I haven t ran for a long time and the past week I started running again. However, as I keep running and running, my heart starts to thump faster and faster and then it starts to feel like it s going to explode. I have no choice but to stop running and wait for it to stop every time. I remember before when I ran in grade 7 and 8 my heart didn t feel like it was going to explode, it felt different. Also, sometimes when I m running my stomach feels like it s burning and I just finished running today and I feel really really light-headed. Is this normal? Is this the result of not running for a long time or do I have heart problems or asthma? I don t have asthma... I think I m getting it though.