
VO2 to the Max!
Sure, you can bench press the most weight, but have you thought about how much oxygen your body can use during exercise?
As we breath in oxygen, our lungs absorb it and turn it into energy called adenosine triphosphate (ATP), which powers our cells and helps us release carbon dioxide. The greater the VO2 max, the more oxygen can be consumed and therefore produce more energy from ATP. The folks running by us like gazelles – as we grip our sides in agony – likely have a high VO2 max.
In his discussion with Joe Rogan, Dr. Peter Attia reminds us that having a VO2 max in the elite category (top 2.5% percent of the population), compared to below-average, results in a five-fold reduction in all cause mortality! Obviously, by the name of the category alone, elite can’t be an easy group to get in to. There are five categories of VO2 max classification and much benefit can be had just from being “not fit at all” to “average fit” – giving you 3 or the 5x in terms of reduction in mortality.
An Elite VO2 Max Results in a Five-Fold Reduction in Mortality
As CrossFit athletes, we are most likely not in the “not fit at all” category. We will begin our journey in Zone 2 – the highest level of aerobic output you can generate while keeping lactate below 2 millimole. Zone 2 is the second level of the five heart rate zones:

- Zone 1
- 50 – 60% of maximum heart rate
- You’ll be able to carry on a conversation in this zone
- Examples are walking at a leisure pace or stretching
- Zone 2
- 60 – 70% of maximum heart rate
- Walking at a brisker place or jogging slowly
- Zone 3
- 70 – 80% of maximum heart rate
- You could talk but likely in shorter sentences
- Example would be a pace that could be sustained for 30 minutes without trouble
- Zone 4
- 80-90% of maximum heart rate
- Running but not sprinting
- Zone 5
- 90 – 100% of maximum heart rate
- Running sprints
- Pedal to the metal
- Not able to speak and can only sustain for short bursts
Lactate Threshold
Lactic acid, also known as lactate, is a substance made by muscle tissue and red blood cells. During rest and low-intensity exercise, blood lactate hovers around 1 – 2 millimole. During high-intensity training it can rise to 20 millimole. When Dr. Attia recommends training in Zone 2, the object is to gradually increase the output we can sustain while keeping lactate threshold in the low-intensity category. To build and improve this aerobic base, we should exercise for 45 minutes in Zone 2 four times a week.
High-Intensity Training
The next step in improving the volume of oxygen our body consumes (VO2 max), is to get out of Zone 2 and get into Zone 5. Yes, pedal to the metal, full throttle, NOS switch engaged.
One metric is called four by four training; four minutes at the highest output you can sustain and four minutes of recovery. Attia says five of those sets once a week will do the trick. Forty minutes and you’re done! However, four minutes feels like an eternity on our air bikes, so work your way up to it. HIIT training is also a great way to train your body for maximum oxygen consumption. Sprint on a treadmill or bike for as long as you can safely, but as hard as you can. If your output truly is in Zone 5, 30 seconds should be difficult to do.
The combination of low-intensity training sustained for 45 minutes and high-intensity spurts will increase the volume of oxygen your body can consume, or VO2 max. Not only will you perform better in class getting a better workout, but improved cardiovascular fitness is important for longevity. In a study published by The Lancet, it was found that ideal cardiovascular health could result in a 4.40 year gain of life expectancy for their female participants and 4.67 year for the male group. A better workout, better fitness now, and adding years onto your life – what’s not to like? Well, all the training on the echo bike I suppose. Godspeed!
2022 06 28