WHY THEY CAN EVEN MAKE YOU FATTER!

BY GETTING us fixated on steps, calories and heart rate, sports trackers can actually cause our fitness to decline.

A study in 2016 found they were less effective for weight loss than following a balanced diet and exercise plan.

The research, published in the Journal of the American Medical Association, tracked 470 overweight or obese people and found that those using trackers lost 7.7lb over two years, while those self-monitoring lost an average of 13lb.

Trackers can make us complacent: when you reach 10,000 steps, you’re tempted to reward yourself with cake. And psychological studies have shown they actively discourage good behaviour: some people are so disheartened by their inability to reach 10,000 steps, they give up exercising.