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Pilot study assessing the influence of skin type on the heart rate measurements obtained by photoplethysmography with the Apple Watch

Sañudo, Borja; De Hoyo, Moisés; Muñoz-López, Alejandro; Perry, John; Abt, Grant


Borja Sañudo

Moisés De Hoyo

Alejandro Muñoz-López

John Perry

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Dr Grant Abt
Reader in Sport and Exercise Physiology and Head of Department for Sport, Health and Exercise Science


Photoplethysmographic imaging (PPG) is currently used to measure heart rate (HR) and the accuracy of PPG can be influenced by pigmentation of the skin; however, the effects of skin color-related artifacts on PPG during exercise remain unclear. This study aimed to assess the agreement between the Apple Watch photoplethysmography sensor and a criterion, for measuring heart rate across a range of intensities during exercise and to determine the influence of skin type on the accuracy of the measure. Forty-five males (20–43 y) completed the Fitzpatrick Skin Scale and were classified into three different skin type groups: a) types II (n = 15), III (n = 15) and IV (n = 15). Participants performed a graded incremental cycle-ergometer test while simultaneously wearing the Apple Watch and a Polar monitor as a criterion measure. Data from both devices were collected in 5-s epochs. Correlations between devices were very good (0.96–0.99 [95%CI: 0.94 to 0.99]). Significant differences were observed between skin types II and III when the intensity of the exercise was increased, albeit with trivial to small effect sizes (ES: 0.05 to 0.28). All significant differences corresponded to

Journal Article Type Article
Journal Journal of Medical Systems
Print ISSN 0148-5598
Electronic ISSN 1573-689x
Publisher Springer Verlag
Peer Reviewed Peer Reviewed
Keywords Heart rate; Agreement; Wearable sensors; Exercise; Skin type