The higher your daily step count, the lower your risk of death per year, according to a new analysis by the US National Cancer Institute – but the link only goes so far.

Public health officials have long encouraged walking as a way of improving general health , but many longitudinal studies on its benefits have focused on people in their early sixties and have sometimes ignored minority groups, such as people of colour.

The new analysis looked at 4840 people who were representative of the US population over the age of …