Fitness tracking, though insanely popular right now, isn't exactly new science.
Leonardo Da Vinci is generally credited with inventing the pedometer: Thomas Jefferson brought a version to America (it involved a pair of weighted balls and a pendulum), and advised one of his nephews that 'Walking is the best form of exercise. Habituate yourself to walking very far.'
That said, it's a science that 2016ers need more than ever: it's literally never been easier to summon a cut-price cab to the exact spot you're standing in, or drink an entire day's worth of calories via something disguised as coffee.
Are they working?
This might be why fitness trackers have never been more popular: according to research analyst Mintel, three million of them were sold in Britain alone last year, with one in seven UK adults now owning some sort of wearable tech. But, considering that we don't collectively seem to be getting any leaner, it's fair to ask: do they work?
Firstly, let's deal with the obvious gripes about them not working in the most literal possible sense. Some tests suggest that these devices aren't always very accurate, and it's possible to argue that they're not tracking the important stuff: but that's like complaining that mobile phones are rubbish because sometimes your reception drops out.
These are teething problems, things that can be sorted out: the current wave of wearables is already getting better at dealing with things like heart-rate tracking, and we're probably less than a year away from getting widespread, affordable trackers that can tell the difference between a press-up and a kettlebell swing.
The future is now
Combine them with the upcoming generation of smartphone-sized molecular sensors, and by the time Star Wars VIII comes out, you'll (probably) be able to track every movement you make and drop of sweat you shed, while getting a near-flawless macronutrient breakdown of everything you put in your mouth. So the real question is: should you?
The unsexy answer, as with most things fitness, is: it depends. Last year, I used a variety of the market's leading fitness trackers to train for, among other things, a half-marathon (1:44, thanks) and my first Tough Mudder. They worked for me, but then I'm the perfect storm of fitness nerd, raised by videogames to try harder at anything that involves points, levels or tiny glowing medals.
Each to their own
Yes, I occasionally got off the Tube a stop earlier to bump up my daily step-count, but I'm the infuriating sort of person who does that anyway: I also sprint up escalators because I don't like waiting, and semi-regularly end up running to meet people in the pub because I never, ever set off on time. I like walking, I like running, I sleep like I've been shot with elephant tranquilizer and the only variables I really think I need to worry about are how much I drink and go on Twitter (spoilers: too much).
Seriously, you'd probably hate me.
On the flipside, some people respond terribly to wearables: just as people don't have as much fun when they're having their productivity assessed in most spheres (studies suggest that even colouring books are less fun when your progress is being emotionlessly tallied). There's even evidence that a few people feel frighteningly beholden to their wearables, ending up joylessly trudging up and down their stairs until their step-counter clicks over the magic 10k marker (which doesn't actually signify anything: it's an arbitrary yardstick originally created to market a Japanese pedometer called the Man-Po-Kei).
Where to from here?
For these people, tracking is probably doing more harm than good - with any form of exercise or eating, the key is to find a system that's sustainable for the long term, and building associations between activity and drudgery is almost exactly the wrong thing to do. If your tracker is making you miserable, here's my advice: give it to somebody who likes videogames, go for a nice walk in the sunshine, and don't worry too much if you fancy a biscuit afterwards. I don't have any evidence that worrying about biscuits will affect sleep, but I do know they're delicious.
What about everyone who falls between these two extremes? Well, that's where fitness tracking seems to shine. Plenty of people I know are in the 'nearly there' stage of fitness: they're already moving about a bit and eating more greens than cake, but for whatever reason they aren't quite seeing the results they want.
Awareness is key
This is where trackers can help: just by making you aware of how much difference it makes to walk slightly further with the dog or step up the pace on the bike, they can help identify easy wins and trouble spots to avoid that can make all the difference to actually enjoying a sustainably active lifestyle. Combined with some very basic (and short-term) calorie-counting, this works even better: spend three days with a notepad jotting down the nutritional content (kcals, protein, sugar, carbs, fat) of everything you eat, and you'll start to see exactly where it's worth swapping a frappucino for an Americano rather than run up 17 flights of stairs to walk it off.
At the very worst, having a neon-coloured wristband counting your steps keeps fitness front-and-centre in your mind, and that might be just what you need to make a change in your life.
Or, of course, you could try a pair of tiny balls strapped to a pendulum in your pocket. It worked for Thomas Jefferson.
The Telegraph, London