Pro athlete career specific cheat code?

@nickinbigd     Hello! 

Edit:  I did some more testing for this.  I discovered that once a sim joins the Athlete / Body Building career using the biology degree, there is no way to change the career branch.  Other careers might allow a branch change if a sim gets a different degree that supports the other branch.  There is no degree that supports the Professional Athlete career.   I was not able to find a cheat to reset the branch.  However, if you're playing on PC or Mac, I did find a couple of mods that will reset the branch; MCCC is one of them.  The MC Cheats module allows you to reset the branch to the level just before the decision point.  If you don't already use MCCC and think you might want to try it, I would suggest some caution because there are some default settings that may alter your game in ways that you may not like; for example the MC Population module may move sims into lots, the MC Pregnancy module may give pregnancies to sims.  It is possible to install the main MCCC mod and only the MC Cheats module just to reset the career branch.  Then you could remove all MCCC and there shouldn't be any other impact on your game.

Note: My original reply below only applies if a sim has not yet joined the Body Builder career.

When a sim gets a degree this allows them to start at a higher level in a career.  As you have noticed for the Athlete career, a degree in Biology allows the sim to enter the Bodybuilder level and there is no degree that promotes the athlete career.  The difference is highlighted by a green icon that shows up when you use the "find job" interaction.  When a sim has a Biology degree, it looks like this...

Notice that the Athlete career does not have this green barbell symbol.

So, if you want your sim to pursue the Athlete career instead, then you would just choose this option from the list.