Research has shown that during moderate exercise, several positive changes occur in the immune system. For instance, immune cells which kill bacteria and viruses circulate through the body more quickly both during and for several hours after exercise.
Just think; every time you go for a brisk walk, your immune system receives a boost that improves your chances of fighting off nasty winter bugs and viruses!
SHOULD YOU EXERCISE WHEN SICK?
As sports medicine experts, we recommend that if you have symptoms of a common cold with no fever (i.e., symptoms are above the neck), moderate exercise such as walking is probably safe. Intensive exercise should be postponed until a few days after the symptoms have gone away. However, if there are symptoms or signs of the flu (i.e., fever, extreme tiredness, muscle aches, swollen lymph glands), then at least two weeks should probably be allowed before you resume training.
STAYING IN SHAPE TO EXERCISE
1 Eat a well-balanced diet. The immune system depends on many vitamins and minerals for optimal function.
2 Avoid rapid weight loss. Low-calorie diets, long-term fasting and rapid weight loss have been shown to impair immune function.
3 Obtain adequate sleep. Major sleep disruption (e.g., three hours less than normal) has been linked to immune suppression.
4 Take rest days.
Keep “within yourself” and don’t push beyond your ability to recover
By Northern Michigan Sports Medicine Center and American Council on Exercise.