The athlete with a cold needs rest, not exercise. One should not run vigorously with a cold, flu, or any viral infection that causes a fever. Although only certain organ systems produce symptoms, the entire body is affected.

It is very important to keep a daily record of your morning pulse when you beging training for any sport or type of exercise program. While still lying in bed, take your pulse a few minutes after awakening in the morning.

As your training progresses, your pulse will gradually become slower. After two or three months, it will plateau. After this point, if your rate is ten or more beats higher one morning; it means you have not recovered from your previous day's run, race, or stress. It is then advisable to take at least one day off until the pulse returns to normal.

The cold is an early warning sign of exhaustion resulting in a breakdown of the body's defense system. Influenza may then gain its entry to the body systems starting with a sore throat and then possibly progressing to a cough. This virus in some way has the ability to get into the cells, reproducing itself, attacking the outer layer of the cell, killing it.

The utmost caution should be taken when you return to exercise, because it's very difficult to know how much fatigue has built up during the actual layoff from your sport. This body fatigue often leads to the overuse syndrome and injury.

Since the muscles can no longer act as shock absorbers, the joints, as well as the muscles, are injured. This fatigue can take many forms such as staleness in performance, which can result in the feeling of heavy legs, loss of zest, poor performance or a rapid pulse.

A cold is a message from your body that you are overstrained. Wait at least three days and make sure there is no fever before returning to your training.

You should rest and keep a good nutritional balance. It has been found that some athletes have had their best performance after the proper and sensible rest period following a cold.

Dr. Robert Weiss is a Fairfield native and has a sports-podiatry practice in Darien. He is a former marathon runner and was a member of the Medical Advisory Committee of the 1984 and the 1988 Olympic Trials.