Strava has introduced a new feature for subscribers that allows athletes to view their activities in 3D, enhancing the visualization of their Personal Heatmaps with detailed topographical representation. This feature, which can be activated via the sidebar, offers an immersive experience of runs, rides, and other activities by displaying routes over varied landscapes and is notably enhanced when combined with Mapbox's upgraded satellite maps. Athletes can customize heatmap colors to better contrast with different terrains, whether urban or rural. Senior Product Manager Will Meyer highlights the value of the collaboration with Mapbox in enriching user experience and motivating athletes. The 3D mode is immediately available to Strava subscribers, who can find more information on Strava's "What's New" page.