Too busy? Not an excuse. On vacation? Doesn't matter. Fitness influencer and booty queen Jen Selter proved that "'No matter where you are or what you have available, there is always an opportunity to get a quick workout in!!'" In an Instagram video, she kills a quick, do-anywhere workout that doesn't require any other equipment than a makeshift box. In this case, Jen used her hotel room's side table to assist her in box lunges and jumps. (I would definitely test the stability of your item first if I were you.) Wherever you are, try this five-minute sequence that targets your butt and legs: