I know this might be a silly, obvious question, but is there a big decrease in your performance if you run, say, 5k and longer distances in loose-fitting sweatpants(think warm-up outfits)? Explain what it is about it that makes you slow down, if the answer to that question is yes.
I did 7 miles today in 57:04 and like to think I could go faster if I were wearing running shorts.