When you push your muscles past their normal range of activity, you actually do damage to the existing muscle you have, but the damage is in the form of microfractures in the muscle fibers themselves. When you are squeezing out the last bit of energy during an intense bench press session, it feels satisfying to hit your goal, but that strain is causing tears in the tissue that your body will need to fix.


Muscle soreness following exercise was thought to be a result of the build-up of lactic acid in the body for many years, but in fact, lactic acid can be used as a fuel source by the body during an intense workout, and is typically gone from the body within an hour or two of the workout. A day later, however, the sensitivity of those muscle’s nociceptors (pain receptors) will be heightened, which is why you feel that aching, stiffness, or soreness in those affected areas. The sensitivity of those pain receptors will decrease as the muscle tissues heal.

While DOMS might be irritating, it’s also a sign that you’re moving in the right direction! DOMS is essentially your body saying that it’s building muscle, because those tiny microfractures in the connective tissue near the muscles must be rebuilt. Satellite cells in the muscles act like stem cells, adding more nuclei to muscle fibers. New muscle proteins must be synthesized and gathered in myofibrils (protein strands). Those microfractures are “sealed” up, but the muscle fibers are now slightly larger and thicker, making them more resistant to similar damage again.

Muscle Man (Photo Credit: tsuneomp / Fotolia)

Muscle Man (Photo Credit: tsuneomp / Fotolia)

The next time you go back to the gym and perform a workout of a similar intensity, you will not suffer from the same level of muscle soreness or DOMS, provided the next workout occurs within a few days to a week. DOMS signals that you have reached a new plateau for that muscle group, and studies show that as long as the intensity of your next workouts are within 10% of that newly established intensity, you won’t experience that same painful repercussion.

Are There Any Ways to Avoid or Moderate DOMS?

As we’ve just explained, DOMS means that you’re seeing real improvement in your body, but it can still be uncomfortable, and people would prefer the boosted muscle growth without a day or two of aching muscles. Fortunately, there are a few ways to avoid DOMS, as well as ways to handle DOMS when it does occur.

Lazy red panda meme

Photo Credit : Wikipedia

Stretching is always suggested before an exercise session, because it will warm up the muscle fibers and prepare them for any strenuous exercise; this will make microfractures less likely, and also increase the endurance and flexibility of those muscles. Your muscle tissue will still tear and improve, but the pain and inflammation is shown to be reduced. A similar effect can be achieved if you include extensive warm-up periods before your full workout.

Some researchers suggest that high-intensity, short-duration workouts can help to prevent DOMS from occurring. Essentially, the body begins to develop exercise-induced analgesia, meaning that it prevents the onset of pain because it has experienced and learned from those rapid bursts of intense exercise in the past.

Classic treatments for muscle pain are still highly effective, including sitting in saunas, taking hot baths, and getting massages, as this will push blood to muscle cells and tissues, speeding up the healing process and lowering the sensitivity of nociceptors in those areas.

Next time you really push yourself at the gym, don’t be surprised if you suffer from some serious DOMS a day or two later. Just remember the classic exercise mantra – No Pain, No Gain!

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About the Author

John Staughton is a traveling writer, editor, publisher and photographer who earned his English and Integrative Biology degrees from the University of Illinois. He is the co-founder of a literary journal, Sheriff Nottingham, and the Content Director for Stain’d Arts, an arts nonprofit based in Denver. On a perpetual journey towards the idea of home, he uses words to educate, inspire, uplift and evolve.

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