If it were a medicine, it would be branded a wonder drug. If it were a new therapy with an exotic name, people would be queuing for a session. No treatment in the history of medicine has achieved what moving your arms and legs about can achieve. Yet more than a decade of effort to persuade us to up our dose has failed.
Someone dies every 15 minutes because they don't take enough exercise. Two thirds of the population fail to do the minimum to maintain health – 30 minutes of moderate physical activity five times a week.
The British Heart Foundation, which published the figures, is launching a three-week TV advertising campaign aiming to get the nation off its rear end. A survey it commissioned found that fewer than four out of 10 people said they would take more exercise even if their life depended on it.
Exercise is known to cut the risk of heart disease and diabetes, protects against breast cancer and colon cancer, builds up the bones and reduces the risk of dying before your time by 30 per cent. It improves mood and brings a sense of wellbeing. Yet despite its benefits, the number of miles walked and cycled since the mid-Seventies has fallen by a quarter.
Mike Knapton, director of prevention and care at the BHF, said: "With our busy lifestyles and labour-saving devices, we've stopped getting the exercise our bodies desperately need. Exercise has become an ugly word, something to avoid. But you'd be amazed how easy it is to up your heartbeat. Just 30 minutes a day will do your heart the world of good."
The Hollywood actress Jane Fonda may have urged a generation to go "for the burn". But ferocious exercise is not necessary. You do not need to be a marathon runner, or even a Sunday jogger.
Vacuuming the house, walking to the bus stop and taking the stairs instead of the lift affect health more than a fistful of blood pressure pills.
Going for a walk is the nation's favourite way of getting exercise, according to the BHF survey. More than a quarter of those polled chose it over dancing, swimming or going to the gym.
Julia Bradbury, who presents the BBC television series Wainwright Walks, said: "Walking is a great way to keep fit. I walk wherever I can, whenever I can. I'm also extremely lucky that some of my work involves walking as part of the job. My recent fell walks through the beautiful Lake District were uplifting for both body and mind."
The TV ad, part of a wider campaign called The Beat, opens with a lone drummer picking up the beat of the city, and then shows other people taking part in activities in time to their heartbeat. It says raising the tempo of the heartbeat for 30 minutes a day, reduces the risk of heart disease by half.