Coach
The Coach is an NPC and is almost always a man, though coaches can be male or female. A neighborhood will usually have three coaches, two male and one female. The coach will yell at a Sim to stop whatever he or she is doing and work out, but that Sim may not do so right away, in which case the player can cancel the Work Out action before he or she starts working out. While the Coach can be very irritating, a locked door can keep him out. If the player can have his target ignore or avoid him long enough, he will give up and leave.
Supposedly, the Coach targets unfit Sims. In practice, he often targets very fit ones.
The Influence option will appear when clicking on a coach, but attempting to influence a coach seems to be ineffective.
Coach is also a job in the Athletic career track. This job has no relationship to the University NPC.