Hello, i am a 19 year old male and i was wondering about an irregular hearbeat that i get randomly when i work out. occasionally when i am performing strenuous physical activity i will feel my heart start to beat faster and harder than normal. it really doesnt hurt but it makes me feel uncomfortable and and i feel like my throat starts to close up, not to the point of not being able to breath though. also i become dizzy and i just want to sit or lay down and relax. this has only happened to me a few times since i was about 17. most always they occur when i am working out but a few have occurred the morning after heavy drinking. the episodes have never lasted more than about an hour and they usually just randomly go away. at first i thought it might have been from something sugary or loaded with caffeine that i drank before a workout but i am not sure. i am a little overweight and i do smoke. hope you can answer my question. thanks for your time