Why can't he "take a class" or "go to the gym" that's in the opposite direction? There are a lot of people who do things in other places. Especially if you live/work somewhere more remote. He could say he just joined a gym somewhere, and wants to go right after work, because he knows that if he goes all the way home, he'll lose the motivation to work out. Better to get it done right after work, before he gets too far into "off work" mode!