VO2 Max – Pros and Cons.

VO2 Max – Pros and Cons

What is VO2 Max?

VO2 max, also known as maximal oxygen consumption, is a measure of a person’s cardiovascular fitness and endurance capacity. It is calculated by determining the maximum amount of oxygen a person can utilize during intense physical activity, expressed in milliliters of oxygen per kilogram of body weight per minute (mL/kg/min). The formula for calculating VO2 max is VO2 max = Q (CaO2 – CVO2), where Q is cardiac output, CaO2 is oxygen pressure in the arteries, and CVO2 is oxygen pressure in the veins.

While VO2 max was once considered a key metric in exercise science and race performance prediction, it has since been proven to not be an accurate predictor of race performance. I want to look at its uses as a metric and its limitations.

 

Uses of VO2 Max.

According to a paper by Kokkinos et al. titled “Cardiorespiratory Fitness and Mortality Risk Across the Spectra of Age, Race, and Sex,” published in 2022, VO2 max is an excellent predictor of mortality. People with a VO2 max of 50 mL/kg/min or higher have a 4 times lower risk of death from all causes. The study observed 750,302 individuals.

You can read more here – https://www.researchgate.net/publication/362406048_Cardiorespiratory_Fitness_and_Mortality_Risk_Across_the_Spectra_of_Age_Race_and_Sex

Just to give you an idea if you are there – A runner with an economical running gait, a VO2 max of 50 mL/kg/min is typically capable of running a 5 km in 22 to 23 minutes.

Want to live longer: Get a high VO2 max reading.

How to Calculate VO2 Max.

In a lab, VO2 max is calculated through the following steps:
– An initial warm-up is performed.
– The intensity of the exercise is gradually increased, usually every 3-5 minutes, until the participant reaches their maximum effort. The exercise intensity can be increased through a variety of methods, such as increasing the speed or incline of a treadmill or increasing the resistance on a stationary bike. Throughout the test, the participant’s oxygen consumption and heart rate are continuously monitored.
– The test continues until the participant reaches their maximum effort, which is indicated by volitional exhaustion, an increase in heart rate plateau, or a plateau in oxygen consumption.
– At this point, the participant’s VO2 max score is calculated. The test is expensive and will provide an accurate measurement of VO2 max.

There is another method that provides a rough estimate of VO2 max, which can be calculated as follows:

Here is the formula to get you going.

VO2 max = 15 x (MHR / RHR), where MHR is your maximum heart rate and RHR is your resting heart rate.

To obtain your RHR, take your pulse a few mornings as you wake up either manually or using an app. Sit up and either take your pulse manually or via an app as you wake up. The HRV4 app is a good option for those tracking HRV (Heart Rate Variability).

Apps such as Strava and Training Peaks can provide data on your maximum heart rate. Another method of testing this is to perform 8 x 300m hill repeats, pushing yourself to the limit on the last rep. (This method should only be performed if you are in good health and not injured).

For example, someone with a max HR of 200 and a resting HR of 50 would have a VO2 max of 60 mL/kg/min. 200/50 = 4. Multiply 4 by 15 and you get a VO2 max of 60 mL/kg/min

Typical VO2 Max Numbers:

High	60 ml/kg/min.	RHR approx. 48 bpm.
Ave	40 to 59 ml/kg/min.	RHR approx. 53 bpm.
Low	<40 ml/kg/min.	RHR approx. 64 bpm.

Factors that adversely affect your morning resting heart rate and hence your VO2 Max.

Seasonal Changes: Your RHR tends to increase in winter, making it an ideal time to focus on building your aerobic base, efficiency, and other related areas.

Alcohol: Drinking alcohol has no health benefits and is best limited to just a few drinks per week. Alcohol will increase your resting HR and decrease your HRV.

Stress: Stress triggers the body’s “fight or flight” response, which is controlled by the sympathetic nervous system. This leads to an increased heart rate, blood pressure, and breathing rate.

Travel: Disrupting your routine through travel can be stressful for the body, leading to an elevated state of alertness.

VO2 Max as an Inaccurate Predictor of Race Performance.

Once considered the most crucial fitness metric, VO2 max has since been proven to be an inadequate predictor of athletic performance due to the concept of the Central Governor, introduced by Tim Noakes. The Central Governor refers to the brain’s ability to monitor and regulate physical exertion based on various inputs, making it a massive data collection center. The brain receives information about factors such as skin temperature, core temperature, oxygen levels, CO2 levels, remaining distance in the race, upcoming hills, hydration levels, H⁺/pH levels, muscle damage, and inflammation levels, among others, and determines the extent of physical exertion. The primary goal of the brain is to keep the body alive, and if it senses any risk, it will slow down the body’s efforts to protect it. This is why, according to Noakes, even if a runner is determined to push harder in the final kilometers of a marathon, their brain may slow them down. However, if a dangerous situation, such as a wild dog appearing on the course, presents itself, the brain may release an additional burst of speed as the immediate threat to survival becomes greater than any other physiological concerns. Thus, the Central Governor ultimately has the most significant impact on athletic performance.

A.M Jones did a 5 year physiological study of a 3000 m runner. This is what he writes in the study –
“The 3000 m race performance improved by 8% from 1991 to 1993 after which it stabilized. In contrast, VO2 max fell from 1991 (73 ml/kg/min) to 1993 (66 ml/kg/min). Submaximal physiological variables such as lactate threshold (from 15.0 to 18.0 km/h) and running economy (from 53 ml/kg/min to 48 ml/kg/min at 16.0 km/h) improved over the course of the study. Despite no increase in VO2 max, the reduction in the oxygen cost of submaximal running caused the estimated running speed at VO2 max to increase from 19.0 km/h in 1991 to 20.4 km/h in 1995.”

In other words, the athlete sped up, whilst VO2 max levels dropped. The two things that did change were a drop in lactate levels and an increase in running economy.

Additionally, Paula Radcliffe’s success in marathons (including three wins in the London Marathon and one in the New York City Marathon) was achieved with unchanged VO2 max levels, despite a significant increase in her training volume. In her earlier days of running she trained between 40 to 50 km per week. As she matured as a runner she picked up her mileage to between 190 to 250 km per week. (She was a big volume runner).

When it comes to athletic performance, we should look at the following factors,
Things like the athlete’s ability to:
– deal with heat
– mitochondrial efficiency
– lactate utilization
– general strength
– efficiency
– self knowledge
– nutritional strategies
– training programs
– injury resistance/ ability to recover
– psychological toughness and backup from close friends/family.

Use VO2 max calculations as a determinant of overall health. Just don’t use it as a race performance predictor.

I really hope that sheds some light on the subject.

Mike Roscoe.
Kinesiologist & Coach.