Validity of heart rate measurements by the Garmin Forerunner 225 at different walking intensities. (18th August 2017)

• Record Type: Journal Article
• Authors: Claes, Jomme; Buys, Roselien; Avila, Andrea; Finlay, Dewar; Kennedy, Alan; Guldenring, Daniel; Budts, Werner; Cornelissen, Véronique
• Is Part Of: Journal of medical engineering & technology. Volume 41:Number 6(2017)
• Page Start: 480
• Page End: 485
• Publication Date: 2017-08-18
• Subjects: Validity -- Garmin -- heart rate -- photoplethysmography -- sports watch; Biomedical engineering -- Periodicals; Medical technology -- Periodicals; 610.28
• DOI: 10.1080/03091902.2017.1333166
• Languages: English
• ISSNs: 0309-1902

Abstract

Abstract: The accuracy of wrist worn heart rate monitors based on photoplethysmography (PPG) is not fully clinically accepted. Therefore, we aimed to validate heart rate measurements of a commercially available PPG heart rate monitor, i.e. the Garmin Forerunner ® 225. Twelve healthy volunteers (six women; mean age: 28 years) performed a treadmill protocol consisting of: five minutes sitting, five minutes standing, 10 minutes walking at 4 km/h, 10 minutes walking at a gradient of 5% and intensity of 4–6 metabolic equivalents (METs), 10 minutes walking at a gradient of 8% and intensity of seven METs or more. Walking speeds were individually determined. Walking bouts were separated by a standardised five minute rest period. Heart rate was measured as the average of the last three minutes standing and of each walking bout. A three lead patch-based electrocardiogram (ECG; Zensor ® ) was used as criterion method. Statistical analyses included Pearson's correlation (r), paired t-tests, root mean squared error (RMSE) and Bland?Altman plots. The mean values per three minutes of every condition did not differ significantly between the Garmin Forerunner ® 225 and the Zensor ® . RMSE was 3.01 beats per minute (bpm) or 2.89%. The Bland–Altman bias was 1.57 bpm. Limits of agreement (LoA) were wide, ranging from 32.53 to 29.40 bpm. However, Pearson's r ranged from 0.650 to 0.868 suggesting moderate to strong validity. Generally, mean heart rates, r values, RMSE and the Bland–Altman bias indicated good overall agreement in this sample of healthy adults, but wide LoA are making it difficult to trust individual measurements.