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Exercise is Medicine: Delayed Onset Muscle Soreness
Author: Dr. Melissa Janse van Vuren
Published: 07/10/2020

So, I think it's safe to assume that almost all of us at one stage or another have woken up, tried to move and been like, “What the heck have I done?" As we lie there willing our aching muscles to move, we try and figure out what activity we did over the last couple of days could have possibly resulted in our current almost incapacitated state. Sometimes the answer is straight-forward and it was simply a new type of exercise we tried that our bodies are unaccustomed to. Or it could even be the result of one of those super-hero moments where we try and relive our glory days, for example trying to prove to your children that you can still do more push-ups or sprint faster than they can even though you haven't trained in 10 years. The result is the same – severe stiffness and pain, and that familiar feeling of regret of why did I push so hard or what was I really trying to prove.

Today, I want to shed some light on a topic many people may not be familiar with. Delayed onset muscle soreness or DOMS, can be a bit technical to understand but I will try and relate it to terms that we are all familiar with.

Let's start by first recapping how muscles work. Basically, our muscles are made up of millions of tiny little strands that overlap each other, and form bigger and bigger bundles that eventually make up the big muscle groups that we can see. At a microscopic level, those tiny fibres, known as filaments, work according to the “sliding-filament theory." Since this isn't a physiology lecture, I'm just going to broadly try and explain it. As your muscles shorten or lengthen, for instance doing a bicep curl or even lifting a fork to your mouth, these tiny filaments slide over each other. For them to work optimally, there has to be a certain degree of contact (just think of gripping someone's hand - in order for there to be a strong grip the majority of the hand has to be in contact with each other.) DOMS comes into play when we overwork our muscles at a length that they aren't trained in, again if you try and imagine helping someone up from the ground with only the tips of your fingers touching. It will be very difficult and sometimes even painful. While doing these actions, our muscles are overstretched at a microscopic level and cause some damage and inflammation, which leads to pain and stiffness and sometimes even swelling.

The exact start, duration and extent of the symptoms you may experience may differ from person to person and also depend on the type of exercise you did. The pain typically peaks one to three days after the exercise and may last up to a week. The swelling may be a little delayed and is usually worse between days two to five, and it may be difficult to move those body parts and they can even feel tight. In the first few days, it may also feel like those muscles just don't want to work properly. These symptoms usually resolve spontaneously within a week or so.

There are also certain types of exercises that seem specifically prone to causing DOMS. I can use myself as an example. About two months ago, I decided to do a home workout to mix it up a little. I did CrossFit for about two and a half years and loved it, so I am quite familiar with push-ups and burpees etc. and this workout happened to have a lot of them. Even though I have mostly been doing trail running and swimming the last year or so, I was quite confident that I could do a few push-ups. 150 push-ups later, I was a bit sore and could feel my arms were burning but I didn't pay too much attention to it. The next day I could feel I was stiffening up, but the day after… oh dear… I couldn't fully bend or straighten my arms. I even had difficulty writing or feeding myself. It was agony, but there was a lot to learn from this experience, and that takes me back to the certain types of exercise that are more likely to lead to an episode of DOMS.

When we use our muscles, they can either shorten, stay the same length or lengthen as they produce power. Let's take those push-ups for example. As you go down in the push up, your tricep muscles lengthen, if you pause at the bottom of your push-up, they are still producing power or force to keep you there even though you aren't moving, and then they shorten again as you push yourself up. It's been found these lengthening or more specifically eccentric exercises, require a lot more strength to perform and are much more likely to cause DOMS. You can also get DOMS doing exercises that you are unfamiliar with and use muscle groups that aren't used to moving that way or even when you just push yourself way too hard that day doing exercises you are used to and overexert yourself.

Ok, so you might be thinking, “Enough about the theory, I'm in pain and what do I do about it?" First, as always, prevention is better than cure. When starting a new form of exercise, start slow and don't push too hard in the beginning. Even though you might not feel so tired, your muscles need time to adapt, especially when doing those eccentric type of exercises. Another tip is to stretch and keep supple as you train.

Now regarding treatment: fortunately, DOMS usually resolves spontaneously, but it often helps to stretch gently before you move. Keep moving through the discomfort and keep exercising but to reduce the intensity of your training for at least one to two days. Anti-inflammatories play a small role but timing is crucial, and as with any medication there are risks and side effects and I would advise rather to use it as directed by a medical practitioner. Heat and cold therapy have also shown to alleviate some of the discomfort and a visit to one of our friendly physiotherapists for a good massage will also help to get you through these tough times.

When should you be concerned? DOMS shouldn't give you what we call systemic symptoms. You shouldn't become feverish, disorientated or confused or be short of breath. You shouldn't see any blood in your urine either. DOMS usually affects both limbs (unless you were doing single arm bicep curls!). If only one limb is sore and swollen, or if you have a history of blood clotting problems and in the cases discussed above, rather seek medical advice or give Campus Health Service a call.

Experiencing DOMS is no reason to stop training even though it can be really painful. Sometimes you might need a bit of guidance and advice to approach exercise in a different way. At CHS, we would love to support you as you journey towards a better, fitter healthier you, so if you are concerned rather chat to us and we will help in some way or another. In the famous words of Bruce Lee – “If you always put a limit on everything you do, it will spread into your work and into your life. There are no limits. There are only plateaus, and you must not stay there, you must go beyond them."

Keep safe and love yourself enough to keep exercising – you deserve it!


  1. Schwellnus M. The Olympic textbook of medicine in sport. Oxford: Wiley-Blackwell; 2008.