Today Pavel expands on one more topic from the Huberman Lab podcast.

You mention sherpas and mitochondria “messed up” due to excessive hypoxia. Could you elaborate on what exactly is going on with the physiology of sherpas?

Are there any implications for everyday folks or athletes who might engage in practices such as breath holds? Can we overdo such practices?

The mitochondria are much more than our cells’ power plants. Scientists call them “the masters of life and death.”

Sherpas exhibit both positive and negative mitochondrial adaptations.

On the positive side, their mitochondria “leak” fewer electrons than lowlanders’, which reduces free radical production, and they have better antioxidant defenses. Sherpas’ cells also use oxygen more efficiently.

On the negative side, sherpas have lower mitochondrial density—a big minus for health, longevity, and performance. Their mitochondria are also worse at fat burning.

It must be stressed that many of the favorable adaptations in sherpas and other extreme highlanders take many generations to accomplish. First gen migrants to high altitude suffer from reduced antioxidant defenses and increased DNA damage.

For lowlanders, super altitude is bad news even in small doses. After an 8-week Himalayan expedition, mountaineers’ muscles showed a 235% increase in a marker of cellular degradation by free radicals.

In contrast, expertly conducted training at moderate altitudes has been proven to be an effective adjunct to endurance athletes’ training. Soviet, Russian, and Ukrainian doctors have successfully used hypoxia to treat a variety of conditions, including serious ones.