The Health Education Authority has begun a three-year campaign to encourage over-16s to be more active, writes Diane Spencer.
The Active for Life project will advertise on ITV and Channel 4 until the end of April to persuade adults to adapt their lifestyles to be more active - not necessarily more athletic.
It hopes to catch young adults who give up physical activity when compulsory school sport ends at 16.
Fitness need not mean taking up squash or jogging. "Sweating and panting are out, doing enough activity to get warm and slightly out of breath is in, " said Nick Cavill, the HEA's physical activity manager.
The key messages of the Pounds 9m-a-year campaign are: make activity part of your life - walk more; use stairs, not lifts; cycle instead of using the car; make exercise fun and build up activity levels slowly to reach a target of half an hour's physical exertion five times a week.
The authority says more than half adults are overweight or obese and a third are sedentary. Eight out of 10 adults think they are fit, but most are not.
HEA research showed that 24 per cent of men and 37 per cent of women take little or no exercise because they do not see themselves as sporty.
Four out of 10 adults claim they don't have time for regular exercise, but two out of 10 say they would like to take more so the campaign will offer ideas and encouragement to put good intentions into action.
The campaign will emphasise the importance of physical activity in preventing coronary heart disease, high blood pressure, diabetes and arthritis. It comes in the wake of the Sports Council's Pounds 14 million national junior programme to encourage more school sport.