Why exercise guidelines fall short

Researchers are calling for a major boost to physical activity recommendations, with a new study linking more weekly exercise to a reduced risk of five common diseases.

A meta-analysis including 174 papers suggests the equivalent of 15 to 20 hours of brisk walking or six to eight hours of running a week is needed to reduce breast and bowel cancer, diabetes, heart disease and stroke.

A co-author of The BMJ study, Dr Lennert Veerman from the University of Queensland, acknowledges that the first minutes of activity that are most advantageous to health. But the results from the study suggest activity needs to be several times more