Doctors are to point lazy patients in the direction of the nearest park as part of a government initiative to tackle obesity.
People with inactive lifestyles will be handed a map of the local area which highlights green spaces, gyms and other sports facilities.
The Let's Get Moving information packs also include advice on diet and reducing the risk of developing conditions such as diabetes.
GPs will check up on the progress of "couch potatoes" after three and six months to try to encourage them to stick with the health kick.
The anti-obesity drive, which is being led by the Department of Health (DH), is being piloted at GP surgeries in London, and is aimed at 16 to 74 year-olds.
Fitness Minister Dawn Primarolo said: "This project will give inactive patients the boost they need to improve their fitness and take that first step towards a healthy, active lifestyle.
"Just making a small increase in activity levels can make a big difference to your overall physical well-being.
"Physically active people are up to 50% less likely to be at risk of major chronic disease such as coronary heart disease, stroke, diabetes and cancer, yet almost three-quarters of adults do not achieve the recommended weekly amounts of physical activity."