Elite endurance athletes around the world train at high altitude to try to improve performance. Assuming you are a serious runner, should you train at altitude? To help determine whether high-altitude training is right for you, consider the following questions and the answers that follow.

What are the physiological adaptations to living at altitude?

There are both positive and negative adaptations to living at altitude:

• Living at altitude causes increased EPO levels which leads to increased red blood cell mass. This is a very positive adaptation.

• Living at altitude causes ventilatory acclimatization (increased breathing), which is a fairly minor negative adaptation (breathing muscles use oxygen).

• Living at altitude causes changes in blood and muscle buffering capacity, which may be positive or negative.

• The degree of performance improvement from altitude training depends on the ratio of positive to negative adaptations. The challenge is to manage the exposure to altitude to maximize the net benefit.

Why live high and train low?

• If an athlete can do the same absolute amount of work at altitude, then training at altitude should lead to an improvement in performance. If, as is generally the case, training intensity is reduced at altitude, then performance may decrease from altitude training.

• Studies have found that living at high altitude and training at low altitude (live high/train low) leads to increased performance, increased red blood cell mass and increased VO2 max.

• Another option is the high/high/low model (live high, do low and moderate intensity training high, and high intensity training low), which is as beneficial as the live high/train low model, and transport logistics are reduced.

How do EPO and red blood cell mass respond to living high and training low?

• Increases in EPO lead to increases in red blood cell mass, but the relationship is not linear.

• Peak EPO level is reached after two to three days altitude exposure and tends to gradually return to baseline after about 25 to 28 days living at altitude.

• The percent increase in EPO level appears to be more important than the absolute increase in EPO in stimulating increases in red blood cells.

• When athletes return to sea level, EPO level is suppressed and red blood cell mass gradually declines.

• Red blood cell mass does not increase for approximately 10 days after EPO increases.

• If you cannot measure EPO directly, then measuring reticulocytes (immature red blood cells) provides an indication of the EPO response.

What about iron levels?

• Athletes should have a blood test 6 weeks before starting altitude training. If serum ferritin is less than 30 ug/l for women or 40 ug/l for men, then increase dietary iron and supplement to increase ferritin prior to altitude exposure. Otherwise, red blood cell response will be reduced.

• If serum ferritin is low, the athlete may still get an increase in reticulocytes after altitude exposure, but they will have low hemoglobin content , and may not mature into red blood cells.

• U.S. Olympic Training Centre supplementation prescription to increase ferritin is 120 to 130 mg of “elemental iron” per day, divided into 2 doses, taken with vitamin C. Take iron supplements 30 min before or 60 min after meals to increase absorption and decrease gastrointestinal distress.

What is the difference between athletes who respond to altitude and those who do not?

There is a large amount of variability between athletes in response to living at altitude. Some have much larger increases in EPO than others at a given elevation. Athletes who have a low EPO response may need to live at higher altitude. The reasons for variability are probably genetic.

	Responders	Non-responders
+ in EPO at peak	>50%	<30%
Duration of EPO peak	Prolonged	Short
+ in RBC mass	Yes	No
+ in VO2 max	Yes	No
- in training intensity at altitude	Slight	Larger

When should an athlete add altitude to the training plan?

Altitude should be treated as a component within a training plan, similar to other variables such as training volume, mechanics, speed, skill, etc. Altitude should be added to an athlete’s training plan either:

• Classic model: before a major competition in the peak phase of training, or

• Pre-high intensity phase model: at the end of a base-building phase. just prior to high-intensity training. Increased oxygen carrying capacity allows higher intensity training and quicker recovery for an increased training stimulus, so the performance increase outlasts the life of the red blood cells. Using this model, the benefits of altitude training last approximately 4 to 6 weeks after returning to sea level.

What about simulated altitude?

• It is unclear whether there is a difference between the physiological response to normobaric hypoxia (e.g. altitude tents or hypoxicator) and hypobaric hypoxia (e.g. living in the mountains).

• Use of altitude houses has been found to produce significant increases in serum EPO, reticulocyte count, red blood cell mass, and hemoglobin.

• Altitude tents should provide the same stimulus as altitude houses if hours of exposure are similar.

• More scientific data is required about intermittent hypoxic training (e.g. hypoxicator.

What is the optimal "dose" of altitude?

• Think of altitude as a drug with a dose-response curve. You need to maximize the benefit and minimize the side effects.

• If an athlete lives too low, then the EPO response is insufficient to substantially increase red blood cell mass. If an athlete lives too high, then may experience excessive ventilatory acclimatization, and other negative side effects.

• There is both scientific and anecdotal evidence that 2,000 to 2,500 meters is the optimal altitude range for many athletes.

Related article:
Iron for runners

Credits:
Text copyright © 2004 by Pete Pfitzinger
Pete Pfitzinger is an exercise physiologist with over 20 years of coaching experience, Pete adheres to the principle that every runner is unique and that training programs must be tailored to the athlete's individual strengths and weaknesses. 

For more articles by Pete Pfitzinger, access: http://www.pfitzinger.com or www.distancecoach.com

This article has informational purpose and  isn't a substitute for professional advice.

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