The views and the (relative) lack of oxygen. To no one’s surprise there is a huge difference running up here versus the 45 feet above sea level where I normally run in Houston. We are renting a house outside Breckenridge for a couple of weeks to beat the Houston heat, and it is amazing.
As for running, it isn’t just the elevation, it is the change in elevation- no real hills in Houston. The most I get is running back up to street level after the path goes down by the bayou.