Hello sir, I am 20 years old. After sprinting 200m 3-4 times I feel that I will fall on ground. And I start feeling that I am not able to stand or walk and I have to sit somewhere. Slowly my visibility also goes down and when I lay on ground I started sweating. This doesn't happens always but sometimes. When I was young and I do pradesh and I have stand for 4-5 hours then this happens and I fell on ground. Please tell me what to do. Thank you.