Fitbit has done a Hoover - it's now so synonymous with fitness trackers that even non-techies use it as shorthand for health-watching bands.
The trouble is, it now offers eight - yes, eight - different types of fitness-tracking wearable, and it’s hard to know where to start. Particularly with the recent arrival of the genre-blurring Alta HR.
Fear not though, because we’ve reviewed them, studied them, and learnt their innermost secrets, to determine which one you should be strapping/clipping onto your body:
Best for: tracking solo sports
Fitbit Surge (£200)
The Surge is the most expensive Fitbit out there and it's £40 dearer than its Blaze brother. Both offer the whole shebang - steps counted, heart rate, calories burned, music control, sports tracking and notifications.
But the Surge also adds the benefit of built-in GPS. This lets you leave the phone at home when you’re out pounding the pavement, is much more accurate it tracking distance than an accelerometer, and means you can export maps to other services like Runkeeper or Endomondo. The only downside is the slightly odd, wedge-shaped body, which is worth trying on before you buy.
Fitbit has been rumoured to be working on a smartwatch for a while, and recent acquisitions like Pebble and Vector suggest that there's some truth to them. But until then, this is the closest you can get to a Fitbit-flavoured Apple Watch or Garmin Forerunner.
Best for: a smartwatch alternative
Fitbit Blaze (£160)
The Blaze takes all the tricks of the Surge, but drops the GPS tracking smarts. This won’t be a massive issue unless you regularly run or cycle and would rather leave your giant phablet behind.
If you don't mind taking your phone out on runs though, you can still track your route, piggybacking off your handset’s GPS. The Blaze is also the most watch-like of all of Fitbit’s offerings, serving up a colour screen and a variety of strap options. Its five-day battery life comfortably beats out its Apple and Android smartwatch rivals too.
Best for: a fitness stats-fest
Fitbit Charge 2 (£140)
Fitbit has paired the now very similar Charge 2 and Alta HR together under the same 'heart-rate and fitness bands' umbrella, so which is the best for you? The main difference is the screen, with the Charge 2's 1.5in OLED display much better for glancing at real-time info and notifications like calls, texts and calendar alerts while you're exercising.
That inevitably also means the Charge 2 has a more watch-like form factor compared to the band-like Alta HR. Though, unlike the Alta HR, it does also pack an altimeter for tracking the numbers of floors you've climbed and a 'Cardio Fitness Level', a real marker of fitness rather than health. It's a close call, but if you want everything short of GPS tracking in a watch-like form factor, the Charge 2 is your best bet.
Best for: all-round health tracking
Fitbit Alta HR (£130)
Fitbit's latest tracker is quite a feat of miniaturisation - it's the first fitness band to pack in an optical heart-sensor, which is particularly handy for tracking both exercise and sleep.
The Alta HR still errs on the side of health rather than sport-tracking, though you can connect it to your phone's GPS to get maps of your runs using the MobileRun feature. Its main strength, though, is sleep-tracking. It's one of only three Fitbits (along with the Blaze and Charge 2) to support the app's new Sleep Stages and Insights features.
These give you extra-fine detail on your sleep patterns and match this with your exercise data to give you advice (for example, there's a strong correlation between your runs and better sleep). The only real downside is that, like all Fitbits other than the Flex 2, it's not waterproof for showers and swimming.
If you want an always-on health tracker with a week-long battery life, and aren't too bothered about getting real-time data from a screen, the Alta HR is the best around. We'll have a full review very soon.
Best for: swimmers and stylehounds
Fitbit Flex 2 (£80)
Want a Fitbit that you can take swimming and wear in the shower? The Flex 2 is your only option, and the good news is that it's also a good health-tracking all-rounder.
You get the usual steps and calories tracked and, thanks to its usually reliable SmartTrack exercise detection, it'll also automatically log runs, bike rides, walks and other workouts. For swimming, it'll also stand by with its virtual clipboard and note down lengths swum, distance and pace.
The downsides? Unlike the Alta HR, there's no heart-rate tracking, support for the Fitbit app's new Sleep Insights feature, or a screen. But it does tick off all the basics and comes in a good range of colours, not to mention gift-friendly bangle and pendant form factors.
Best for: stripped-down health tracking
Fitbit One (£80)
The Fitbit One is essentially the original Flex morphed into a clip-on form factor.
Its screen lets it display the time and it can track your sleep, although you’ll have to manually set it to do so before you nod off. The basic steps and calories are all counted, but again, there are no fancy heart rate tracking or automatic exercise detection tricks here.
It's showing its age (four and half years, at the time of writing), but it's still an affordable prod in the right direction (that's away from the sofa).
Best for: cash-strapped newbies
Fitbit Zip (£50)
At £50, the Zip is the cheapest in the entire Fitbit range, and offers basic tracking in the form of steps taken, distance travelled, and calories burned.
Aside from displaying the time (but lacking the silent alarm functionality present on all of its brothers and sisters), that’s pretty much it. The benefit to all this simplicity, apart from the price, is its massive six-month battery life, whicn comes thanks a coin cell battery.