If you want to know your body’s cardiovascular fitness level, there is no better way than to test your body’s maximal oxygen uptake or the VO2 max level. Here is an article that will help you to understand VO2 max.
The Merriam-Webster Dictionary defines VO2 max as “the maximum amount of oxygen the body can utilize during a specified period of usually intense exercise”. This depends on body weight and the strength of the lungs.
VO2 max is an acronym for maximal oxygen uptake and is also known as aerobic capacity, aerobic power or maximal oxygen uptake. In simple words, it is the amount of oxygen consumed when a body is in maximum physical exercise in a given time period. It is an indicator of cardiovascular fitness, and knowing the max VO2 levels helps in understanding the aerobic endurance level of a person. This is important to make exercise and training regimes more effective and in increasing an athlete’s performance.
How is VO2 Max Measured
The measurement unit of max VO2 is milliliters of oxygen consumed per minute by one kilogram of body weight (ml/min/kg). The most famous and widely used formula for calculating max VO2 is the Fick equation:
|VO2 max = Q(CaO2 – CVO2)|
In the above equation, ‘Q’ stands for cardiac output, ‘Ca’ stands for arterial oxygen content and ‘Cv’ stands for venous oxygen content.
VO2 Max Test
VO2 max levels can be measured by taking a test at a professional sports lab. In a standard sports lab, they make use of various modern equipment, like oxygen and carbon dioxide analyzer and an ergometer, to give a precise and accurate max VO2 level of a person. However, there are some easy max VO2 tests that can be conducted easily, like the ones mentioned below.
- 2.4 km Run Test: Run for 2.4 km at maximum speed in six laps. Record the time taken to cover each lap and the overall time taken to cover the entire 2.4 km. Use the lap timings to analyze pace judgment and the overall time to calculate VO2 max.
- Critical Swim Speed: Swim 400 m and record the total time taken. After a 10 m recovery break, swim for 50 m while recording the time. Use a VO2 max calculator to calculate max VO2 levels.
- Treadmill Test: Run on a treadmill with a starting slope of 0 degree and a speed of 7 miles/hr (11 km/hr). Increase the slope by 2 degrees at the end of every minute (without taking a pause in the run), till you are no longer able to continue and record the time spent in running. Use a VO2 max online calculator or calculate using the following formula:
|VO2 max = 42 + (Time on the treadmill x 2)|
- Uth-Sørensen-Overgaard-Pedersen Estimation: When maximum heart rate (HRmax) and heart rate when at rest are known, the score can be measured using this formula:
|VO2 max = 15(HRmax/HRrest)|
- Cooper Test: Run at maximum speed for 12 minutes. Then note the distance covered in meters (d12) and calculate the score using the following formula:
|VO2 max = (d12 – 505)/45|
Factors Affecting VO2 Max
he levels of VO2 max differ from person to person, subject to various causes, some of which are beyond human control. Having an active lifestyle (like in the case of sportsmen) greatly improve max VO2 levels but it is not the sole determinant of max VO2 levels. Some of the factors that affect a person’s max VO2 levels are listed below.
|VO2 Max Levels|
|18 – 30||43 – 56||33 – 46||40 – 85||35 – 75|
*The highest scores of max VO2 was recorded at 96 (7.3 l/min for 76 kg of body weight), in 2005 for Espen Harald Bjerke (a Norwegian cross-country skier). VO2 max is in ml/min/kg.
- Altitude: Max VO2 levels decrease with increase in the altitude. Certain VO2 max scores have been known to drop by 9 to 10% with increase in every 1 km over an altitude of 1.6 km.
- Genetics: The size of the different organs of the body and the types of muscle fiber are determined by a person’s genetic makeup. According to a study done by Cerritos College in California, around 30% of a person’s VO2 max scores are determined by his/her genes.
- Gender: Men are usually physiologically larger than women. So it is but natural that men score higher when it comes to max VO2 levels as compared to women. Studies show that on an average, men have 10 to 15 percent higher max VO2 scores as compared to women.
- Cardiac Output and Oxygen Carrying Capacity: Cardiac output is the amount of blood the cardiac (heart) muscles pump out per minute and is measured in liters. Higher amounts of cardiac output means higher amounts of oxygen available to the body for consumption, which in turn increases a person’s VO2 max scores. Oxygen carrying capacity refers to the amount of oxygen found in the blood or a person’s hemoglobin count. Greater the hemoglobin count, greater the oxygen saturation in the blood and better the max VO2 scores.
- Peripheral Limitations: It is related to mitochondrial enzyme (assists mitochondria in producing ATP), muscle diffusion capacity and capillary density and they are important in determining max VO2 scores.
- Lactate Threshold: It is the point at which there is a sudden increase in the lactate levels in the blood when the body has reached its peak during an intense exercise. Higher the lactate threshold, greater the endurance levels of the body.
Despite the limiting factors, improving VO2 max scores is possible, if an appropriate exercise or training regime is followed. A point to be noted here is that VO2 levels cannot be increased beyond a certain score. This endpoint differs from person to person depending on various factors (most of which are mentioned above). That is the reason why there is very little possibility of increasing an athlete’s VO2 max scores. As for those who want to improve: the best way to improve max VO2 scores is by working out on sustained aerobic conditioning, but only after consulting a certified physiologist or professional personal trainer.