VO2 Max

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VO2 Max & Why it Matters

Note: The chart referenced is included at the end of this text, and also in the video at 1:54

VO2 Max

VO2 is the volume of oxygen that your body is utilizing in a given period of time. For example, if you are sitting down and listening to this then your body is likely using between 200 and 300 ml of oxygen per minute. If I were to ask you to stand up and walk around, your body would likely be using one liter of oxygen per minute. VO2 Max is the maximum amount of oxygen that your body is able to utilize at maximal exertion levels. It is indexed by your body weight, so VO2 Max is measured in ml of oxygen per minute, per kg of bodyweight. VO2 Max is the best tool we have to assess your overall cardiorespiratory fitness level. The higher the value, the better. Your VO2 Max is affected by your age, gender, genetics, overall health and overall fitness level.

Why does it matter?

VO2 max is considered one of the best indicators of overall health. VO2 Max is an important measurement that should be considered a vital sign as outlined in a recent statement by the American Heart Association. A higher VO2 Max has been consistently linked to longevity and improved healthspan. 

Two important factors that contribute to a high result are: 

  1. How much blood your heart is able to pump to your muscles with each beat (so a fitter heart can pump more), and 

  2. How efficiently your muscles can extract oxygen from that blood and put it to use. 

This process involves so many systems in our body, which is why it’s such an effective assessment of overall health and fitness.

The chart included below shows why VO2 Max really matters for your quality of life.

VO2 max provides a good estimation of what we are able to do physically. We require a certain VO2 Max in order to perform different activities of daily living. On the x-axis of the chart is age, and the y-axis is VO2 Max. Each horizontal line indicates an activity, with the corresponding VO2 Max that is needed in order to perform that activity (you need about 25 to walk 3MPH up a steep hill, you need 50 to jog 6MPH up a steep hill). 

Then, look at the diagonal lines – the top one represents someone who is really fit (i.e., a relatively high VO2 Max at every age), and the bottom line is someone who is not very fit. At age 75, the fit person can still briskly climb stairs (requiring a VO2 Max of about 32); the not-very fit person doesn't have a high enough VO2 Max to do that. VO2 Max really matters for your quality of life!

Now, notice how V02 Max declines sharply as we age, and this corresponds with the ability to do FEWER activities of daily living. I like using this graph as a tool to work backwards. For example, at the age of 75 I want to be able to briskly climb stairs, which will require a VO2 Max of 32. If I follow this curve backwards, this means that at the age of 40, my goal is to achieve a V02 Max of 50. This is a good reminder that we need to train and exercise if we want to maintain our quality of life at any age. 

And VO2 max has a real impact on predicted length of life. If you can imagine the population divided into 4 groups based on their V02 Max we would have 4 quartiles. Moving from the bottom quartile (i.e. lowest VO2 Max) to the quartile just above it, is associated with a 50% reduction in all-cause mortality. 

And we don’t see benefits only at the low end. Those with already high VO2 Max scores can continue to improve; there is no indication of an upper limit to the benefits you gain by improving your cardiorespiratory fitness. 

While everyone has a different capacity for improvement, any improvement can only make you healthier now and in the future.

Strategies to Improve your VO2 Max

Members will ask me if it is possible to improve their VO2 score. The answer is yes. In order to improve your VO2 max, you need to spend time training at 80% or higher of your max heart rate. There are different ways of achieving this and it depends on how much time you are able to dedicate to your exercise plan. 

If you are doing more than 10 hours a week of cardiorespiratory fitness (cardio), which is probably a small portion of members, the typical recommendation is to follow an 80/20 rule, meaning about 80% of workout time is spent doing moderate exercise, for example, at 60-70% of heart rate. Often this type of cardio is referred to as Zone 2, and it should feel like you can carry on a conversation while exercising, but only with difficulty. The other 20% of time would be dedicated to higher-intensity interval training. We’ll talk more about what that might involve later.

If instead, you are consistently exercising, say, 5 days a week, and totaling less than 10 hours, the recommendation for your cardio exercise is more like 50% moderate, 50% higher-intensity. 

If you’re a more infrequent exerciser, maybe 2-3 times a week and certainly far less than 10 hours total, the balance should be tipped in favor of higher-intensity exercise. If you’re starting from zero, of course, you’d want to work your way up to higher intensity workouts overall.

 So what are examples of that higher-intensity cardio that can help improve VO2 Max? The key is to introduce sustained periods of the highest intensity you can manage, typically anywhere from 1 minute to 4 minute intervals, with periods of rest in between.

One well-known (and very tough) method is the Norwegian 4x4 Interval Training Protocol. Here, you’re doing a 4-minute interval at about 85% - 95% of your max heart, or as hard as you can sustain, followed by rest (e.g., very light running or walking) for 3 minutes, and then repeating that combination 4 times, for a total of 28 minutes, in addition to your warmup and cool-down.

Another method is the one-minute on, one-minute off protocol. This is where you sustain the highest intensity you can for one minute, followed by a one-minute recovery period. You would aim to do about 10 repeats, for a 20-minute total. 

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