400m sports day

Today ezdeen dun wan run 400m then he let me run but i know i will lose got so many pros... Then i run 400m i run too much energy i should run slow first then somemore i go see behind if i never look behind i will never get last. Daamit i now visualise my mistake. If next time i run i will never look behind and beginning dun run too fast. I will win the sports day if i got a chance for 400m and 8x50m>:(