Hello Im new to this site. Over the past 2 years I have noticed when I run at a moderate pace my abdomen starts to burn, sometimes horribly, and pains shift from my back and stomach, almost like a gas pain. And When Im doing 400 meter runs, Im sucking air like crazy, and comming in last, like 10 seconds behind the next group almost. And also sometimes it feels like im choaking on my tonsil or something, rarely happens tho like 1 out of 15, doing a on track workout, not on road run. Is this asthma? It seems little heavy in my chest when I do run moderate or hard, I feel the air coming in easily but my chest just feels heavy, muscle tention or asthma?

Thankyou. :)