CIRQA and WHOOP look alike: a sensor on a fabric strap, no screen, and every number in a phone app. For HRV they differ in which part of the night the number covers, the score built on it, the price and the evidence behind it. For Garmin’s watches against WHOOP, see Garmin vs WHOOP.
Documentation checked: 22 October 2026. Prices are from the makers’ US stores on 21 October 2026, and the CIRQA arm band’s on 22 October 2026. Both companies change their apps, plans and prices often.
What is the Garmin CIRQA band?
Garmin announced the CIRQA Smart Band on 21 July 2026 as its first screen-free smart band, at a suggested retail price of $199.99 (Garmin Newsroom). It is a small module on a fabric band. Its single button starts an activity; you read everything else, HRV included, in the Garmin Connect app.
Garmin’s announcement lists heart rate variability in CIRQA’s sleep data, and HRV Status and Training Readiness among its training features (Garmin Newsroom); the CIRQA product page lists both as well (Garmin, CIRQA product page). The module takes Garmin’s 24 mm fabric bands, for the wrist or the arm; Garmin says it is not compatible with third-party bands (CIRQA owner’s manual, changing the band).
Wrist or upper arm: where CIRQA and WHOOP are worn
CIRQA goes on the wrist, above the wrist bone, or on the upper arm, above the elbow. Garmin’s manual asks for a lightly snug fit, with the module on the outside of the arm and where you will not lie on it in your sleep (CIRQA owner’s manual, putting on). The upper arm band is sold separately: $59.99 in Garmin’s US store on 22 October 2026 (Garmin, accessory bands).
You also tell the app where it is. The band “uses the wearing location of the device to determine health and activity tracking metrics”, and you set it under User Profile, Wearing Location in Garmin Connect (CIRQA owner’s manual, wear location). Each activity can have its own band position.
WHOOP asks for a snug fit one finger-width above the wrist bone; if you can see the green sensor lights, the band is too loose. For lifting, boxing and other fast wrist movement, it suggests WHOOP Body apparel, which holds the sensor on the bicep, torso or calf (WHOOP Support, accuracy).
Garmin CIRQA
Set the wear location in Garmin Connect
- Wrist Above the wrist bone, lightly snug, with the band that comes with it.
- Upper arm Above the elbow, module on the outside of the arm. The arm band is sold separately.
WHOOP
The band, or WHOOP Body apparel
- Wrist One finger-width above the wrist bone, snug enough that the green lights do not show.
- Bicep, torso or calf In WHOOP Body apparel, which WHOOP suggests for lifting, boxing and other fast wrist movement.
Two outline figures of a person. Left, Garmin CIRQA: spot 1 on the wrist, just above the wrist bone; spot 2 on the upper arm, above the elbow, with an arm band sold separately. Right, WHOOP: spot 1 on the wrist, one finger-width above the wrist bone; spot 2, drawn as an outline, on the bicep, the torso or the calf, in WHOOP Body apparel.
Pick one place for the night and keep it. If you move CIRQA from the wrist to the arm, change the setting too, and treat the next weeks as a new series rather than a change in you.
What HRV does Garmin CIRQA show?
CIRQA’s HRV shows up in several places in Garmin Connect, under the same names Garmin uses on its watches:
- Overnight HRV. The Health status card shows heart rate variability and respiration; you can open each to see its history and your baseline Baseline Your own usual HRV level and range, built from weeks of readings taken the same way. Comparing a reading with your baseline says more than comparing it with other people. More about Baseline (CIRQA owner’s manual, home settings).
- HRV Status. The card “displays your seven-day average of your overnight heart rate variability” (CIRQA owner’s manual, home settings). Garmin rates that average as Balanced, Unbalanced or Low against your own baseline range, which takes about three weeks of nightly wear to build, and shows Poor when the baseline itself falls below age-based norms (Garmin, HRV Status).
- Sleep coach. It recommends how much sleep you need from your sleep and activity history, circadian rhythm Circadian rhythm The body's 24-hour clock. Heart rate is lower and vagal HRV higher at night than by day, so readings are only comparable when they are taken at the same time of day. More about Circadian rhythm and HRV Status (CIRQA owner’s manual, sleep tracking).
- Body Battery. A level from 5 to 100 built from heart rate variability, stress, sleep quality and activity (CIRQA owner’s manual, Body Battery).
- Training Readiness. A morning score “based on your sleep quality, recovery and more”, in the words of Garmin’s CIRQA product page. The announcement lists it too (Garmin Newsroom); CIRQA’s owner’s manual does not mention it.
What unbalanced HRV status means goes through each status.
CIRQA with a Garmin watch
If you wear CIRQA and a Garmin watch on the same account, Garmin Connect lets you choose a primary wearable. It “sets the priority data source for daily health metrics like steps and sleep”, and Garmin advises picking the device you wear most (CIRQA owner’s manual, unified training status). In the pages we read, Garmin does not say which device’s HRV feeds HRV Status when both record the same night. Wear one of them to bed each night and make it the primary wearable.
How CIRQA and WHOOP measure HRV overnight
Both take their HRV from sleep, through a sensor on the back of the band. They summarise different stretches of the night.
Garmin
Garmin’s HRV Status page says “compatible Garmin devices calculate HRV continuously while you are sleeping”. In the morning you see the average for the whole sleep period, a chart of 5-minute windows, and the highest 5-minute value of the night (Garmin, HRV Status). That page is written about Garmin’s watches and does not name CIRQA, but CIRQA’s manual calls its value “overnight heart rate variability”, and we found no Garmin page saying CIRQA does it differently. Garmin’s page describes RMSSD RMSSD Root mean square of successive differences: an HRV metric built from how much each heartbeat interval differs from the next, in milliseconds. It mainly reflects vagal activity. More about RMSSD , a standard measure of how much the gap between heartbeats changes, without saying outright that the device reports it.
WHOOP
WHOOP shows HRV in milliseconds with each Recovery, and its developer documentation names the field for RMSSD (WHOOP developer documentation). The Dial study quotes WHOOP describing the value as a “dynamic average during sleep” weighted towards your last slow-wave (deep) sleep stage. WHOOP does not publish the weights. It says the WHOOP 5.0 and MG also use ECG ECG A recording of the heart's electrical activity, taken with electrodes on the skin. ECG-based RR intervals are the reference standard for measuring HRV. More about ECG technology for some sleep measurements, HRV among them (WHOOP Support, accuracy).
Why the two numbers differ
HRV changes with sleep stage. In a sleep-lab study of 15 healthy young men, median RMSSD was 67.3 ms in slow-wave sleep and 79.7 ms in REM sleep (Herzig and colleagues, 2018). A value weighted towards deep sleep can sit apart from a whole-night average, and each company filters the signal its own way. Garmin itself warns that differences in the timing and length of a measurement make comparisons between devices hard (Garmin, HRV Status).
The model below draws one simulated night and shades the hours each method reads. The Garmin line follows the method Garmin describes for its devices.
Same night, different numbers
A teaching model, not a measurement
Sleep stages lights out to waking
HRV every 5 minutes (RMSSD) 20 to 60 ms
- Garmin
- 47.1 ms RMSSD
The average of 5-minute windows over the whole sleep period the watch detects, brief wakes included.
Same night, same heart: Garmin 47.1 ms and WHOOP 54.6 ms, because each device averages different hours.
The buttons work when JavaScript is on. The window for each device is listed in the description.
Two charts over eight hours of simulated sleep. The top chart is a hypnogram stepping between awake, REM, light and deep sleep, with deep sleep mostly in the first half and REM mostly in the second. The bottom chart is a line of HRV values, one per five minutes, that rise gently through the night and dip during wakeful minutes. One button per device shades the part of the night that device averages. Garmin: 47.1 ms RMSSD. WHOOP: 54.6 ms RMSSD. Same night, same heart: Garmin 47.1 ms and WHOOP 54.6 ms, because each device averages different hours.
Training Readiness vs WHOOP Recovery
Garmin Training Readiness runs from 1 to 100. Garmin’s Instinct 2 watch manual lists its inputs as HRV Status, last night’s sleep score, recovery time, acute load, sleep history and stress history (Garmin Instinct 2 owner’s manual). For CIRQA, Garmin’s announcement and product page list Training Readiness, and the product page says only that it is based on “your sleep quality, recovery and more”. CIRQA’s owner’s manual does not mention the score, so Garmin has not said whether the band uses the same inputs as the watch.
WHOOP Recovery is calculated when you wake, from 0 to 100%. Its inputs are resting heart rate Resting heart rate How many times your heart beats per minute while you are fully at rest. For adults it is usually 60 to 100 beats per minute, and lower in well-trained athletes. More about Resting heart rate and HRV, plus blood oxygen and skin temperature for WHOOP 4.0 members (WHOOP developer documentation).
What is in a readiness score?
From the makers' own documentation
- HRV : named by the maker HRV status (the seven-day average against your baseline range), and the stress history of the last 3 days, which itself comes from HRV.
- Resting heart rate : not named Not named by the maker.
- Breathing rate : not named Not named by the maker.
- Sleep : named by the maker Last night’s sleep score and the sleep history of the last 3 nights.
- Temperature : not named Not named by the maker.
- Activity or load : named by the maker Acute load (recent training) and recovery time.
Garmin's Training Readiness names 3 of the six inputs: HRV, sleep and activity or load. The manual lists the six factors. It does not say how they are weighted.
- HRV : named by the maker Heart rate variability; the API field for it is named hrv_rmssd_milli.
- Resting heart rate : named by the maker Resting heart rate.
- Breathing rate : not named Not named by the maker.
- Sleep : not named Not named by the maker.
- Temperature : named by the maker Skin temperature, for WHOOP 4.0 and later.
- Activity or load : not named Not named by the maker.
Also: Blood oxygen (SpO2) on WHOOP 4.0 and later. Sleep and breathing rate are not named in the developer documentation.
WHOOP's Recovery names 3 of the six inputs: HRV, resting heart rate and temperature. WHOOP lists the measurements that "factored into the score" but not how they are combined.
A list of scores, one per device, with six inputs for each: HRV, resting heart rate, breathing rate, sleep, temperature and activity or load. Garmin's Training Readiness names 3 of the six inputs: HRV, sleep and activity or load. The manual lists the six factors. It does not say how they are weighted. WHOOP's Recovery names 3 of the six inputs: HRV, resting heart rate and temperature. WHOOP lists the measurements that "factored into the score" but not how they are combined.
Neither company publishes its weights. A Training Readiness of 60 and a Recovery of 60% sit on different scales built from different inputs, and either can fall on a night your HRV rose, so read the HRV behind the score. Recovery scores explained lists each score’s inputs.
Is CIRQA accurate for HRV?
We found no published study of CIRQA’s HRV. Until someone compares it with an ECG, its accuracy is unknown.
What is known for Garmin and WHOOP
The closest evidence is a 2025 home study. Dial and colleagues had 13 healthy adults wear several devices at home, with a Polar H10 chest-strap ECG as the reference, for 536 nights in total. For overnight RMSSD:
| Garmin Fenix 6 | WHOOP 4.0 | |
|---|---|---|
| Nights compared | 150 | 289 |
| Concordance (CCC) | 0.87 | 0.94 |
| Average error (MAPE) | 10.52% | 8.17% |
| Average error in ms | 5.29 | 4.17 |
| Authors’ rating | Poor | Moderate |
Overnight RMSSD against a chest-strap ECG (Dial and colleagues, 2025). A concordance of 1 means perfect agreement.
The authors report the Fenix 6’s percentage error as significantly higher than WHOOP’s; the gap in milliseconds was not significant. These rows do not carry over to CIRQA. The Fenix 6 is a watch, while CIRQA is a different device that may sit on the arm, and Garmin has not said whether it uses the same sensor or software. WHOOP has since replaced the 4.0 with the WHOOP 5.0 and MG, and no study has tested either of them this way. Garmin vs WHOOP covers the study, and the other Garmin and WHOOP studies, in more detail.
Informal tests of CIRQA
Two informal tests have been published. Neither is peer-reviewed, and each comes from one person:
- CIRQA against WHOOP MG, overnight. The reviewer behind the5krunner wore CIRQA on the wrist and a WHOOP MG on the bicep, alongside other trackers, for about two weeks, with no chest strap as a reference. CIRQA’s HRV read higher than WHOOP’s on every night but one. The reviewer was taking medication that affects heart rate and sleep, and concluded that CIRQA’s HRV trend is worth watching against its own baseline but not against other brands’ numbers.
- Heart rate and sleep stages. Notebookcheck reported preliminary tests by the researcher Rob ter Horst, with a Polar H10 chest strap for heart rate during exercise and an EEG-based system for sleep stages, on a small sample. The report gives no HRV results.
The reviewer put the gap down to method rather than physiology: Garmin averages the whole night, and WHOOP weights its value towards deep sleep. Two bands that disagree cannot show which one is closer to an ECG.
Does CIRQA need a subscription?
No. Garmin says CIRQA tracks its features “without the need for a subscription” (Garmin Newsroom), and a Garmin Connect account is free (CIRQA owner’s manual, Garmin Connect). The optional Garmin Connect+ subscription, as CIRQA’s manual lists it, adds AI insights, LiveTrack extras, live workout data, training guidance, nutrition logging, a performance dashboard and social features (CIRQA owner’s manual, Connect+). HRV Status is not on that list. Garmin’s CIRQA page lists voice-guided meditation, guided breathwork and guided workouts as needing a Connect+ plan (Garmin, CIRQA product page), and CIRQA’s manual says the same of workouts the app guides you through.
WHOOP sells its device only as part of a membership. Every plan includes a device, a charger and Recovery (WHOOP, membership). The Stress Monitor, which reads heart rate and HRV against your own HRV baseline, comes with the Peak and Life plans, not One (WHOOP Support, Stress Monitor).
CIRQA vs WHOOP cost over three years
| Option | Device | Membership | 1 year | 3 years |
|---|---|---|---|---|
| Garmin CIRQA Smart Band | $199.99 | None | $199.99 | $199.99 |
| WHOOP One | Included | $199 a year | $199 | $597 |
| WHOOP Peak | Included | $239 a year | $239 | $717 |
Device price plus the membership WHOOP requires, from each maker’s US page on 21 October 2026 (see Sources). WHOOP One and Peak include a WHOOP 5.0. Tax, shipping, straps and apparel are not included.
In the first year, CIRQA and WHOOP One cost about the same. The gap opens when the membership renews: after three years WHOOP One has cost $397.01 more than CIRQA, and WHOOP Peak $517.01 more. WHOOP Life, with the WHOOP MG, was $359 a year. Wearing CIRQA on the arm adds the $59.99 arm band; we did not price WHOOP Body apparel.
What HRV tracking costs over three years
US prices, 21 October 2026
Each price, and the page it was read on, is in the table.
A step chart of the money spent on HRV tracking from the first day to the end of year 3, one line per option. A device bought outright is a flat line; a yearly membership steps up at the start of each year. Garmin CIRQA Smart Band: $199.99 on the first day, $199.99 by the end of year 3. WHOOP One membership: $199 on the first day, $597 by the end of year 3. WHOOP Peak membership: $239 on the first day, $717 by the end of year 3.
Cheapest HRV tracking sets these against chest straps and watches, from $69.90.
Battery, charging and missed nights
Both bands take their nightly HRV only from sleep, so a night without the band leaves a gap. WHOOP marks a Recovery as unscorable when there was not enough data (WHOOP developer documentation), and Garmin builds HRV Status from nights you wear the device to bed (Garmin, HRV Status).
- CIRQA lasts up to 10 days (CIRQA owner’s manual, specifications). It charges by cable through a port on the back of the module, in up to 90 minutes (CIRQA owner’s manual, charging), so it comes off; charge it while you are awake. Battery Saver turns heart rate off (CIRQA owner’s manual, power manager), and with heart rate off the band does no sleep tracking (CIRQA owner’s manual, health and wellness), so leave Battery Saver off at night.
- WHOOP quotes 14 or more days for the WHOOP 5.0 and MG (WHOOP, membership). Its battery packs slide onto the sensor and charge it while you wear it; the wired Basic Charger, which comes with the One plan, is not made to be worn (WHOOP Support, charging; WHOOP, membership).
Getting your HRV data out
- CIRQA: Garmin Connect can export a day of wellness data, including HRV, as FIT files, and Garmin emails a download link for an export of your whole account (Garmin Support). With USB file access turned on, the band itself shows up on a computer, though a Mac needs Garmin Express to read it (CIRQA owner’s manual, connecting to a computer).
- WHOOP: an in-app export emails you a link to CSV files, including one with Recovery, resting heart rate and HRV for each day (WHOOP Support, export).
CIRQA or WHOOP: which is better for HRV?
For HRV alone, the trade-offs are:
- Evidence. WHOOP 4.0 agreed moderately with an ECG in one study; CIRQA has no study. Neither current WHOOP model has been tested the same way.
- What you read. CIRQA gives HRV Status, a slow 7-day signal built from HRV alone, plus Training Readiness. WHOOP gives a nightly value and a daily Recovery that mixes in other inputs.
- Cost. You buy CIRQA once, with no subscription. WHOOP costs about the same in the first year and more each year after.
- Fit. Both can go on the wrist or the upper arm. CIRQA needs a separate arm band; WHOOP has apparel for the bicep, torso and calf.
- Charging. WHOOP can charge on your wrist with a battery pack, though not with the One plan’s Basic Charger; CIRQA comes off to charge.
If you already sleep in a Garmin watch that shows HRV Status, CIRQA gives you the same metrics in the same app, without a screen. A chest strap, the reference in the Dial study, reads the heart’s electrical signal and needs no subscription; the chest-strap guide explains how. For each device on its own, see Garmin HRV Status and WHOOP HRV, and how long a baseline takes if you are switching from one to the other.
When to talk to a doctor
Neither band diagnoses anything, and neither HRV Status nor Recovery is a medical test; Garmin’s manual for CIRQA states: “This is not a medical device” (CIRQA owner’s manual, more information). Talk to a doctor if low HRV or a Low status comes with feeling unwell, lasting fatigue, palpitations, dizziness or chest pain, whatever the number.