Another dubious study claims fitness trackers don't help you shape up

Why do all these studies use such terrible devices?
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Another new study has claimed that fitness trackers are unlikely to help people become more active.

The report published in the The Lancet Diabetes and Endocrinology studied 800 participants who were split into three groups: control (no tracker); Fitbit (given a Fitbit Zip to track steps); charity (financial incentives given to charity); and cash (participants given financial rewards). Steps were then tracked over a twelve-month period, and the results are interesting.

Essential reading: How to use your fitness tracker to actually get fit

In a six month period the findings showed that the cash incentive group unsurprisingly logged the most "moderate-to-vigorous physical activity" (MVPA), which was the key outcome the researchers were looking for.

The long story short is that over six months compared to control the cash group was up 29 mins per week, the charity +21 mins and the Fitbit +16 minutes. The conclusion of the study, Fitbits don't actually increase activity in a meaningful way, as 16 minutes per week isn't actually that helpful. That's what the report says, anyway.

And that's where a lot of the reporting seems to end. But there's more.

Fast-forward to 12 months after the cash incentives stopped and the Fitbit group was logging +37 mins active time than the control, the charity group +32 minutes and the cash group? Well, they only managed 15 minutes per week more. So the long term effect seems totally different.

We have a few problems with the study. Firstly, it seems set up to conclude that fitness trackers don't help people get more active. But the results show that Fitbit users logged +37 minutes of moderate to vigorous activity per week than the control at the end of the study. We're not sure why the study has such a negative conclusion. 37 more minutes of MVPA seems like a positive outcome for those struggling to get active.

"We identified no evidence of improvements in health outcomes, either with or without incentives, calling into question the value of these devices for health promotion," the report concluded.

The study also suffers the same problem as the JAMA research we reported last week, which highlighted that a group that used a fitness tracker lost less weight than a group that didn't. Firstly, why on earth did the Fitbit group get a Fitbit Zip? That device is a simple pedometer, most likely used because it's cheap.

What's more, the study looks for minutes of "moderate to vigorous activity". The Zip does nothing to promote vigorous activity. The two are unrelated. If it was a measure of steps then the participants were given the right tool for the job – but it wasn't. Very strange indeed.

Of course, there are takeaways here. Step trackers are pieces of plastic that record your physical activity. They don't actually do the fitness for you. Anyone looking to get fitter can benefit from them if used in the right way, and they can provide motivation – if you want to get outside and do the hard work.

Another dubious study claims fitness trackers don't help you shape up

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James Stables


James is the co-founder of Wareable, and he has been a technology journalist for 15 years.

He started his career at Future Publishing, James became the features editor of T3 Magazine and and was a regular contributor to TechRadar – before leaving Future Publishing to found Wareable in 2014.

James has been at the helm of Wareable since 2014 and has become one of the leading experts in wearable technologies globally. He has reviewed, tested, and covered pretty much every wearable on the market, and is passionate about the evolving industry, and wearables helping people achieve healthier and happier lives.

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