From what you have here, you can log a player's participation by creating a new record in Workout Participation and selecting a player and a coach for it.
Is this where you are having the trouble? If so, you can put a portal to WorkOutParticipation on the Player layout. Then put _fk_CoachID inside the portal row formatted with a value list of pk_Coach_ID and Full Name values so that you can select the coach.
But I also see another table named "WorkOut" so I'm not sure if that's what you really want/need here...
For some reason I can't get the coaches to link up. When I select a number on the _fk_coaches ID on the workout participation layout it never populates. It looks like it should work as Ive done things like this before but for some reason tis not working.
You'll need to put it under a microscope and see where the issue is. What you describe could be an issue with your layout design, the relationship or the value list that you are using to enter coach ID's.
Thanks Phil, for some reason the serial numbers weren't creating fr the coaches so that is why I couldnt select them. Of all the things that I have messeup on this is a first for me