Oxygen uptake measures how efficient your body is and gives you an assessment of your fitness level. In a clinical setting, you can receive continuous data because of the instruments used to get this figure. For the individual, you will need to rely on an indirect method for deriving the maximum oxygen uptake. Either way, you will have a means of measuring fitness which you can then use to improve your oxygen uptake and performance.
Oxygen Consumption Calculation
Measuring oxygen consumption, particularly the maximum figure, provides an estimation of your aerobic capacity. Your body can produce energy during exercise with or without the presence of oxygen. Using methods with oxygen produces about 36 molecules of ATP, the energy currency of the body. In anaerobic conditions, this figure drops to 2 ATP molecules. The capacity to use one method or another depends upon your body's ability to take in sufficient amounts of oxygen. In its absence, it will continue to produce energy regardless.
Measuring oxygen uptake or consumption can be evaluated directly in a clinical setting. This type of testing typically uses a treadmill or stationary bike as an ergometer to measure control exercise intensity. The subject wears a mask with a breathing tube connect to oxygen and carbon dioxide analyzers to measure consumption and output. Trials are timed with a stopwatch.
Indirect testing provides an estimation of oxygen uptake. The scientific literature contains several tested protocols for calculating this figure. Your equipment will vary with the test; The Bruce treadmill test, or exercise stress test, uses a treadmill and stopwatch. You will also need a calculator. The test includes a defined set of incline and speed levels, and exercising as long as you are able. VO2 max for men is calculated as 14.8 - (1.379 x T) + (0.451 x T2) - (0.012 x T3). For women, the calculation is 4.38 x T - 3.9, with T equal to the time you were able to exercise.
You can also use online calculators to estimate maximum oxygen uptake. Many of these calculators require the input of data you collect in the field on a one-mile track. You will need a heart rate monitor and a scale, and will time yourself with a stopwatch. The Rockford walk test calculation varies with gender. For women, the calculation is 139.168 - (0.388 x age) - (0.077 x weight in lb.) - (3.265 x walk time in minutes) - (0.156 x heart rate). The equation for men is the women's calculation plus 6.318. This calculation for VO2 Max is appropriate for untrained individuals.