WHOOP vs Oura vs Garmin for Recovery

Last verified November 2, 2026. We only include figures we could trace to a published study, an FDA record or a named source. Where a current model hasn't been independently tested, we say so and give the result for the closest model that was.

We haven't tested these devices ourselves.

The short version

For overnight HRV and resting heart rate, Oura has the strongest independent evidence: its Gen3 and Gen4 rings agreed most closely with an ECG strap over 536 nights, WHOOP 4.0 came second, and an older Garmin watch came third¹. Sleep staging is only fair to moderate on all three^2,3. Each brand's recovery score is a formula it hasn't published or independently validated⁴. WHOOP costs the most over two years because the membership is required. Garmin costs the most up front but needs no subscription. Choose Oura for sleep and HRV, WHOOP if you want daily strain coaching in a band, and Garmin if you train with GPS.

Side by side

	WHOOP	Oura	Garmin
Current models	WHOOP 5.0; WHOOP MG (Life membership)5	Oura Ring 5 (June 2026); Ring 4 still sold6	fenix 9 (flagship)7; Forerunner 570 (mid)8; Cirqa band9
Form	Screenless band	Ring	Watch or screenless band
Price and subscription	One $199, Peak $239, Life $359 a year; hardware included; membership required10	Ring 5 $399 to $499; Ring 4 from $349; membership $5.99 a month or $69.99 a year, needed for most data6	fenix 9 $999.99 to $1,099.997; Forerunner 570 $549.998; Cirqa $199.99; Connect+ optional at $69.99 a year9
Two-year cost	$398 to $718	$489 to $639	$199.99 to $1,099.99 (plus $139.98 if you add Connect+)
Battery (claimed)	14+ days5	6 to 9 days (Ring 5)6	10 to 29 days (fenix 9, by size); up to 11 days (Forerunner 570); up to 10 days (Cirqa)
Overnight HRV vs ECG (tested model)	CCC 0.94 (4.0)1	CCC 0.99 (Gen4), 0.97 (Gen3)1	CCC 0.87 (Fenix 6)1
Resting heart rate vs ECG	CCC 0.91 (4.0)	CCC 0.98 (Gen4), 0.97 (Gen3)	Not scored (timestamp problems)
Sleep stages vs polysomnography (kappa)	0.37 (4.0)3; 0.44 (3.0)2	0.43 (Gen2)2; 0.65 (Gen3, Oura-funded)11	0.21 (Vivosmart 4)3; 0.25 (Forerunner 245)2
Recovery score	Recovery, 1 to 99%	Readiness, 0 to 100	Training Readiness, 1 to 100; Body Battery
FDA-cleared features	ECG on MG (K243236)12	None found	Garmin ECG App (K221774) on supported watches, including fenix 913,7
Wellness blood pressure feature	Blood Pressure Insights (Life). FDA warning letter July 2025, closed June 2026 after changes14	Blood Pressure Signals trends (Ring 5)6	None
GPS	No (uses phone)	No (uses phone)	Yes on watches; no on Cirqa

Battery and model details come from the sources cited in each row. The tested models are older than the ones on sale. For Oura, the Gen4 result is the closest to the current Ring 5. For WHOOP and Garmin, the gap is larger.

Accuracy: what independent studies found

HRV and resting heart rate

The Dial study, funded by the US Air Force Research Laboratory, compared five wearables with a Polar H10 ECG strap over 536 nights from 13 adults¹. Oura Gen4 had the closest HRV agreement (CCC 0.99, mean error 6.0%), then Oura Gen3 (0.97, 7.2%), WHOOP 4.0 (0.94, 8.2%) and Garmin Fenix 6 (0.87, 10.5%). Garmin's resting heart rate couldn't be scored. Thirteen people is a small sample, but the many nights make the averages stable. The Garmin tested dates from 2019, and newer Garmin sensors haven't been published against ECG yet.

Sleep

All three are good at telling sleep from wake and poor at catching time awake in bed, so they overestimate sleep. WHOOP 4.0 overestimated it by 24 minutes and a Garmin Vivosmart 4 by 38 minutes in one study³. Stage-by-stage agreement is fair to moderate: kappa 0.43 (Oura Gen2), 0.44 (WHOOP 3.0) and 0.25 (Garmin Forerunner 245) in a 53-person lab study². Oura's claim of 95% sleep staging accuracy for the Ring 5¹⁵ hasn't been independently tested. An Oura-funded study of the Gen3 found a kappa of 0.65¹¹.

What a "recovery score" actually is

Each brand turns overnight signals into one daily number. The inputs overlap, but the weighting is secret, so the same night can score differently on each device. A 2025 review of 14 such scores from 10 brands found that none disclosed its formula and few had any published validation⁴.

	WHOOP Recovery	Oura Readiness	Garmin Training Readiness
Scale	1 to 99%: green 67+, yellow 34 to 66, red 33 or below	0 to 100: 85+ optimal, 70 to 84 good, under 70 pay attention	1 to 100, in five bands from Poor to Prime
Inputs the brand names	HRV, resting heart rate, sleep performance, respiratory rate16	Sleep, sleep balance, sleep regularity, previous day activity, activity balance, resting heart rate, HRV balance, body temperature, recovery index17	Sleep score, recovery time, HRV status, acute training load, sleep history, stress history18
Weighting published	No	No	No
Independent validation of the score	None found	None found	None found

Does acting on these numbers help? The closest evidence is HRV-guided training: in a meta-analysis of 8 studies and 199 people, adjusting training to daily HRV improved HRV itself, but gains in endurance performance were small and not significant¹⁹. Use the score as a prompt to look at the raw numbers. A run of low HRV and high resting heart rate over several days is more informative than one red day.

Cost over two years

Over two years, at yearly billing and list prices checked November 2, 2026: WHOOP costs $398 (One), $478 (Peak) or $718 (Life with the MG), all of it membership¹⁰. Oura costs about $489 for a Ring 4 or $539 to $639 for a Ring 5, including $139.98 of membership⁶; paying monthly instead adds about $4. Garmin is the hardware price alone: $199.99 (Cirqa), $549.99 (Forerunner 570) or $999.99 to $1,099.99 (fenix 9), plus $139.98 if you choose Connect+^7,8,9. Our full two-year cost table adds Apple Watch, Polar and Ultrahuman, with battery claims. We couldn't load the brand stores directly, so confirm at checkout.

Which to choose

Oura: best evidence for sleep and HRV

Pick Oura if you mainly want overnight HRV, resting heart rate and sleep trends and don't want anything on your wrist. It has the strongest independent HRV data of the three¹ and names every input to its Readiness score. Budget for the membership; without it you see very little. It has no GPS and no FDA-cleared features.

WHOOP: daily strain and recovery coaching in a band

Pick WHOOP if you want a screenless band, a coaching-heavy app and long battery life, and you accept a required membership. WHOOP 4.0 tested well on HRV¹. Choose Life with the MG only if you want the FDA-cleared ECG feature¹²; Blood Pressure Insights is a wellness estimate, not a cleared reading¹⁴.

Garmin: training first, recovery included

Pick Garmin if you run, ride or train with GPS and want recovery data on the same device with no required subscription. The Forerunner 570 is the mid option and the fenix 9 is the flagship with an ECG app⁷. The tested Garmin was weaker on HRV than Oura or WHOOP, but it was a 2019 model¹. If you don't need GPS, the Cirqa band ($199.99) is Garmin's answer to WHOOP, with no required subscription⁹. For the rest of the range, see our Garmin watch guide.

Before you buy any of them

None of these is a medical device for HRV, sleep or recovery. Their cleared features are ECG spot checks only. If you use an iPhone and want the most cleared heart features, or you want the cheapest option with no subscription, our best recovery wearables guide covers Apple Watch, Polar and Ultrahuman too, with the full evidence map. Our heart rate recovery guide explains a measure you can track on any of them.

References

FDA records were checked through 510kdatabase.net and RegDataLab on November 2, 2026; the WHOOP closeout letter was read on fda.gov. PubMed Central pages didn't load for us, so some study details come from the journal page, DOAJ or a summary, as noted.

1. Dial MB, Hollander ME, Vatne EA, Emerson AM, Edwards NA, Hagen JA. Validation of nocturnal resting heart rate and heart rate variability in consumer wearables. Physiological Reports, 2025;13(16):e70527. 13 adults, 536 nights; Oura Gen3 and Gen4, WHOOP 4.0, Garmin Fenix 6 and Polar Grit X Pro against a Polar H10 ECG strap. Funded by the Air Force Research Laboratory. doi:10.14814/phy2.70527 Source
2. Miller DJ, Sargent C, Roach GD. A validation of six wearable devices for estimating sleep, heart rate and heart rate variability in healthy adults. Sensors, 2022;22(16):6317. 53 adults, one lab night; Apple Watch S6, Garmin Forerunner 245 Music, Polar Vantage V, Oura Gen2, WHOOP 3.0 and Somfit against polysomnography. doi:10.3390/s22166317 Source
3. Schyvens AM, Peters B, Van Oost NC, et al. A performance validation of six commercial wrist-worn wearable sleep-tracking devices for sleep stage scoring compared to polysomnography. Sleep Advances, 2025;6(2):zpaf021. 62 adults; Apple Watch Series 8, WHOOP 4.0, Garmin Vivosmart 4, Fitbit Charge 5 and Sense, Withings Scanwatch. doi:10.1093/sleepadvances/zpaf021 Source
4. Doherty C, Baldwin M, Lambe R, Burke D, Altini M. Readiness, recovery, and strain: an evaluation of composite health scores in consumer wearables. Translational Exercise Biomedicine, 2025;2(2):128-144. doi:10.1515/teb-2025-0001 Source
5. WHOOP. Which membership is right for you? (features by tier; Heart Screener and Blood Pressure Insights need WHOOP Life and WHOOP MG). Checked 2 November 2026. Source
6. Oura. Oura Ring: what to know in 2026 (Ring 5 and Ring 4 prices, membership $5.99 a month or $69.99 a year, battery, sensors). Updated 15 October 2026. Source
7. the5krunner. Garmin fenix 9 specifications (launched 25 August 2026; $999.99 for 43 and 47 mm, $1,099.99 for 51 mm; ECG app region-dependent; skin temperature; HRV status; Training Readiness). Checked 2 November 2026. Source
8. DC Rainmaker. Garmin Forerunner 570 and 970 in-depth review (overnight skin temperature added; no ECG app on the 570). May 2025. Source. Garmin's 15 May 2025 announcement: suggested retail $549.99; up to 11 days of smartwatch battery (press release reprint). Announcement
9. TechRadar. Garmin Cirqa review ($199.99; Connect+ $6.99 a month or $69.99 a year is optional). 6 August 2026. Source
10. Engadget. Why would you pay $359 for the most expensive Whoop membership? (One $199, Peak $239, Life $359 a year). 29 August 2026. Source
11. Robbins R, Weaver MD, Sullivan JP, et al. Accuracy of three commercial wearable devices for sleep tracking in healthy adults. Sensors, 2024;24(20):6532. 35 adults, one night of polysomnography; Oura Ring Gen3, Apple Watch Series 8 and Fitbit Sense 2. Funded by Oura Ring Inc.; the lead author sits on Oura's medical advisory board. doi:10.3390/s24206532 Source
12. 510(k) K243236: WHOOP ECG (electrocardiogram) Feature (1.0), product code QDA (OTC electrocardiograph software), cleared 4 April 2025 (FDA data via 510kdatabase.net). Source
13. 510(k) K221774: Garmin ECG App, Garmin International, product code QDA, decision 12 January 2023 (FDA data via RegDataLab). Source
14. U.S. FDA, CDRH. Closeout letter to WHOOP, Inc. (re: warning letter of 14 July 2025 on Blood Pressure Insights), 17 June 2026, posted 23 June 2026. Cites FDA's General Wellness guidance as revised on 6 January 2026. Source
15. 9to5Google. Oura Ring 5 price increases, gets thinner (Oura's claims of 99% heart rate accuracy against ECG and 95% sleep staging accuracy against sleep labs). 28 May 2026. Source
16. WHOOP. How does WHOOP Recovery work? (inputs: HRV, resting heart rate, sleep performance, respiratory rate; green 67-99%, yellow 34-66%, red 1-33%). Checked 2 November 2026. Source
17. Oura. What is your Readiness Score? (nine contributors; 0-100 scale). Checked 2 November 2026. Source
18. Garmin. Training Readiness, Forerunner 265 owner's manual (factors and 1-100 scale). Checked 2 November 2026. Source
19. Manresa-Rocamora A, Sarabia JM, Javaloyes A, Flatt AA, Moya-Ramón M. Heart rate variability-guided training for enhancing cardiac-vagal modulation, aerobic fitness, and endurance performance: a methodological systematic review with meta-analysis. IJERPH, 2021;18(19):10299. doi:10.3390/ijerph181910299 Source