Ever since I strapped on a Fitbit One in 2012 — back when wristband trackers weren’t a thing — I’ve worn a fitness tracker that measured an ever-increasing array of health parameters. Over time, they’ve grown in size from tiny to the massive Apple Watch Ultra 2 that I wear every day. There is one category, however, that takes the form factor in the opposite direction: smart rings. After wearing the smart ring—Bengaluru-based Ultrahuman’s Ring Air—24×7 for the better part of five months and the Noise Luna Ring for just over a month, here’s what works, what doesn’t (yet), and what we can look forward to in the smart ring space in the coming months are coming.

Log of the Rings

First, Ring Air ( ₹28,499), a health tracker with a bunch of sensors, including a heart rate monitor, a six-axis motion sensing unit and a skin temperature sensor, all packed into an 8mm wide and 2.4mm thick titanium ring. As with the Luna ring ( ₹19,999), is light and unobtrusive, so much so that its existence on the finger was not noticed after the first week. Comes in 10 sizes and five finishes; a sizing kit is sent as soon as you order to ensure the correct fit. The build quality is good; I haven’t rubbed my ring in all these months, but I imagine it won’t do so well if you like to lift weights or work with outside tools.

These sensors record heart rate, movement, and body temperature data to give you a report on three scores: a movement index, a sleep index, and a recovery score—how regularly you’ve moved, how rested you are, and how well your general health will be. While the Luna Ring follows a similar approach (sleep, activity and readiness), the Ring Air’s secret weapon is a companion app that displays your key results and lets you dig deeper into individual markers.

At any given time, you can see your heart rate, VO2 Max (maximum oxygen consumption) and skin temperature, along with little lifestyle prompts. I learned about my adenosine clearance window, which tells me whether or not I should consume caffeine at a certain time, or how to stay in tune with my body clock by knowing when is the best time for sun exposure or exercise, or my ideal bedtime.

Submit yourself to it and you’ll feel somewhere between “hacking your health” and “letting an algorithm decide your day for you.”

You can also log various exercises, but the rings don’t automatically detect the exercise if you start exercising and don’t log the activity. Now, whether you want to do this or not, brings me to the most important consideration of smart rings, at least for now.

How accurate are the rings?

Smart rings require higher accuracy than wrist-worn monitoring devices due to the fact that fingers have a higher perfusion index and arterioles and thus serve as a richer and more accurate source of biomarker information. This works better for some metrics than others – sleep tracking, for example, is great, and it’s the main reason why many who don’t want to wear smartwatches to bed would prefer a ring instead.

The Ring Air was able to determine with fairly high accuracy when I fell asleep, when I had restless sleep, the quality of my sleep stages, and the sleep index and recovery score were accurate estimates of how tired or awake I felt the next morning.

Jitesh Luthra, an entrepreneur-in-residence at Leo Capital, who has been using the Ring Air for over six months, adds that while he chose the product because it was lightweight and best for sleeping, the fact that the ring tracked his metrics without adding another screen was the main reason. .

Activity tracking was a bit of a mixed bag, especially when you pit smart rings against wrist-worn wearables. Step tracking during my daily walks on the Ring Air was closer to the actual number than the Watch Ultra 2, but I noticed that playing the piano or typing a furious email had the unintended effect of adding phantom steps. Live heart rate monitoring needs work—even according to Ultrahuman, it’s optimized for measurements at rest, not while moving (still in beta).

While I wouldn’t count on any smart ring as my sole source of exercise data, they do give you a good sense of how active you’ve been on a day-to-day basis, which might be enough of an indicator for most. Meanwhile, Noise has confirmed its accuracy through independent studies from IIIT Hyderabad.

dr. Ashish Contractor, Director, Department of Rehabilitation and Sports Medicine, Sir HN Reliance Foundation Hospital, Mumbai, agrees: For parameters like steps and calories, a general feeling is good enough, says the doctor. He thinks accuracy becomes more important if you’re monitoring an EKG for someone with a heart rhythm problem, an ability that smart rings don’t have.

What’s on the horizon?

The manufacturer is excited about the category, given how convenient the rings are to use and the data they unlock, minus the screen time and daily charging.

Globally, the space is dominated by Finnish company Oura and its third-generation ring ($299 and up), and while its wide array of sensors and strong connectivity to share data with other apps make it a top pick, the subscription model for advanced insights could turn off potential users. Late last year, Oura filed suit against Ultrahuman for patent and copyright infringement, and then sued two other smart ring brands, RingConn and Circular, earlier this year. Clearly, there is a lot at stake as the number of brands looking to enter the category will only grow.

The action heats up with Amazfit launching the Helio smart ring and Movano with its female-focused Evie ring launching at CES 2024.

Samsung announced the launch of the Galaxy Ring later this year—perhaps it would be an ecosystem play first and foremost, working to complement the richer exercise and activity data from Galaxy smartwatches with 24×7 sleep and movement data from the ring. Maybe even Galaxy AI play through AI-based coaching?

The same goes for Apple’s much-rumored smart ring, which could significantly improve Apple’s sleep tracking. The ring could even act as an input interface for iPhone, Mac and Vision Pro. Inevitably, the biggest reason the Galaxy Ring and anything Apple launches will be a hit with the mainstream will be due to their joint (and rather substantial) marketing to the Android and Apple faithful.

Tushar Kanwar, tech columnist and commentator, posts @2shar.