'National Physical Fitness Day' is usually ZIM's (and Dib's) least favorite day. But this year- President Man will be coming to Skool to congratulate the winners! IN PERSON! And ZIM must be one of those winners- so he can kidnap President Man! Thus begins THE BULKENING. Of course- Dib figures out what's going on- and in this case- the only way to defeat ZIM... IS TO GET PHYSICAL.