Hits and myths: No need to cancel a run in the rain
Q: Can running in the rain make you ill?
The straight answer: No
The facts: It is a popular view that running in the rain can increase your chance of falling ill. Exposure to the cold rain and damp air, with the physical exertion, is thought to weaken the body's defences, making us vulnerable to cold and flu viruses.
As children, many of us were admonished for playing in rainstorms and were quickly dried off before the water droplets made us ill.
But there is no reasonable explanation for this belief. According to Dr Linda Hui, chief physician at Matilda Medical Centre, there is no scientific evidence to back up the correlation between running in the rain and illness. Colds and flu are spread by viruses.
These viruses are often present in the respiratory secretions of infected individuals, and are typically transmitted through sneezing, coughing, talking, and through contact with surfaces that have been contaminated. So any cold and flu symptoms that are experienced after a run in the rain are related to a viral infection.
But this old wives' tale is not wholly a myth. Dr Shiv Gill, a general practitioner at My Health Partners Medical Clinic in Singapore, says that running in the rain can sometimes trigger allergies and asthma attacks.
"Strenuous activities like running increase the strain on your lungs, causing you to breathe harder and faster," says Gill.
"If you have asthma, running in the rain can worsen your asthma symptoms, because you are forced to breathe in cold air.
"Your lungs therefore have to work harder than usual, plus, because you're breathing in so fast, the air you exchange does not have a chance to warm up," she says.
When conditions are windy, more fungal spores and pollen are also carried through the air, triggering allergies and asthma symptoms like wheezing.
A study published in the journal Allergy found that the number of asthma sufferers seeking treatment for asthma attacks increases when there are thunderstorms.