The Fitbit Charge is an activity tracker that displays fitness stats right on your wrist. It's the replacement for the Force, which never launched in the UK. It's better than the Force, thanks to a couple of handy additions: automatic sleep tracking and call notifications. It also has a redesigned buckle that's less likely to come apart while you're on the move.

Fitbit Charge: new features

Auto sleep tracking means you can go to bed and wake up without worrying about pressing a button to tell the Charge that's what you're doing. It works well, too, and the sleep graphs accurately show when you fell asleep and woke up. Plus, you get a breakdown of deep and light sleep: it isn't as detailed as the Jawbone Up3's tracking, but it can still help you identify any sleep issues and the vibrating alarm can wake you in the morning.

Call notifications mean you'll get a buzz and a name or number on your wrist when someone phones. You still have to take the call on the paired smartphone because there's no built-in speaker or mic, but it does mean you'll miss fewer calls.

Fitbit Charge: app and design

The Charge also measures your steps, distance covered, calories burned and flights of stairs climbed, all of which are shown on the display. Unlike the forthcoming Charge HR, this band doesn't monitor your heart rate.

In the app, you can see even more facts and figures, including the number of minutes you were active and the total amount of deep sleep you got the previous night. If you want to, you can enter the food and drink you eat each day and track your weight with Fitbit's Wi-Fi scales. However, there's still no UK food database, so you're still better off using MyFitnessPal, which is compatible with the Fitbit app.

The tracker comes in three sizes and various colours, although initially only models with a black strap are available.

We've found that the battery lasts for nine days between charges, which is longer than Fitbit claims. It's frustrating that you still need a proprietary charging cable, though, as they're easy to lose.

The band is water resistant so you can go for a run in the rain or shower in it, but it's recommended not to swim with it.

It's possible to track workouts by using the built-in stopwatch. You can later tag the activity in the app and choose how strenuous, for example, your cycle ride was.

Although the Charge can't track different types of exercise like the new Surge 'superwatch' can, you can use a relatively new feature in the app - Mobile Run - to track running, walking and hiking stats and map routes using your iPhone’s GPS. Fitbit hopes to make this feature available to Android and Windows Phone users shortly.

Fitbit has also added Challenges to the app, which adds even more motivation to smash through your daily step goal.

Fitbit Charge: verdict

At £99, the Charge is far from the cheapest activity tracker. However, unlike certain rivals - including Fitbit's own Flex - the Charge's display is a big advantage. There's also a big advantage buying into a popular system, as you're more likely to find friends to compete with than if you buy a lesser-known tracker.

It's by no means the most expensive, either, and if you're specifically after a wristband with a display and don't need a heart-rate monitor, it's a superb choice which, combined with the excellent app and online dashboard, offers real motivational tools to get you fitter, healthier and maybe even a little lighter.