on your mark, get set, go
on your mark(s), get set, go
An instruction to begin something, typically some kind of competition. The phrase is commonly used at the beginning of a race to indicate when the competitors can start. Is everyone ready? OK then, on your mark, get set, go!
on your mark, get set, goand ready, set, go
[in preparing to start a race involving speed] move to the starting point, get set to move, go. Runners on your mark, get set, go.