Is it ever safe to work out when you've got a cold? You might be surprised by what two experts have to say

It's that time of year.

Should you ever workout with a cold? A woman stretching
(Image credit: Getty Images)

It's that time of year again: days are getting darker and temperatures colder, prompting thousands around the globe to Google, should you exercise with a cold? It's the age-old conundrum - of knowing what will make you feel better, and what'll ultimately make you feel a lot worse.

Getting ill can be quite annoying, especially if you have a jam-packed schedule and limited time to fit your workouts in. That said, forcing your body through gruelling sessions when it's trying to ward off infection can also make you sicker for longer.

The research on it is mixed, making matters even more confusing. In a landmark 1990s study, doctors gave 50 participants the common cold virus and then split them into two groups. One group did 40 minutes of moderate exercise every other day, and one group didn’t exercise at all. Interestingly, the researchers found no difference in illness length or severity between the two groups - in short, they concluded that working out moderately didn't prolong or exacerbate their colds.

Other research published in 2014 concluded that working out regularly may also prevent you from getting a cold in the first place. 

That said, most medical experts you speak to will generally warn against carrying on your normal workout routine if you're feeling under the weather. Want to know the definitive answer when it comes to knowing when to workout and when to rest? We've asked two top personal trainers for the take, once and for all. Don't miss our guides to cosy cardio and tips for exercising in cold weather, while you're here. 

Should you workout with a cold? A top trainer explains

So... can I workout when I'm ill?

As Chloe Whylie, elite athlete and Fiit trainer, explains, the general rule of thumb when it comes to training with a cold is to give yourself adequate rest to help speed up recovery. "It’s an important balance to strike between staying active and giving your body the rest it needs to recover," she stresses.

She advises the following: "Before hitting the gym or heading out for a run, start with a simple check to understand where your symptoms are."

 She recommends doing a body scan and noting:  

  • If your symptoms are confined to above the neck - think a mild headache, sore throat or slight cold
  • If your symptoms are below the neck, your body aches or you have a fever

If you fall into the former camp, she shares that - generally speaking - it's safe to continue some light to moderate exercise.

Aching or have a fever? Not so much. "Do ensure you're resting your body and taking on fluids to rehydrate," she recommends. Palomie Patel, personal trainer and owner of F45 Camden, agrees, adding: "Symptoms like aching muscles and a rise in body temperature are all warnings that exercise can be left for another day. To add further stress onto the body in the form of physical exercise is a recipe for disaster and leaves you at high risk of being side-lined from doing what you love for longer due to the potential excess fatigue physically and on the body’s nervous system."

Wondering why? Well, when you have a cold your body will be fatigued and your muscles will be inflamed, putting you at high risk of injury, shares the trainer. Bottom line: your body’s signals are your best guide, she stresses. "If you start to feel worse during your workout or experience increased fatigue, stop," she shares. "Pushing through a workout for the sake of working out will only be more of a detriment. The key is to be mindful, adjust your workout accordingly, and most importantly, listen to your body."

Does sweating out a cold work?

Next question, as you'll have heard the age-old myth - does sweating out a cold ever work? "The concept of sweating out a cold comes from the notion of heat being generated through relatively intensive exercise," explains xxx. "The theory is that it can work to flush out toxins in the body through perspiration (aka sweat) and speed up the process of recovery."

So, does it actually work? "In the short term, you may feel temporary relief in the nasal or chest areas, however, this doesn't necessarily signify your cold has gone completely, which can take from seven to fourteen days," she adds. 

Rather than focusing on your workouts, instead:

  • Staying hydrated: "Aim to get eight to ten hours sleep each night," she recommends.
  • Being mindful of diet: "Avoid food and drink that cause dehydration such as alcohol, caffeine and foods with high salt content," she adds.

Ultimately, you want to allow your body the necessary downtime to rest and recover without placing unnecessary stress which can prolong or even worsen a cold.

When can I get back to exercise?

Bottom line: both experts recommend waiting until symptoms are no longer present before you start exercising again. 

Word from the wise - rest up, enjoy the downtime, and up your intake of energy boosting foods, too. 

Ally Head
Health, Sustainability and Relationships Editor

Ally Head is Marie Claire UK's Health, Sustainability, and Relationships Editor, eight-time marathoner, and Boston Qualifying runner. Day-to-day, she works across site strategy, features, and e-commerce, reporting on the latest health updates, writing the must-read health and wellness content, and rounding up the genuinely sustainable and squat-proof gym leggings worth *adding to basket*. She regularly hosts panels and presents for things like the MC Sustainability Awards, has an Optimum Nutrition qualification, and saw nine million total impressions on the January 2023 Wellness Issue she oversaw, with health page views up 98% year on year, too. Follow Ally on Instagram for more or get in touch.