What Does It Take? Developing a Smartphone App that Motivates Older Adults to be Physically Active

TL;DR

This study investigates the feasibility of Senior Fit, a standalone smartphone app designed to motivate physically active living among older adults. Through a two-phase design, the authors compare a traditional SMS/paper intervention (Phase 1) with a six-month, unsupervised app deployment (Phase 2) in 25 participants aged 65–85, incorporating offline functionality and on-device pose detection. Results reveal mixed engagement: some participants benefited from video guidance and reminders, while others faced usability barriers, privacy concerns, and a desire for broader personalization and automatic tracking. The findings highlight design tensions between automation and control, and between external social platforms and in-app social support, offering concrete recommendations for inclusive, flexible, and privacy-conscious mobile fitness tools tailored to older adults. These insights inform future long-term deployments and scalable digital health interventions in aging populations.

Abstract

Maintaining physical activity is essential for older adults' health and well-being, yet participation remains low. Traditional paper-based and in-person interventions have been effective but face scalability issues. Smartphone apps offer a potential solution, but their effectiveness in real-world use remains underexplored. Most prior studies take place in controlled environments, use specialized hardware, or rely on in-person training sessions or researcher-led setup. This study examines the feasibility and engagement of Senior Fit, a standalone mobile fitness app designed for older adults. We conducted continuous testing with 25 participants aged 65-85, refining the app based on their feedback to improve usability and accessibility. Our findings underscore both the potential and key challenges in designing digital health interventions. Older adults valued features such as video demonstrations and reminders that made activity feel accessible and motivating, yet some expressed frustration with manual logging and limited personalization. The Facebook group provided encouragement for some but excluded others unfamiliar with the platform. These results highlight the need for fitness apps that integrate flexible tracking, clear feedback, and low-barrier social support. We contribute design recommendations for creating inclusive mobile fitness tools that align with older adults' routines and capabilities, offering insights for future long-term, real-world deployments.

Figures (3)

• Figure 1: Single leg stance detection via phone camera (top) and seated hamstring stretch without detection (bottom).
• Figure 2: BlazePose keypoints bazarevsky2020blazepose (left) and example body points detected by Blaze-pose during the team's training phase for the "Single Leg Stance" exercise.
• Figure 3: Participant satisfaction with Senior Fit's tracking.