girl: "Baby does my butt look big in this?"
boy: turns and stares at his girlfriends ginormous butt - "hmmm, um....maybe, possibly you could think about doing some exercycling. Maybe."
A trip to a grocery store, convenience store, or gas station for the sole purpose of buying an excessive amount of junk food and sugary drinks, usually with friends. A chud run often happens late at night and ends with everyone involved hating themselves afterwards.