I'm 16 years old, male, 6'3", 185 lbs. I have been prescribed Vyvanse to treat my ADD symptoms for about two years (currently at 70mg), and the results have been amazing. I have maintained a 4.0 GPA or higher in every grading period so far in my highschool career. But, I have recently noticed that I often get dizzy while doing cardio workouts, and a dangerously high heart rate. However, I'm in no means out of shape, and am extremely ripped.