Can exercise boost your immune system? Yes, if you do it correctly – here’s how

Convinced something ‘is going around’? You could be right. People on Reddit are claiming they’re experiencing the ‘worst cold ever’ this winter, while the UK’s Health Security Agency has issued advice over rising flu and RSV cases. The good news is that exercise could help protect you from catching anything. We asked Women’s Health Collective trainer India Morse for her advice, including whether you really can ‘sweat it out’ if you’re already sick, and what type of exercise is best to boost your immune system.

When can exercise boost my immune system?

‘Exercise certainly can boost your immune system, but it’s worth keeping in mind that – as ever – prevention is better than cure. If you’ve already contracted symptoms, it will take more time to recover. The standard rule of thumb is that you should avoid training until your symptoms are above the neck, like congestion, sneezing or a sore throat. Studies show that exercising with more severe symptoms can make you feel worse, so it’s important that you listen to your body.’

What type of exercise can boost my immune system?

‘Once you feel ready, research by the Journal of Sport and Health Science has shown that moderate-intensity aerobic exercise can stimulate cellular immunity by increasing the circulation of immune cells in your body. This means your body will be better prepared to fight off future infections, while the increased blood flow will provide your cells with the oxygen and fresh nutrients needed to get back to full health.

‘The aforementioned study recommends daily workouts lasting 30-45 minutes, but as you’re already unwell, start with 15 minutes of mild to moderate exercise and see how you feel the following day. Try a light jog or a short outdoor speed walk to avoid infecting others, if your illness is contagious.’

How can exercise boost my immune system?

‘Other research has shown that your body temperature increases and remains elevated for a short time after a workout. This rise in body temperature can prevent bacteria from growing, while helping your body to fight off infection, since it stimulates your immune system and bacteria and viruses can’t survive in higher temperatures.

‘Another big bonus of exercise is its ability to supercharge sleep quality, and research shows that sleep can weaken your immune system and make you more susceptible to the common cold and cardiovascular and metabolic disorders, since sleep is when your body produces antibodies – proteins in your cells that bind to unwanted substances and get rid of them.

‘Naturally, you’re probably feeling more stressed than usual if you’re already unwell. Moderate exercise has also been proven to slow down the release of stress hormones, while separate research has shown that stress can impact your immune system by impairing the function of natural killer cells (or NK cells), which protect you from infection and disease. The more consistent you are with moderate exercise, the stronger your NK cells.’

How often should I exercise to boost my immune system?

‘Remember that exercise is more effective in staving off illness than it is in curing it. As research proves, stick to 30-45 minutes of daily moderate exercise, like brisk walking, tennis, Pilates, yoga or riding a bike and, I’d wager that the number of sick days you’ll take will reduce. If you do happen to be someone that’s already feeling unwell, rest up until your symptoms move above the neck, and ease off if you start to go downhill. Patience is a virtue.’

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Bridie is Fitness Director at Women’s Health UK. She spends her days sweating over new workouts, fitness launches and the best home gym kit so you have all that you need to get fit done. Her work has been published in Stylist, Glamour, Cosmopolitan and more. She’s also a part-time yoga teacher with a habit of nodding off mid savasana (not when she’s teaching, promise).