To do this in Strava, it would require everyone to have their phone with them to continually transmit their location.  Only a fraction of people actually carry their phones with them in races.  The live tracking for events work because it is a timing system specific to the event that is set up to track and record locations either at specific reading points (timing mats) or with GPS transponders.  

Just for events and if the athletes opt-in. 

Strava + RTRT for all types of major running and cycling events. Show the athlete's profile photo moving along the map and be able to click on their profile photo to see their training in Strava.