The best smart rings - our expert shares his 4 top choices

It’s easy to take for granted the extent of the miniaturisation that’s occurred during the lifetime of most of us. If you wanted a machine in the 1960s that was capable of replicating the computing power, storage, radio and user interface of a modern smartwatch, you would need a multiroom facility the size of a house, with hundreds of racks, dozens of operators and immense power consumption.

Fitness rings, however, which first appeared ten years ago, are another level of technological miracle again even from smartwatches. Pioneered by the Finnish company Oura, which still leads the field, they boast sleekly built, featureless bodies with sophisticated electronics on a near-microscopic scale, a range of sensors and LEDs, and sufficient battery to keep the ring powered up for seven days at a time. They are also genuinely stylish. 

The latest, the Oura 4 (from RRP £349, plus a £5.99 a month subscription, Oura ring) monitors your biometrics 24/7 – from the steps you walk to heart rate, sleep, body temperature, stress levels, ECG, heart rate variation (HRV) and more.

They are superb for tracking sleep, being less bulky than a wristwatch. Users have even reported the ring accurately predicting illness hours ahead of any symptoms appearing. 

The companion Oura app is really refined compared to how it was in 2015 – easy to use and full of insights. If you sleep badly or your ‘readiness’ score is low, it will advise you to take it easy that day. If you’re stressed, it suggests (a little annoyingly, if I’m honest) mindfulness articles and recordings. 

All rather amazing, but Oura now has competition. The best known and promoted rival comes from a six-year-old Indian company, Ultrahuman. Its popular Ring AIR is cheaper at RRP £329 (Argos) and a little lighter and thinner than the Oura model. The app, however, is not quite as slick, and the ring’s battery lasts more like five days. A big plus, though, is that, unlike Oura, Ultrahuman doesn’t require an irritating monthly subscription.

Cheaper still is the RRP £299 RingConn Gen 2 (Amazon), from a very new Chinese company. It is subscription-free and has the added ability to monitor sleep apnoea. 

And that might have been that – electronic rings are useful but expensive – had I not heard from Worcester reader John Dimmock, who bought a ring he’s delighted with on Temu, the cheap and cheerful Chinese site, for just £4.68. It is one of several it offers for under £10 by a brand called Youth Demon.

He is particularly impressed by the app. (Even more remarkably, John may actually have overpaid – Amazon offers one called Denash for a princely £1.53.) 

Who is the baddie in this equation – the big companies for overcharging or the minnows for nicking their technology? It’s hard to say, but I suspect the latter.

Hard to resist trying a cheapie, though, to see if a ring does what you need – which for most people is just sleep and step tracking. You can always get a serious model if you’re taken with the smart ring idea.