The Democratic nomination race has been going for more than a year, keeping candidates and campaign staffers away from their families for unexpectedly long periods.
"This race gives new meaning to that phrase 'marathon, not a sprint,' but these last few months have been more like sprinting through a marathon," said Jen Psaki, Obama's traveling press aide told The Washington Post.
Psaki reportedly decided to let the lease run out on her Chicago apartment in light of her being there so little since December.
"Sometimes, yes, of course," Obama said when asked if he was fatigued.
The race likely won't slow down any time soon, especially since Clinton's win in Pennsylvania, the Post reported.
"I will either try to get more sleep ... or, you know, have somebody that, you know, is there, as a reminder to me," Clinton said when voter Tom Rooney asked her about violence in Bosnia, referencing her erroneous claim to have landed there under sniper fire.