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 six different types of fitness-tracking wearable, and it’s hard to know where to start. Particularly with the recent arrival of powerful Fitbit Ionic.
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: a phone-free Fitbit
Fitbit Ionic (£300)
The Ionic is like all of the best bits from Fitbit’s other trackers rolled into one.
That doesn’t mean it’s the best smartwatch you can buy (far from it), but it is the best all-round Fitbit ever, particularly if you want to track runs, bike rides and swimming.
It’s the only Fitbit with built-in GPS (although the Blaze and Charge 2 can piggyback off your phone’s GPS) and the only one, other than the Flex 2, that’s fully waterproof.
Want to store music, use third party app or make mobile payments? Again, it’s your option in the land of Fitbitania.
While the Ionic has impressive stamina for a smartwatch, the downside of all this extra functionality is that it’ll only last a few days between charges (and even less if you go big on using GPS).
Compared to something like the Apple Watch, the smartwatch functionality is also pretty limited, with the app count currently standing at just two (Strava and Weather).
Still, even taking into account the steep price tag, it’s one of the best choices around for getting daily health insights with a smattering of sport tracking. And it'll only get better from here.
Best for: pretending to own a smartwatch
Fitbit Blaze (£160)
The Blaze might look like a smartwatch, but don't be fooled – it's more like a basic tracker in watch clothing.
It lacks the Ionic's built-in GPS, third party apps, musical talents and waterproofing.
So what can it do? Accurate heart-rate tracking, multi-sport modes, sleep-tracking and a seven day battery life, all fronted by a lovely colour screen.
Take it out with your phone and it'll fill in many of its functionality gaps too, including GPS, music controls and alerts for calls and texts.
So while it's nowhere near the standalone smartwatch it resembles, it can do a passable impression when hooked up to your phone.
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.
Best for: swimmers and stylehounds
Fitbit Flex 2 (£80)
Want a Fitbit that you can take swimming and wear in the shower? Other than the Ionic, the Flex 2 is your only option - and the good news is that it's also a fine 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: 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.