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Posts tagged ‘oxygen’

What is Vo2Max?

Some people have probably heard of this, some may have not. For those that haven’t I will give a quick explanation of what it is and why is so important.

Vo2Max,  means the maximal capacity of the body to transport and use oxygen during dynamic exercise using large muscle groups. In other words, Vo2max is the maximum way to produce energy aerobically while you run, bike,swim, etc.Remember from my last blog (click here), that we can produce energy 2 ways: Aerobic and Anaerobic.

  1. The anaerobic system is the fastest way the body has to produce energy, the bad thing about it is that we cannot maintain this system during long periods. This system is used especially during short-intense exercise, like for example, a 100 meter race.
  2. The aerobic system produces energy at a lower pace but it can be maintained  for much longer periods. For example, when we run a marathon most of the energy will come from that system.

Vo2Max is measured in milliliters of oxygen per minute per kilogram of body weight (ml/min/kg) and the highest Vo2max recorded was a Norwegian cross-country skier with 94ml*kg*min!!

Why is it important to have a high Vo2Max?  Because all else being equal, a higher VO2 max is an advantage: it means that your body can take in more oxygen and deliver it to your muscles, enabling you to run faster for a given effort. So let us put an example: Imagine person A has a Vo2Max of 64ml*kg*min and person B has a Vo2Max of 52ml*kg*min and they are going to run a 8km race. The most likely thing that will happen is that person A will win because of the higher Vo2Max.

Now that we understood what Vo2Max is and how important it is in endurance events, I will talk about how we can improve it. But for that you will have to wait until my next blog 🙂



Why altitude affects performance

I think many people have heard that exercising at altitude is harder than exercising at sea level but most people don’t know exactly why. I will try to explain that in this blog.

First we have to talk about atmospheric pressure and what it is and what it means. In simple words, atmospheric pressure is a measure of the weight of a column of air directly over that spot. At sea level, the weight of that column of air is greatest and it equals more or less to 760mmHG. Most of you will know that air is composed of Nitrogen 79.04%, Oxygen 20.93% and Carbon Dioxide 0.03%. These percentages remain constant regardless of altitude. So, at sea level where atmospheric pressure is 760mmHG, the partial pressure of Nitrogen would be 600.7 (79.04% of 760mmHG), of Oxygen it would be 159.1mmHG (20.93 % of 760mmHG) and 0.2mmHg for Carbon Dioxide (0.03% of 760mmHG). Ok, so as we start to climb the atmospheric pressure is going to decline, the percentages of the gases will remain constant but the partial pressure of each gas will be lower. This is because the air is less dense, and each liter of air contains fewer molecules of gas. Let’s look at some examples to visualize this:

1. Mexico city is at 2,210 meters, the atmospheric pressure there is around 585mmHG meaning that the partial pressure of oxygen would be 122mmHg ( 20.93% of 585mmHG);

2. Mount Everest is at 8,048 meters, the atmospheric pressure there is around 253mmHG, which would mean that the partial pressure of oxygen would only be 53mmHg ( 20.93% of 253mmHG).

So there you have the answer, since the air is less dense the partial pressure will be lower so every time you breath you will inhale less molecules of oxygen. If there is less oxygen you will get tired quicker. But does altitude affect exercises where oxygen is not a factor, like jumping??? I will talk about that in my next blog,,,

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