Is it okay to exercise when you are sick?

I recently came across this interesting article from www.mercola.com discussing whether you should exercise or rest when you are sick.  I found it interesting as my body has recently succumbed to a cold and I was wondering whether I felt like exercising of not.    You can read the full article on their website.  Here is a brief summary, and some key take home points I picked up from the article.

The key point from the article is that it is generally wise to avoid all but gentle exercise when you are sick as it will be an additional stressor that your body will not respond well to. When you are sick your body needs to heal itself and rest helps with this.  If you add more stress to the system with intense exercise you can easily exceed your body’s recovery capacity and you could get worse and prolong your recovery.  However, moderate exercise, like walking, is generally fine, BUT you need to listen to your body.  If something doesn’t feel right, then stop and get it looked at.  It is better to be safe than sorry.

For those that like more detail
Exercise and Sport Sciences Reviews noted:
"Prolonged intense exercise causes immunosuppression, whereas moderate-intensity exercise improves immune function and potentially reduces risk and severity of respiratory viral infections."
 
Dr Mercola said “Intensive exercise boosts production of cortisol, a stress hormone which inhibits the activity of natural killer cells—a type of white blood cell that attacks and rids your body of viral agents. This is why running a marathon can actually increase your chances of getting sick shortly thereafter. In fact, elite endurance athletes can suffer anywhere from two to six times as many upper respiratory infections during a year, compared to average, active individuals.”

When is it okay to exercise when you're sick?
One of the interesting points for me from Dr Mercola was that if your symptoms are above your neck, it is usually okay to exercise (although at a lower intensity as mentioned above).  These symptoms may be:

• Runny nose
• Sneezing
• Sore throat
• Headache, nasal congestion

Dr Mercola said that “increasing your body temperature by sweating from exercise will actually help kill many viruses”.  He continued to say “In fact, according to research, exercising with a cold may be well advised. At the end of one 10-day trial, those who exercised 40 minutes every-other day, at 70 percent of their maximum heart rate, felt better than those who remained sedentary—even though the clinical severity and duration of their symptoms were virtually identical”. 

When shouldn’t you exercise when you're sick?
According to Dr Mercola, if your symptoms are primarily below your neck, exercise should generally be avoided.  These symptoms may be:

• Fatigue
• Widespread body aches and muscle aches
• Vomiting, upset stomach and/or stomach cramps
• Fever
• Coughing or chest congestion

Of course all of this information is very generalized.  The key to this is no matter what your symptoms are, you need to be very careful and listen to your body.  If you don’t feel up to exercising, then don’t, get some rest instead. If symptoms persist, please seek medical advice.

If you want more information, please read the full article.  The link is below.

References

• http://fitness.mercola.com/sites/fitness/archive/2012/12/14/exercise-when-sick.aspx