Improving Your VO2 Max
If you missed our previous emails on how you can test your own VO2 max and its connection to longevity, you can check it out here. It may be helpful to review before today’s email anyway. For everyone else, we’re going to keep moving. We know how important your VO2 max is, but how do you improve it? To fully grasp this, we need to know a little more about our biology.
What are the mitochondria?
Mitochondria are “the powerhouse of the cell." They are the engine that processes fuel sources to create energy for the body. They have the ability to use different inputs (primarily fat) to create ATP. ATP stands for Adenosine Triphosphate. For the sake of simplicity, ATP is the “energy currency” for the body. Whenever your body uses energy, it is spending ATP. In order to spend it, it has to be created from somewhere. Usually this comes from fatty acids, glucose or lactate.
Your mitochondria’s job is to produce ATP by any means necessary. And in a healthy individual, it is designed to do this efficiently using fat and oxygen. At rest or low intensity exercise your body is able to get adequate amounts of oxygen to your muscle cells. The demand for oxygen is relatively low and your mitochondria can easily turn fat into ATP in the presence of oxygen. But there is an exercise intensity where mitochondria are no longer getting enough oxygen. As you increase the speed of your run or the resistance on your bike chain, your muscles are demanding more oxygen to match the workload.
Your heart responds by increasing the speed and power of each heartbeat to try to keep up. Now your mitochondria are still burning some fat for energy, but they are still struggling to keep up with the demand for ATP. So they switch to burning some glycogen that’s been stored in the muscle and glucose that is in the bloodstream. When these sugars used for energy, the result is lactate.
Lactate Production
Lactate is not necessarily bad, but it is typically not helpful during exercise. Lactate creates an acidic environment in the cell. This interferes with performance, and in high amounts, contributes to the muscle burn that you feel with higher intensity exercises. Your mitochondria actually have the ability to use this lactate for energy. And at slower intensities, a trained athlete can use this lactate for energy at the same rate that it is being produced. The result? You can continue exercising at that pace for extended periods of time. This is what’s happening during a marathon run for example. That continuous pace is producing SOME lactate but the body is simultaneously using it to make more ATP. So the levels in the blood never rise above a certain threshold (2.0 mmol/L)
But when the intensity is too high for too long, the lactate levels shoot up. The cells are now burning primarily glucose for energy, and producing far more lactate than they can dispose of. The result? Your legs feel heavy and your pace is forced to slow down. You can maintain this intensity for a little while during a competitive race, but eventually the acidic environment is going to interfere with performance. You see this when a mile runner is hitting the wall on the home stretch of a race. The lactate is building and they only have a brief amount of time they can maintain that pace before the muscles stop working properly.
Why does it matter?
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