Hypoxic Training in Natural and Artificial Altitude

https://www.germanjournalsportsmedicine.com/archive/archive-2022/issue-3/hypoxic-training-in-natural-and-artificial-altitude/

Hypoxic Training for Mountaineering: Training for Mountain Everest

https://www.go2altitude.com/mountaineering.php

Hypoxic training methods

https://www.sciencedirect.com/science/article/pii/S2095254615000836

Why Do Athletes Train at High Altitudes?

https://www.livescience.com/32750-why-do-athletes-train-at-high-altitudes.html

The Top 10 Towns for High-Altitude Running Hello, red blood cells!

https://www.outsideonline.com/1926461/top-10-towns-high-altitude-running/

History of altitude training and the first hypoxicator!

https://altolab-usa.com/pages/the-history-of-altitude-training-iht

History of altitude training

https://whatsnewinfitness.com.au/altitude-training-history-professor-chris-mclellan