Yeah, I have craters in my arm from donating. They always had trouble on my left, and would mess up pretty frequently on the other. As @loopy says, some of them are very green, so don’t hesitate to ask them to get some help! I got to the point I could direct them. Also, it can definitely zap your energy, especially if you are dehydrated, so lots of coconut water was always my trick. The potassium really helps rehydrate faster than water