Why You Shouldn't Train When You're Sick

The days are shorter, the nights are colder, and there is a crisp chill in the air.  This means that down here in the Southern Hemisphere, cold and flu season is here. This begs the question - should you exercise when sick?

Now, before I tell you all about my top nutrients for immune support (stay tuned for a later blog), I want to talk about the second most popular question my athletic and sporty clients ask me at this time of year ...
“Can I train if I’m sick with...?”
Often, I’ve got an athlete sitting opposite me who is asking if they can train or compete with a cold, flu, or infection.

And whilst everyone experiences colds and flu differently, I do have some general rules I ask my clients to consider.

Is it above or below?

A general rule of thumb I offer is; if the symptoms are limited to above the neck, you may consider a workout.

Any symptoms below the neck (or systemic, like fever), I recommend you give yourself a couple of rest days.

Above the neck

Symptoms above the neck include those you may have with a common cold, such as:
  • a runny nose
  • nasal congestion
  • sneezing
  • or minor sore throat.
One caveat though. Please remember, even a common cold is contagious and can affect everyone differently.

If you choose to work out with above the neck symptoms, consider doing so from home and lighten the intensity and duration

Below the neck

At the other end of the spectrum, we have below the neck signs and symptoms. These include coughs of all shapes and sizes, from dry hacking to productive.

It also includes:
  • muscle aches and pains
  • fever
  • fatigue
  • dizziness
  • and any gastro symptoms.
If you have any below the neck symptoms, I strongly advise that you take a rest day, or sit out of the event/race you’re scheduled to do.

Don’t spread your germs

There’s nothing grosser than having the person next to you at the gym hacking and sneezing away.

If you choose to work out whilst you’re unwell, please take a moment to think about your fellow training buddies or gym sharers.

Even with COVID regulations stipulating that folks with cough or cold symptoms do not enter, I know full well there are folks who ‘soldier on’ and keep training.

Whilst this attitude is potentially dangerous to yourself, you’re also knowingly exposing a lot of other folks to your cold or flu germs.

So, if you’re going to work out with above the neck signs and symptoms, try an online workout at home. Since the advent of COVID, there are no shortages of excellent resources online.

You give me fever...

I’ve already touched on fever, above. Fever is a systemic sign, making it a “below the neck” symptom. Whilst fevers can be a sign of many things, they are often a sign of viral or bacterial infection.

Fever is when the body raises the temperature to help combat whatever is overwhelming it. When you have a fever, you may also experience dizziness and fatigue.

There are a few reasons why you shouldn’t train or compete when you have a fever.

Body temperature

First, exercise raises our body temperature.If you already have a temp, and you get hot and sweaty in the gym, you may pop yourself into the dangerous temperature zone. This can increase your risk of fainting or other more dangerous outcomes.

Decrease in strength and coordination

During a fever, we also have a decrease in muscle strength and coordination. Having reduced reaction time, balance, coordination and strength whilst training, particularly during a weight session, can lead to poor technique and may result in injury.


And finally, fever increases the risk of dehydration. And training and sweating will only compound dehydration, which leads to further complications.

To put it simply, if you have a fever - don’t work out – have a rest day!

Worried about your gains?

Many folks think that by taking a day or two off when they’re unwell (or even in general!) that they’ll lose all their hard work in the gym.  They worry their muscles will atrophy or their cardiovascular fitness will decrease.

There have been many studies that found muscle strength only starts declining after 10 days off, and muscle size only starts shrinking after 3 weeks off. So please bear this in mind.

It’s so important to give your body adequate rest and time off when you’re unwell so that it’s ready to start growing and improving once you’re able to get back to it.

Coming back too soon after illness means your body just won’t have the fuel, energy, and strength to work on fighting illness, recovering from illness, as well as recovering and growing post-training.

Listen to your body

So, this month I invite you to really listen to your body. Does it need a rest day? Would training today actually be a hindrance to fitness, as opposed to a benefit?

If you’re not sure whether you should exercise while sick, imagine if sick you were training next to you at the gym.

Would you be grossed out, worried, or concerned about them? If yes, it’s a rest day!

If you’re finding you’re constantly getting colds or flus, and it’s affecting your training and events, it might be time to dive a bit deeper.

**NOTE not sure if you want to promo 1:1 consults or not? I am currently taking on more clients for 1:1 private consultation. Reach out here.