I'm from northern VA and did my first trip this year. You can prepare your legs in KY but not your lungs. I never felt short of breath per se but you definitely notice the air is thinner. The lack of humidity is also a big change from the east but a welcome one in my opinion. My major mistake was not getting well hydrated before the trip and it cost me after the hike in. Bad cramps at night for 2 days. Everyone handles the altitude differently but you'll most likely be fine. It wasn't as bad as I imagined it would be but I'll definitely be in better shape next time. A word of caution though....once you go west and hear that first bugle you'll be hooked.