What is VO2 max, and what is a good score?

When you cycle or run, your muscles use oxygen to release energy. Your lungs, blood and circulation deliver that oxygen to the working muscles. VO2 max describes the combined capacity of this system at maximum effort. It is an important marker of cardiorespiratory fitness, rather than a complete assessment of your physical abilities.

The relative value, ml/kg/min, accounts for body weight. The absolute value is commonly expressed in litres per minute. Losing weight can increase the relative number without an equivalent improvement in absolute oxygen uptake. When comparing tests, it helps to consider both values alongside workload, test method and how you felt on the day.

There is no single good number for everyone. Reference values depend on age and sex, and on whether the test used a bicycle or a treadmill. Training, genetics and the background of the reference population also matter. Use an appropriate comparison group rather than a stand-alone threshold such as “above 50”.

The updated 2022 FRIEND references use measured data. This table shows median cycle-ergometer peak oxygen uptake in ml/kg/min, using the effort criterion RER at least 1.10. A median is the reference group’s midpoint, not a target everyone must reach or a disease threshold. These are not treadmill or wearable references. Population and selection affect the values; use them as comparisons, not universal labels of good or poor fitness.

A large observational study from Cleveland Clinic, published in JAMA Network Open in 2018, found an association between greater treadmill fitness and lower mortality during follow-up. It included more than 122,000 people referred for testing. It did not directly measure every participant’s oxygen uptake through a mask.

An association does not prove that reaching a particular VO2 max gives you a particular number of extra years. The participants were not a random sample of the population, either. Fitness is relevant, but a test score cannot provide an individual life expectancy or replace a clinical assessment of your health.

Sports watches typically use heart rate, speed and personal details to estimate fitness. Heat, hills, medication, sensor errors and the activities you perform can affect the result. A watch can be useful for following a trend, but that is different from measuring breathing gases directly during a controlled exercise test.

A mask test measures oxygen and carbon dioxide in breathing gases as exercise intensity increases. HBOT Global’s Performance Test uses PNOĒ on a bicycle. The report can also provide training zones and information about breathing and estimated fuel use. These findings describe the conditions of the test and are not a medical diagnosis.

Regular training matters more than chasing a particular score. Many people combine longer, comfortable sessions with harder intervals. “Zone 2” is a practical label, but the boundaries depend on how zones are calculated. A test can help make intensity targets more concrete, rather than relying only on generic heart-rate formulas.

One or two interval sessions a week may suit some people, but this is not a universal starting prescription. Build gradually from your current activity level and allow time for rest and sleep. If you have symptoms, a medical condition or concerns about strenuous exercise, seek individual advice instead of following a general article.

Retesting after three to six months can be useful following a consistent training block. There is no need to schedule a test if its result will not change your decisions. Use the same equipment, test mode and preparation where possible. Small differences can reflect ordinary measurement variation, rather than certain improvement or decline.