FILE: Activity · OPENED JUL 20 2026 · REV 1 LIVE FILE

Activity Research Desk

What the evidence shows about activity tracking, mortality risk, and step/calorie accuracy — rated by strength of evidence, updated as new studies publish.

activity hub Evidence files: HRV·RHR·Sleep·VO2 Max·Wearable ECG·CGM·Recovery·Blood Oxygen·Respiratory Rate·Stress·Temperature

does device-measured physical activity predict better health outcomes

KnowYourPrime evidence rating Emerging Evidence currently favors the claim, but more confirmation is needed.

Higher device-recorded physical activity reflects a genuine reduction in health risk, particularly mortality risk.

Anchor-grade evidence affirms the core relationship.
Multiple supporting studies are consistent with the core relationship.
The claim rests on a single anchor whose finding affirms it; a second independent affirming anchor is needed to reach Established.
Some evidence conflicts on secondary points that do not change the core direction.

12 studies scored · 1 anchor · 7 supporting · 3 conflicting · Last reviewed Sep 4, 2026

do activity trackers make people more active

KnowYourPrime evidence rating Emerging Evidence currently favors the claim, but more confirmation is needed.

Using a consumer wearable activity tracker increases how physically active people actually become.

Systematic-review or meta-analytic evidence affirms the core relationship.
The claim rests on a single anchor whose finding affirms it; a second independent affirming anchor is needed to reach Established.
Some evidence conflicts on secondary points that do not change the core direction.

3 studies scored · 1 anchor · 1 supporting · 1 conflicting · Last reviewed Sep 4, 2026

are consumer wearables accurate enough to trust for step count and heart rate

KnowYourPrime evidence rating Established Strong, consistent evidence supports the claim.

Consumer wearables measure step count and heart rate accurately enough to be meaningful.

Systematic-review or meta-analytic evidence affirms the core relationship.
Multiple supporting studies are consistent with the core relationship.
Some evidence conflicts on secondary points that do not change the core direction.

What would change this rating

A new core-hitting conflicting study, a retraction of an anchor, or a failed replication would lower this rating.

57 studies scored · 5 anchor · 49 supporting · 2 conflicting · Last reviewed Sep 4, 2026

are consumer wearables accurate enough to trust for calorie/energy-expenditure estimates

KnowYourPrime evidence rating Uncertain Evidence is conflicting, inconsistent, or difficult to interpret.

Consumer wearables measure calorie/energy-expenditure accurately enough to be meaningful.

Multiple supporting studies are consistent with the core relationship.
An anchor study was assessed but its own reported finding runs contrary to this claim, so the evidence is treated as unsettled rather than affirming.
An anchor study was assessed but its own reported finding runs contrary to this claim, so the evidence is treated as unsettled rather than affirming.
An anchor study was assessed but it does not test this claim’s core relationship directly, so the evidence is treated as unsettled rather than affirming.
An anchor study was assessed but its own reported finding runs contrary to this claim, so the evidence is treated as unsettled rather than affirming.
At least one unresolved conflicting study bears on the core claim, capping the rating until reconciled.
Some evidence conflicts on secondary points that do not change the core direction.

18 studies scored · 4 anchor · 12 supporting · 2 conflicting · Last reviewed Sep 4, 2026

does 220 minus age (or similar age-based formulas) accurately predict max heart rate

KnowYourPrime evidence rating Uncertain Evidence is conflicting, inconsistent, or difficult to interpret.

Age-based formulas such as 220-minus-age accurately predict an individual's true maximal heart rate.

An anchor study was assessed but its own reported finding runs contrary to this claim, so the evidence is treated as unsettled rather than affirming.
An anchor study was assessed but its own reported finding runs contrary to this claim, so the evidence is treated as unsettled rather than affirming.

2 studies scored · 2 anchor · Last reviewed Sep 4, 2026

Studies in Pool80

Claims Rated5

Last PubMed SyncSep 4, 2026

Next Scheduled ReviewSep 11, 2026

15 systematic reviews 2 RCTs 40 observational 11 validity studies 12 other

MAINTAINED BY The KnowYourPrime Research Desk · reviewed against new evidence on a rolling basis

Evidence for: Higher device-recorded physical activity reflects a genuine reduction in health risk, particularly mortality risk.

12 scored

Anchor Studies1

Wearable-device-measured physical activity and future health risk.

Journal

Nature medicine · 2020

PMID

32807930

RCR

14.5

Citations

253

Study type

Primary study

Sample size

[ not stated in the abstract ]

accelerometryenergy metabolism

Supporting Studies7

Association of Perioperative Steps and Heart Rate Variability from Wearable Devices with Surgical Outcomes.

Journal

Journal of the American College of Surgeons · 2026

PMID

42089531

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

humansfemale

Predicting incident type 2 diabetes using wearable activity and polygenic risk: A survival-modeling study in All of Us.

Journal

The Journal of clinical endocrinology and metabolism · 2026

PMID

41396877

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

humansdiabetes mellitus, type 2

Digital Biomarkers for Depression Screening With Wearable Devices: Cross-sectional Study With Machine Learning Modeling.

Journal

JMIR mHealth and uHealth · 2021

PMID

34694233

RCR

8.5

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

adultbiomarkers

Preoperative Decline and Postoperative Recovery of Wearable-Derived Physical Activity over a Four-Year Perioperative Period in Total Knee and Hip Arthroplasty.

Journal

Sensors (Basel, Switzerland) · 2026

PMID

42280838

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

humansarthroplasty, replacement, hip

Impact of Extravalvular Remodeling on Wearable Smartwatch-Recorded Physical Activity in Patients Undergoing Transcatheter Aortic Valve Implantation for Severe Symptomatic Aortic Stenosis.

Journal

Journal of the American Heart Association · 2026

PMID

41944153

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

humansaortic valve stenosis

Association Between Wearable Device Measured Activity and Patient-Reported Outcomes for Heart Failure.

Journal

JACC. Heart failure · 2023

PMID

37498273

RCR

3.0

Citations

Study type

Randomized controlled trial

Sample size

[ not stated in the abstract ]

humansfemale

Device-Measured Sleep Characteristics, Daily Step Count, and Cardiometabolic Health Markers: Findings From the Prospective Physical Activity, Sitting, and Sleep (ProPASS) Consortium.

Journal

Circulation. Cardiovascular quality and outcomes · 2025

PMID

40703058

RCR

1.4

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

humansfemale

Conflicting Studies3

[title unavailable]

Sample size

[ not stated in the abstract ]

Bears on

Secondary point

[title unavailable]

Sample size

[ not stated in the abstract ]

Bears on

Secondary point

[title unavailable]

Sample size

[ not stated in the abstract ]

Bears on

Secondary point

Retired / Excluded1

Validity of energy expenditure estimation methods during 10 days of military training.

Journal

Scandinavian journal of medicine & science in sports · 2019

PMID

31136027

RCR

2.7

Citations

Study type

Validity study

Sample size

[ not stated in the abstract ]

accelerometryadult

Evidence for: Using a consumer wearable activity tracker increases how physically active people actually become.

3 scored

Anchor Studies1

Consumer-Based Wearable Activity Trackers Increase Physical Activity Participation: Systematic Review and Meta-Analysis.

Journal

JMIR mHealth and uHealth · 2020

PMID

30977740

RCR

23.1

Citations

406

Study type

Meta-analysis

Sample size

[ not stated in the abstract ]

exercisefitness trackers

Supporting Studies1

A Web-Based Pedometer-Mediated Intervention Maintains Benefits After Pulmonary Rehabilitation: A Pilot Study.

Journal

International journal of chronic obstructive pulmonary disease · 2026

PMID

42610055

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

humanspilot projects

Conflicting Studies1

[title unavailable]

Sample size

[ not stated in the abstract ]

Bears on

Secondary point

Evidence for: Consumer wearables measure step count and heart rate accurately enough to be meaningful.

57 scored

Anchor Studies5

Reliability and Validity of Commercially Available Wearable Devices for Measuring Steps, Energy Expenditure, and Heart Rate: Systematic Review.

Journal

JMIR mHealth and uHealth · 2021

PMID

32897239

RCR

36.5

Citations

452

Study type

Systematic review

Sample size

[ not stated in the abstract ]

energy metabolismfitness trackers

Accuracy and Acceptability of Wrist-Wearable Activity-Tracking Devices: Systematic Review of the Literature.

Journal

Journal of medical Internet research · 2022

PMID

35060915

RCR

17.7

Citations

142

Study type

Systematic review

Sample size

[ not stated in the abstract ]

exercisefitness trackers

Keeping Pace with Wearables: A Living Umbrella Review of Systematic Reviews Evaluating the Accuracy of Consumer Wearable Technologies in Health Measurement.

Journal

Sports medicine (Auckland, N.Z.) · 2024

PMID

39080098

RCR

13.6

Citations

Study type

Systematic review

Sample size

[ not stated in the abstract ]

humansexercise

Accuracy and Precision of Energy Expenditure, Heart Rate, and Steps Measured by Combined-Sensing Fitbits Against Reference Measures: Systematic Review and Meta-analysis.

Journal

JMIR mHealth and uHealth · 2022

PMID

35416777

RCR

7.7

Citations

Study type

Meta-analysis

Sample size

[ not stated in the abstract ]

accelerometryenergy metabolism

Validity of Wrist-Worn photoplethysmography devices to measure heart rate: A systematic review and meta-analysis.

Journal

Journal of sports sciences · 2020

PMID

32552580

RCR

4.2

Citations

Study type

Meta-analysis

Sample size

[ not stated in the abstract ]

accelerometryactivities of daily living

Supporting Studies49

The validity and reliability of consumer-grade activity trackers in older, community-dwelling adults: A systematic review.

Journal

Maturitas · 2018

PMID

29704922

RCR

7.7

Citations

111

Study type

Systematic review

Sample size

[ not stated in the abstract ]

actigraphyaged

Wearable activity trackers-advanced technology or advanced marketing?

Journal

European journal of applied physiology · 2022

PMID

35445837

RCR

9.4

Citations

Study type

Review

Sample size

[ not stated in the abstract ]

fitness trackershumans

Recommendations for determining the validity of consumer wearable and smartphone step count: expert statement and checklist of the INTERLIVE network.

Journal

British journal of sports medicine · 2021

PMID

33361276

RCR

6.7

Citations

Study type

Systematic review

Sample size

[ not stated in the abstract ]

adolescentadult

Wrist-worn devices for the measurement of heart rate and energy expenditure: A validation study for the Apple Watch 6, Polar Vantage V and Fitbit Sense.

Journal

European journal of sport science · 2023

PMID

34957939

RCR

7.3

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

malehumans

Standardizing Analytic Methods and Reporting in Activity Monitor Validation Studies.

Journal

Medicine and science in sports and exercise · 2020

PMID

30913159

RCR

5.6

Citations

Study type

Review

Sample size

[ not stated in the abstract ]

accelerometrycalibration

Quality Evaluation of Free-living Validation Studies for the Assessment of 24-Hour Physical Behavior in Adults via Wearables: Systematic Review.

Journal

JMIR mHealth and uHealth · 2022

PMID

35679106

RCR

3.9

Citations

Study type

Systematic review

Sample size

[ not stated in the abstract ]

adultexercise

Recommendations for Determining the Validity of Consumer Wearables and Smartphones for the Estimation of Energy Expenditure: Expert Statement and Checklist of the INTERLIVE Network.

Journal

Sports medicine (Auckland, N.Z.) · 2022

PMID

35260991

RCR

3.3

Citations

Study type

Systematic review

Sample size

[ not stated in the abstract ]

checklistenergy metabolism

Assessment of 24-hour physical behaviour in adults via wearables: a systematic review of validation studies under laboratory conditions.

Journal

The international journal of behavioral nutrition and physical activity · 2023

PMID

37291598

RCR

2.7

Citations

Study type

Systematic review

Sample size

[ not stated in the abstract ]

humansadult

Sensing leg movement enhances wearable monitoring of energy expenditure.

Journal

Nature communications · 2021

PMID

34257310

RCR

3.6

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

energy metabolismexercise

A catalog of validity indices for step counting wearable technologies during treadmill walking: the CADENCE-adults study.

Journal

The international journal of behavioral nutrition and physical activity · 2022

PMID

36076265

RCR

3.5

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

adultchild

Using Free-Living Heart Rate Data as an Objective Method to Assess Physical Activity: A Scoping Review and Recommendations by the INTERLIVE-Network Targeting Consumer Wearables.

Journal

Sports medicine (Auckland, N.Z.) · 2025

PMID

39893599

RCR

3.6

Citations

Study type

Review

Sample size

[ not stated in the abstract ]

humansheart rate

Validity of Apple Watch 6 and Polar A370 for monitoring energy expenditure while resting or performing light to vigorous physical activity.

Journal

Journal of science and medicine in sport · 2023

PMID

37517888

RCR

2.0

Citations

Study type

Randomized controlled trial

Sample size

[ not stated in the abstract ]

young adulthumans

A meta-analysis of Fitbit devices: same company, different models, different validity evidence.

Journal

Journal of medical engineering & technology · 2022

PMID

34881682

RCR

1.8

Citations

Study type

Meta-analysis

Sample size

[ not stated in the abstract ]

databases, factualenergy metabolism

Are Wrist-Worn Activity Trackers and Mobile Applications Valid for Assessing Physical Activity in High School Students? Wearfit Study.

Journal

Journal of sports science & medicine · 2022

PMID

36157395

RCR

2.9

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

accelerometryadolescent

Validity of energy expenditure estimation methods during 10 days of military training.

Journal

Scandinavian journal of medicine & science in sports · 2019

PMID

31136027

RCR

2.7

Citations

Study type

Validity study

Sample size

[ not stated in the abstract ]

accelerometryadult

Step-count outcomes of 13 different activity trackers: Results from laboratory and free-living experiments.

Journal

Gait & posture · 2022

PMID

36030707

RCR

2.6

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

adulthumans

Validity of Wrist-Worn Activity Trackers for Estimating VO 2max and Energy Expenditure.

Journal

International journal of environmental research and public health · 2020

PMID

31443347

RCR

1.9

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

adultenergy metabolism

Accuracy of the Multisensory Wristwatch Polar Vantage's Estimation of Energy Expenditure in Various Activities: Instrument Validation Study.

Journal

JMIR mHealth and uHealth · 2020

PMID

31579020

RCR

1.5

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

accelerometryadult

Criterion-Related Validity of Consumer-Wearable Activity Trackers for Estimating Steps in Primary Schoolchildren under Controlled Conditions: Fit-Person Study.

Journal

Journal of sports science & medicine · 2024

PMID

38455433

RCR

1.0

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

femalehumans

Raw Photoplethysmography as an Enhancement for Research-Grade Wearable Activity Monitors.

Journal

JMIR mHealth and uHealth · 2024

PMID

39331461

RCR

1.6

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

photoplethysmographyhumans

Fitness band accuracy in older community dwelling adults.

Journal

Health informatics journal · 2020

PMID

28743215

RCR

0.7

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

accelerometryaged, 80 and over

Factors associated with validity of consumer-oriented wearable physical activity trackers: a meta-analysis.

Journal

Journal of medical engineering & technology · 2021

PMID

33750250

RCR

0.4

Citations

Study type

Meta-analysis

Sample size

[ not stated in the abstract ]

databases, factualenergy metabolism

Apple watch accuracy in monitoring health metrics: a systematic review and meta-analysis.

Journal

Physiological measurement · 2025

PMID

40199339

RCR

1.9

Citations

Study type

Meta-analysis

Sample size

[ not stated in the abstract ]

humansenergy metabolism

Validation of an Open-Source Smartwatch for Continuous Monitoring of Physical Activity and Heart Rate in Adults.

Journal

Sensors (Basel, Switzerland) · 2025

PMID

40363363

Citations

Study type

Validity study

Sample size

[ not stated in the abstract ]

humansheart rate

Comparison of consumer-grade wearable devices with a research-grade instrument for measuring physical activity in a free-living setting.

Journal

PloS one · 2026

PMID

41729926

Citations

Study type

Comparative study

Sample size

[ not stated in the abstract ]

humanswearable electronic devices

Validity of four low-cost smartwatches in estimating energy expenditure during cycling in Chinese untrained women.

Journal

PloS one · 2025

PMID

40986546

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

adultfemale

Performance Evaluation of Device-Based Algorithms to Estimate Step Counts in Free-Living Adults Compared with Direct Observation.

Journal

Medicine and science in sports and exercise · 2026

PMID

42456002

Citations

Study type

Comparative study

Sample size

[ not stated in the abstract ]

humansalgorithms

Is my smartwatch a valid witness? A systematic review and meta-analysis.

Journal

Forensic science international · 2026

PMID

41819643

Citations

Study type

Meta-analysis

Sample size

[ not stated in the abstract ]

humanswearable electronic devices

Validation of a novel multi-sensor wearable for measuring heart rate, steps, and energy expenditure in laboratory and simulated free-living protocols.

Journal

Physiological measurement · 2026

PMID

42229511

Citations

Study type

Validity study

Sample size

[ not stated in the abstract ]

humansenergy metabolism

Benchmarking open-source step counting algorithms for wrist-worn devices.

Journal

Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference · 2025

PMID

41335822

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

humansalgorithms

Aggregation Periods Influence Step Count Error in Low-Power Wearables.

Journal

Sensors (Basel, Switzerland) · 2025

PMID

41305204

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

humanswearable electronic devices

Accurate measurement of simulated slow and altered walking activity: Apple Watch best in class wearable devices.

Journal

PloS one · 2025

PMID

41124109

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

humanswearable electronic devices

Step Count Accuracy of the Life Plus Connected Watch at Different Localizations and Speeds in Healthy Adults, Patients With Cardiovascular Disease, and Patients With Peripheral Artery Disease: Step Count Validation Study in Laboratory Settings.

Journal

JMIR formative research · 2025

PMID

39930990

Citations

Study type

Validity study

Sample size

[ not stated in the abstract ]

humansperipheral arterial disease

[title unavailable]

Sample size

[ not stated in the abstract ]

Validation of a wireless device-driven method of estimating caloric expenditure during running.

Journal

Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme · 2026

PMID

42330544

Citations

Study type

Validity study

Sample size

[ not stated in the abstract ]

humansenergy metabolism

Accuracy of energy expenditure estimation by the Apple Watch in EMS-supported exercise.

Journal

Physiological measurement · 2025

PMID

40825349

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

humansenergy metabolism

Validity of a Consumer-Based Wearable to Measure Clinical Parameters in Patients With Chronic Obstructive Pulmonary Disease and Healthy Controls: Observational Study.

Journal

JMIR mHealth and uHealth · 2024

PMID

39504450

RCR

2.9

Citations

Study type

Observational study

Sample size

[ not stated in the abstract ]

humanspulmonary disease, chronic obstructive

Step count accuracy and reliability of two activity tracking devices in people after stroke.

Journal

Physiotherapy theory and practice · 2018

PMID

28777710

RCR

3.0

Citations

Study type

Comparative study

Sample size

[ not stated in the abstract ]

actigraphyadult

Accuracy of wearable physical activity trackers in people with Parkinson's disease.

Journal

Gait & posture · 2018

PMID

29729611

RCR

3.7

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

accelerometryaged

The Effect of Assistive Devices on the Accuracy of Fitbits in Healthy Individuals: A Brief Report.

Journal

International journal of environmental research and public health · 2025

PMID

40724167

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

humansmale

Wearable technology for mobility measurement in orthopedics and traumatology: a comparison of commercially available systems.

Journal

Archives of orthopaedic and trauma surgery · 2025

PMID

40088311

Citations

Study type

Comparative study

Sample size

[ not stated in the abstract ]

humanswearable electronic devices

Comparison of Students' Physical Activity at Different Times and Establishment of a Regression Model for Smart Fitness Trackers.

Journal

Sensors (Basel, Switzerland) · 2025

PMID

40292814

Citations

Study type

Comparative study

Sample size

[ not stated in the abstract ]

humansmale

Analysis of a Medically Certified, Wrist-Worn Sensor for the Assessment of Heart Rate and Energy Expenditure During Daily Activities in Patients With Chronic Heart Failure or Coronary Artery Disease and Recreational Athletes: Validation Study.

Journal

JMIR cardio · 2026

PMID

41027033

Citations

Study type

Validity study

Sample size

[ not stated in the abstract ]

heart rate determinationenergy metabolism

Consumer Smartwatch Technology in Health and Performance Research: Validity, Limitations, and Real-World Applications.

Journal

Sensors (Basel, Switzerland) · 2026

PMID

42515370

Citations

Study type

Review

Sample size

[ not stated in the abstract ]

humansdigital health

Step count accuracy of StepWatch and FitBit One™ among individuals with a unilateral transtibial amputation.

Journal

Prosthetics and orthotics international · 2019

PMID

29623810

RCR

1.5

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

accelerometryadolescent

Validity and Reliability Evaluation of Four Commercial Activity Trackers' Step Counting Performance.

Journal

Telemedicine journal and e-health : the official journal of the American Telemedicine Association · 2019

PMID

29303680

RCR

0.9

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

accelerometryadult

Validity of Wearable Activity Monitors during Cycling and Resistance Exercise.

Journal

Medicine and science in sports and exercise · 2018

PMID

29189666

RCR

8.0

Citations

132

Study type

Validity study

Sample size

[ not stated in the abstract ]

adultbicycling

Assessment of step accuracy using the Consumer Technology Association standard.

Journal

Journal of sports sciences · 2019

PMID

29958058

RCR

1.3

Citations

Study type

Comparative study

Sample size

[ not stated in the abstract ]

adolescentadult

Validity of the "Samsung Health" application to measure steps: A study with two different samsung smartphones.

Journal

Journal of sports sciences · 2019

PMID

30332917

RCR

0.9

Citations

Study type

Validity study

Sample size

[ not stated in the abstract ]

abdomenactigraphy

Conflicting Studies2

[title unavailable]

Sample size

[ not stated in the abstract ]

Bears on

Secondary point

Activity trackers are not valid for step count registration when walking with crutches.

Journal

Gait & posture · 2019

PMID

30798092

RCR

0.9

Citations

Study type

Validity study

Sample size

[ not stated in the abstract ]

Bears on

Secondary point

adultarthroplasty, replacement, knee

Retired / Excluded1

Designing wearable computing devices for improved comfort and user acceptance.

Journal

Ergonomics · 2020

PMID

31437415

RCR

0.6

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

adultconsumer behavior

Evidence for: Consumer wearables measure calorie/energy-expenditure accurately enough to be meaningful.

18 scored

Anchor Studies4

Reliability and Validity of Commercially Available Wearable Devices for Measuring Steps, Energy Expenditure, and Heart Rate: Systematic Review.

Journal

JMIR mHealth and uHealth · 2021

PMID

32897239

RCR

36.5

Citations

452

Study type

Systematic review

Sample size

[ not stated in the abstract ]

energy metabolismfitness trackers

Accuracy and Acceptability of Wrist-Wearable Activity-Tracking Devices: Systematic Review of the Literature.

Journal

Journal of medical Internet research · 2022

PMID

35060915

RCR

17.7

Citations

142

Study type

Systematic review

Sample size

[ not stated in the abstract ]

exercisefitness trackers

Keeping Pace with Wearables: A Living Umbrella Review of Systematic Reviews Evaluating the Accuracy of Consumer Wearable Technologies in Health Measurement.

Journal

Sports medicine (Auckland, N.Z.) · 2024

PMID

39080098

RCR

13.6

Citations

Study type

Systematic review

Sample size

[ not stated in the abstract ]

humansexercise

Accuracy and Precision of Energy Expenditure, Heart Rate, and Steps Measured by Combined-Sensing Fitbits Against Reference Measures: Systematic Review and Meta-analysis.

Journal

JMIR mHealth and uHealth · 2022

PMID

35416777

RCR

7.7

Citations

Study type

Meta-analysis

Sample size

[ not stated in the abstract ]

accelerometryenergy metabolism

Supporting Studies12

Exercise Intensity and Activity Energy Expenditure of Professional Golf Players in Official Competitive Setting.

Journal

Sports health · 2024

PMID

37278287

RCR

1.2

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

humansmale

Comparison of Students' Physical Activity at Different Times and Establishment of a Regression Model for Smart Fitness Trackers.

Journal

Sensors (Basel, Switzerland) · 2025

PMID

40292814

Citations

Study type

Comparative study

Sample size

[ not stated in the abstract ]

humansmale

Comparison of consumer-grade wearable devices with a research-grade instrument for measuring physical activity in a free-living setting.

Journal

PloS one · 2026

PMID

41729926

Citations

Study type

Comparative study

Sample size

[ not stated in the abstract ]

humanswearable electronic devices

Validity of Galaxy Watch for Estimating Energy Expenditure During Intermittent Running: Cross-Sectional Study.

Journal

JMIR formative research · 2026

PMID

41849635

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

humansenergy metabolism

Validity of four low-cost smartwatches in estimating energy expenditure during cycling in Chinese untrained women.

Journal

PloS one · 2025

PMID

40986546

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

adultfemale

Leveraging Accelerometry and Heart Rate Data from Consumer Wearables to Predict Physical Activity in Children: A Device Agnostic Approach.

Journal

Medicine and science in sports and exercise · 2025

PMID

40197719

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

humanschild

Developing and comparing a new BMI inclusive energy expenditure algorithm on wrist-worn wearables.

Journal

Scientific reports · 2025

PMID

40537505

Citations

Study type

Comparative study

Sample size

[ not stated in the abstract ]

humansenergy metabolism

Journal

JMIR cardio · 2026

PMID

41027033

Citations

Study type

Validity study

Sample size

[ not stated in the abstract ]

heart rate determinationenergy metabolism

Consumer Smartwatch Technology in Health and Performance Research: Validity, Limitations, and Real-World Applications.

Journal

Sensors (Basel, Switzerland) · 2026

PMID

42515370

Citations

Study type

Review

Sample size

[ not stated in the abstract ]

humansdigital health

Assessment of laboratory and daily energy expenditure estimates from consumer multi-sensor physical activity monitors.

Journal

PloS one · 2017

PMID

28234979

RCR

5.3

Citations

Study type

Primary study

Sample size

[ not stated in the abstract ]

accelerometryadult

Improving energy expenditure estimates from wearable devices: A machine learning approach.

Journal

Journal of sports sciences · 2020

PMID

32252598

RCR

2.1

Citations

Study type

Validity study

Sample size

[ not stated in the abstract ]

accelerometryactivities of daily living

Validity of Wearable Activity Monitors during Cycling and Resistance Exercise.

Journal

Medicine and science in sports and exercise · 2018

PMID

29189666

RCR

8.0

Citations

132

Study type

Validity study

Sample size

[ not stated in the abstract ]

adultbicycling

Conflicting Studies2

[title unavailable]

Sample size

[ not stated in the abstract ]

Bears on

Secondary point

Validity of Activity Trackers in Estimating Energy Expenditure During High-Intensity Functional Training.

Journal

Research quarterly for exercise and sport · 2020

PMID

31046630

RCR

1.9

Citations

Study type

Validity study

Sample size

[ not stated in the abstract ]

Bears on

Core claim

accelerometryadolescent

Evidence for: Age-based formulas such as 220-minus-age accurately predict an individual's true maximal heart rate.

2 scored

Anchor Studies2

Age-Predicted Maximal Heart Rate in Recreational Marathon Runners: A Cross-Sectional Study on Fox's and Tanaka's Equations

Journal

Frontiers in Physiology · 2018

PMID

29599724

Sample size

[ not stated in the abstract ]

Target Heart Rate Formulas for Exercise Stress Testing: What Is the Evidence?

Journal

Journal of Clinical Medicine · 2024

PMID

39337046

Sample size

[ not stated in the abstract ]

01On Our Desk

In Progress

What we're reading right now

A study only enters a claim's evidence once it's read in full and weighed against what's already in file.

Identified

Queued

Under Review

Extracted

Pending Consensus

Nothing on the desk this cycle.

02Research Log

JUL 20 2026

doi:10.2196/11819 entered as anchor on the behavior change claim.

doi:10.1007/s00421-022-04951-1 entered as supporting on the measurement validity claim.

doi:10.1007/s40279-022-01665-4 entered as supporting on the measurement validity claim.

doi:10.1007/s40279-024-02077-2 entered as anchor on the measurement validity claim.

doi:10.1007/s40279-024-02159-1 entered as supporting on the measurement validity claim.

doi:10.1016/j.forsciint.2026.112901 entered as supporting on the measurement validity claim.

doi:10.1016/j.gaitpost.2022.08.004 entered as supporting on the measurement validity claim.

doi:10.1016/j.jsams.2023.07.005 entered as supporting on the measurement validity claim.

doi:10.1016/j.maturitas.2018.03.016 entered as supporting on the measurement validity claim.

doi:10.1038/s41467-021-24173-x entered as supporting on the measurement validity claim.

doi:10.1080/02640414.2020.1767348 entered as anchor on the measurement validity claim.

doi:10.1080/03091902.2021.1893395 entered as supporting on the measurement validity claim.

doi:10.1080/03091902.2021.2006350 entered as supporting on the measurement validity claim.

doi:10.1080/17461391.2021.2023656 entered as supporting on the measurement validity claim.

doi:10.1088/1361-6579/adca82 entered as supporting on the measurement validity claim.

doi:10.1088/1361-6579/adfcaf entered as supporting on the measurement validity claim.

doi:10.1088/1361-6579/ae76b8 entered as supporting on the measurement validity claim.

doi:10.1109/embc58623.2025.11253635 entered as supporting on the measurement validity claim.

doi:10.1111/sms.13488 entered as supporting on the measurement validity claim.

doi:10.1136/bjsports-2020-103147 entered as supporting on the measurement validity claim.

doi:10.1139/apnm-2025-0395 entered as supporting on the measurement validity claim.

doi:10.1177/1460458217720399 entered as supporting on the measurement validity claim.

doi:10.1186/s12966-022-01350-9 entered as supporting on the measurement validity claim.

doi:10.1186/s12966-023-01473-7 entered as supporting on the measurement validity claim.

doi:10.1249/mss.0000000000001966 entered as supporting on the measurement validity claim.

doi:10.1249/mss.0000000000003989 entered as supporting on the measurement validity claim.

doi:10.1371/journal.pone.0331399 entered as supporting on the measurement validity claim.

doi:10.1371/journal.pone.0333504 entered as supporting on the measurement validity claim.

doi:10.1371/journal.pone.0342543 entered as supporting on the measurement validity claim.

doi:10.2196/14534 entered as supporting on the measurement validity claim.

doi:10.2196/18694 entered as anchor on the measurement validity claim.

doi:10.2196/30791 entered as anchor on the measurement validity claim.

doi:10.2196/35626 entered as anchor on the measurement validity claim.

doi:10.2196/36377 entered as supporting on the measurement validity claim.

doi:10.2196/57158 entered as supporting on the measurement validity claim.

doi:10.2196/58964 entered as supporting on the measurement validity claim.

doi:10.23736/S0022-4707.24.15888-4 entered as supporting on the measurement validity claim.

doi:10.3390/ijerph16173037 entered as supporting on the measurement validity claim.

doi:10.3390/s25092926 entered as supporting on the measurement validity claim.

doi:10.3390/s25226998 entered as supporting on the measurement validity claim.

doi:10.52082/jssm.2022.356 entered as supporting on the measurement validity claim.

doi:10.52082/jssm.2024.79 entered as supporting on the measurement validity claim.

doi:10.1038/s41591-020-1012-3 entered as anchor on the physiological claim.

JUL 20 2026

doi:10.1007/s00421-022-04951-1 entered as supporting on the device motion validity claim.

doi:10.1007/s40279-022-01665-4 entered as supporting on the device motion validity claim.

doi:10.1007/s40279-024-02077-2 entered as anchor on the device motion validity claim.

doi:10.1007/s40279-024-02159-1 entered as supporting on the device motion validity claim.

doi:10.1016/j.forsciint.2026.112901 entered as supporting on the device motion validity claim.

doi:10.1016/j.gaitpost.2022.08.004 entered as supporting on the device motion validity claim.

doi:10.1016/j.jsams.2023.07.005 entered as supporting on the device motion validity claim.

doi:10.1016/j.maturitas.2018.03.016 entered as supporting on the device motion validity claim.

doi:10.1038/s41467-021-24173-x entered as supporting on the device motion validity claim.

doi:10.1080/02640414.2020.1767348 entered as anchor on the device motion validity claim.

doi:10.1080/03091902.2021.1893395 entered as supporting on the device motion validity claim.

doi:10.1080/03091902.2021.2006350 entered as supporting on the device motion validity claim.

doi:10.1080/17461391.2021.2023656 entered as supporting on the device motion validity claim.

doi:10.1088/1361-6579/adca82 entered as supporting on the device motion validity claim.

doi:10.1088/1361-6579/adfcaf entered as supporting on the device motion validity claim.

doi:10.1088/1361-6579/ae76b8 entered as supporting on the device motion validity claim.

doi:10.1109/embc58623.2025.11253635 entered as supporting on the device motion validity claim.

doi:10.1111/sms.13488 entered as supporting on the device motion validity claim.

doi:10.1136/bjsports-2020-103147 entered as supporting on the device motion validity claim.

doi:10.1139/apnm-2025-0395 entered as supporting on the device motion validity claim.

doi:10.1177/1460458217720399 entered as supporting on the device motion validity claim.

doi:10.1186/s12966-022-01350-9 entered as supporting on the device motion validity claim.

doi:10.1186/s12966-023-01473-7 entered as supporting on the device motion validity claim.

doi:10.1249/mss.0000000000001966 entered as supporting on the device motion validity claim.

doi:10.1249/mss.0000000000003989 entered as supporting on the device motion validity claim.

doi:10.1371/journal.pone.0331399 entered as supporting on the device motion validity claim.

doi:10.1371/journal.pone.0333504 entered as supporting on the device motion validity claim.

doi:10.1371/journal.pone.0342543 entered as supporting on the device motion validity claim.

doi:10.2196/14534 entered as supporting on the device motion validity claim.

doi:10.2196/18694 entered as anchor on the device motion validity claim.

doi:10.2196/30791 entered as anchor on the device motion validity claim.

doi:10.2196/35626 entered as anchor on the device motion validity claim.

doi:10.2196/36377 entered as supporting on the device motion validity claim.

doi:10.2196/57158 entered as supporting on the device motion validity claim.

doi:10.2196/58964 entered as supporting on the device motion validity claim.

doi:10.23736/S0022-4707.24.15888-4 entered as supporting on the device motion validity claim.

doi:10.3390/ijerph16173037 entered as supporting on the device motion validity claim.

doi:10.3390/s25092926 entered as supporting on the device motion validity claim.

doi:10.3390/s25226998 entered as supporting on the device motion validity claim.

doi:10.52082/jssm.2022.356 entered as supporting on the device motion validity claim.

doi:10.52082/jssm.2024.79 entered as supporting on the device motion validity claim.

doi:10.1007/s40279-024-02077-2 entered as anchor on the energy expenditure validity claim.

doi:10.2196/18694 entered as anchor on the energy expenditure validity claim.

doi:10.2196/30791 entered as anchor on the energy expenditure validity claim.

doi:10.2196/35626 entered as anchor on the energy expenditure validity claim.

doi:10.3389/fphys.2018.00226 entered as anchor on the max heart rate formula validity claim.

doi:10.3390/jcm13185562 entered as anchor on the max heart rate formula validity claim.

JUL 20 2026

Manual restructuring: genesis founded a single combined "measurement-validity" claim (steps + heart rate + energy expenditure). Split into device-motion-validity and energy-expenditure-validity because the anchor evidence itself draws a clear line: energy-expenditure accuracy is consistently and specifically worse than step/heart-rate accuracy across every anchor, and a combined claim risked understating that finding under one averaged rung.

max-heart-rate-formula-validity founded from 2 manually-seeded, individually-verified papers (not the automated crawl) -- exercise-physiology literature on age-predicted HRmax formulas (220-minus-age, Fox, Tanaka) is not indexed under this cluster's wearable-device MeSH anchors.

JUL 24 2026

pmid:34927069 entered as conflicting on the behavior change claim.

pmid:38097380 entered as conflicting on the device motion validity claim.

pmid:38097380 entered as conflicting on the energy expenditure validity claim.

pmid:33868705 entered as conflicting on the physiological claim.

pmid:38179306 entered as conflicting on the physiological claim.

pmid:39167192 entered as conflicting on the physiological claim.

JUL 24 2026

pmid:34927069 entered as a conflicting study on the behavior change claim, flagged as bearing on a secondary point, not the core direction.

Because it does not hit the core claim, it does not cap the rating and is tracked as an open question.

JUL 24 2026

pmid:38097380 entered as a conflicting study on the device motion validity claim, flagged as bearing on a secondary point, not the core direction.

Because it does not hit the core claim, it does not cap the rating and is tracked as an open question.

JUL 24 2026

pmid:38097380 entered as a conflicting study on the energy expenditure validity claim, flagged as bearing on a secondary point, not the core direction.

Because it does not hit the core claim, it does not cap the rating and is tracked as an open question.

JUL 24 2026

pmid:33868705 entered as a conflicting study on the physiological claim, flagged as bearing on a secondary point, not the core direction.

Because it does not hit the core claim, it does not cap the rating and is tracked as an open question.

JUL 24 2026

pmid:38179306 entered as a conflicting study on the physiological claim, flagged as bearing on a secondary point, not the core direction.

Because it does not hit the core claim, it does not cap the rating and is tracked as an open question.

JUL 24 2026

pmid:39167192 entered as a conflicting study on the physiological claim, flagged as bearing on a secondary point, not the core direction.

Because it does not hit the core claim, it does not cap the rating and is tracked as an open question.

AUG 14 2026

doi:10.1007/s00402-025-05803-1 entered as supporting on the device motion validity claim.

doi:10.1016/j.gaitpost.2018.04.034 entered as supporting on the device motion validity claim.

doi:10.1080/09593985.2017.1354412 entered as supporting on the device motion validity claim.

doi:10.2196/56027 entered as supporting on the device motion validity claim.

doi:10.2196/69343 entered as supporting on the device motion validity claim.

doi:10.3390/ijerph22071100 entered as supporting on the device motion validity claim.

doi:10.3390/s25061726 entered as supporting on the device motion validity claim.

doi:10.3390/s26144486 entered as supporting on the device motion validity claim.

doi:10.1038/s41598-025-99963-0 entered as supporting on the energy expenditure validity claim.

doi:10.1177/19417381231175149 entered as supporting on the energy expenditure validity claim.

doi:10.1249/mss.0000000000003721 entered as supporting on the energy expenditure validity claim.

doi:10.1371/journal.pone.0331399 entered as supporting on the energy expenditure validity claim.

doi:10.1371/journal.pone.0342543 entered as supporting on the energy expenditure validity claim.

doi:10.2196/69343 entered as supporting on the energy expenditure validity claim.

doi:10.2196/83090 entered as supporting on the energy expenditure validity claim.

doi:10.3390/s25061726 entered as supporting on the energy expenditure validity claim.

doi:10.3390/s26144486 entered as supporting on the energy expenditure validity claim.

doi:10.1097/xcs.0000000000001857 entered as supporting on the physiological claim.

doi:10.1161/jaha.125.047277 entered as supporting on the physiological claim.

doi:10.1210/clinem/dgaf673 entered as supporting on the physiological claim.

doi:10.2196/24872 entered as supporting on the physiological claim.

doi:10.3390/s26113319 entered as supporting on the physiological claim.

AUG 21 2026

doi:10.2147/copd.s611518 entered as supporting on the behavior change claim.

doi:10.1080/00140139.2019.1657184 entered as retired on the device motion validity claim.

doi:10.1089/tmj.2017.0264 entered as supporting on the device motion validity claim.

doi:10.1177/0309364618767138 entered as supporting on the device motion validity claim.

doi:10.1080/02640414.2020.1746088 entered as supporting on the energy expenditure validity claim.

doi:10.1371/journal.pone.0171720 entered as supporting on the energy expenditure validity claim.

doi:10.1016/j.jchf.2023.05.033 entered as supporting on the physiological claim.

doi:10.1111/sms.13488 entered as retired on the physiological claim.

SEP 4 2026

doi:10.1016/j.gaitpost.2019.02.009 entered as conflicting on the device motion validity claim.

doi:10.1080/02640414.2018.1491941 entered as supporting on the device motion validity claim.

doi:10.1080/02640414.2018.1527199 entered as supporting on the device motion validity claim.

doi:10.1249/mss.0000000000001471 entered as supporting on the device motion validity claim.

doi:10.1080/02701367.2019.1603989 entered as conflicting on the energy expenditure validity claim.

doi:10.1249/mss.0000000000001471 entered as supporting on the energy expenditure validity claim.

doi:10.1161/circoutcomes.124.011873 entered as supporting on the physiological claim.

SEP 4 2026

doi:10.1016/j.gaitpost.2019.02.009 entered as a conflicting study on the device motion validity claim, flagged as bearing on a secondary point, not the core direction.

Because it does not hit the core claim, it does not cap the rating and is tracked as an open question.

SEP 4 2026

doi:10.1080/02701367.2019.1603989 entered as a conflicting study on the energy expenditure validity claim, bearing on the core claim.

It caps the rating until reconciled.

04Revision Log

JUL 20 2026

max heart rate formula validity: opened at Uncertain

Opened at Uncertain by rule from the current evidence for: Age-predicted maximal-heart-rate equations match an individual’s actual measured maximal heart rate..

JUL 20 2026

energy expenditure validity: opened at Uncertain

Opened at Uncertain by rule from the current evidence for: Consumer wearable devices measure energy expenditure with accuracy comparable to reference standards..

JUL 20 2026

device motion validity: opened at Established

Opened at Established by rule from the current evidence for: Consumer wearable devices measure step count and heart rate with accuracy comparable to reference standards..

JUL 20 2026

behavior change: opened at Emerging

Opened at Emerging by rule from the current evidence for: Wearable activity tracker use increases physical activity participation..

JUL 20 2026

physiological: opened at Emerging

Opened at Emerging by rule from the current evidence for: Higher wearable-measured physical activity is associated with lower all-cause mortality risk..

This page interprets published research. It is not medical advice. The KnowYourPrime Research Desk rates the evidence supporting a claim, not the claim itself. It does not diagnose or treat. Talk to your own doctor about your health.