i used to run on an indoor track and i could never run on a treadmill. now, i can pretty much only run on a treadmill. i don't know if i have issues with pacing or what. i tried to go for a run tonight outside and i just CAN'T do it.
i'm still going to run at the gym because i like the treadmill, but i want to be able to run outside, too. how can i improve my endurance outside?