Regular exercise boosts body's immune system and means colds less bad if you do get one...

On the same day that the mainstream press reports that scientists in Cambridge may be close to discovering a cure for the common cold, a study by researchers at a university in the United States suggests that daily exercise such as cycling can go a long way towards preventing the ailment being caught in the first place.

The study, published today in the British Journal of Sports Medicine, has been carried out by academics at the Appalachian State University (ASU) in North Carolina, adds that regular exercise can also reduce the severity of symptoms if you do catch a cold.

Researchers found that taking part in exercise can boost the number of immune system cells circulating in the body, and while the effect is only temporary, taking part in exercise regularly means that the body becomes more vigilant of viruses and bacteria that can cause conditions such as the common cold, reports the website Wales Online.

Dr Mark Ridgewell, a doctor at Sport Wales, told the website: “Moderate amounts of aerobic exercise, such as jogging, brisk walking and cycling, during the cold and flu season will help prepare the body for an invasion of foreign bacteria by stimulating blood circulation and improving the body’s cardiac function.

“This assists the body’s production of macrophages – vital white cells that attack bacteria.

“Once infected, the body is more readily prepared to attack the virus quickly.

“So while exercise will not prevent us from catching cold and flu altogether, a person who does physical activity on a regular basis is less likely to suffer for a long period of time and doubles their chance of withstanding infection when it takes hold over homes and workplaces.”

The ASU study was based on 1,000 adults aged up to 85 years, monitoring their respiratory health for a 12-week period in autumn/winter 2008. Six in ten of the participants were female, while four in ten were aged between 18 and 39. A further four in ten were middle aged, while around quarter were aged 60 and above.

The participants recorded details of how often they exercised and how fit they felt according to a scale of one to ten. Other information regarding factors that can impact the body’s immune system, such as diet, lifestyle and stress, was also recorded.

The study found that there were more days in which cold symptoms were reported during winter as opposed to autumn – thirteen versus eight – and that older, married men were less likely to say that they were suffering from the condition.
However, the most significant other factors of those analysed were people’s perception of their fitness and the level of exercise they performed.

Participants who said that they took part in exercise on at least five days a week – a profile that commuting cyclists would clearly fit – said that they suffered symptoms indicative of the common cold at a rate some 43% to 46% lower than that of those who exercised at most on one day each week.

The study also found that among the most active participants, the severity of symptoms was 31% lower than average, and among those who said they felt the fittest, it was 41% lower.

The report’s authors commented: “These data indicate that high perceived physical fitness and near-daily aerobic activity are important correlates of reduced upper respiratory tract infection frequency, severity and symptomatology.”

Debbie Lawrence, director of Fitness Wales, told Wales Online: “My knowledge has always included the fact that exercise boosts the immune system and my personal experience has been that when I am more active and fitter – and less stressed – I have rarely experienced colds or at least can battle them off more quickly.

“It is great to see the benefits of physical activity being flagged up.

“All we have to do now is get people to get moving more so they can experience the benefits for themselves.”

Born in Scotland, Simon moved to London aged seven and now lives in the Oxfordshire Cotswolds with his miniature schnauzer, Elodie. He fell in love with cycling one Saturday morning in 1994 while living in Italy when Milan-San Remo went past his front door. A daily cycle commuter in London back before riding to work started to boom, he's been news editor at road.cc since 2009. Handily for work, he speaks French and Italian. He doesn't get to ride his Colnago as often as he'd like, and freely admits he's much more adept at cooking than fettling with bikes.