Whoop vs Garmin Cirqa vs Polar Loop

These three look nearly alike on a wrist, and that's where it stops. Whoop sells a membership with a band attached. Garmin and Polar sell a band. The choice is less about sensors than about which app you want to open every morning.

I haven't worn any of them. Results below belong to the named outlet, and I checked this on 3 November 2026.

The price is not verified yet. £179.99 on garmin.com (UK), checked 3 November 2026. £107.64 on polar.com (UK), checked 3 November 2026.

Whoop's own site refused my request, so its details here come from Tom's Guide and TechRadar. I'm giving no Whoop figure in pounds, and no cost comparison involving Whoop, until there's a UK price I can verify.

How you pay for each

You can't buy a Whoop band alone. Tom's Guide describes three membership tiers, and the tier decides your features: the entry plan skips the stress monitor and Healthspan, for example.

Garmin says the Cirqa needs no subscription. TechRadar adds that Garmin Coach sits behind the optional Connect+ tier, and that live heart-rate broadcasting was briefly locked there too until Garmin reversed it. Polar calls the Loop subscription-free. TechRadar found a paid Polar training programme exists, but thinks it fits Polar's watches better.

Between the two you can price, the Loop costs £107.64 against £179.99 for the Cirqa.

Sleep and recovery readings

Here's the honest position. I found no peer-reviewed study of the Whoop 5.0, Cirqa or Loop against a sleep lab.

The nearest thing is an older model. Schyvens 2025 (peer-reviewed, 62 adults, 52 male, mean age 46) tested six wearables including the Whoop 4.0 against polysomnography. As a group they spotted sleep with sensitivity above 90%, but caught wakefulness far less well, with specificity of 29% to 52%. That's a different Whoop, so read it as a sign of what wrist bands find hard, not a score for the 5.0. My sleep accuracy explainer goes through the stages.

Recovery scores are harder still. Lepley 2026, a peer-reviewed narrative review, says "there is no gold standard" for them and calls the composite scores "largely unvalidated". Treat Whoop's Recovery and Garmin's Training Readiness as prompts to think about your week.

None of these bands is a medical device. If you have symptoms or concerns about your sleep or heart, talk to a clinician.

Heart rate in workouts

Reviewers' results are independent and non-peer-reviewed, and small.

TechRadar's Cirqa reviewer spent a week comparing it with a Polar H10. Most workouts landed within 1 to 3 bpm (the review gives both 1 to 2 and 2 to 3), with one strength session about 10 bpm off. A separate TechRadar test compared the Loop and the Amazfit Helio Strap with a Garmin Venu 4. Peak readings were typically within 2 bpm, and all three recorded the same 167 bpm maximum in a static bike class. TechRadar calls Whoop "competitive" for general workout heart rate, without a figure I can quote for the 5.0.

The peer-reviewed data again stops at the 4.0. In Van Oost 2025 (24 students aged 18 to 27, walking only, against 12-lead ECG), the Whoop 4.0's median error was 8.52%. That protocol never reached interval intensity, and it doesn't describe the 5.0.

Gadgets and Wearables says the Cirqa's workout accuracy still needs more real-world testing. I agree. If hard sessions matter, use a chest strap.

Training use and battery

The Cirqa does the most for someone who trains. It can broadcast heart rate, and Expert Reviews praises how complete its run records feel with Connected GPS borrowing your phone's position. TechRadar notes the limit: with no display, it's no good for timed runs or intervals. Pair it with a watch for those.

The Loop's weak point is software. TechRadar's Loop review calls it a good heart-rate tracker let down by a lack of features and frustrating software, and it says Polar has a redesign planned. TechRadar also found it won't share heart rate with other devices.

Whoop's app is the reason people pay. Gadgets and Wearables rates it the best-developed recovery platform of the group. TechRadar did find the clasp comes undone by itself, which sounds maddening on a band meant for 24-hour wear.

On battery, Whoop claims the most. Expert Reviews measured the Cirqa at 26% after seven days, which supports Garmin's claim. I read no equivalent measurement for the others. TechRadar lists Whoop's band at 29 g against the 26.5 g in the Tom's Guide figures, and I couldn't check it at source.

Which to pick

Garmin watch already on your wrist? Buy the Cirqa. It feeds the same Connect data, and my Fitbit Air vs Helio Strap comparison covers lower-cost screenless options if the price puts you off.

Want a daily recovery story and happy with a membership? Whoop, once you've seen the UK price.

Polar user with years in Flow? The Loop makes sense. For anyone else I'd look at the Cirqa first. The sleep goal page lists the rest.