The health-enhancing benefits of physical activity are well established. Ongoing population physical activity surveillance is critical for benchmarking and priority-setting, especially in low- and middle-income countries (LMICs) where economic transitions have led to rapidly changing lifestyles and the rise in non-communicable diseases. Since its inception, global physical activity surveillance has relied on questionnaires, which are subject to reporting bias. Wearable devices provide opportunities to continuously measure physical activity with greater granularity across various intensities, activity types, postures and bouts. Recent evidence suggests that device-measured physical activity has a stronger association with mortality outcomes than reported physical activity.1

For decades, wearable-based surveillance systems have been in the limelight–demonstrating the potential for accurate physical activity measurements.2 Such ‘traditional’ systems involve an accelerometric sensor attached to the participant’s body and often require manual data downloading and laborious data processing. Despite improved accuracy, logistical barriers (table 1) have prevented wearables from being scaled up and implemented globally, especially in LMICs. Addressing these barriers, as per the WHO global action plan on physical activity,3 requires rethinking wearable systems, addressing logistic barriers and developing more accessible and cost-efficient systems for implementation in a wide range of countries, including LMICs (figure 1).

The current challenges of using traditional wearable systems and how new technologies can address …