The equipment required for a high level cardiopulmonary exercise test is prohibitively expensive, but fortunately we have "quick and dirty" (back of the envelope) calculations from more available data. The test is obviously both fitness dependent but effort dependent and varies according to age and sex.
2. From Wikipedia:
Cooper test
Kenneth H. Cooper conducted a study for the United States Air Force in the late 1960s. One of the results of this was the Cooper test in which the distance covered running in 12 minutes is measured. Based on the measured distance, an estimate of VO2 max [in mL/(kg·min)] is:[5]
where d12 is distance (in metres) covered in 12 minutes
An alternative equation is:
where d12 is distance (in miles) covered in 12 minutes
For example, a few years ago, I did a Cooper test (after training) on my treadmill, running 1.35 miles in 12 minutes, translating to 37.27 ml/(kg.min).
3. Here are some extreme VO2 max values recorded (from topendsports.com), such as Lance Armstrong's 84.
4. How can you improve your VO2 max? Training! Your VO2 max will improve as you add both muscle mass and train at higher intensity for higher durations. Of course, that also taxes your heart (coronary artery disease), lungs (asthma), and musculoskeletal system (arthritis). Your physician can assess your suitability for higher intensity exercise.
5. VO2 max for basketball. Just as all players do not have the same ability, they have different aerobic capacities by position. This Serbian study showed that guards had higher VO2 max than wings or centers.