Runners in Santa hats are part of the Nikolauslauf Tübingen, a winter half marathon in Tübingen with roots going back to 1976. It is a classic 21 km race with one main ranking, usually drawing about 3,500 to 4,500 participants near the end of the running year.
The course is a single lap, offering runners one continuous route rather than repeated loops. The event's idea is simple: meet running friends and clubmates one more time before the year ends. Post-SV Tübingen is behind the race, and the organization has built a long-running timing setup that moved from shoe chips to RFID bibs, with live results, on-site registration, certificate printing, and several timing mats supporting a large field.