Exercising to beat a cold may seem counterintuitive, but previous research has shown people who exercise get over colds more quickly and have milder symptoms. A study that found mice who exercised had less inflammation and tissue damage after an infection may explain why this is the case. Inflammation is the body’s natural response to fighting infections; however, inflammation also causes tissue damage. Fat cells produce inflammatory chemicals when they enlarge, as they do in obesity, that might also contribute to excess inflammation and tissue damage during an infection. Regular exercise appears to shrink fat cells, resulting in lower levels of these damaging, inflammatory chemicals. For the study, which was published in the journal Scientific Reports, researchers divided 28 male mice into two groups: the first group performed a moderately strenuous swimming exercise for ten minutes, five days a week, for three weeks, while the second group remained sedentary and did not exercise. After this three-week period, researchers infected half of the mice in each group with a drug-resistant S. aureus strain (which causes skin infections and pneumonitis in both mice and people). They then measured specific markers of inflammation in the mice and looked at their inflammation-related lung damage. Here is what they found:

• The exercising mice had lower levels of inflammatory markers circulating in their blood than the sedentary mice.
• The exercising mice infected with S. aureus experienced less of a rise in inflammatory markers in their lungs than the infected sedentary mice.
• Infection with S. aureus caused more lung tissue damage in the sedentary mice than in the exercising mice.

These findings suggest that exercise can reduce inflammation and protect against tissue damage during an infection, perhaps by shrinking fat cells and reducing inflammation in the body. Since this was an animal study, it may not predict the effects of regular exercise on inflammation in humans. However, we all know that exercise provides a bounty of health benefits, so it’s safe to say that getting regular exercise will help you stay healthy in other ways as well.

Source: Scientific Reports