Can i have a heart attack from too much exercise?

Yes: The heart is a muscular organ and like any muscle can be overworked to the point of failure. Studies have shown that even well trained marathon runners show signs of heart failure during marathons. To avoid overexerting your heart, train in a graduated fashion in moderation. Work with your physician and a trainer to establish a good cardio training regimen.

No : Theoretically yes, but in actuality, the risk is exceptionally low, even in people with known heart disease. In your age group, the answer is no with confidence.