Aof is certainly a relevant trigger for sports and exercise.
However, I just realized something about working out. I have a difficult time during certain periods to find the time and actually do any exercise, besides from working to and from work. I have Exercise, or rather get and stay fit as an area of focus. I'm very difficult to get to the actual exercise though.
I just figured out that if I set every workout as a project, then, for example every set is a task for that project. Every workout schedule I have come across is then a project with tasks to cross over.
So I could really see that a workout would be a project. Don't know if it will work, but I have never tried that approach before, so it might work.