Something you should do every day, along with staying crispy. Alexander Ludwig frequently livs it up, and he encourages his fans to do the same via twitter. Liv it up and stay crispy have also become well-loved inside jokes of the Hunger Games fandom.
Alexander Ludwig: be social, don't take anything too seriously, liv it up
THG fandom: bitch you need to liv it up before I smack the crispy out of you