A television advertising campaign has been launched to encourage people to improve their fitness for the sake of their hearts.
It comes after a poll by the British Heart Foundation (BHF) found only 38% of people would exercise more after being told their lives depended on it.
The three-week publicity drive is based around people taking exercise to the "beat" of their heart.
The charity claims that raising heart rates by 30 minutes a day can halve the risk of heart disease.
It recommends that people take 30 minutes of exercise five times a week, but only a third of UK adults achieve this minimum benchmark.
Dr Mike Knapton, director of prevention and care at the BHF, said: "This is a deadly serious issue. With our busy lifestyles and labour-saving devices, we've stopped getting the exercise our bodies desperately need.
"For many people, exercise has become an ugly word, something to avoid at all costs - but you'd be amazed how easy it is to up the tempo of your heartbeat.
"Just 30 minutes a day will do you and your heart the world of good. The BHF is trying to show people that it can be fun too."
A BHF survey of 2,000 adults found 15% use the British weather as an excuse for inactivity.
Some 8% of women said housework is their favoured source of exercise. A motivating factor for women exercising is their figure (17%), compared with 7% of men.