The author's making a slightly different point to the one you're trying to argue: > the benefits of exercise massively outweigh the risks of even a dangerous a

The author's making a slightly different point to the one you're trying to argue: > the benefits of exercise massively outweigh the risks of even a dangerous activity like climbing. In other words, the risks of heart attack, diabetes and other diseases are worse than rock climbing, even if you go climbing twice a week.