This is a conundrum that all us runners face at some point, and it's very relevant at this time of year. The dreaded head cold hits and whilst you feel awful, you don't want to lose training time. So what should you do? A good general rule to follow is if the issue lies above the neck, for example a blocked nose, sneezing, sore throat etc and you don't have a fever, then you're ok to continue running at a light intensity.
If however, the issue has spread to below the neck and you're experiencing symptoms such as chest congestion, intense coughing, vomiting etc, then you must completely stop training and seek advice from a doctor. Whilst this can be frustrating it's a far better option than training through it and spending a lot more time on the sidelines.
Please note this is general advice. The best thing you can do is listen to your body and be sensible when it comes to your training choices.
Written by Marc Brown