Should I exercise when I'm sick?

17:00, Sep 03 2012
Most adult New Zealanders will get three or so “colds” a year.

Q: "I'm a mother of three with a busy job who likes to keep fit. I run most days. I've been struck by one cold/virus after the next for the past couple of months, but typically keep exercising when I'm unwell. Often I have my usual energy, though - I'm just a bit blocked up. When should I exercise and when shouldn't I? Does exercise help or hinder my immunity?'' Sarah

A: Sarah, thanks for the question.

First, make sure you are generally in good health. Most adult New Zealanders will get three or so "colds" a year. If you are greatly exceeding this number, or feel as though your colds don't go away in the timeframe you would expect, it is worth a visit to your GP. They can ensure you don't have an underlying health condition that might be making you more susceptible.

Second, look at your lifestyle.

- Are you eating well? We know that a balanced diet is important for maintaining a healthy immune system. Rapid weight loss, or any deficiencies in your diet, will make you more susceptible to infections.

- Are you getting enough sleep? Sleep deprivation will put you at greater risk of infections.


Ensure your training regime is realistic, and you are well hydrated, especially while exercising.

All these aspects of your life can make you more or less robust when it comes to fighting off any bugs you might encounter.

Unfortunately, research around exercise and colds is a bit lacking. The most sensible advice I can give is to listen to your body. If you feel terrible, don't exercise. It is likely to make you worse, and possibly put you at risk of becoming seriously unwell with a secondary infection.

This is also the advice for anyone who suffers from asthma or heart disease. Working out when you have a cold will only put extra stress on your heart and lungs. Take it easy for a few days, and you are likely to be up and running again a lot sooner.

American athletes use the ''neck-up/neck-down'' rule. If your symptoms are predominantly neck-up (ie, runny nose, sore throat and congestion), mild exercise is likely to make you feel better. They do advise "stepping down" your training, though - so if you normally go for a run, consider going for a brisk walk until you are back in top form. Exercise releases endorphins which should leave you feeling more energised than staying on the couch with a box of tissues. Exercise also activates some of the "fighter" cells in the immune system, so in theory it should help your body get rid of the infection a bit sooner. However, if you have symptoms below the neck as well (ie, fever, chesty cough, muscle aches), you should avoid exercise entirely until you feel better. A workout may make you feel better, due to the release of those fabulous endorphins, but you are likely to pay the price later with a cold that is more severe and lasts for longer.

The good news is that people who exercise regularly (at least five times a week) are much less likely to get colds in the first place. They will also get sick for fewer days and feel much less unwell, according to a large study conducted in Seattle. So keep up the exercise, Sarah, but next time you are unwell, perhaps spend a few days taking it easy.

- Cathy Stephenson is a GP, medical forensic examiner and mother of three. If you have a question for her, write to her c/o Features Editor, The Dominion Post, PO Box 3740, Wellington 6140, or e-mail

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