VO2 Max is the maximum volume of oxygen the body can consume during intense exercise while breathing air at sea level. This is different than the amount of oxygen the lungs can inhale. VO2 is a measurement of how much of the oxygen inhaled the body uses. The volume is expressed as a rate either in liters per minute (L/min) or milliliters per kg body weight (ml/kg/min).
Why is it important for performance?
Oxygen is used by mitochondria in the muscle cells to produce ATP; the fuel for all cellular processes in the body. In order to convert food energy to usable ATP, cells consume oxygen. At rest, muscles use very little ATP or energy. Muscle cells that are contracting have a high demand for ATP. Therefore muscles in action will consume oxygen and generate carbon dioxide during exercise. Oxygen-rich air is inhaled into the lungs allowing oxygen-rich blood to flow throughout the body. CO2 (carbon dioxide) rich, oxygen depleted blood returns to the heart. Oxygen-depleted air returned ti the lungs and exhaled.
High VO2 Max levels will allow for more oxygen to be consumed by working muscles. To receive this oxygen and use it to make ATP for muscle contraction, our muscle fibers are dependant on 2 things: 1. External delivery system to bring oxygen from the atmosphere to working muscles cells 2. Mitochondria to carry out the process of aerobic energy transfer
How Can I improve VO2 Max?
There are two ways to improve VO2 Max; increased volume or increased intensity. Long Slow Distance (or LSD workouts as they are called) will improve the body’s delivery system by improving heart strength, increase capillaries, and strengthening the overall cardiovascular system. This is why most professional cyclists and triathletes tend to do long slow workouts in the off season.
VO2 max improvements only occur if you are keeping intensity constant (or the same) as you increase mileage. If you increase your mileage but decrease your intensity, little improvement will occur in VO2 Max. It is important to remember mileage should be increased gradually with careful attention towards preventing over-training and injury.
The second and more potent approach to enhancing VO2 Max is through increased intensity. Exercise intensities at close to 100% of MHR (Max Heart Rate) are the best way to improve your VO2 Max. The best way to complete a significant volume of running at 100% MHR is through intervals of 3-5 minutes with equal amounts of recovery in between. Track workouts or intervals re good examples. Exercising at greater than 100% MHR will not improve VO2 Max more than exercising at 100%. It will just leave you more fatigued.
A decrease in weight that is the result of fat loss may result in increased VO2 Max. However, an accompanied loss in any muscle will negate improvements by fat loss.
Other things to keep in mind: Some people assimilate more to oxygen than others. The delivery of oxygen to muscles is limited by:
1. Hemoglobin, the oxygen-binding protein in red blood cells. This is why men tend to have better VO2 max values than women.
2. Number of capillaries surrounding the muscle cell. LSD workouts will help you increase capillary development.
3. Cardiac Output – Maximum volume of blood that the heart can pump each minute.
4. Mitochondria available in muscle cells to produce aerobic energy