Why does exercising make me stay awake?

I exercise/work out (however you want to call it, I prefer the term exercising) before sleeping... and... whenever I do.. I can't sleep for awhile... yesturday.. I was going to start doing crunches but my brother called and we talked for like an hour.. then I thought "wow its way too late" so I went straight to bed...and I fell asleep in like.. 3 min.

When I exercise...I usually do pushups/crunches

when you excersize it pumps blood to your heart and keeps your body moving giving you a surge of energy. you should never excersize before sleep.if you have to excersize at night do it at least three hours before you go to sleep.

It appears you need more time separation between exercise and going to bed - difference between your body 'being all keyed-up' or 'relaxed', more prepared for sleep...Good luck !!