Saturday, December 10, 2016

Effects of Altitude on Oxygen Consumption

As stated in a previous blog, there are a number of limitations of cardiovascular training. One in particular being, change in atmospheric pressure due to altitude. As altitude rises, atmospheric pressure decreases, which in turn impair the respiratory system. The percentage of the different components of air we breathe (oxygen, nitrogen, and carbon dioxide) are the same at sea level and at altitude, the only thing that changes is that the air is less dense. The decrease in air density causes there to be fewer molecules of gas in each liter of air. The change in partial pressure is also caused by the increase in altitude which in turn has an effect on hemoglobin and oxygen transport. 2
As stated in a previous blog, one of the limitations of oxygen uptake was the amount of oxygen the respiratory system can utilize during high intensity workouts. Adding higher altitude to this problem gives the situation even more limitations. Altitude initially causes an increase in pulmonary ventilation, an increase in cardiac output, and a decrease in VO2max when exercising. Knowing the importance of a training athletes VO2max, we know traveling to high altitudes would be detrimental to training, or would it?1


After a three to six-month acclimatization period, the body naturally adjusts to altitude hypoxia and adaptations that could benefit training occur. There are longer-term adjustments that happen after the initial acclimatization period that can benefit an athlete's training program and performance. An increase in red blood cell production, increase in hematocrit level, an increased capillary density of skeletal muscles, and an increase in number of mitochondria. Which all of these things can lead to an increase in maximum oxygen consumption. The benefits of these are very similar to the benefits of
blood doping, but are conversely an ethical ergogenic aid.1

This information on altitude adaptation on oxygen consumption is very useful for athletes trying to get an edge in competition, but there are some drawbacks. When the athlete trains at a high altitude and gains the benefits of altitude training and returns back to sea level, the adaptations will slowly revert back to pre-exposure of high altitude.2  Within weeks to months, the athlete will have lost the advantages and will be back to the level of performance he was before, or even below that due to the fact that the amount of training volume is limited because of the change in altitude.1 This, of course, led to the want to harvest those benefits without the drawbacks. Some of the training methods that accomplish that task will be discussed in the next blog.
1Baechle, T.R. and Earle, R.W. Essential of Strength and Conditioning. National Strength
and Conditioning Association. 2008;

2Powers, S.K. and Howley, E. T. Exercise Physiology. Theory and Application to Fitness and Performance. 2015; (9): 481-483, 541-551.

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