Don't Want to Get Sick? Break a Sweat: Physical Fitness Curbs Colds

(Nov. 2) -- Incorporating fitness into your daily lifestyle can do more than mitigate stress and help maintain a healthy weight. Just in time for the winter sniffles, a new study concludes that a physically fit body can also ward off the common cold.

What did the study determine?

Around 1,000 adults were tracked throughout fall and winter. Those who exercised at least 20 minutes a day, five days a week, experienced 43 percent fewer "sick days" due to upper respiratory tract infections than those who didn't work out.

The results held steady even after controlling for factors like body mass index, age and overall stress levels.

As an added bonus, physically fit participants reported less severe symptoms when they did fall ill. They ranked their symptoms as 40 percent less intense than more sedentary -- and sickly -- participants.

Why does fitness fend off colds?

This study isn't the first to make a connection between physical health and fewer sore throats. But experts still aren't sure exactly why the link exists. Some theories:

Endorphins, the neurotransmitters responsible for that post-workout buzz, are thought to offer an immune system boost.

And exercise also appears to temporarily increase levels of white blood cells, deemed the "Marine Corps and Army of the immune system" by David Nieman, the study's lead author.

"As the days add up, it adds up to improved protection [from] the viruses that can make you sick," he told CNN.

Boo! I hate fitness.

It's easier to prevent a cold than cure one, but if laziness is your thing, then a groundbreaking finding from scientists at Cambridge offers reassuring news.

Just this week, the research team debunked a long-standing belief that antibodies could only ward off viruses outside of the body's cells.

In fact, they appear capable of entering infected cells and triggering a defense protein -- TRIM21 -- that fights illness from inside the cell membrane.

"Antibodies are formidable molecular war machines; it now appears that they can continue to attack viruses within cells," Cambridge's Sir Greg Winter told The Independent. "This research is not only a leap in our understanding of how and where antibodies work, but more generally in our understanding of immunity and infection."

Harnessing TRIM21 for a pharmaceutical intervention could yield effective cold-busting drugs. So maybe someday, the only physical activity you'll have to engage in to get better from the common cold is picking up a prescription.

Follow Surge Desk on Twitter.