Aerobic Capacity (VO2 Max)

Metabolic Testing

Does an assessment of your aerobic capacity (i.e., VO2 Max) provide any real value to an athlete or exerciser? There is a common perception these days that the VO2 Max score has limited value especially with the more fit individuals. Is this true?

Answer: With regards to the VO2 Max score I think this analysis is for the most part correct. By itself, if you are already a consistent exerciser, this fitness score will only provide a description of your top aerobic potential or the “size of your aerobic engine” and that value only changes a little bit if you are already training regularly. If you are sedentary or in poor health your aerobic capacity is a very important indicator. For unhealthy individuals the VO2 Max score will typically be low and if the VO2Max is low this status is associated with an increased risk of heart disease and diabetes. On the other hand, for people who already exercise regularly the VO2 Max score is an interesting value to compare with the norms but really does not tell you a whole lot about how effective your endurance training has been lately. However, metabolic testing like the type that determines the VO2 Max, ( see our Cardio-Metabolic Exercise profile as an example) can provide much more than the VO2 Max score, it also provides markers like your ventilatory and anaerobic thresholds which can be very sensitive measures to evaluate how your training has been recently and the affect on your sustainable power, sustainable calorie burn potential, and overall endurance. Additionally, it can give you individualized information to help set-up your own training parameters (intensity, duration, frequency) to help you avoid over or under training. Athletes who know their training limitations and parameters are also better able to avoid common overuse injuries due to training errors. Metabolic testing like the CMP test is a great tool to help you glean very individualized metabolic information to help form nutritional strategies for weight management and fuel replenishment during exercise or racing.

What is the CMP?

Basically the Cardio-Metabolic Exercise Profile is an analysis of a number of important components of your cardiovascular and metabolic function. This testing measurement begins in a resting state, and gradually progresses to a level of higher exercise intensity. During the gradual increase in intensity several trend changes in your ventilory (i.e., changes in O2 and CO2 volume due to internal and external respiration) can be observed through the use of a metabolic analyzer. These trend changes can be used to describe various degrees of energy usage and fatigue. The heart rates and pace or power outputs identified during the points of change can be used to set-up your own individual training parameters. Additionally, by using a technique called Indirect Calorimetry, this test can reveal how many calories a you will burn per minute while exercising at different zone levels, and how many of those calories are utilized as fat versus carbohydrate, and perhaps even more importantly for the endurance athlete, how efficient is an athlete at using oxygen at different levels of exercise intensity. VO2 or the “volume of oxygen” is merely a measurement of the amount of oxygen that a person is able to take in and utilize in their body.

So to summarize, although your aerobic capacity is an important measure of your health it does not represent the whole picture related to your endurance potential. For those who are serious about training to their potential other metabolic testing parameters can be very effective at optimizing health and endurance performance. To get tested go to the Fit Stop and sign up for a CMP assessment or if you cannot get to a lab check out the CMS, a self test which you can do at home to estimate your own threshold.

Keep training to finish strong!