This is what happens in your body when you run in height

Running in height is not the same as running at sea level. On occasion we have been talking about height training, today we will focus more on what happens in our body when we run in height : breathing, circulation, metabolism and performance.

To clarify concepts: what do we mean by “running in height”? From the 1000 meters of altitude the pressure and quantity of oxygen of the air begin to vary substantially, but it is from the 1500 meters of height when there is a significant physiological impact .

The effects that we next see that our body will suffer when we run in height will happen in a person who is not adapted to such means. For example, a rider who is accustomed to run at sea level or less than 500 meters and who one day climbs to run above the 1500 meters of altitude :

The more height, the less oxygen we can breathe

The air we breathe consists of a fixed proportion of gases: 79.04% nitrogen, 20.93% oxygen and 0.03% carbon dioxide. That is to say, whether we are in the sea or on high of Everest, this proportion is maintained. But, as we reach higher height, the pressure of these gases becomes smaller, which makes it difficult for oxygen to pass from the alveoli to the blood. Therefore, height hinders the breathing process.

This has an important practical consequence and is that, getting less oxygen for breathing, we increase our respiratory rate when we are in height . This will not be noticed at 1000 meters in height, but when we exceed 2000-3000 meters, even at rest we can see how the respiratory rate increases. Generally, the consumption of oxygen (VO2 max), from 1500 meters, is reduced by 11% for every 1000 meters we climb.

This feeling of lacking air in our respiratory system depends on the adaptation to the height of each person and their physical condition . A person with more physical condition is able to capture more oxygen for each breath, although the gas pressure is lower when being in height.

Of course, if we can not get all the oxygen-for-breath we are accustomed to at sea level, our running physical performance is reduced: our race rhythms are affected downwards.

More height, more danger of dehydration

The air temperature usually drops one degree for every 150 of altitude. Getting colder as we reach higher altitude also means that absolute humidity becomes lower, since cold air contains little water. This low absolute humidity of the air favors the dehydration of the corridor.

The dry air that we are in height causes that we lose more water by respiratory evaporation and by evaporation through the sweat. And that does not mean that in height we sweat more, but the water of our body evaporates quickly to have a drier air.

More height, more risk of burns

The intensity of the solar radiation increases as the height increases, as the light passes through less atmosphere thickness and absorbs less radiation. And if at the height we add the snow factor, the more radiation we will receive, as it reflects on the snowflakes and our skin is more exposed.

Therefore , if we are going to run in height and, above all, if we are going to be surrounded by snow, we must use a factor of high sun protection and also compulsory the use of sun protection goggles.

Heart rate increases with height

The height causes the plasma volume of blood to be reduced. This causes a greater concentration of red blood cells in the blood and the heart costs more to move, which compensates for beating more times per minute .

If we run with a heart rate monitor, we will notice that for a normal stroke intensity, our pulsations are higher . For a person trained and adapted to the height, this difference in pulsations will be minimal or zero.

We produce more lactic acid when running in height

Just the other day we saw how lactic acid affects athlete fatigue. If at the height the big problem is that we have less oxygen, our metabolism compensates by creating more energy from the anaerobic metabolism (not dependent on oxygen).

This anaerobic metabolism will provide us with more energy and faster , but also gives rise to a compound that will affect our performance: lactic acid or lactate. For similar intensities at sea level, at altitude our body will generate more lactic acid , which leads to more premature fatigue if we do not reduce the intensity of the race. That’s what we said at the beginning: in height we have to adjust the running intensities to the low.

Practical conclusions if you are going to run in height

After what we have seen, we can draw some practical conclusions if we are thinking of doing a race that involves running at more than 1500 meters in height:

• If the race is important or demanding, it is advisable to be exposed to altitude for a few days for our body to acclimatize.
• Emphasize hydration, even if we are not thirsty. You must hydrate yourself constantly, especially during the race.
• Use sun protection for skin and eyes. The excess of solar radiation, besides being very harmful, can cause us to be insolated or heat stroke.
• Take into account the height factor when calculating the intensity or pace of the race. Here a heart rate monitor can help us control these intensities.