Seven years ago I spent a few days on the island of Capri, off the coast of Italy. At the top of the island was a famous hostel where everyone who visits ends up staying. My friends and I got lost trying to find it. Out of nowhere came a very old man who led us down twisting paths, first to a view of the Italian coast and then on to the hostel. I couldn’t help notice that this man, despite being old and short in height, was incredibly fit. His arms were like tree trunks and he moved with the agility of a mountain goat. I decided right then that this was the musculoskeletal system that I wanted when I became an old man. This feeling overcame me again, years later on the Inca trail where the Quechua porters (some quite old) made us a look like pathetic weaklings. If anyone has seen the Motorcycle Diaries they will recall the scene where Che and his buddy are forced to crash out on the Inca trail, just as a Quechua guide runs by them.

Earlier this week NPR had a fun story (MUST listen) about an article that appeared in the June 17th issue of the Journal Science. The paper is titled, Energetics of Load Carrying in Nepalese Porters, by Bastien et. al. [paid subscription required].

Nepalese porters routinely carry head-supported loads equal to 100 to 200% of their body weight (Mb) for many days up and down steep mountain footpaths at high altitudes. Previous studies have shown that African women carry head-supported loads of up to 60% of their Mb far more economically than army recruits carrying equivalent loads in backpacks. Here we show that Nepalese porters carry heavier loads even more economically than African women. Female Nepalese porters, for example, carry on average loads that are 10% of their Mb heavier than the maximum loads carried by the African women, yet do so at a 25% smaller metabolic cost.

Come on. You can’t possibly read that and not want a body like that!

The town of Namche (at an altitude of 3500 m) near Mount Everest hosts a weekly bazaar. Porters (Fig. 1A), predominantly ethnic Rai, Sherpa, or Tamang, typically take 7 to 9 days to travel to Namche from the Kathmandu valley. The route, no more than a dirt footpath, covers a horizontal distance of 100 km, with total ascents (river crossings to mountain passes) of 8000 m and total descents of 6300 m.

One day before the bazaar, we counted 545 male and 97 female porters (and 32 yaks) en route to Namche; others passed by earlier and later in the darkness. We weighed randomly selected porters and their loads (4). The men carried loads of 93 ± 36% of their Mb (mean ± SD, n = 96 male porters), whereas the women carried 66 ± 21% of their Mb (n = 17 female porters). The youngest porter was 11 years old, and the oldest 68; the greatest load measured was 183% of Mb, and 20% of the men carried >125% of their Mb. More than 30 tons of material were ported to Namche that day.

Now, of course I know these guys have a hard life. I have witnessed it first hand. The science of it is nonetheless fascinating. Other NPR listeners chimed in.