People who are active five or more days each week are 43 per cent less likely to catch a cold than those who exercise only one day or less, researchers find
FORGET VITAMIN C – if you want fewer and less severe colds this winter take exercise.
Research published this morning says regular exercise reduces cold incidence by almost half and severity by more than a third.
Exercise is known to stimulate the body’s natural defences against infection, and this study of 1,000 individuals seems to prove it.
Details of the study are published online in the British Journal of Sports Medicine, a British Medical Journaltitle.
The US researchers wanted to confirm earlier but much smaller trials looking for a link between taking regular exercise and the chances of catching an autumn or winter cold.
They set up two groups – one during the autumn and one during the winter of 2008 – tracking their health status over a 12-week period.
Ages of the study participants ranged from 18 to 85, with 60 per cent females and 40 per cent males.
The researchers took other factors into account including exposure to stress – which can influence the infection-fighting immune system – diet, marital status, education and the person’s weight.
Subjects were then asked how physically fit they thought they were and how frequently they exercised.
The study produced compelling results indicating regular exercise and overall fitness could help keep general upper respiratory tract infections at bay.
Those who exercised five or more days each week were 43 per cent less likely to catch a cold than those who exercised only one day or less per week.
Those who had high fitness levels took 46 per cent fewer sick days than those who declared a low level of fitness.
The severity of colds was also reduced, the researchers found.
The “severity and symptomatology” for the regular exercisers was 32 per cent reduced and reached 41 per cent in the fittest individuals.
Colds seemed more common during the winter months, with an average of 13 sick days overall for all subjects and nine days in the autumn, the researchers say.
They also believe they know why exercise helps – it triggers a temporary rise in the number of immune system cells circulating around the body.
“Although the immune system returns to pre-exercise levels within a few hours after the exercise session is over, each session may improve immunosurveillance against pathogens that reduce overall [cold] incidence and symptomatology,” they report.