While good scales have been round for ages, physique composition evaluation continues to be a reasonably new characteristic for wearables. Case in level, the Samsung Galaxy Watch 4 was the primary smartwatch to natively embody the characteristic. Amazon’s Halo Band was the primary health tracker with the characteristic. Both of those launched up to now two years. Meanwhile, Apple has but to deal with physique composition. For Apple Watch homeowners, you’ll have to show to equipment just like the $149 Aura Strap 2.

Like good scales, the Aura Strap 2 determines your physique composition by way of bioelectric impedance evaluation (BIA). BIA works by sending a weak electrical present by your physique to calculate your physique fats proportion, lean muscle mass, water, and generally area of interest metrics like bone mass. This explicit strap measures fats, muscle, water, visceral fats (the dangerous kind of fat), protein, lean mass, and minerals (a proxy for bone mass).

Compared to the corporate’s first iteration of the machine, this one is 20 % slimmer and 5 % narrower. The measurement course of has additionally been simplified. Instead of taking three steps on the unique Aura Strap, all you need to do is contact your palm to the strap’s electrode and wait 30 seconds. Purportedly, these design modifications allow Aura to report 16 occasions extra knowledge, and Aura Devices claims the second-gen strap delivers about 95 % accuracy in comparison with a DEXA scan — the scientific gold normal for figuring out physique composition.

That’s already a major overhaul, however the Aura Strap 2 additionally modifications how you place it on. Instead of clasps, it now opts for a stretchable band that resembles Apple’s Solo Loop band. That generally is a professional or con. If you’re utilizing the Apple Watch primarily for well being monitoring, then you definately’re in all probability already conscious of how vital match is. Loose matches make for inaccurate metrics, so that you need the BIA sensor to relaxation flush in opposition to your pores and skin. That’s tougher to do with a stretchy band. Out of the field, the Aura Strap 2 comes with the medium-sized strap preinstalled and three further sizes in additional small, small, and enormous. The medium strap didn’t match my tiny hen wrists. Neither did the small. Thankfully, the additional small did the trick — although I’ve pals with even smaller wrists than mine. If your wrist doesn’t fairly match one of many 4 straps, you’re out of luck as a result of there’s no technique to regulate the strap.

But whereas the additional small band match my wrist, it was a ache to stretch over my palms. I’ve larger-than-average palms, and there’s solely a lot you’ll be able to stretch the strap. (I can use an iPhone 12 Pro Max single-handed with zero issues, and my fingers can stretch 9 keys on a piano.) Thankfully, the corporate says it’s secure to take into the bathe and pool, that means you don’t must take it off greater than as soon as a day. So whereas I usually take off my Series 7 to bathe — you gotta let your wrists breathe, people! — I stored it on to keep away from taking the strap off. I additionally dreaded placing on the strap within the morning and taking it off at evening. I’ll admit that this can be an issue that’s particular to my physique, nevertheless it’s one thing to pay attention to in case you have giant palms.

Another strap-related gripe: to vary strap sizes, you need to open the casing that homes the battery and electrode. The annoying factor is you’ll be able to’t merely pop it open together with your fingers. The strap comes with a bit of guitar choose that you just use to wedge it open, however should you’re like me, you’ll in all probability lose it inside seconds. But not less than you can even use a bank card. This is tedious if it’s essential to attempt a number of bands to seek out your right measurement, although it isn’t prone to be an enormous problem past setup and when it’s essential to substitute the battery itself. Aura says the coin cell battery ought to final about six months should you take a single studying per day. I can’t say whether or not that’s true, as I haven’t been utilizing the strap for that lengthy. However, after a few week of testing with 2–3 checks per day, I’ve about 76 % left.

Otherwise, the Aura Strap 2 is refreshingly easy to make use of. There are clear directions on the best way to take measurements each within the iPhone app and on the watch itself. To take a studying, all you need to do is put your palm in opposition to the electrode with the Aura app open on the watch. Aura does suggest that you just stand together with your arms out in entrance of your chest — type of such as you’re about to do a Russian squat dance with out the precise squat — however that’s it.

This is a big step up from the Galaxy Watch 4. When I reviewed the BIA characteristic on that watch, Samsung gave me a laundry listing of issues I needed to examine to get an correct studying. That listing included ensuring I wasn’t menstruating or sporting jewellery. It was annoying to make use of should you wore the watch in your proper wrist, as you needed to reach around to access the buttons. None of those was a problem with the Aura Strap 2. While it did suggest taking measurements at across the similar time every day, I didn’t have to fret about my interval, my jewellery, or which wrist I wore the Series 7 on, as Apple allows you to customise your watch’s orientation.

My outcomes had been additionally constant from studying to studying. They additionally roughly correspond to outcomes I received on the Galaxy Watch 4 and the Amazon Halo View. However, in contrast to these units, the Aura app gave me a lot better context for a way these metrics associated to one another. Every different machine has informed me that I’m chubby or overweight primarily based on physique fats proportion. While physique fats proportion is extra useful than BMI, it’s an incomplete image. For occasion, my waist-to-hip ratio — one other technique of measuring your danger of coronary heart illness primarily based in your stomach fats — is properly inside a standard vary. Also, my good scale typically places me at 27–31 % physique fats. Basically, you must at all times take into account these units will help you measure progress, however they might not be correct in terms of your particular well being.

That’s why I used to be impressed when the Aura app mentioned that whereas my physique fats proportion was a smidge above regular vary, I had an total “good balance of fat and muscle.” Generally, you don’t get way more than straight numbers with physique composition options. I additionally appreciated how the app described every metric and the way I ought to interpret it. For instance, my visceral fats proportion was 1 %. Normally, I’d assume that’s a superb factor. However, the app famous that having visceral fats beneath the conventional vary would possibly point out I don’t have sufficient for my bodily wants and to examine with my physician if my visceral fats was out of vary for a sustained time period. It additionally defined that the “norm” was primarily based on the final inhabitants and didn’t essentially consider my particular person metabolism, way of life selections, or my private norms.

If you do have a particular physique objective — whether or not it’s to drop a few pounds or get jacked — the Aura app may even contextualize the place you’re at and the best way to get there. I set my objective as an “athletic” physique with muscle achieve. The app, in flip, informed me I’m about 80 % of the way in which there already and really helpful I improve my caloric consumption by 10–15 %, add extra protein to my food regimen, and do not more than three exercises per week.

The better part is that weight is just not a giant focus of this app. You do must enter it initially, however even should you set your objective to lose fats, it by no means recommends that you just “lose weight.” Instead, it recommends that you just cut back your carb and sweets consumption for 2 weeks and cross-train.

But whereas I appreciated the additional evaluation and context, I didn’t love that a variety of it’s locked behind a paywall. If you need month-to-month stories on health and diet, guided exercises, or an upcoming characteristic that allows you to chat with a private coach, you need to pay $9.99 month-to-month or $79.99 yearly. I can’t definitively say whether or not the additional charge is value it, as I examined a pre-launch model of the app. The exercise library I had entry to was easy and simple to observe however restricted to at least one exercise per physique space and talent degree (newbie, intermediate, superior). Likewise, I didn’t get the total month-to-month report expertise as I’ve solely been testing for a pair weeks. You’re already spending $150 on an adjunct. Adding a subscription makes enterprise sense, nevertheless it’s one more factor to pay. And individuals who’d be inclined to purchase this machine doubtless already pay for a number of fitness-related subscriptions.

Ultimately, I used to be pleasantly stunned by the Aura Strap 2. It’s not good, however then once more, few accessible physique composition devices are. What units this aside is a greater app that provides holistic insights and context. It’s admittedly a distinct segment product, however should you’re an Apple Watch proprietor who’s involved in altering your physique composition? You may do a lot, a lot worse.

Photography by Victoria Song / The Verge