Physiological Effects of Altitude Training to Improve VO2 Max

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Physiological Effects of Altitude Training to Improve VO2 Max

by Brendan Gabriel

Introduction | Discussion | Conclusion

Altitude training is a practice often used by athletes in endurance sports such as running, cycling and cross-country skiing. There is a lower partial pressure of oxygen at altitude. This makes it harder to transport oxygen to the muscles.

It is believed that the adaptions the body makes in training at hypoxia will benefit the athlete at lower altitudes. Training is usually carried out at an altitude of 2000m-3000m [Ref 2]. This height is believed to be the optimum balance between stress and training intensity.

I will look at the effects of hypoxia training on the cardiovascular system, the muscles, and the metabolic pathways. I also want to decide whether altitude training improves VO2 max compared to sea-level training, and if so which type is best.

Altitude training is believed to stimulate red blood cell production (RBC). This helps O2 transport to the muscles, but there are other adaptionís the body makes. Some researchers believe that altitude training does not increase RBC count for a long enough period and the fact that an athlete cannot train at as high an intensity as at lower altitudes make altitude training worthless.

I want to look at some of the adaptions the body makes after training at hypoxia. I will be looking at the

  1. effects on the lungs
  2. effects on the heart
  3. effects on the blood/ vessels
  4. effects on metabolic pathways
  5. effects on the muscles

Effects of Hypoxia

These are the effects on the body at altitude without acclimatisation;

Since there is a lower partial pressure of O2, there will be less O2 in the lungs at altitude. This means there will be less O2 transferred to the blood

For exercise this means there is less O2 available to the muscles Heart rate is increased at training and at rest. [Ref 2]

Blood lactate levels are increased at higher hrís [Ref 2]

VO2 max has been shown to decrease at altitude [Ref 2]

Hypoxic ventilory response(HVR) is the increase in ventilation in response to hypoxia, this increases at altitude [Ref 4]

There is an acute response in pulmonary ventilation (breathing). The rate is increased both at rest and during training. This is to compensate for the lower pressure of oxygen. As a result alkalosis develops. To compensate for this the kidneys excrete more bicarbonate and the buffering capacity of blood can be decreased at altitude. [Ref 2]

Effects of Training at Hypoxia

In conditions of hypoxia, effects include

  1. Increases red blood cells and haemoglobin mass. [Ref 2]
  2. It affects the heart rate: studies show that sub maximal heart rate (hr) at altitude was decreased after altitude training for 2-3 weeks. [Ref 2] maximal hr was decreased at altitude training [Ref 6]
  3. After acclimatisation maximal blood lactate levels are decreased during altitude training [Ref 6]
  4. Altitude training can affect the blood vessels; Capillary length density increases after any intensity training in hypoxia. [Ref 1] higher levels of capillary growth factors were also recorded after training under high intensity training [Ref 1]
  5. Hypoxic ventilory response is increased after endurance training [Ref 4]
  6. An increase in the oxidative capacity of muscles was observed. This could be due to subsarcolemmal mitochondrial density increasing after altitude training. [Ref 3]  


A graph to show increase in mitochondrial enzymes after high intensity, hypoxic training.

Altitude training

Fig. 1* Combined changes in either mitochondrial-coded (cytochrome oxidase 1, NADH dehydrogenase subunit 6) or nuclear-coded (cytochrome oxidase 4, succinate dehydrogenase) mRNAs of oxidative enzymes. Values are means Ī SE in percent changes. Significant percent change between averaged pre- and post training values, * P < 0.05; difference between pre- and post training values is considered to be a tendency, (*) P < 0.10.  

KEY: nor=normoxia Hyp=hypoxia High=high intensity Low=low intensity


 [Ref 1]-J Appl Physiol 91: 173-182, 2001;
8750-7587/01 $5.00
Vol. 91, Issue 1, 173-182, July 2001
Molecular adaptations in human skeletal muscle to endurance training under simulated hypoxic conditions
 [Ref 2]Cross Country Skiing: Olympic Handbook of Sports Medicine
By Heikki Rusko
Contributor Heikki Rusko
Published by Blackwell Publishing, 2003
ISBN 0632055715, 9780632055715
 [Ref 3] J Appl Physiol 81: 1946-1951, 1996;
8750-7587/96 $5.00
Journal of Applied Physiology
Vol. 81, No. 5, pp. 1946-1951, November 1996
Muscle tissue adaptations of high-altitude natives to training in chronic hypoxia or acute normoxia
 [Ref 4] J Appl Physiol 88: 1221-1227, 2000;
8750-7587/00 $5.00
Vol. 88, Issue 4, 1221-1227, April 2000
Cardiovascular response to hypoxia after endurance training at altitude and sea level and after detraining
 [Ref 5] The Use of Blood Doping as an Ergogenic Aid.
ACSM Position Stand
Medicine & Science in Sports & Exercise. 28(10):127-134, October 1996.
Sawka, Michael N. Ph.D., FACSM, (Chair); Joyner, Michael J. M.D.; Miles, D. S. Ph.D., FACSM; Robertson, Robert J. Ph.D., FACSM; Spriet, Lawrence L. Ph.D., FACSM; Young, Andrew J. Ph.D., FACSM
 [Ref 6] J Appl Physiol 83: 102-112, 1997;
8750-7587/97 $5.00
Journal of Applied Physiology
Vol. 83, No. 1, pp. 102-112, July 1997
"Living high-training low": effect of moderate-altitude acclimatization with low-altitude training on performance
Benjamin D. Levine1 and James Stray-Gundersen2
 [Ref 7] British Journal of Sports Medicine. 40(2):e4, February 2006.
Roels, B 1; Hellard, P 2; Schmitt, L 3; Robach, P 4; Richalet, J-P 5; Millet, G P 1