My nose get runny when i start boxing?

My nose constantly gets runny when i get heated or boxing and it frustrates me. Why is my nose only runny when i box? What can i do?|||Same thing happens to me when I eat hot food in summer, try using a neti pot, you can usually get them at pharmacy and as gross as it sounds when you use it it dislodges the snot basically in your nose and drains it out, that should help with the runny nose. There only $20 as well just to let you know.