Sensors (Basel) September 2024 PMID 39409260

The Validity of Apple Watch Series 9 and Ultra 2 for Serial Measurements of Heart Rate Variability and Resting Heart Rate.

Ben O'Grady, Rory Lambe, Maximus Baldwin, Tara Acheson, Cailbhe Doherty

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Mentions

22
Peak: 15 in Sep 2024
across 2 sources since Mar 2024

Extended reach

114,024
potential audience

Total likes

477

Video views

42,141

Mentions per month

Mar 2024 – Jul 2025

Where it's discussed

  • X / Twitter17 posts
  • YouTube5 videos

AI synopsis

What people are saying

Discussions point out that while the study validates the Apple Watch's resting heart rate measurements, skepticism remains about its HRV accuracy, exemplified by comments like 'poor agreement' and questions about filtering methods, which reflect cautious engagement and interest in the device's clinical reliability.

AgreementNeither agree nor disagree

The comments reflect mixed opinions, with some acknowledging the research but also expressing skepticism about the accuracy of wristband measurements.

InterestModerate interest

There is a moderate level of interest, as posters recognize the significance of the study and its implications for fitness and health monitoring.

EngagementModerate engagement

Posts show some engagement by referencing specific results and concerns, such as the limitations in measurement agreement and filtering methods.

ImpactNeutral impact

The discussions suggest a moderate impact, highlighting ongoing debates about using consumer devices for serious health assessments, but not indicating widespread change or acceptance yet.

Abstract in brief

  • This study evaluated the accuracy of the Apple Watch Series 9 and Ultra 2 in measuring heart rate variability (HRV) and resting heart rate (RHR), comparing them to a professional chest strap device (Polar H10) considered the standard.
  • Results showed that Apple Watches tend to underestimate HRV values, with an average difference of about 8.31 milliseconds, and the measurements were not within the acceptable equivalence range, highlighting limitations in their current HRV algorithms.
  • While RHR measurements from the Apple Watch were quite accurate, the discrepancies in HRV data suggest that consumer wearable devices need improved algorithms before being reliably used for clinical or high-performance purposes.]

Top posts

Most liked on X and Bluesky
Andrew Flatt
@andrew_flatt · X

Still not a big fan of HRV estimation from wristbands. Poor agreement between the Apple Watch (Series 9 & Ultra 2) and Polar H10 for resting HRV. Limitation: filtering methods unclear. https://t.co/eUn68S6w5j https://t.co/OcLKr0pJFw

Sep 28, 2024 · 78 likes · 14 shares · 8,751 followers View post →
Thomas LeBosquet
@lebosquet · X

I will continue using chest strap for during training heart rate measurement & AM HRV checks. Great to see people studying latest gen equipment though. https://t.co/mbj5cIeROf

Oct 7, 2024 · 3 likes · 660 followers View post →
Sensors MDPI
@Sensors_MDPI · X

✨Editor's Choice Article✨ O’Grady, B.; et al. The Validity of Apple Watch Series 9 and Ultra 2 for Serial Measurements of Heart Rate Variability and Resting Heart Rate. Sensors 2024, 24, 6220.

Jul 22, 2025 · 2 likes · 6,979 followers View post →
Sprint Science
@spikesonly · X

RT @andrew_flatt: Still not a big fan of HRV estimation from wristbands. Poor agreement between the Apple Watch (Series 9 & Ultra 2) and…

Sep 28, 2024 · 14 shares · 33,983 followers View post →
javierbutra
@javierbutra · X

RT @andrew_flatt: Still not a big fan of HRV estimation from wristbands. Poor agreement between the Apple Watch (Series 9 & Ultra 2) and…

Sep 29, 2024 · 14 shares · 14,340 followers View post →
南部 博昭(Hiroaki Nanbu)
@Hiroaki_Nanbu · X

RT @andrew_flatt: Still not a big fan of HRV estimation from wristbands. Poor agreement between the Apple Watch (Series 9 & Ultra 2) and…

Sep 28, 2024 · 14 shares · 1,640 followers View post →

All mentions

Sensors MDPI
@Sensors_MDPI · X

✨Editor's Choice Article✨ O’Grady, B.; et al. The Validity of Apple Watch Series 9 and Ultra 2 for Serial Measurements of Heart Rate Variability and Resting Heart Rate. Sensors 2024, 24, 6220.

Jul 22, 2025 · 2 likes · 6,979 followers View post →
Thomas LeBosquet
@lebosquet · X

I will continue using chest strap for during training heart rate measurement & AM HRV checks. Great to see people studying latest gen equipment though. https://t.co/mbj5cIeROf

Oct 7, 2024 · 3 likes · 660 followers View post →
Gabriel Pérez
@gperez441 · X

RT @andrew_flatt: Still not a big fan of HRV estimation from wristbands. Poor agreement between the Apple Watch (Series 9 & Ultra 2) and…

Sep 29, 2024 · 14 shares · 288 followers View post →
Sebastian Catana
@sebastiancatana · X

RT @andrew_flatt: Still not a big fan of HRV estimation from wristbands. Poor agreement between the Apple Watch (Series 9 & Ultra 2) and…

Sep 29, 2024 · 14 shares · 69 followers View post →
javierbutra
@javierbutra · X

RT @andrew_flatt: Still not a big fan of HRV estimation from wristbands. Poor agreement between the Apple Watch (Series 9 & Ultra 2) and…

Sep 29, 2024 · 14 shares · 14,340 followers View post →
PD
@dp2pd2 · X

RT @andrew_flatt: Still not a big fan of HRV estimation from wristbands. Poor agreement between the Apple Watch (Series 9 & Ultra 2) and…

Sep 28, 2024 · 14 shares · 34 followers View post →
南部 博昭(Hiroaki Nanbu)
@Hiroaki_Nanbu · X

RT @andrew_flatt: Still not a big fan of HRV estimation from wristbands. Poor agreement between the Apple Watch (Series 9 & Ultra 2) and…

Sep 28, 2024 · 14 shares · 1,640 followers View post →
André B. Coelho
@AndBastosCoelho · X

RT @andrew_flatt: Still not a big fan of HRV estimation from wristbands. Poor agreement between the Apple Watch (Series 9 & Ultra 2) and…

Sep 28, 2024 · 14 shares · 328 followers View post →
Robb!e
@RobbieG_PhD · X

The Validity of Apple Watch Series 9 and Ultra 2 for Serial Measurements of Heart Rate Variability and Resting Heart Rate. https://t.co/hpfO0m3FCr

Sep 28, 2024 · 176 followers View post →
Paul Williams
@PaulWillBirds · X

RT @andrew_flatt: Still not a big fan of HRV estimation from wristbands. Poor agreement between the Apple Watch (Series 9 & Ultra 2) and…

Sep 28, 2024 · 14 shares · 897 followers View post →
Chris Brands
@ChrisBrands · X

RT @andrew_flatt: Still not a big fan of HRV estimation from wristbands. Poor agreement between the Apple Watch (Series 9 & Ultra 2) and…

Sep 28, 2024 · 14 shares · 692 followers View post →
Madhan Ramanathan
@sportsphysiouk · X

RT @andrew_flatt: Still not a big fan of HRV estimation from wristbands. Poor agreement between the Apple Watch (Series 9 & Ultra 2) and…

Sep 28, 2024 · 14 shares · 1,134 followers View post →
Anthony Osnacz ✝️
@aosnacz · X

RT @andrew_flatt: Still not a big fan of HRV estimation from wristbands. Poor agreement between the Apple Watch (Series 9 & Ultra 2) and…

Sep 28, 2024 · 14 shares · 303 followers View post →
ME/CFS Research
@cfs_research · X

RT @andrew_flatt: Still not a big fan of HRV estimation from wristbands. Poor agreement between the Apple Watch (Series 9 & Ultra 2) and…

Sep 28, 2024 · 14 shares · 1,185 followers View post →
Pedro Gull
@GullPedro · X

RT @andrew_flatt: Still not a big fan of HRV estimation from wristbands. Poor agreement between the Apple Watch (Series 9 & Ultra 2) and…

Sep 28, 2024 · 14 shares · 33 followers View post →
Sprint Science
@spikesonly · X

RT @andrew_flatt: Still not a big fan of HRV estimation from wristbands. Poor agreement between the Apple Watch (Series 9 & Ultra 2) and…

Sep 28, 2024 · 14 shares · 33,983 followers View post →
Andrew Flatt
@andrew_flatt · X

Still not a big fan of HRV estimation from wristbands. Poor agreement between the Apple Watch (Series 9 & Ultra 2) and Polar H10 for resting HRV. Limitation: filtering methods unclear. https://t.co/eUn68S6w5j https://t.co/OcLKr0pJFw

Sep 28, 2024 · 78 likes · 14 shares · 8,751 followers View post →