Coronary heart disease is a killer which accounts for one in four male deaths and one in five female deaths every year in Britain - a total of 135,000 deaths a year. It costs the UK healthcare system around £1.6 billion. But just 30 minutes of moderate physical activity such as regular walking on five or more days a week will significantly reduce the risks of a heart attack.

According to the British Heart Foundation (BHF), 70% of adults do not take enough exercise, even though walking is the 'perfect exercise' to prevent coronary heart disease: it is free, available to almost everyone, requires no special equipment and has a low impact on joints. Walking can also be incorporated into daily life such as the commute to work, or can be treated as a social or recreational activity.

Use of a pedometer - a small device worn at the waist that counts the number of steps taken - is widely recognised as supporting regular walking by tracking progress and encouraging the setting of new goals. The display may also read out distance, speed, time and calories burned as well as any other statistics manufacturers and designers deem relevant. However, most pedometers on the market are sports 'gizmos' that are overly complex to use, expensive and have an image that excludes those most at risk from heart disease, such as older people and low income groups.

The challenge is to develop a more socially inclusive pedometer, one that is affordable and easy to use and reflects people's real needs.