Good Luck
Expression
がんばれ
まあ、結果を気にせずに、頑張れよ！
Well, don’t worry about the results, just try your best!
Remember 頑張る? This is just another form of that, this time you're telling someone to 頑張る, making this word mean something along the lines of good luck or do your best! Speaking of which, 頑張れ, you!
The reading comes from 頑張る.