I rest my head on a boulder and struggle to catch my breath. We are about half way up the relatively short approach to base camp and I am feeling weak and debilitated by the high attitude. How are we going to make it up a 2,500ft big wall if I can’t even hike 10 minutes without stopping to rest? After about a month climbing in the Cordillera Blanca, or the Peruvian Andes just outside of Huaraz, Peru, I have become accustomed to the roller coaster ride that is climbing at altitude