Nairobi, March 1 -- For many runners today, the workout does not end when the shoes come off. It continues on screens, watches syncing with phones, apps uploading routes and communities reacting in real time. Fitness technology has woven itself into running culture, shaping how athletes train, measure progress and connect.

For Christine Khanili, a restorative dental surgeon and aspiring Comrades ultramarathon finisher, digital tracking evolved with her ambitions. When she moved from short races to endurance events, she switched from an Apple Watch to Garmin for its stronger battery life.

"I needed something that could last longer," she says. Her watch automatically shares workouts to Strava, which she considers the social layer of her t...