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

September 2024 Sensors (Basel)

Synopsis of Social media discussions

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.

A
Agreement
 Neither agree nor disagree

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

I
Interest
 Moderate level of interest

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

E
Engagement
 Moderate level of engagement

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

I
Impact
 Neutral 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.

Social Mentions

YouTube

5 Videos

Twitter

17 Posts

Metrics

Video Views

15,738

Total Likes

276

Extended Reach

87,621

Social Features

22

Timeline: Posts about article

Top Social Media Posts

Posts referencing the article

Understanding Heart Rate Variability and Wearable Device Accuracy

Understanding Heart Rate Variability and Wearable Device Accuracy

This video explores the history, science, and practical applications of HRV, including measurement methods and factors affecting accuracy. It also discusses the validation of Apple Watch Series 9 and Ultra 2 for HRV and resting heart rate monitoring.

Dr Cailbhe Doherty

March 9, 2024

9,198 views

Understanding Heart Rate Variability: Measurement and Interpretation Techniques

Understanding Heart Rate Variability: Measurement and Interpretation Techniques

HRV Heart Rate Variability shows how your body responds to stress exercise and recovery. This video explains what HRV is, how to measure it, and what your numbers mean. It also covers the difference between HRV and pulse rate variability and discusses wearable device accuracy.

Dr Cailbhe Doherty

April 5, 2025

4,158 views

Assessing Apple Watch Series 9 and Ultra 2 for Heart Rate Variability Accuracy

Assessing Apple Watch Series 9 and Ultra 2 for Heart Rate Variability Accuracy

This video summarizes a study evaluating the Apple Watch Series 9 and Ultra 2's accuracy in measuring heart rate variability and resting heart rate, compared to professional devices. Findings highlight limitations in HRV measurement accuracy.

Dr Cailbhe Doherty

April 19, 2025

1,065 views

Understanding Heart Rate Variability: Measurement, Significance, and Applications

Understanding Heart Rate Variability: Measurement, Significance, and Applications

Heart rate variability HRV measures the time between heartbeats. This video covers what HRV is, its importance for health and stress, measurement methods, and the use of wearables. Essential for health tracking and understanding your body's response.

Dr Cailbhe Doherty

June 7, 2025

869 views

Evaluating Apple Watch Series 9 and Ultra 2 for Heart Rate Variability Accuracy

Evaluating Apple Watch Series 9 and Ultra 2 for Heart Rate Variability Accuracy

This video summarizes a recent study on the accuracy of the Apple Watch Series 9 and Ultra 2 in measuring heart rate variability and resting heart rate, highlighting limitations in their current algorithms compared to professional devices.

Dr Cailbhe Doherty

June 28, 2025

449 views

  • Sensors MDPI
    @Sensors_MDPI (Twitter)

    ✨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.
    view full post

    July 22, 2025

    2

  • Thomas LeBosquet
    @lebosquet (Twitter)

    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
    view full post

    October 7, 2024

    3

  • Gabriel Pérez
    @gperez441 (Twitter)

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

    September 29, 2024

    14

  • Sebastian Catana
    @sebastiancatana (Twitter)

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

    September 29, 2024

    14


  • @javierbutra (Twitter)

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

    September 29, 2024

    14

  • PD
    @dp2pd2 (Twitter)

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

    September 28, 2024

    14

  • 南部　博昭(Hiroaki Nanbu)
    @Hiroaki_Nanbu (Twitter)

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

    September 28, 2024

    14

  • André B. Coelho
    @AndBastosCoelho (Twitter)

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

    September 28, 2024

    14

  • Robb!e
    @RobbieG_PhD (Twitter)

    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
    view full post

    September 28, 2024

  • Paul Williams
    @PaulWillBirds (Twitter)

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

    September 28, 2024

    14

  • Chris Brands
    @ChrisBrands (Twitter)

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

    September 28, 2024

    14

  • Madhan Ramanathan
    @sportsphysiouk (Twitter)

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

    September 28, 2024

    14

  • Anthony Osnacz ✝️
    @aosnacz (Twitter)

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

    September 28, 2024

    14

  • ME/CFS Research
    @cfs_research (Twitter)

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

    September 28, 2024

    14

  • Pedro Gull
    @GullPedro (Twitter)

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

    September 28, 2024

    14

  • Sprint Science
    @spikesonly (Twitter)

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

    September 28, 2024

    14

  • Andrew Flatt
    @andrew_flatt (Twitter)

    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
    view full post

    September 28, 2024

    78

    14

Abstract Synopsis

  • 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.]