Investigating the accuracy of Apple Watch VO2 max measurements: A validation study.

VO2 max is a measure of cardiorespiratory fitness and a key indicator of overall health. It is predictive of cardiovascular events and shows a strong inverse association with all-cause mortality. Increased cardiorespiratory fitness is associated with reductions in coronary artery disease, diabetes a...

Full description

Saved in:
Bibliographic Details
Main Authors: Rory Lambe, Ben O'Grady, Maximus Baldwin, Cailbhe Doherty
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2025-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0323741
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850270568868216832
author Rory Lambe
Ben O'Grady
Maximus Baldwin
Cailbhe Doherty
author_facet Rory Lambe
Ben O'Grady
Maximus Baldwin
Cailbhe Doherty
author_sort Rory Lambe
collection DOAJ
description VO2 max is a measure of cardiorespiratory fitness and a key indicator of overall health. It is predictive of cardiovascular events and shows a strong inverse association with all-cause mortality. Increased cardiorespiratory fitness is associated with reductions in coronary artery disease, diabetes and cancer. Apple Watch offers a less resource-intensive and more feasible alternative to the gold standard assessment for VO2 max, indirect calorimetry, but the accuracy of its measurements remains uncertain. This study aimed to assess the validity of VO2 max estimates from Apple Watch in comparison to indirect calorimetry. Thirty participants wore an Apple Watch for 5-10 days to generate a VO2 max estimate. Subsequently, they underwent a maximal exercise treadmill test in accordance with the modified Åstrand protocol. The agreement between measurements from Apple Watch and indirect calorimetry was assessed using Bland-Altman analysis, mean absolute percentage error (MAPE), and mean absolute error (MAE). Overall, Apple Watch underestimated VO2 max, with a mean difference of 6.07 mL/kg/min (95% CI 3.77-8.38). Limits of agreement indicated variability between measurement methods (lower -6.11 mL/kg/min; upper 18.26 mL/kg/min). MAPE was calculated as 13.31% (95% CI 10.01-16.61), and MAE was 6.92 mL/kg/min (95% CI 4.89-8.94). These findings indicate that Apple Watch VO2 max estimates require further refinement prior to clinical implementation. However, further consideration of Apple Watch as an alternative to conventional VO2 max prediction from submaximal exercise is warranted, given its practical utility.
format Article
id doaj-art-e0fc2c898e2c4dd49fff20f1fc1cbb2a
institution OA Journals
issn 1932-6203
language English
publishDate 2025-01-01
publisher Public Library of Science (PLoS)
record_format Article
series PLoS ONE
spelling doaj-art-e0fc2c898e2c4dd49fff20f1fc1cbb2a2025-08-20T01:52:33ZengPublic Library of Science (PLoS)PLoS ONE1932-62032025-01-01205e032374110.1371/journal.pone.0323741Investigating the accuracy of Apple Watch VO2 max measurements: A validation study.Rory LambeBen O'GradyMaximus BaldwinCailbhe DohertyVO2 max is a measure of cardiorespiratory fitness and a key indicator of overall health. It is predictive of cardiovascular events and shows a strong inverse association with all-cause mortality. Increased cardiorespiratory fitness is associated with reductions in coronary artery disease, diabetes and cancer. Apple Watch offers a less resource-intensive and more feasible alternative to the gold standard assessment for VO2 max, indirect calorimetry, but the accuracy of its measurements remains uncertain. This study aimed to assess the validity of VO2 max estimates from Apple Watch in comparison to indirect calorimetry. Thirty participants wore an Apple Watch for 5-10 days to generate a VO2 max estimate. Subsequently, they underwent a maximal exercise treadmill test in accordance with the modified Åstrand protocol. The agreement between measurements from Apple Watch and indirect calorimetry was assessed using Bland-Altman analysis, mean absolute percentage error (MAPE), and mean absolute error (MAE). Overall, Apple Watch underestimated VO2 max, with a mean difference of 6.07 mL/kg/min (95% CI 3.77-8.38). Limits of agreement indicated variability between measurement methods (lower -6.11 mL/kg/min; upper 18.26 mL/kg/min). MAPE was calculated as 13.31% (95% CI 10.01-16.61), and MAE was 6.92 mL/kg/min (95% CI 4.89-8.94). These findings indicate that Apple Watch VO2 max estimates require further refinement prior to clinical implementation. However, further consideration of Apple Watch as an alternative to conventional VO2 max prediction from submaximal exercise is warranted, given its practical utility.https://doi.org/10.1371/journal.pone.0323741
spellingShingle Rory Lambe
Ben O'Grady
Maximus Baldwin
Cailbhe Doherty
Investigating the accuracy of Apple Watch VO2 max measurements: A validation study.
PLoS ONE
title Investigating the accuracy of Apple Watch VO2 max measurements: A validation study.
title_full Investigating the accuracy of Apple Watch VO2 max measurements: A validation study.
title_fullStr Investigating the accuracy of Apple Watch VO2 max measurements: A validation study.
title_full_unstemmed Investigating the accuracy of Apple Watch VO2 max measurements: A validation study.
title_short Investigating the accuracy of Apple Watch VO2 max measurements: A validation study.
title_sort investigating the accuracy of apple watch vo2 max measurements a validation study
url https://doi.org/10.1371/journal.pone.0323741
work_keys_str_mv AT rorylambe investigatingtheaccuracyofapplewatchvo2maxmeasurementsavalidationstudy
AT benogrady investigatingtheaccuracyofapplewatchvo2maxmeasurementsavalidationstudy
AT maximusbaldwin investigatingtheaccuracyofapplewatchvo2maxmeasurementsavalidationstudy
AT cailbhedoherty investigatingtheaccuracyofapplewatchvo2maxmeasurementsavalidationstudy