The Moov Now is not your typical activity tracker. Rather than monitoring your exercise and letting you know how many steps you've taken and how great you're doing, it's designed to be a personal sports coach which speaks to you while you work out. We recently spent a month being bossed around by this little puck, to see whether it's the best wearable for knocking you into shape.

The original Moov, which we saw in 2014, broke the mold for fitness trackers by also working as a smart sports coach. Worn on your wrist or ankle, it tracked movement in 3D and aimed to motivate you with sports-specific audio and visual coaching via a smartphone. However, while well-received, the bulky device had decidedly first generation looks and ho-hum battery life.

Moov Now addresses those issues, and more, by being much more streamlined, both in terms of the physical device and the user experience. The slimmed down and now sleek tracker, which comes in a number of colors, is considerably smaller than its predecessor and its stretchy wrist and ankle bands (which look way better than they sound) make it something you wouldn't mind wearing everyday.

The small puck, which contains a 9-axis motion sensing system including an accelerometer, gyroscope and magnetometer, now uses a replaceable coin battery (CR2032). This should be good for six months of activity tracking or 100 hours of active coaching. A sole LED is used for feedback, which is basically limited to letting you know it's working. This means there's no on-wrist display, or the ability to use it as a watch, also lacking is any vibration alarm.

Upgrades on the app front include what was a suite of several sports-specific apps having now been rolled into one (for iOS or Android). This gives users a much better experience when it comes to both selecting the workout you are about to embark on and get coached through, or check your activity tracking.

Unfortunately, while the Moov Now is billed as a smart sports coach with activity tracking, its general all day activity tracking is somewhat limited compared to the competition. Rather than logging a combo of steps, distance, floors climbed and heart-rate like devices such as the Fitbit Charge HR, Jawbone Up, and Garmin Vivoactive, Moov Now only tracks your active minutes.

This is apparently because the Moov team think active minutes, which are used by the World Health Organization in its exercise recommendations of 30 min per day, is a better way of encouraging an active lifestyle. This is indicative of the it-knows-best attitude of the Moov Now. While this might well be the best approach when it comes to sports coaching (which we'll get to shortly) it can feel limiting very quickly if you are used to activity tracking using a range of measurements.

For example, it can be satisfying to break your 15,000 step per day target, and there are plenty of exercises which won't register as active minutes. During our test of the Moov Now, a 60 minute yoga session didn't register as active minutes, while the walk to the studio did. Without the ability to use a more relevant metric, or log this workout information in another way, it's easy to get to the point of not wanting to use the Moov Now for general activity tracking.

Sleep tracking is also limited compared to some other trackers and will just break down sessions of shut-eye to periods of restorative sleep and log when you dozed off and woke up. If wrong, this data can be edited. On the plus side, the lightweight Moov Now is one of the most comfortable trackers we've used at night. The lack of flashing heart-rate monitor also means it's less likely to disturb your sleep.

Luckily, the situation is much better when it comes to logging specific workouts and the sports coaching modes which make the Moov Now something special. Users are able to select from a number of walking, running and cycling workouts designed to do things like train you to run further or improve your pace, and Moov Now will guide you through the exercise with vocal instructions via your smartphone.

All of these workouts will require you to have a phone with you and wear the Moov Now either around your wrist or ankle. Once that's done you select the level you want to be pushed to (the variety of levels will cover everyone from unfit beginners to seasoned athletes). Vocal coaching via your headphones can then tell you what to do and give you form tips based on the movement of the tracker.

The real-time audio feedback and instruction from the Moov Now means you can act on what it's saying straight away, unlike the post-workout data summaries you get with most trackers. While you can also connect a bluetooth heart-rate monitor in the app, its readings will only be logged for post-workout review, not used as part of the smart coaching, which is a shame as this feature impressed on the TomTom Spark Cardio + Music.

The Running Efficiency mode instantly made workouts feel more constructive than my usual unstructured and meandering runs. Here, with the Moov Now on an ankle, you are told how fast you should be going in each interval with a target cadence, and if you slow down you'll soon be told to pick up the pace. Any lapses in form will also be greeted with the Moov Now voice coach telling you to soften the impact on your feet, or to try not to rotate your hips.

Trying out the Sprint Intervals option, with the Moov Now constantly pushing and giving instructions to go faster, soon had me panting for breath and hating the sound of that calm voice. It felt much like the experience of having a personal trainer, and did encourage me to push harder than when using other trackers which are more carrot than stick with their reward badges.

That said, while working out, you'll also be offered words of encouragement in the way of phrases like "Come on, you've got this!" "You can do it!" or "Keep at it, nice work". While this sounds cheesy, there are enough phrases, and they are delivered in such a way it doesn't feel like it. In fact it's nice to have a break from being told to go faster. And if you get sick of the voice, you can always lower coaching frequency.

Once you've finished a workout you can then review your stats along with a map from your phone's GPS, in much more detail. In walking and running modes, measured units include steps, calories burned, cadence, range of motion and an impact score. In Cycling, metrics include cadence, tallest climb, fastest sprint, and Moov will tell you when to change gear to save energy or increase your cardio workout. There's also the option to analyze your swimming (where you leave your phone somewhere dry) with Moov recording info about your laps, stroke rate, distance per stroke and turn time.

Other at-home coaching features of the Moov Now include a 7 Minutes+ workout, with a video of the exercises (jumping jacks, squats…) playing on your phone along with an audio explanation of what you should be doing. During this time the Moov Now will count your reps, and does so more accurately than the Tickr X did when we tested it. Results are also logged so you can try to do more next time.

A Cardio Boxing mode, which ideally involves having two Moov Nows with one on each wrist, is somewhere between Wii Sports and Dance Dance Revolution. After a video guide you'll be air-punching jabs, hooks and uppercuts to timed targets until your arms start to ache and you think they are going to drop off. Yes, you'll look a fool doing it, but you'll get one heck of a workout.

Moov has previously said that more smart coaching modes will be made available with mentions of modes for martial arts, yoga and golf, though they are yet to appear, and there's no word on when they will.

We were simultaneously wowed and frustrated during our time with the Moov Now. The impressive active sports coaching alone makes this a wearable worth buying, even if it will kick your butt. The sports coaching features, telling you in real-time what to do and how to do it, means the Moov Now will be able to deliver the results if you're willing to do as it says.

We found being pushed to go faster or for longer during each workout much more motivational than the usual reward systems used with most activity trackers. If anything we'd actually like to see it go even further, with Moov Now also telling you to get out for a run if you've not done it recently.

However, the activity tracking limitations seem unnecessarily restrictive and not worth the full-time wrist real-estate. We ended up just using during workouts. The Moov-knows-best attitude of not logging steps, and all the other metrics we've come to expect of other trackers seems odd given there's presumably no technical reason it can't do this. That said, maybe it just makes it more like a real life personal trainer!

The Moov Now is hard to compare to other fitness trackers, because it's more sports coach than it is tracker. While devices like the TomTom Spark offer some training features, nothing comes close to what the Moov Now can do, it really is in a category of its own … it's just a shame it's not also a more complete activity tracker.

The Moov Now sells for US$80.

Product page: Moov Now

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