In order to engage in any aerobic or physical activity, our muscles require that oxygen be delivered to them and then utilized in order to perform the repetitive movements of the activity.  VO₂ Max, or maximal oxygen uptake, is a measure of the maximum volume of oxygen the body can consume during intense exercise.  Hence, the value is widely regarded as a critical indicator of cardiorespiratory fitness and endurance. 

When it comes to VO₂ max, numerous studies have shown two things to be blatantly true. 

#1.  The higher your VO₂ max, the lower your risk for cardiovascular mortality and all cause mortality

#2.  VO₂ max declines with age

Consider these two charts that come from a study of over 120,000 adults.  The first chart, Performance Group by VO₂ max, categorizes adults by age and sex.  Then the adults are placed into 1 of 5 categories based on their VO₂ max.  You can see that as the adults age, the VO₂ max begins to decline. Take the elite males (top 2.3% VO₂ max for age) as an example. In this study, an elite 18 year old male had a VO₂ max greater than 58.  Compared to an elite male age 75 who only has a VO₂ max greater than 41. Clearly, VO2 max is declining as we age.

Now take a look at the second chart which comes from the same study.  This chart allows us to appreciate the magnitude of the association between low VO₂ max and mortality risk.  The top of the chart lists various comorbidities such as smoking and diabetes.  The 95% hazard ratio for smoking is 1.41.  Basically what this means is that an adult smoker’s risk of death is 1.41 times (or 41%) greater than an adult non smoker, all other things being equal.  Now look at the VO₂ max comparisons in the chart.

In the Low vs Elite group comparison, the 95% hazard ratio is 5.04.  Meaning that an adult who has a VO₂ max in the “low” (bottom 25% for age) category compared to an adult who has a VO₂ max in the “elite” category has a 504% higher risk of mortality. 

Even if we take the very last group comparison, “high vs elite”, we see a hazard ratio of 1.29.  Meaning there is a 29% increased risk of mortality for someone with a VO₂ max in the 75th to 97.6 percentiles vs someone with a VO₂ max in the 97.7 percentile and above.  Although this was only significant if you were in the groups aged 70 and above.

What becomes abundantly clear from looking at this data is that being unfit with a low VO₂ max has a much greater influence on lifespan than co-morbidities such as smoking, diabetes and hypertension.   

The higher your VO₂ max, the more reserve or excess energy you have.  And in turn you will have a higher likelihood of being able to fight off a respiratory infection or tolerate a cancer treatment.  This is likely an important contributor to why individuals with high VO₂ max have a reduced risk of mortality

Why else would you want a high VO₂ max?

Having a high VO₂ max not only reduces your risk of death, but it also means an improved quality of life when we are older.  Our ability to perform tasks of daily living and other various activities as we age is dependent on our VO2 max.  Consider the graph above.  You can see the VO₂ max that is required in order to perform a range of activities from running fast to walking down a flight of steps.  At Marathon Direct Primary Care, we like to reverse engineer this graph.  What would you like to be able to physically accomplish when you are 70, 80 or even 90s years old?  We take that information along with your initial VO2 max data to create a playbook for achieving and maintaining the VO2 max that you want.

How to improve VO2 max

You can improve your VO2 max through consistent aerobic activity.  Consistent activity will lead to denser mitochondria in your skeletal muscle over time and hence an increased use of oxygen in muscle.  One study showed that performing aerobic exercise for 45 minutes 3 times a week over the course of 12 weeks improved VO2 max by 18-30%.

Additionally, high intensity interval training (HIIT) has been shown to promote increases in VO2 max.  HIIT workouts involve short bursts (I like 3-7 minutes) of intense activity followed by a period of rest.  This training stimulates both aerobic and anaerobic systems.  It has repeatedly been shown that HIIT is the best way to improve VO2 max

Consider this triangle.  The base of the triangle is your aerobic capacity.  And the peak of the triangle is your VO2 max.  The wider your base, the higher your peak (VO2 max) will be.

It is crucial that you achieve a high VO2 max when you are younger in preparation for the inevitable decline that comes with age.  On average, VO2 max declines by 10% each decade starting in your 40s and exercise can help slow this decline.

How to measure VO2 max

At Marathon Direct Primary Care, our patients receive VO2 max testing every 3-6 months so we can track results over time.  This consists of a 12 minute test that is performed either on a treadmill or stationary bike while wearing a VO2 analyzer.  Our goal for all of our patients is to achieve a VO2 max that is considered elite for their age group.  

The Bottom Line on VO2 Max

The current evidence suggests that the most effective way to increase lifespan and healthspan is through consistent aerobic activity over a long period of time (a lifetime, really) to achieve the highest possible VO2 max. Although absolute maximal aerobic capacity declines with age, consistent and targeted training may provide the energy reserves you’ll need to handle temporary physiologic stresses of illness as well as to participate in activities that you enjoy. This ability, to engage in activities with the people you love, is the essence of what comprises quality of life,  especially in your final decades of life.  

All materials contained in this blog post are for informational purposes only and should not be construed as medical advice.  Please consult with your physician concerning any and all medical questions and/or problems.

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