The Growing Market for Fitness Trackers

Market Overview

The global market for fitness trackers is experiencing significant growth. Research firm IDC reported that over 100 million fitness trackers were sold in 2016. These devices attract not only serious and recreational athletes but also medical researchers who are utilizing them for studies in diverse fields such as exercise, metabolism, neurology, asthma, and cancer.

The Importance of Heart Rate Monitoring

A critical feature of fitness trackers is heart rate measurement, expressed in beats per minute (bpm). This metric serves as an essential indicator of exercise intensity and provides insights into how sleep, stress, illness, and medication influence the body.

Accuracy of Heart Rate Monitoring in Fitbit Charge 2

Research Study Overview

A groundbreaking study conducted by researchers in Italy and the UK assessed the heart rate accuracy of the Fitbit Charge 2, one of the most popular fitness trackers available. This study, published in the journal PLoS ONE, is the first to investigate the heart rate measurement accuracy of this device.

Study Methodology

Participants were instructed to ride a stationary bike and elevate their heart rates as much as possible. They could slow down or rest whenever needed, as the primary focus was on measuring the heart rate accuracy of the Fitbit Charge 2 rather than evaluating training techniques. Each participant wore the tracker on their non-dominant wrist while simultaneously being connected to a clinical measuring system, the ProComp Infiniti T7500M, which served as the control.

Findings on Heart Rate Accuracy

The study revealed that the Fitbit Charge 2 consistently underestimated heart rates, with an average underestimation of -5.9 bpm. However, for some participants, this discrepancy could be as high as 30 bpm.

Implications and Future Research

The findings suggest that the Fitbit Charge 2 may not be suitable for serious exercise monitoring or medical research due to its potential inaccuracies in heart rate measurement. Further investigations are necessary to identify the causes of this underestimation, including factors such as exercise type and tracker positioning. Additionally, the study authors highlighted the need for comparative research involving the Fitbit Charge 2 and other fitness trackers on the market.

Reference

Benedetto et al. “Assessment of the Fitbit Charge 2 for monitoring heart rate” PLoS ONE 13(2): e0192691. 2018.