by Sarah Knapton  |  21 February 2017

Devices and health apps that advise people to walk 10,000 steps a day could be doing more harm than good, scientists have warned.

Around three million fitness trackers are sold in Britain each year, with the promise of monitoring and improving activity levels.

However, Dr Greg Hager, an expert in computer science at Johns Hopkins University, said many apps and devices had no real evidence base and that a one-size-fits-all approach could be harmful for some people.

Dr Hager told delegates at the American Association for the Advancement of Science annual meeting in Boston that the 10,000 steps doctrine was based on just one study of Japanese men dating back to 1960.“Some of you might wear Fitbits or something equivalent, and I bet every now and then it gives you that cool little message ‘you did 10,000 steps today’,” he said. “But why is 10,000 steps important? Is that the right number for any of you in this room? Who knows? It’s just a number that’s now built into the apps.“I think apps could definitely be doing more harm than good.”

In 2013, the NHS established a Health Apps Library to provide patients with a choice of health and treatment software and GPs were encouraged to recommend apps to their patients.Yet the University of Liverpool found that just 15 per cent of those listed for depression were proven to be effective.Dr Steve Flatt, of the university’s psychological therapies unit, who co-authored the study published in the BMJ, said: “This field is currently in its infancy and can currently be likened to the snake oil salesmen of the 1860s.

“There is every likelihood that apps will actually be very useful in managing all sorts of ailments, physical and psychological, but unfortunately the designing and testing stages seem to have been largely missed out in the race for profits.”

Simon Leigh, a health economist who co-authored the BMJ paper, said: “A GP, endocrinologist or other fitness specialist would unlikely recommend 10,000 steps for most people.”

Research last year by the University of Pittsburgh concluded that people who used a wearable technology device lost less weight than those undertaking standard weight loss techniques.Dr John Jakicic said not everyone was physically capable of doing 10,000 steps. “If you are elderly or infirm then this is not going to be good for you,” he said.“We need to be careful about relying solely on these devices. However, there is a place for these, and so we need to be careful not to throw the baby out with the bathwater in my opinion.”