What is the optimal altitude and oxygen range?
Most experienced coaches, physiologists, and researchers agree that for HiLo training, “Hi” should be carried out in the “High” altitude region — between 8000 ft and 12,000 ft. Some athletes will use the “Very High” altitude range from 13,000 to 18,000 ft, but in the “Very High” altitude range, the risk increases that you will start weakening and losing muscle mass. In terms of oxygen concentration, the optimal “High” altitude range is equivalent to 15.4% to 13.2% oxygen. The “Very High” range is from 13.1% to 10.5% oxygen. See our Altitude Chart for the relationship between altitude and oxygen concentration, and for definition of the altitude regions (use your browser’s back button to return to this page).
