When one suffers from a cold virus (not flu) what is your suggested timetable for returning to exercise, and what are the positive and negative signs to look out for?

The neck check principle used in sports medicine is one of the most simple and effective ways to determine whether you should be exercising with a cold. If you have symptoms above the neck, such as stuffy or runny nose, and feel you would like to exercise then you can do so but at a lower intensity. If you have symptoms below the neck, such as stiffness or achy limbs, sore throat and tightness of chest, it is best to avoid vigorous exercise because this is indicative of a possible viral infection and exercise may exacerbate your symptoms. If you have a cold, apply the neck check principle daily until you feel you have symptoms only above the neck; then if you feel you'd like to introduce moderate-paced exercise, do so but apply no more than 75% of your effort. If after 10 minutes into your workout you feel comfortable, then continue but at the same reduced intensity. In your first week, I'd recommend no more than three training sessions at the reduced intensity, increasing to four in the second and third week. By the end of the third week you should feel you can be training to near full capacity. Avoid large changes in body temperature; in cold weather make sure you start warm, taking off layers as your body temperature rises with an effective warm up. Post-exercise, keep warm - in my experience, too sharp a drop in your body temperature is a fast way to get another cold.

· Joanna Hall is a fitness expert (joannahall.com). Send your exercise questions to Weekend, 119 Farringdon Road, London EC1R 3ER (weekend@theguardian.com).