Garmin CIRQA Test: Where the Data Vanishes

The launch of the Garmin CIRQA at $199.99 with no subscription required was one story. The second one starts now. The band has been through weeks of accuracy testing against the Whoop 5.0, Fitbit Air, Polar Loop and Amazfit Helio. Those tests turned up a flaw that can wipe an entire session out of an athlete’s data.

The test was run by DC Rainmaker, who wore seven screenless devices at once. A CIRQA on the wrist and a second unit on the bicep, plus the Whoop 5.0, Fitbit Air, Polar Loop, Amazfit Helio and Oura Ring 5. As a reference he alternated between a Polar H9 chest strap and a Garmin HRM-600. Data was collected across a range of temperatures, from 32°C (90°F) in Spain to 10°C (50°F) in Newfoundland.

Wrist against bicep: a difference that matters

Indoors and in warm conditions the CIRQA on the wrist did very well. It caught intervals and recoveries as accurately as the chest strap.

The trouble started in the cold. On a three hour road and gravel ride in rain at 16°C (61°F), every wrist band got it wrong, not only the CIRQA. The 400 m repeats at 17°C (63°F) went the same way. The same session at 29°C (84°F) came out noticeably better, so temperature is the most likely explanation. The same band worn on the bicep handled those intervals cleanly.

There is a counterpoint in the test. The second CIRQA unit, worn by the author’s wife on a similarly cold ride, produced very good numbers. It even beat the Fenix 8. Variation between individual units and how they are worn is part of the picture.

The conclusion is straightforward. For anyone buying a CIRQA for interval training, the bicep gives genuinely different data quality than the wrist.

The real problem: a missed workout erases data permanently

This is the most serious finding of the test. The CIRQA keeps its heart rate sensor in a low power mode until it detects a workout. Accuracy only goes up once activity is recognised.

The problem is that the device sometimes fails to detect a session, or part of one. Heart rate from that period simply is not recorded. Manually extending the activity window after the fact does not repair it. Whoop and the Fitbit Air, by contrast, hold full heart rate data regardless of when the start and end of a workout are marked.

In practice this hurt. On a three and a half hour ride into the mountains, the CIRQA decided the workout was over. It closed the activity just after the top of the climb, roughly at the 90 minute mark. The last 45 minutes disappeared from the data, including climbs with heart rate above 160 beats per minute.

Shorter bike commutes were inconsistent. A 20 minute and a 30 minute commute went undetected, while a 25 minute and a 70 minute one were picked up.

The activity detection ranking from the test:

1. Whoop, with occasional misses
2. Fitbit Air, just behind it and practically as good
3. Garmin CIRQA, good and improving, though it still gets lost at lower intensity
4. Amazfit Helio, which picks up elevated heart rate well but does not recognise the type of workout and often ends the activity early
5. Polar Loop, barely a pass

Sleep: data yes, sleep stages no

On sleep, the test compares time to fall asleep and wake time, total sleep time and overnight HRV. Those are the numbers that can actually be verified. Sleep stages were deliberately left out. Even the devices treated as reference points hit them with accuracy of around 80%. Comparing something nobody measures reliably only misleads.

What this means for a triathlete

For an age-grouper who trains mostly at steady pace or on a trainer, the CIRQA on the wrist is enough.

It looks different for athletes building fitness on intervals, which are the backbone of preparation for 70.3 and full distance. The risk of losing whole blocks of training data is real then, particularly in the colder months.

The bicep limits the problem for heart rate accuracy itself. It does not solve workout detection, because that is handled in software. There is good news on that front. Garmin improved automatic detection over the ten to twelve days of testing, and did it without a firmware update, purely through changes in the app and on the server side.

The CIRQA costs $199.99 and has been on sale since 24 July 2026. Core features carry no subscription, while the extended analytics in Connect+ remain paid at $6.99 per month.

This sits alongside Wahoo and COROS Team Up Against Garmin on Data Sync. Racelify lists triathlons worldwide by date and distance.