Popularized by MGK (Machine Gun Kelly)'s EST movement, "Lace Up" is a life mantra. Basically it means that no matter what, get up, "Lace Up" your Chuck Ts (MGK's shoe of choice), and get out there and make things happen. People who sat around, even in dark times, accomplished little. It's those who, no matter what, get up and face the day, fight for what they want to happen, that change the world.
"I don't know if I can do this, man..."
"Come on! Lace Up!"