Vyvanse 50mg without adhd..........?

Ok so. I have a 50mg vyvanse pill from a friend. ive took aderall before. i do not have adhd.. I was wondering what bad side effects this would have on me. all i am doing is taking the pill regular orally just the 50mg it makes me focus better and be more outstanding. i have no allergies to anything and no past heart problems or anything. i was wondering what the worst this could do to me being i do not have adhd. and also can i exercise while on this pill? it gives me the motivation to want to do alot of lifting and running.