Is your fitness watch making you gain weight?
By Fahad Maniar
Picture this, It’s Christmas morning and the obligatory exchange of gifts ensues. My wife hands me a tiny little box, rather underwhelming if I am honest but as I unwrap the gift, to my surprise, it’s something every fitness enthusiast would dream of!
Yes, my lovely wife had bought me a Fitbit smart watch.. but it was the HR model to boot and that meant it had a (rather inaccurate) heart rate monitor.
This meant two things to me. Firstly, I am a geek and I love to measure everything and secondly, I am also very interested in HRV training – that’s heart rate variability. I got into the concept of HRV training when I was training for fights and when I paid closer attention to heart rate, I found that my recovery rate between rounds was faster so I really liked the idea of having the Fitbit HR especially since I am a certified Hear rate conditioning coach with NESTA.
My first night with the Fitbit was exciting because I got to track my sleep. Again, the geek in me relished waking up to check the stats. In fact, I became one of those addicted to my smart watch, taking it off only to shower. Yes, one of those people!
I no longer use my Fitbit any more, mostly because I lost it but guess what, my fitness progress hasn’t slowed down one iota.
But where am I going with all of this?
Well, interestingly, a study was done at the University of Pittsburgh in the USA. They took 420 people and put them on a calorie controlled diet and exercise regime. Half of the group were asked to track things the old fashioned way and the other half were given a fitness tracker to monitor their progress.
After two years, they collated the data and noticed something quite interesting. The group with the fitness trackers loss LESS WEIGHT than those without!
One of the causes of this was brought to light by the lead of this experiment, John Jakicic who stated that the watches would measure an estimate of calorie expenditure based on steps, heart rate and movement which were grossly exaggerated by the watch and in turn, people felt that they were able to eat far more than they actually were allowed.
Remember I said the heart rate itself was inaccurate? Well when I was fight training and measuring my Heart Rate, I did use a polar monitor at one point, more accurate than a smart watch and I could get my heart rate up to 158 beats per minute treadmill sprints. When I did the same exercise using the Fitbit, I couldn’t get past 100bpm and that’s when I knew something was not right.
Now, I am not saying you should ditch the Fitbit or the smart watch – One of the benefits of having the watch is the way it gamifies fitness and encourages you to get your step count to 10,000 per day but it is important to understand that their calorie expenditure estimates are not accurate and if you’re relying solely on that to work out how much you should be eating then don’t be surprised if, like the group in the experiment, didn’t lose as much weight as they would have hoped for.