Is it safe to work out when you’re feeling under the weather? While many active people might feel uneasy at the thought of total bedrest, not focusing on full recovery in those first few days of feeling unwell could make your health deteriorate faster. Dr Rebecca Robinson (Consultant Physician in Sport & Exercise Medicine at Marylebone Health) shares her advice on whether she thinks it is safe to exercise when sick.

It can be tempting to work out when unwell. Are there any guidelines we can follow to gauge when we are too sick to exercise?

When we are sick our bodies need to rest and recover. Even for elite sportspeople, being ill draws on a physiological reserve and it’s hard to perform at our best in sport. So, advocating total rest at the start of a new illness can stop symptoms more quickly and prevent us overdoing it – in case what felt like a mild cold was the start of a more severe flu like illness.

If it’s a common cold and symptoms are ‘above the neck’ (limited to blocked nose, sore throat and no fever), there’s no evidence that it’s harmful to exercise. However, taking a few days rest, as well as adding zinc and vitamin C to your agenda, will probably help you recover faster.

If your symptoms are ‘below the neck’ (including feverishness, temperature, chesty cough, or you think you have Covid or the  flu), do rest until these abate because it can be harmful to your health to train through it.

How long does a typical common cold require off exercise?

A typical cold lasts two-to-seven days but you might notice you feel fatigued or have a higher heart rate than expected for a few more days after. You don’t need to take the whole time off, but in the first couple of days, diverting your energy to rest can help speed up your recovery. After the initial few days, it’s completely okay to swap the gym for a walk outside for a day.

Remember to be kind and limit the spread of illness. By avoiding the gym on the first couple of days of illness, you’re less likely to spread germs when your symptoms are at their most infectious. If your symptoms are more severe, including feeling feverish, a longer lay off is needed.

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Will taking time out from exercise impact your progress?

A few days off will absolutely not harm your progress and might actually enhance it – rest is what the body uses to repair and adapt within a regular training programme.

If you need to take more than two weeks off due to illness, you may lose a small percentage of fitness, so it’s important to get back into your routine steadily when you are feeling better.

If you’re worried about taking just one or two days off, it’s worth checking in with how you feel about your routine and commitment to exercise – there’s a possibility you could be experiencing exercise dependence if you’re unwilling to give yourself much-needed rest days.

What could happen if you don’t let your body rest?

At the least, the impact of exercising when you’re ill is that it prolongs symptoms, because the body cannot use the same energy needed to exercise and recover at the same time. You also risk overstressing your body into a period of under-recovery (under recovery syndrome) – a much higher heart rate than expected for the same exercise intensity that you might have been able to manage before. Whilst this is not directly harmful, it can lead to a prolonged period of fatigue, which will impact your long-term progress.

Exercising with a viral illness can also over challenge your heart and lungs, and in more significant cases, lead to inflammation near the heart.

What is the best way to return to exercise after having been out with an illness?

Ease back into your routine and protect your recovery. Never try to make up for a missed high-intensity workout by rushing into it. When you do feel better, set an easy paced session, check that your heart rate response is where you’d expect it to be and don’t be afraid to step back for an extra day if you are still feeling fatigued or running a higher heart rate.

If all is well, get back into your routine by adding low-impact exercises like Pilates or yoga to help stretch stiff muscles, help upper body mobility and include breathwork.

For more information and advice, visit marylebonehealthgroup.com