The Science of Altitude Training

Some notes on altitude training and the effects of altitude

• At altitude there is lower air pressure. This lower pressure means that each lung full of air has less oxygen (lower partial pressure of O2). This results in lower oxygen saturation in the blood (Hypoxia).
• The human body adjusts to lower blood oxygen saturation in many ways. One adaption is an increase in red blood cells, but the performance improvements from altitude training may come from other sources.
• There is great individual variability in the response to altitude. Some studies have classified subjects as 'responders' and 'non-responders' due to the significance of this variability. This variability can change over time within an individual. I met someone in Tanzania who had been a porter on Kilimanjaro (19,334 ft) until he lost his ability to cope with the altitude.
• Some variability may be due to differences in iron intake/availability. Low blood iron (serum ferritin < 20 ng/ml female, < 30 ng/ml male) may limit the body's ability to generate new red blood cells, which is part of the altitude adaptation. Studies in the USSR and CIS have shown genetic factors as well.
• The effects of altitude are non-linear. From sea level to Leadville (10,170 ft), your blood oxygen levels drop 6% from 96% to 90%. Going up another 4,000 ft to Pike's Peak (14,110), blood oxygen levels drop a further 8% to 82%.
• Running is harder at altitude as seen by the VO2max drop. At Leadville your VO2max will drop by ~15% (range 4-30%)
• Athletes' performance may drop noticeably even at relatively low altitudes. At 1,900 ft, a 5 minute maximal exertion test was 6% (male) and 4% (female) lower than at sea level.
• Athletes may suffer more at altitude than sedentary people, and men more than women.
• Generally 'live high, train low' seems to work better than 'live high, train high'. Intermittent Hypoxic Exposure may have additional benefits over other Altitude Training Approaches.
• Altitude acclimatization generally takes 1-2 weeks, with 4 weeks as the recommended minimum to achieve benefits.
• Training needs to be reduced at altitude, and this reduction can lead to detraining. 'Live high, train low' and Intermittent Hypoxic Exposure help mitigate this problem.
• Altitude acclimatization generally seems to last several weeks.
• It is a myth that if you can't arrive at altitude with time to acclimate, it's best to arrive near within a day of your event. The longer you have to acclimate, the better.
• There is evidence to suggest that humans can adapt to survive at the altitude of Everest.

1 See Also

• Altitude Training Approaches
• Comparison of Altitude Training Systems
• Book Review of Altitude Training and Athletic Performance
• Intermittent Hypoxic Exposure and Intermittent Hypoxic Exposure 101
• Chronic Mountain Sickness
• Viagra, Exercise and Altitude