We are delivering our fitness and nutrition coaching online to stop the spread of COVID-19. Learn More

Doing Exercise Whilst Sick: Yes or No?

Many of us have likely heard of the concept of ‘sweating out a cold’, but is this just an old (and crucially, unproven) wives’ tale? Or if there is some truth to the idea, when is it ok to work out when under the weather, and how sick is ‘too sick’ to exercise?

If one thing’s for sure, not all colds are created equal and (probably frustratingly) the answer to this burning question contains a hearty portion of ‘it depends’.

The delicate balance

There is always a balance between your body’s ability to perform in physical ability, and your immune system’s ability to fight infection. Think of having a cold as as additional job that your body has to do. It’s already juggling all of the normal functions, including breathing, pumping blood around your body, moving you around, digesting food – so if fighting off infection is also added to the mix, that to-do list is just getting longer, so it’s no wonder we can feel tired and wiped out. Doing physical exercise further adds to that list. Combating illness and exercising are both stressors to the body, so it is unsurprising that in most cases it’s hardly a winning combination for fitness gains or your ability to bounce back from being ill.

Isn’t there such thing as ‘Immune-Boosting’ exercise?

Whilst there is research suggesting that doing light exercise can help boost your immune system over time, but there’s no evidence to suggest that exercising whilst you have a cold will shorten the duration of the illness – so try to think of exercise more as a kind of preventative measure. As a general rule – the fitter and healthier you are to begin with (an in turn, the better shape your immune system is in), the more likely you are to make a swift recovery when you fall ill.

The Feel-Good Factor

That being said, fitness can help you feel better, for all the same reasons that it can when you’re feeling well. Exercising releases a range of hormones and endorphins that have mood boosting effects, and can even act as a natural pain killer, so a bit of gentle exercise could give you that feel good factor, but it’s important to note that this is independent of the cold; it would not actually be battling the cold itself.

Breathe Easy

If you’re simply feeling bunged up and congested, doing a little light exercise outdoors could help temporarily combat some of the symptoms of the common cold. Breathing in fresh (and at this time of year, certainly colder than indoor) air can help open up the nasal passages, so you might consider taking the 5 minute stroll to your local shop to pick up a pack of Lemsip instead of jumping in the car!

Red Flags

Whilst there may be a few positives to doing a some gentle exercise if you’re a little under the weather, there are also times when it’s got to be a firm no from us. Here are some definite red flags when it comes to your illness symptoms that indicate now is not the time to be working out. 


If you are unwell with Covid, we would urge you not to exercise, even at home. Isolation can be incredibly boring, but knowing how symptoms can quickly worsen for some sufferers and present major breathing challenges in the worst cases, now is the time to play it safe (even if you don’t feel you have it that bad) and rest. Rest, rest, rest.


If you have a fever, it will be impacting your body’s ability to regulate temperate to causing you to overheat faster than normal. Working out will further increase your temperature. Not to mention, extra sweating will cause your body to be dehydrated, at a time when you really want to ensure your fluids are topped up. So if you’re battling a raised temperature, avoid the exercise without a doubt. Consider a gentle walk at most, but nothing that will further meddle with your body’s thermostat. 

Stomach Bug

It’s unlikely that you would feel you would want to exercise with a tummy bug, but if you’re tempted, don’t be! Not only could it exacerbate your symptoms, but the bug will likely mean you’re dehydrated and underfueled, so exercising (even at home) is a no go. A gentle walk or stretch will likely do no harm, but certainly avoid getting a sweat on!

No Covid, fever or stomach bug – is that a green light?

Not exactly. Take a step back and look at the bigger picture. Are you well enough to carry on with your other normal daily activities, like going out to work, running errands, picking up the kids from school? If the answer is no, the cross that workout off your to-do list without a doubt. If however you’re just feeling a little under the weather, start with some low-level movement and take it from there. Have you ever been home sick, lying on the sofa and suddenly feeling a lot better.. then you get up and make yourself a drink and find you’re exhausted one again? We’ve all been there. To avoid overdoing it, start by taking a stroll outside and notice how you feel not just immediately after, but a few hours after too. How are your energy levels? If you genuinely feel better for it, perhaps a brisk walk the next day might make you feel good, but keep it low intensity, and be sure to hydrate!

The Bottom Line

Often we can feel like a broken record saying this, but once again, we will conclude by reminding you that every body is different. How fit and healthy we are are prior to getting sick, the state of our immune system and its ability to fend off infection, what other stressors we each have in our lives, and generally how we respond to exercise. It’s good to be aware that even the ‘same cold’ can affect people in different ways, and viruses will change and mutate so your experience after dabbling a bit of fitness last time you were bunged up could have a completely different outcome to the next time you catch a cold. So be aware of your body and what feels good, steer clear of exercise if you have any fo the ‘red flag’ symptoms, and make sure you’re checking the other boxes along the way – keeping hydrated, getting plenty of sleep, and feeding yourself with nutritious food.

Whatever you do… don’t spread it

Regardless fo these person-to-person differences though…one thing we know for certain is that exercising or not, you are guaranteed to risk spreading your germs if you turn up to the gym, rather than staying at home. So if you’re bunged up or coughing and desperate to do some exercise, and know that your body responds well to getting a bit of a sweat on, then by all means give it a go – but please consider everyone else first… and take your low level, immune-boosting exercise outside!

Sources: Various blogs and articles which contain links to the relevant research, which can be found here – Healthline, Precision Nutrition, WebMD, Womens Health



book a
free intro

Talk with a coach about your goals, get the plan to achieve them.