Altitude

I'm on vacation in the mountains. I went for a run today and noticed that it was a bit more difficult than usual. Part of that is that I haven't been running daily recently as I heal from my surgical procedure. But I think part of it is also the altitude. Not that I'm mile high (we didn't go to Colorado), but when you usually run at sea level, it doesn't take much of a change to feel the difference. It's okay, though...I'll keep running. Just maybe slower.