As the weather starts to do what, in Alabama, it seems to do best- fluctuating like crazy... We start to hear sniffling and coughing everywhere we go. I know my sinuses are going crazy already so I decided to take this next blog entry and talk a little bit about how your fitness levels can have an effect on looming threat of cold and flu viruses.
As a graduate student at UAB, I find it hard to put "facts" out there for others if I can't even find a study to back my information up; luckily in 2008 Dr. David Nieman and his research team at Appalachian State University studied 1,000 adults for 12 weeks during the winter season (what we like to refer to as "cold and flu" season) and found that those who exercised more than 5 times per week had 43% fewer respiratory infections than those who were more sedentary (Exercising only one day or less per week). They also reported finding that those who reported being more fit than others their age had 46% fewer infections than those who reported not being in as great of shape. Of all the factors studied (including age, gender, education level, body weight, diet and mental stress), physical activity and fitness levels ended up being the most powerful predictor of sick days. (1)
While the study did not investigate the reasons for this effect, previous work may give us a clue. Exercise, especially moderate exercise can increase circulation of the body's sentry immune cells whose job is to patrol the body and nab any potential viral/bacterial invaders. The more cells circulating and on duty, the more likely they will be able to dispatch the cold and flu agents before an infection can be established. (2-4)
On the other hand, extremely vigorous forms of exercise, including working out for hours at the gym and running marathons, can have a negative effect on your immune system. Studies show that extreme workouts can decrease the number of white blood cells flowing throughout your body while increasing the level of stress hormones in the bloodstream. These emergency hormones help you cope with the physical stress but can also increase your likelihood of illness.
Can Exercise Aggravate my Flu Symptoms?
While mild exercise can help boost your immune system, you may want to be gentle on yourself if you already have the flu. That's when it's time to listen to your body, and give it time to recover.
The bottom line? Rest your body when you have the flu. Allow your body a chance to adjust to the stress of illness. Your immune system functions best when it is not stressed or in overdrive.
Tips on avoiding the flu virus in the gym:
- Clean your equipment before AND after use (remember, the person who got on that treadmill before you could have been coughing up a lung and might NOT sanitized the treadmill when they finished their workout)
- Avoid touching your face during a workout, use a clean towel rather than your hand, arm or sweaty shirt to wipe sweat out of your eyes! (during the cold and flu season you might want to bring your own)
- Drink plenty of water (water is a natural flush for your system, don't let hydration get put on the back-burner as the weather gets colder)
- Wash your hands often and well
- steer clear of others that might be sick, if you see them coughing and sneezing, you may not want to stand right next to them to do your bicep curls...
(1) Upper respiratory tract infection is reduced in physically fit and active adults
(2) Role of lung macrophages on susceptibility to respiratory infection following short-term moderate exercise training
(3) The effects of moderate exercise training on natural killer cells and acute upper respiratory tract infections.
(4) Immune response to exercise training and/or energy restriction in obese women.