What's the safest type of exercise? Certainly not the short and intensive kind - that can cause asthma-like attacks, even if you've never suffered from the disease before. Children in particular could experience a sudden asthma-like attack following intense exercise over a short period. Even healthy children can suffer from a sudden decrease in lung function, say researchers. The latest study, from the University of California's Irvine and Miller Children's Hospital, involved 56 children with no history of asthma or allergy. Researchers already know that intense exercise can cause wheezing and a decrease in lung function, but the new study is the first to recognise the same thing happens to healthy children. (Source: Proceedings of the ATS 2010 International Conference, New Orleans).