JMIR Publications

ABSTRACT

Background:

Given the global burden of insufficient physical activity (PA) in childhood, effective behavioral interventions are needed to support increased PA levels. Novel technologies can help expand the reach and accessibility of these programs. Despite the potential to use HR to target moderate to vigorous PA (MVPA), most HR research to date has focused on the accuracy of HR devices or used HR for PA surveillance, rather than as an intervention tool. Furthermore, most commercial HR sensors are designed for adults, and their suitability for children is unknown. Further research about the feasibility and usability of commercial HR devices is required to understand how children may use HR during PA.

Objective:

This study explored the use of a chest-worn HR sensor paired with real-time HR display as an intervention tool among pre-adolescent children. This study also explored the usability of a custom-designed app (Connexx) for viewing real-time HR.

Methods:

Researchers developed Connexx, an HR information display app that also contains an HR analytics portal to view HR tracking. Children were recruited via flyers distributed at local public schools, word-of-mouth, and social media posts. Eligible participants were ages 9-12 without medical contraindications to MVPA. Participants took part in a single in-person study session where they monitored their own HR using a commercial HR sensor, learned about HR, and engaged in a series of physical activities while using the Connexx app to view their real-time HR. Researchers took field note observations about participant interactions with the HR devices. Participants engaged in a semi-structured interview about their experience using Connexx and HR during PA, and completed the System Usability Scale (SUS) about the Connexx app. Study sessions were audio and video recorded and transcribed verbatim.

Results:

Participants (N=11; 55% male; 82% non-Hispanic White) were on average 10.4+1.0 years old. Data from observations, interviews, and SUS all indicate pre-adolescent children can use real-time HR information during MVPA. Observational and interview data indicated that the participants were able to understand their HR after a basic lesson and demonstrated the ability to make use of their HR information during PA. Interview and SUS responses demonstrate that the Connexx app was highly usable, despite some accessibility challenges (e.g., small display font). Feedback about usability issues has been incorporated into a redesign of Connexx including larger, color-coded fonts for HR information.

Conclusions:

The results of this study indicate that pre-adolescent children understood their HR data and were able to use it in real time during PA. The findings suggests that future interventions to target MVPA with this population should test strategies to use HR and HR monitoring as direct program targets.