What Is VO2 Max?

Vo2 max(or Vo2 Peak) unit of measurement in the Vo2 Max Test.  It is the peak volume of oxygen that the respiratory system can obtain and the cardiovascular system can deliver to our muscular system per kilogram of bodyweight per minute (Relative VO2). It is expressed as ml/kg/min. This is the largest volume of oxygen your respiratory system can bring in for your body to use, but this does not guarantee that delivery is optimized; that is the circulatory system’s job. Everyone’s system is different, which is why testing is Vital. 

How is it measured?

Vo2 max can be found either Directly using gas analysis or indirectly using equations.  Indirectly testing we use gas levels (o2 and Co2) and heart rate to understand the health and performance of the cardiovascular and respiratory systems. The tool we use to measure this is called a metabolic analyzer, formerly a metabolic cart. 

What do gas levels and heart rates have to do with Vo2 max?

Fuel Utilization is represented as RQ or Respiratory Quotient which is the ratio of carbon dioxide to oxygen. 

Co2/O2 

when the ratio = .7 (meaning we have more oxygen than carbon dioxide) we use fat.  

When the ratio = .9 or higher meaning the carbon dioxide is almost equal to or greater than the amount of oxygen we will use carbohydrates. 

When the ratio is between those numbers it will be a blend of fat and carbohydrates. 

V02 Peak = Where carbon dioxide exhalation is equal to oxygen inhalation.. 

Heart rates are different for everyone based on your age, gender, and metabolic conditioning status. They cannot be judged 

Your heart rate will be close to HRMAX at Peak VO2. 

Why is this important?

 This measurement has a list of norms laid out by the American College of Sports Medicine (ACSM). Vo2 max is based on age, gender, and metabolic conditioning status. ACSM has reported that every 3.0 ml/kg increase in relative vo2 translates to a 33% decrease in all-cause mortality and 13% decreased risk of development of Cardiovascular Disease (CVD). Cancer, diabetes, stroke, CVD are all related to Vo2max. The higher you vo2max the lower your risk of poor health and wellness. 

Performance issues are health issues. This is important because the higher Vo2 Peak is the larger amount of oxygen you will have to use to supply the muscles for aerobic exercise. This allows for higher work intensities/ loads and a lowered rating of perceived exertion due to a higher rate of cardiac output. This will push back the point ventilatory threshold 2(VT2) at which you switch fuel sources from fats to carbohydrates. Vo2 peak is also a sign of your physiological age as those with a high vo2 max have a lower resting heart rate which can add years to your life. 

  Training w/ Vo2 peak

Vo2 peak is a cardiorespiratory measurement that allows us to understand the overall health and performance of the cardiovascular system. Thus, it allows us to analyze exactly where someone’s health and fitness is with the purpose of giving exact recommendations to help create lasting change.

 Here is what positive adaptation looks like: 

Low-intensity adaptations include decreased heart rate, increased capillary density, increased number and size of mitochondria, increase of VT2, lowering of blood pressure, and initial lowering of vo2 max. 

High-intensity adaptations include the increase of (VT2), an increase of Vo2 max, and an increase in performance measurements.  

Important: Higher Vo2 max cannot be achieved without first increasing low intensity work capacity. 

Low intensity must be prescribed at the proper heart rate in correlation with the percentage of V02 peak. 

Meaning that if you don’t train at the correct heart rate you will not be getting the conditioning you are intending. Heart rate zones are vital for proper training of the cardiovascular system.