To put forth the necessary effort or energy to do or pursue something, especially in the face of any doubt or trepidation. Often used as words of encouragement. Sam: "I'm thinking of asking Dave out on a date, but what if he says no?" Mike: "Just go for it, dude! You'll never know unless you ask!"I knew I wouldn't win the marathon, but I still went for it with everything I had.
go for it
to do what you need to without additional thought I always have a strategy when I race, but Fran just goes for it.She shouldn't worry so much, she should just go for it.