We all know that exercise is good for us - but how much do we need to do before it has any beneficial effects?
The good news is that moderate, regular exercise is just as good as the sweaty, macho variety.
Researchers divided up 111 overweight people into four exercise groups: no exercise at all; a low exercise group that did 12 miles of brisk walking a week; a moderate exercise group that did 12 miles jogging a week; and a high level group that completed 20 miles of jogging a week.
Researchers found that all the exercise groups showed improvements when LDL and HDL cholesterol levels were measured. Levels of fitness achieved, and any weight lost, were irrelevant (N Engl J Med, 2002; 347: 1522-4).