It is easier to run behind someone and match their pace than it is to lead a race. It is also easier to run faster for shorter distances. A rabbit is someone that runs a fast pace for less than the full race distance so the real racers can be pulled through the early miles and save energy for their push to the finish.

Races want runners to run fast times, because that makes them prestigious. Runners want to run fast times, for obvious reasons. So races provide rabbits which lures fast runners to those races.

Here you go: “A marathon or half marathon pacer is a volunteer runner that runs a race at a specific pace for a target finish time. Pacers are usually veteran runners that have racing and pacing strategies they have mastered which they utilize during the course of the race. Pacers wear some type of signage/object such as a sign, balloon, or shirt identifying their target finish time.”

Link: https://halfmarathonforbeginners.com/what-is-a-pacer-in-runn...

I’m not ChatGPT, but here is the Wikipedia article that may be of interest. Wikipedia describes “Pacemakers serve the role of conveying tangible information about pacing on the track during a race”

https://en.m.wikipedia.org/wiki/Pacemaker_(running)