And drinking chlorinated water – much better if it is fluoridated too – is even “better” for your health.
Children who swim regularly in chlorinated pools are five times more likely to develop asthma, research has found.
Swimming is recommended as a good form of exercise for asthmatics because the warm humid air is less likely to trigger attacks than other physical activities.
But mounting research is suggesting that the chlorine used to keep the pools clean could be contributing to the development of the condition.
Researchers in Belgium studied the effects of swimming in outdoor pools regularly from a young age and found a strong link.
Previously the same team have found that indoor pools may also increase the risk of asthma in children.