Fitbit just made the slimmest fitness band with continuous heart rate monitoring. With expanded sleep features and week-long battery life, it's a...

Up to 7 days of battery life on a single charge; Insightful sleep-tracking features; Automatic exercise tracking now includes heart rate zones

Lack of built-in or smartphone-connected GPS

The Fitbit Alta was popular with our testers and performed well during our lab tests. The tracker has a stylish design, with a touchscreen that displays all the information you need to track your daily activity like steps and calories burned.

Sends hourly movement reminders; Displays smartphone notifications; SmartTrack senses the type of exercise; Sweat and splashproof; Interchangeable wristbands; Easy-to-swipe touchscreen; User-friendly app; Sleek and comfortable fit; Automatic sleep tracking

Hard-to-use strap; Tough to read in sunlight; No heart rate monitor; Relatively short battery life

Fitbit is arguably one of the most well-known companies when it comes to activity tracking, monopolising around 70 per cent of the market. It not only offers a huge selection of devices in comparison to its competitors, but it also offers an excellent interface to match.

Best Fitbit design to date; excellent 5-day battery life; comfortable to wear; nice display; notifications; accurate step-tracking; fantastic app platform

No heart-rate monitoring; no altimeter; no waterproofing; inaccurate distance-tracking; display not always super responsive nor visible in bright light

In fact, the Fitbit Alta HR is the world's slimmest exercise band with a built-in heart rate sensor. On the design side, the Fitbit altar HR is virtually identical to the previous model.

If you've ever been in the market for a fitness tracker, chances are you have heard of Fitbit. The company is the obvious leader in wearable devices, as per reports from market researcher IDC , but it has been facing growing competition from Apple, Xiaomi and Jawbone, which have all been grabbing...

Thin and stylish; Accurate automatic sleep and activity tracking; Great battery life; Helpful hourly reminders to move

SmartTrack sometimes detects exercise when there is none; Notifications aren't very useful; No waterproofing; Classic and leather straps can be a hassle to put on

I've said it before and I'll say it again: The best activity tracker is the one you'll actually wear every day, otherwise there's no point in buying one at all. Fitbit's new $150 Alta HR is the one most people would wear not just every day, but all night-and that's worth every penny.

The Alta HR is Fitbit's most stylish heart-rate tracker to date. It lacks an altimeter for stair and hill climbing stats, but its 24/7 heart-rate monitor will help you get fitter, lose weight, and better monitor your sleep.

Fitbit's Alta fitness wristband looks to the lower-end of the market, with a sleek and user-friendly device.

Super small and light, this is the first device that I'm wearing on my opposite wrist as a pure tracker and not as a watch replacement.I've gone through multiple watch replacement models and I just don't like any of them enough to give up a well-made timepiece.

Tiny; HR Tracking; Accurate

Not waterproof; tap to touch confuses some..

If you're looking for an attractive, affordable fitness tracker that can handle the basics with little to no problems at all, you should consider the Fitbit Alta. Hardcore gym rats should look elsewhere.

- Sleek; modern design - Silicone strap is very comfortable - 5-day battery life - Accurate step and sleep tracking - Affordable price point - Companion app is easy to use

- Interchangeable bands are pricey - Silicone band can be difficult to put on - No waterproofing - Charging cable is short and awkward to use