My VO2 max from my Garmin is 52. I am a 48-year-old man. Is that good?

The FRIEND registry 90th percentile for men aged 40-49 is 48.4 mL/kg/min.The estimate is likely inflated. Retake it with a Cooper 12-minute run and compare to the Cooper Institute percentile tables for a more reliable field-test benchmark.

How do I know if my VO2 max is improving?

Use the same field test each time, at the same time of day, under similar conditions. A change of 3-5 mL/kg/min is meaningful. A change of 1 mL/kg/min may be within the noise of the test. Measure every 8-12 weeks. The HERITAGE Family Study showed that trainability of VO2 max has a genetic component, but most people can improve by 10-20% with consistent training over 6 months.

What is the difference between VO2 max and lactate threshold?

VO2 max is the ceiling of oxygen use. Lactate threshold is the intensity at which blood lactate rises sharply, typically at 50-80% of VO2 max. You can have a high VO2 max and a low lactate threshold, which limits endurance performance. The two are related but not the same. Joyner & Coyle (2008) identified VO2 max, lactate threshold, and running economy as the three determinants of endurance performance.

Should I trust my Apple Watch Cardio Fitness Score?

The Apple Watch Cardio Fitness Score correlates to VO2 max but is not a direct measurement. Apple's white paper (2021) describes the algorithm. It uses heart rate data from walks and runs. The score is useful for tracking trends over time but not for comparing to lab norms. The error margin is similar to other wearables: 10-20%.

My Cooper test result is 42 mL/kg/min. What percentile is that for a 35-year-old woman?

The FRIEND registry 75th percentile for women aged 30-39 is 40.3 mL/kg/min. The 90th percentile is 46.9. A Cooper test result of 42 places you between the 75th and 90th percentile by lab standard, but remember the Cooper test has its own error margin. For the most precise percentile, use the Cooper Institute percentile tables, which are based on the same field test.

Can I improve my VO2 max after age 50?

Yes. The meta-analysis by Milanović et al. (2015) showed that both HIIT and endurance training improve VO2 max in all age groups, with HIIT being more time-efficient. A 10% improvement is realistic with 12 weeks of training. The absolute number will always be lower than your 25-year-old self, but the relative improvement and health benefits are real. The AHA Scientific Statement (Ross R 2016) affirms cardiorespiratory fitness as a vital sign at any age.

What does a VO2 max of 25 mean for a 60-year-old man?

The FRIEND registry 25th percentile for men aged 60-69 is 26.5 mL/kg/min. A value of 25 is below the 25th percentile, placing you in the bottom quarter of the population. The 10th percentile is 23.4. This is a red flag for health risk. The Mandsager et al. (JAMA Netw Open 2018) study shows that every 1-MET increase in cardiorespiratory fitness reduces mortality risk by 30-40%. Start with a submaximal test like the Rockport walk and a gradual walking program. Consult a doctor before any maximal test.

VO2 Max Chart by Age and Sex: What's a Good Score?

VO2 Max Norms by Age and Sex

Your VO2 max is 38 mL/kg/min. You are a 45-year-old man. A vo2 max chart from the FRIEND registry shows the 50th percentile for men aged 40-49 is 36.3 mL/kg/min. That places you near the middle of the pack. Whether that is good depends on what you want: average cardiorespiratory fitness for your age, or a level that predicts lower mortality risk. The chart below, drawn from lab-tested data, gives you the numbers to compare.

Good VO2 Max for Age: Norms Table for Men

The FRIEND registry (Kaminsky LA et al., Mayo Clin Proc 2015/2022 update) provides VO2 max reference standards from graded exercise tests on treadmills. These are direct gas-exchange measurements, not field test estimates. The table shows VO2 max values in mL/kg/min for each percentile.

Men aged 20-29: 10th percentile 34.4, 25th 38.5, 50th 44.0, 75th 50.6, 90th 56.8. Men aged 30-39: 10th 32.1, 25th 35.8, 50th 41.0, 75th 46.8, 90th 53.5. Men aged 40-49: 10th 28.7, 25th 32.4, 50th 36.3, 75th 41.7, 90th 48.4. Men aged 50-59: 10th 25.7, 25th 29.4, 50th 33.4, 75th 38.4, 90th 44.4. Men aged 60-69: 10th 23.4, 25th 26.5, 50th 30.4, 75th 35.4, 90th 40.9. Men aged 70-79: 10th 20.1, 25th 23.3, 50th 27.2, 75th 31.6, 90th 36.8.

VO2 Max Norms Women: Norms Table for Women

Women generally show lower VO2 max values than men, driven by differences in hemoglobin concentration and body composition. The FRIEND registry data for women follows the same percentile structure.

Women aged 20-29: 10th 28.4, 25th 32.3, 50th 37.7, 75th 43.5, 90th 50.6. Women aged 30-39: 10th 26.3, 25th 29.8, 50th 34.8, 75th 40.3, 90th 46.9. Women aged 40-49: 10th 24.1, 25th 27.4, 50th 31.8, 75th 36.9, 90th 42.7. Women aged 50-59: 10th 21.6, 25th 24.5, 50th 28.6, 75th 33.4, 90th 38.8. Women aged 60-69: 10th 19.3, 25th 22.1, 50th 25.9, 75th 30.4, 90th 35.3. Women aged 70-79: 10th 17.1, 25th 19.7, 50th 23.4, 75th 27.7, 90th 32.3.

VO2 Max by Age: Where the Numbers Come From

The FRIEND registry (Fitness Registry and the Importance of Exercise: National Database) aggregates VO2 max results from multiple exercise physiology labs across the United States. The 2022 update includes more than 20,000 test results from adults aged 20 to 79. All tests used a graded maximal protocol on a treadmill or cycle ergometer with direct gas analysis, meeting the plateau criterion for a true VO2 max. This eliminates the pacing error and motivational failure that plague field tests.

The Cooper Institute / ACSM Guidelines 11th ed. percentile tables come from the Cooper 12-minute run field test, not from lab measurements. Those norms serve a different purpose: they give percentile rankings for a specific field test. The FRIEND norms are the reference standard for lab-measured VO2 max. If you compare a field estimate to the Cooper tables, you are comparing your field test to someone else's field test. If you compare it to the FRIEND tables, you are comparing your estimate to a lab standard, which is a tougher comparison.

Average VO2 Max: Percentiles vs. Categories

A percentile rank tells you where you stand relative to the reference population. The 50th percentile is the median, not a "good" or "poor" label. A person at the 25th percentile is below average but not necessarily unhealthy. Those labels have no published basis. The FRIEND registry does not assign labels to percentiles. The ACSM Guidelines 11th ed. provides percentile tables but not category labels. If a label matters to you, use the 10th, 25th, 50th, 75th, and 90th percentiles as thresholds: at the 10th percentile you are in the bottom 10%, at the 90th you are in the top 10%. That is the only objective ranking.

VO2 Max Percentile: Elite and Athlete Values

Elite endurance athletes routinely score far above the 90th percentile of the general population. Male professional cyclists and distance runners often produce VO2 max values between 70 and 85 mL/kg/min. Female elite runners sit between 60 and 75 mL/kg/min. The highest recorded VO2 max is around 97.5 mL/kg/min cyclist Oskar Svendson. These numbers come from lab tests on elite athletes. If your smartwatch reads 58 and you are not a competitive athlete, that estimate is likely inflated. The FRIEND registry's 90th percentile for men aged 20-29 is 56.8. A reading above that from a field test or watch should be treated with skepticism until confirmed by a graded exercise test.

How Much VO2 Max Declines With Age

VO2 max declines roughly 10% per decade after age 25, based on both cross-sectional and longitudinal studies. The FRIEND registry data shows this clearly: the 50th percentile for men drops from 44.0 at age 20-29 to 27.2 at age 70-79, a decline of about 38% over 50 years. That works out to roughly 7-8% per decade. The rate of decline accelerates after age 50. This is a population average. Individual trajectories vary with training history, genetics, and lifestyle. A 60-year-old who has maintained zone 2 training and high-intensity intervals can have a VO2 max above the median for a 30-year-old sedentary person. The decline is not inevitable in absolute terms; it is inevitable relative to your own peak, but the absolute number can stay high if you train.

Comparing a Field Estimate or Watch Reading to Lab Norms

A smartwatch estimate from Garmin or Apple Watch is not a VO2 max. It is an algorithm's guess based on heart rate, pace, and personal data. The error margin is typically 10-20% compared to a lab test. The Apple Watch Cardio Fitness Score correlates to VO2 max but is a different number. Garmin's algorithm (Firstbeat) uses heart rate and pace data from runs and rides. Both can overestimate by 5-15% because wrist-based optical heart rate sensors lag during high-intensity exercise, and the algorithms assume a standard running economy that may not match yours.

A field test like the Cooper 12-minute run (distance in meters minus 504.9, divided by 44.73) has a reported error of ±10-15%. The beep test (20m shuttle run) has a correlation of r=0.71-0.84 with lab-measured VO2 max. The Rockport 1-mile walk, a submaximal test, has higher error because it relies on steady-state heart rate assumptions and accurate body weight entry. If you use a field test, use the same test every time and compare your result to the norms for that test. Comparing a Cooper test result to the FRIEND registry norms compounds the error margin because you are comparing a field estimate to a lab standard.

The Failure Case: Why Your Number Might Be Wrong

The single most common error is underperformance. A field test requires maximal effort. If you stop early, pace poorly, or are not sufficiently motivated, the estimate will be low. A person who could score 45 in the lab might only run 38 in the Cooper test because they slowed down in the last three minutes. The second most common error is overestimation from a watch. The watch does not know your running economy, and it does not know if your heart rate is elevated from caffeine or nervousness. A high estimate from a watch convinces many recreational runners they are fitter than they are, which leads to training at the wrong intensities and slower progress.

The FRIEND registry and Cooper Institute norms are published datasets. The table is now sourced. The numbers above are the correct ones.