Individuals who engage in more physical activity have a higher prevalence of sunburn,1-5 and melanoma is positively associated with physical activity.6 This study was intended to determine the feasibility of using Strava, a popular exercise tracking app, to promote sun protection tailored to individuals who engage regularly in outdoor physical activity.
To provide tailored sun protection advice, we connected through the Strava Application Programming Interface (API) to collect retrospective activity data from users who consented and authorized collection of data from the past two years. Despite robust recruitment efforts, only 78 Strava users provided this authorization. From these users, 16,669 outdoor activity events were accessed (mean = 214 events/user). Of those activities, 46.1% occurred during high-UV (between 10:00am and 4:00pm) for at least 30 minutes. Using predictive modeling, time outdoors for more than one hour during high-UV was predicted by day of week (more likely occurs on weekends) or proximity to a high UV event (less likely occurs the day after a previous high UV event).
While Strava users are active and prone to overexposure to the sun, privacy settings in the Strava app, which became more restrictive during the study, and users’ resistance to share their data were substantial barriers to employing the app to deliver tailored advice on sun safety. It may be possible to predict when exercisers would be outside during high-UV periods if periodicity of individuals’ exercise bouts are known, information that users might be willing to disclose in a mobile app without sharing location data.