The idea of walking 10,000 steps a day was invented as part of the marketing campaign for an early pedometer ahead of the 1964 Tokyo Olympics. The Japanese character for 10,000 looks rather like a person walking so the device was called the Manpo-kei or 10,000 steps meter.

This history means that some are sceptical about whether the recommendation of 10,000 daily steps really has any health value. New research from the University of Sydney published in the journals JAMA Internal Medicine and JAMA Neurology shows it’s pretty close.

The research suggests that while every little helps, about 9800 steps hits the sweet spot when it comes to dementia: 9,800 steps was the ‘optimal dose’ to lower the risk of dementia by 50%. But risk was reduced by 25% at as low as 3,800 steps a day.

Similar associations were seen for cardiovascular disease and cancer incidence. Overall, every 2,000 steps lowered risk of premature death incrementally by 8-11%, up to approximately 10,000 steps a day.

The research also suggested that walking faster increased the benefits as getting the heart pumping boosts blood flow which helps the arteries repair themselves against the inflammation that causes disease. ‘The take-home message here is that for protective health benefits people could not only ideally aim for 10,000 steps a day but also aim to walk faster,’ said co-lead author Dr Matthew Ahmadi.

Professor Tim Olds, a behavioural epidemiology researcher at the University of South Australia, told The Guardian that for the majority of people, the more exercise they do the better. But with diminishing returns. ‘The first 5,000 steps does much more good than the next 5,000 steps and so on,” he said. “If the first unit gives you one unit of good, the next unit is another half unit of good.’

Just as well for our health that it wasn’t the Japanese character for 50 that looks like a person walking.