There’s a way to simultaneously help both Planet Earth and one’s own health, report scientists from Imperial College London, in England. The researchers examined four years of data from the country’s Department for Transport National Travel Survey beginning in 2005, the year before free bus passes were available for people ages 60 and older. The study team found that those with a pass were more likely to walk frequently and take more journeys by “active travel”—defined as walking, cycling or using public transport.

Staying physically active helps maintain mental well-being, mobility and muscle strength in older people and reduces their risk of cardiovascular disease, falls and fractures. Previous research by Taiwan’s National Health Research Institutes published in The Lancet has shown that just 15 minutes of moderate daily exercise lowers the risk of death in people over 60 by 12 percent, and another study at Newcastle University found that 19 percent of Britain’s adults achieve their recommended amount of physical activity through active travel alone.

Public health organizations in the UK believe that “incidental” exercise, such as walking to and from bus stops, may play a key role in helping seniors keep fit and reduce social exclusion.