While marathons in general don’t pull punches, this one in particular can be pretty sharp. The race starts in downtown Leadville and goes up to 13000’ at Mosquito Pass, turns around and goes up and down a few more times before a long steep downhill back into town. It is one that gets uncomfortable fast especially if you haven’t been acclimatized to the altitude. That being said one of the number one lessons as an endurance athlete - Embrace and Prepare for Discomfort.