a while back my marathon-running friends were saying it took them 3 miles before they felt like they were in the running groove. at the time, it took me about 1 mile and i decided that it was the way to go - i usually only go 4-6 miles, so having a 1 mile warm-up sounds much better than a 3.
tonight i realized that i've hit the point where it takes me 3 miles to get in the groove. ugh. i went 3.7 miles...that is rough.
i guess it's good that i'm in pretty good shape...but this is a tough side-effect.