This reminded me of the Quechuan porters (or Chaskis, in their language) that work on the Inca Trail to Machu Picchu. For four days, they carry 24 kg of camping gear and tourists' bags, ascending and descending as much as 1,200 meters in a day, including one steep 900-meter ascent to an elevation of 4,115 meters (if I'm remembering correctly). Oh, and they do it all in worn-out sandals.
Many years later, as he faced the firing squad, Colonel Aureliano Buendía was to remember that distant afternoon when his father took him to discover ice.
Apparently there is a movie about one such Chaski, though I haven't seen it: http://www.michacrafilm.com/.