Should I have protein powder before or after exercise?

Using your protein powder before or after workouts is a great time for it. Especially if you don't eat surrounding exercise, it can help improve recovery. If you're trying to decide which time to go with, choose when protein is usually missing in your diet. 

Generally, though, emphasizing carbohydrates before your workout is helpful to fuel you through it. Protein is then singled out more so afterward to recover and rebuild, but beforehand works too.