The immune system is a complex defense network to keep your body healthy from harmful bacteria, viruses and other microbes. Many things can influence the health of the immune system such as: diet, exercise, stress and sleep levels. Regular exercise is thought to be beneficial for building a strong immune system.
However, there is a balance between exercise and immune function. Over training with exercise can increase likelihood to get sick and exercising when you are really sick could further lower the immune system.
Being sick can throw a wrench in your workout schedule. Maybe you’re training for a race and have some key workouts you want to hit this week. But, just on time, now you have a cold.
See Also: Can dietary supplements prevent common colds?
Should you still go out and exercise?
A general rule of thumb exercising with a cold is usually fine as long as your symptoms are in your head. If you have chest congestion, a fever or body aches you should probably take a rest day.
Another general rule is to listen to your body. Your overall health should come before fitness goals. If you are really not feeling well, take a rest day so you can heal up quicker.
What are your symptoms?
According to Dr. Laskowski from Mayo Clinic (1), exercising with a head cold should be ok. If symptoms are above your neck: runny nose, nasal congestion and watery eyes, you can still exercise you may just want to lower the intensity of your workout.
If you have body aches, fever, chest congestion or an upset stomach, you’re better off taking a rest day.
Exercising with these symptoms could interfere with getting better and could increase risk for dehydration or electrolyte imbalances if you work up a sweat from exercise.
If you have a head cold, moderate exercise shouldn’t interfere with your immune system fighting off your cold. A study (2) from Ball State University looked at the effect exercise had on severity and duration of an upper respiratory infection in people who were exercising.
All subjects were infected with a cold and were put into one of two groups: moderate exercise every other day or no exercise at all.
Researchers found there was no difference between groups for severity and duration of sickness.
Lower your intensity
If you have a cold, you can exercise but you may want to avoid higher intensity workouts. Don’t expect any record breaking workouts to come about when you are sick. Keeping the exercise to a moderate intensity is recommended.
If you try pushing yourself too hard while being sick, you will probably just get frustrated and exacerbate some of your symptoms.
You may need to take extra breaks during your workout to blow your nose or just to recover, and that’s ok.
If your workout schedule has you doing a higher intensity workout on a day you are sick, switch it for a moderate exercise workout.
You could even do an alternative exercise when you are sick such as for example a recumbent bike or elliptical instead of running.
Keep your germs to yourself
If you work out in a public setting like a gym, it may be ok for you to moderately exercise while you’re sick.
However, you are potentially spreading your germs to others at your gym. If you are exercising while sick in public, make sure to follow hygienic practices.
Cover your sneezes and coughing and wipe down equipment after you use it. Wash your hands as often as you can.
Consider doing your workout at home or outside when you are sick instead of going to the gym. It’s a common courtesy to other gym goers, and hopefully they will follow the same courtesy as well.
Listen to your body
The first few days you are sick, you may feel extra tired. Your immune system takes energy to fight off harmful cells in your body. If you are feeling extra tired, your body may do better from extra sleep instead of exercise.
Listen to your body. If you need sleep and are physically too exhausted to work out because you are sick, take the sleep.
Taking a day or two off working out while you are sick won’t derail your exercise goals. You may be able to work through a head cold, but if you have other symptoms, listen to your body and take care of yourself first.
Overtraining and immune health
Regular exercise may help promote immune health as does a healthy diet, healthy stress levels and adequate sleep.
However, too much exercise can actually lower immune function. In fact, one symptom of overtraining syndrome is an increased frequency of upper respiratory infections.
Over training syndrome can occur if an athlete is exercising too much and performance actually decreases.
Researchers are still understanding how exercise impacts immune health and how too much exercise can lower immune function.
One theory (3) is over exercising can produce tissue trauma which can produce inflammatory cytokines. These cytokines can lower cell mediated immunity.
How do you know if you are overtraining?
If you are constantly feeling tired, getting sick and have a lowered exercise performance despite a very high level of training, you may have overtraining syndrome.
Most people don’t have to worry about this even if you are exercising every day. Overtraining is usually seen in elite athletes or people training for long endurance competitions.
If you have a head cold because of overtraining issues, speak with a sports medicine doctor or athletic trainer on how to best taper back your exercise levels to improve fitness and overall health.
