VO2 = Q X A-VO2 DIFF
The Fick equation. You may have read about it or heard about it on the street, but do you really understand it? The Fick equation is used to determine the rate at which oxygen is being used during physical activity. It’s not an equation you are going to use on a daily basis. You will most likely never actually directly measure your stroke volume or oxygen extraction.
So if you don’t use it in real life, who cares? Because it is the basis for how the body responds to the demand of physical activity. The principle behind the Fick equation is the foundation to a lot of other learning skills.
The Fick equation determines the rate at which a person uses oxygen in their body – which is also known as VO2 (the volume of oxygen uptake). Your maximum VO2 is the greatest amount of oxygen you can take in and utilize, and is a value that can be influenced by genetics and training. Maximal VO2 is typically used to measure how aerobically fit an individual is. The greater the VO2 max value, the more efficient the individual is at getting oxygen to their tissues and getting their tissues to utilize that oxygen.
During every activity we are using some percentage of our Max VO2. But how do we measure VO2? Well, we look at two things:
How much oxygen is used by the cells is called oxygen extraction. Oxygen extraction looks at how much oxygen is taken from the blood to be used by the cells to make ATP for energy. Oxygen extraction rates are measured by the difference in oxygen saturation of the blood going to the tissues (in the arteries) and of the blood returning to the heart (in the veins). This is known as the arterio-venous difference or A-VO2 difference.
Do you see how the Fick equation comes together now? You take your Q and your A-VO2 and put them together. Vo2 = Q x A-VO2 difference Do you see the importance of understanding Fick? If you know what components make up aerobic capacity (HR, SV, A-VO2 diff) you may have a better understanding of how you can influence those variables to increase your Max VO2.
"Never give up," The key is consistency. However, things do happen and days will be missed. Refocus and stay the course.