Reliability of heart rate mobile apps in young healthy adults: exploratory study and research directions

Background: Recently, a number of smartphone apps appeared that allow for heart rate measurements basing on the photoplethysmography principle. In fact, almost every smartphone now has a camera with flash that could be used for that. Some studies appeared on the reliability of some of those apps, with heterogeneous results.Objectives: The present study aims at adding up evidence in particular during physical activity, by comparing 3 apps on two different platforms (IOs and Android), on a broad range of heart rates. As gold standard, heart rate has been measured with a traditional heart rate monitor.Results: The results suggest that heart rate apps might be used for measuring heart rate for fitness aims for many individuals, but further research is needed to i) analyse influence of smartphone features; ii) identify personal factors hindering measurements, and iii) verify reliability on different measurement sites