Learn what VO2max is, why it matters for your health, and how to measure and improve it safely with science-backed methods.
VO2max — or maximal oxygen uptake — is the amount of oxygen your body can absorb and use per minute of intense physical activity. It’s a direct measure of how powerful your heart is, and how efficiently your lungs, blood vessels, and muscles work together under stress. In simple terms: VO2max reflects your endurance capacity.
A higher VO2max means your cardiovascular system is stronger, more elastic, and more capable of sustaining energy output. A lower VO2max means reduced capacity — and greater risk of decline.
VO2max decreases on average by 1% per years, accelerating in older age. This decline is associated with:
• Increased risk of cardiovascular disease
• Reduced energy and lower work capacity
• Greater vulnerability to illness and longer recovery times.
VO2max isn’t fixed — it’s trainable. With the right exercise, your body can increase its pumping capacity and effectively improve both performance and health outcomes.
VO2max is the golden standard in endurance sports. It reflects how efficiently the body delivers and uses oxygen during high-intensity activity. The higher your VO2max, the more energy your muscles receive, the longer you can maintain performance, and the faster you recover. VO2max isn’t just a sports metric.
Top athletes like Cristiano Ronaldo, Messi, and clubs such as Real Madrid, Barcelona, Celtic, as well as national sports federations and Olympic athletes have all focused on improving VO2max to gain a competitive edge.
Increasing VO2max in sport results in:
• Higher endurance and sustained power
• Faster recovery between high-intensity efforts
• Lower energy cost at every speed — making you more efficient
It’s measurable, trainable, and directly correlated with success in both individual and team sports.
Outside of sports, VO2max becomes even more critical. It reflects the pumping capacity of your heart and the elasticity of your vascular system.
When these systems weaken, your body’s ability to deliver oxygen drops — and so does your ability to recover, resist illness, or maintain independence.
“Your VO2max says more about your physical health than any other parameter we know — a far stronger indicator of health than blood pressure, cholesterol, or BMI combined.”
- prof. Jan Hoff
A higher VO2max correlates with:
• Lower risk of cardiovascular disease, diabetes, and lifestyle-related illness
• Faster recovery from events like surgery or infection
• Improved circulation, metabolism, and brain health
• Shorter rehabilitation time and reduced frailty as you age
Most people aren't aware of the importance of their VO2max — but they should. It tells you more about your health than any other measurement.
The Dallas Bed Rest and Training Study by Saltin et al.1 (1968) is one of the most cited experiments in exercise science — and for good reason. It revealed just how sensitive your VO2max is to inactivity, and how critical movement is for heart health. The study showed that three weeks of strict bed rest for five healthy 20-year-old men resulted in a 27% dramatic drop in VO2max, alongside reduced cardiac output and stroke volume.
But if inactivity accelerates aging, can training reverse it? That’s exactly what a recent two-year study by Howden et al.2 (2018) has shown. They decided to investigate whether high-intensity exercise program could reverse cardiac aging in previously sedentary middle-aged adults. Participants who performed 4–5 sessions of aerobic exercise per week, including at least one 4x4 interval, experienced a 25% increase in VO2max and significant improvements in their heart elasticity and pumping function — reversing decades of sedentary heart aging. The study concluded that committed exercise starting in midlife can restore youthful heart function and reduce the risk of heart failure later in life.
The effect of age and VO2max has been throuorugly researched for decades. A study by Støren et al.3 (2017) showed that all age‑groups responds well to HIIT training and improved their VO2max by 9‑13%, with no significant drop in responsiveness by age. These findings imply that individuals across age all have a great potential for cardiovascular improvements, and that HIIT may be used as an excellent strategy for healthy aging.
Many forms of exercise are promoted for health, but a study by Helgerud et al.4 (2007) shows that only a few actually improve VO2max in an effective way — and intensity plays a critical role. A well-known study set out to compare the effectiveness of four popular training methods:
• Long Slow Distance (often referred to as Zone 2)
• Lactate Threshold Runs
• 15/15 Intervals (15 seconds high, 15 seconds low)
• 4x4 Minute Intervals (at 90–95% of HRmax)
All groups trained with equal total workload, but the results weren’t equal.
Fun fact: The 15/15 group had to perform 47 intervals per session to match the total work of the other methods. This is a lot of start and stop and thus very difficult to administer.
The takeaway? If you want to improve VO2max efficiently, 4x4 intervals offer the most potent and practical method available.
Traditionally, VO2max is measured in a laboratory environment. This usually involves a treadmill or bike test performed to the point of exhaustion while wearing a mask that analyzes gas exchange. While accurate, this method is:
• Expensive
• Time-consuming
• Uncomfortable
• Inaccessible for many individuals, especially those recovering from illness or surgery
More recently, validated digital methods for measuring VO₂max have emerged. In a study by Helgerud et al.5 (2017), the technology now used in both Myworkout GO and Myworkout 4x4 accurately estimated VO₂max through a standardized in-app walking and running protocol — with a margin of error as low as 4.5%, compared to 3% for traditional laboratory testing.
Myworkout 4x4:
• Utilizes DEM technology, your phone’s sensors and GPS to map the terrain in real-time
• Requires no mask, lab, or maximum-effort testing
• Is affordable, safe, accessible, and repeatable in real-world conditions
With the Myworkout app, you can measure your VO₂max with scientific accuracy, using only your smartphone.
When you exercise with the app, it estimates your biological age and your VO₂max based on how far you've run, and at what speed and incline you've had during an interval. This measurement then calibrates the app — allowing it to understand your individual capacity.
From there, the app knows when you’re exercising in the right intensity zone (High-Intensity Training) — the zone where real health improvement happens — even when you’re doing other kinds of exercise. Decades of international research have confirmed that exercising in this range is the most effective way to improve heart function, endurance, and overall health.
When you stay in that zone, the time you spend there is tracked as HIT minutes (High-Intensity Training minutes). Accumulate 32 HIT minutes per week, and you’re actively building capacity — your capacity increases and your biological age decreases. Keep it up, and you’ll build a streak that turns your progress into motivation — gamifying your health journey one week at a time.
The app calculates VO2max and biological age by assessing how much work you are able to perform during a standard 4x4-minute high-intensity interval session. It's done differently outdoors, on the mill and at the machine.
No special equipment is needed to get started with and enjoy MyWorkout. All you need is a smartphone. Our cutting-edge technology measures your capacity with scientific accuracy, even more accurately than wearables.
However, if you already use wearables, you can integrate them with our app. You can find instructions for integrating third parties here.
For some people, it's fun and motivating to use a heart rate monitor when exercising, for others it's not. With Myworkout GO, you can choose whether you want to use your heart rate as a guide or not. It also works perfectly well without a heart rate monitor. Without heart rate monitoring, you use your own breathing to control the intensity. During the intervals, you should breathe heavily without feeling any discomfort.
To benefit from a heart rate monitor, you need to know your maximum heart rate. If you don't know what your maximum heart rate is, you won't get any benefit from using a heart rate monitor. Remember that there is no shortcut to finding your maximum heart rate. The methods used to calculate your maximum heart rate are very inaccurate, as there are large individual differences in maximum heart rate.
Unlike direct VO₂max measurement with a mask — where your total oxygen uptake is measured and then divided by body weight to get VO₂max in milliliters per kilogram — the app measures the work you’re able to perform during a standardized test. From that, it directly calculates VO₂max in milliliters per kilogram of body weight.
Because walking or running naturally involves carrying your own body weight, that load is already accounted for in the calculation.
When training on equipment that measures power output (watts), you’ll need to enter your weight to calculate VO₂max accurately.
By using our method, you trade a small amount of accuracy — about 93% compared to 97% with direct mask measurement — for accessibility and convenience. It allows you to test yourself with an acceptable margin of error, without the need for specialized medical equipment.
Myworkout 4x4 is our app for personal use — designed for anyone who wants a simple, guided way to improve health and fitness with just 16 minutes of training, twice a week. It’s built around the same science and technology used in clinical research but tailored for an individual journey that’s clear, motivating, and easy to follow.
Myworkout GO is for organizations — companies, insurance providers, gyms, and clinics — that want to make health measurable and engaging on a larger scale. It includes the same scientifically proven 4x4 training and VO₂max measurement tools, but adds features for teams, campaigns, and corporate wellness programs.
Both apps are built on the same scientifically validated exercise methodology and underlying technology, with distinct use cases for individual and organizational users.
If your company or organization uses Myworkout GO for Business, you can still enjoy the Myworkout 4x4 experience for your own personal training — your data and progress stay synced across both.
If you’re an individual looking to take control of your health, start with Myworkout 4x4.
If you represent a business, insurer, gym, or clinic and want to make Myworkout part of your health offering, schedule a meeting with us to learn more about Myworkout GO for Business.
Improving your VO2max isn’t just about performance. It’s about ageing better and slowlier. Research3 shows that you can improve VO2max by 9‑13% through high‑intensity interval training in 8 weeks. The same training effects are regardless of age.When your heart works more efficiently, your body moves better, your systems age slower — you gain years of functional life, not just more years alive. That’s why VO2max is the most important number in health. Measure it. Train it. Add years to your life.
