We’re relying on smartwatches for all kinds of information, including how our heart rate and rhythm behave during exercise and rest. However, according to a recent study, smartwatch measurements may be less accurate in people with darker skin tones.
The research included 469 participants and pooled data from multiple studies to examine how skin tone may affect the accuracy of heart data in wearables. Screening 622 scientific papers, the researchers identified ten studies that reported heart rate and rhythm data for consumer wearable technology according to a participant’s race or skin tone. Four indicated that heart rate measurements were significantly less accurate in darker-skinned individuals than lighter-skinned individuals or measurements from validated devices, such as chest strap monitors or electrocardiograms. Although there was no difference in heart rate accuracy, one study reported that wearable devices recorded significantly fewer data points for people with darker skin.
Most wearables aim a beam of light at the wrist, detecting how much light is absorbed. Greater light absorption indicates a greater volume of blood flowing through the veins under the skin. This signaling process might not work as well in darker skin with more melanin, which absorbs light. For more information on wearable technology and your heart health, visit cardiosmart.org/topics/wearable-technology.