Studies that show short-term benefits of running?

I figured this was the best topic to post under.

I'm writing a paper on the benefits of running, and I need to use legitimate studies.

My main points are: short term physical benefits, long term physical benefits, mental benefits, and then my counter argument/risks of running.

I've found studies for everything except short term physical benefits. I know they exist. I know (I suppose I don't, without any studies) that your body essentially becomes more efficient. Your bones become more dense, your body becomes better at using oxygen/carbs/etc. Your muscles get stronger and more coordinated with your brain. etc etc etc I could go on for ages. - You can find this on a million fitness sites.

BUT, I seriously can't find any studies that show this. I'm trying to steer clear of mental benefits, since that's a topic in itself. All I have is a questionnaire of about 80% of smokers quitting, and some weird study on hemoglobin I need a translator for.

This doesn't have to do with anything, but I read an entire study on participants running on a treadmill with catheters and rectal thermometers for 30 minutes at a time and realized a little cramp in my run is nothing.