What is VO2 max?

VO2 max, also known as maximal oxygen uptake, measures the maximum amount of oxygen an individual can utilise during intense exercise. It is a key indicator of cardiovascular fitness and aerobic endurance — essentially, how effectively your body can deliver oxygen to your muscles and how efficiently your muscles can utilise that oxygen. VO2 max is usually expressed in millilitres of oxygen per kilogram of body weight per minute (mL/kg/min) and is influenced by factors such as age, gender, and training status. This measurement is often used to assess a person’s aerobic capacity and track improvements in fitness levels over time.

Typically, VO2 max testing is conducted in a laboratory setting using specialised equipment to accurately measure an individual’s oxygen consumption during strenuous exercise. These days, however, fitness trackers such as smartwatches have made it possible to estimate VO2 max without the need for elaborate setups. By using sensors to monitor heart rate, movement, and other physiological data, these devices can provide a reasonably accurate assessment of your cardiovascular fitness. This enables you to track your health and the impact of your lifestyle choices, allowing you to make informed decisions about your exercise regimen.

The table below shows the VO2 max measurement by age and gender. It was created by researchers that measured VO2 max in healthy, untrained subjects in America, Canada and 7 European countries to establish norms in males and females (aged 6-75 years). This data underscores a crucial point: a higher VO2 max is not just a measure of fitness but also a powerful predictor of health. It is associated with a significantly lower risk of all-cause mortality (a lower risk of dying from any cause) and in particular a lower risk of heart disease.

 

Why is this measurement important?

As you may have noticed in the table above, the VO2 max tends to naturally decrease as you age. This is due to a natural decrease in the heart’s efficiency to circulate blood, the lung’s reduced gas exchange ability and losing muscle as we age. Considering that VO2 max looks at how efficiently the heart, lungs, and muscles work together, the higher your VO2 max, the better you will age. This is because a higher VO2 max means the body can perform daily activities more efficiently, with less fatigue and stress on the heart. No wonder research shows that people with higher VO2max levels tend to have a lower risk of dying from any cause, in particular heart disease [1].

The findings from a 2018 study [2] indicate that individuals with a below-average VO2 max have double the risk of all-cause mortality, meaning they are twice as likely to die at any given moment. To provide some context, a person who smokes has a 40% risk of all-cause mortality. This means that having a poor VO2 max for your age and gender is more harmful to your health than smoking (although this does not imply that smoking is encouraged!).

Putting in the hard work at an earlier age to ensure that you develop a higher VO2 max, creates a cardiovascular protective buffer. This means that despite the natural decrease in VO2 max with age, you have a greater chance of remaining in the upper percentiles for your age, keeping you fitter and more resilient for longer. Naturally, this helps you maintain an active and independent lifestyle well into your older years. While you may take many activities for granted now, having this extra capacity will ensure the likelihood of managing everyday activities such as carrying groceries to/from your car, climbing stairs or running after your grandchildren without huffing and puffing.

 

Ways to improve your VO2 max

High-Intensity Interval Training (HIIT):

• HIIT alternates between short bursts of high-intensity exercise and recovery periods. This pushes your cardiovascular system to its maximum capacity, which is highly effective for improving VO2max.
• How to Do It: For example, you could sprint for 30 seconds, then walk or jog for 1-2 minutes. Repeat for 20-30 minutes. My favourite method is skipping rope.

Endurance Training:

• Long-duration, moderate-intensity exercises help improve the heart and lung capacity to sustain oxygen usage over time.
• How to Do It: Activities like running, cycling, rowing, or swimming at a consistent pace for 30-60 minutes, 3-4 times a week. Aim for exercises that keep you in the aerobic zone, which is typically around 60-75% of your maximum heart rate (subtract your age from 220 to calculate your MHR)

Interval Training:

• It involves varying your pace throughout your workout (i.e. while running, alternate between faster sprints and slower jogging or walking for unpredictable intervals). This enhances both aerobic (with oxygen) and anaerobic (without oxygen) capacity.
• It adds variability to your workouts, preventing plateau and helping increase VO2 max.

Strength Training:

• While strength training is primarily for building muscle, it supports VO2max improvement by enhancing overall fitness and stamina. Stronger muscles use oxygen more efficiently.
• Sarcopenia, or age-related muscle loss already starts around the age of 30, where adults tend to lose 3-5% of muscle per decade. From the age of 50, estimates of muscle loss is about 1-2% per year. Without intervention (i.e. remaining physically active and in particular engaging in strength training), this results in 10-15% loss per decade.
• How to Do It: Incorporate 2-3 strength training sessions per week, focusing on compound movements like squats, deadlifts, and lunges that engage large muscle groups.

 

While a high VO2 max measurement is not the be-all and end-all, enough research indicates its significance, particularly the devastating health consequences if you are below average for your age. The wonderful thing about our bodies is that there’s always room for improvement. You just need to have sufficient motivation and knowledge to take action. The question is: Will you?

 

References:

[1] Kodama S, Saito K, Tanaka S, et al. Cardiorespiratory Fitness as a Quantitative Predictor of All-Cause Mortality and Cardiovascular Events in Healthy Men and Women: A Meta-analysis. JAMA. 2009;301(19):2024–2035. doi:10.1001/jama.2009.681

[2] Mandsager K, Harb S, Cremer P, Phelan D, Nissen SE, Jaber W. Association of Cardiorespiratory Fitness With Long-term Mortality Among Adults Undergoing Exercise Treadmill Testing. JAMA Netw Open. 2018;1(6):e183605. doi:10.1001/jamanetworkopen.2018.3605