Cardiorespiratory fitness (CRF) is commonly assessed through VO₂max or VO₂peak, while MET-based estimates and activity surveys provide related but different views. The statistics below separate direct exercise-test results from self-reported participation, behavioral estimates and observational health associations.
Key Cardiorespiratory Fitness Statistics
The most broadly useful figures include:
- In 2014–2016, the FRIEND reference cohort recorded median VO₂max of 41.9 mL O₂/kg/min for U.S. men aged 20–29.
- In 2014–2016, the FRIEND reference cohort recorded median VO₂max of 31.0 mL O₂/kg/min for U.S. women aged 20–29.
- In 2014–2016, median VO₂max was 19.5 mL O₂/kg/min for U.S. men aged 70–79 in the FRIEND reference cohort.
- In 2014–2016, median VO₂max was 14.8 mL O₂/kg/min for U.S. women aged 70–79 in the FRIEND reference cohort.
- The FRIEND study included 4,494 maximal cycle-ergometer tests from adults aged 20–79 across 27 U.S. states during 2014–2016.
- The Norwegian reference study found mean VO₂max of 54.4 mL O₂/kg/min among men aged 20–29.
- The Norwegian reference study found mean VO₂max of 43.0 mL O₂/kg/min among women aged 20–29.
- In 2024, 48.0% of U.S. adults aged 18 and older met the minimum aerobic-activity target in the Healthy People 2030 measure.
- In 2020, 38.2% of adults in U.S. nonmetropolitan counties met the aerobic guideline.
- In 2020, 28.5% of adults in the U.S. West met both aerobic and muscle-strengthening guidelines.
- In 2022, about 31% of adults worldwide, approximately 1.8 billion people, did not meet activity recommendations.
- If current trends continue, global adult inactivity is projected to reach 35% by 2030.
- A 37-cohort meta-analysis through December 2021 included 2,258,029 participants and 108,613 all-cause deaths.
- Through December 2021, each 1-MET higher CRF was associated with an all-cause mortality relative risk of 0.89.
- Reviews published from 2002 through March 2024 found each 1-MET higher CRF associated with 11%–17% lower all-cause mortality.
- Reviews published from 2002 through March 2024 found high versus low CRF associated with heart-failure incidence HR 0.31.
- In post-diagnosis cancer patients, each 1-MET higher fitness was associated with all-cause mortality HR 0.74.
- In a meta-analysis of cohorts published from 1980 through February 2023, obese-unfit adults had CVD mortality HR 3.35 versus normal-weight fit adults.
Contents
- VO₂max statistics by age and sex
- Aerobic-activity participation data
- Global inactivity trends
- CRF and mortality outcomes
- Cardiovascular disease and cancer outcomes
- Older adults and clinical populations
Cardiorespiratory Fitness Statistics: VO₂max by Age and Sex
VO₂max expresses the maximum rate of oxygen use during a maximal exercise test, usually relative to body mass. Reference values vary with protocol, equipment, cohort selection and whether the test uses a cycle ergometer or treadmill.
The FRIEND Registry’s U.S. reference work used 4,494 maximal cycle-ergometer tests from adults aged 20–79 across 27 states during 2014–2016. It was a reference dataset, not a national probability sample, and it included adults without cardiovascular disease who completed maximal testing (Reference Standards for Cardiorespiratory Fitness Measured With Cardiopulmonary Exercise Testing Using Cycle Ergometry: Data From the FRIEND Registry).
| Group | Period | Median VO₂max |
|---|---|---|
| U.S. men, age 20–29 | 2014–2016 | 41.9 mL O₂/kg/min |
| U.S. women, age 20–29 | 2014–2016 | 31.0 mL O₂/kg/min |
| U.S. men, age 70–79 | 2014–2016 | 19.5 mL O₂/kg/min |
| U.S. women, age 70–79 | 2014–2016 | 14.8 mL O₂/kg/min |
These cycle-ergometer medians should not be treated as directly interchangeable with treadmill norms. They also describe reference-test performance, not the percentage of the U.S. population reaching a particular fitness threshold.
A Norwegian reference study used treadmill testing in healthy volunteers and reported mean VO₂max of 54.4 mL O₂/kg/min for men aged 20–29 and 43.0 mL O₂/kg/min for women aged 20–29. Across men and women aged 20–90, VO₂max declined by approximately 3.5 mL O₂/kg/min per decade; the comparison is cross-sectional rather than a longitudinal estimate (Aerobic capacity reference data in 3816 healthy men and women 20-90 years).
The same Norwegian reference data reported maximal heart rate of 196 beats/min for men aged 20–29 and 194 beats/min for women aged 20–29, with maximal heart rate declining approximately 6 beats/min per decade. These are reference patterns from the study population, not universal individual predictions.
Aerobic-Activity Participation and Cardiorespiratory Fitness Data
Activity participation is a behavioral indicator related to CRF, but it is not a direct VO₂max measurement. Healthy People 2030 defines the U.S. aerobic target as at least 150 moderate or 75 vigorous minutes weekly and uses age-adjusted National Health Interview Survey self-report.
| U.S. measure | Period | Share meeting target |
|---|---|---|
| Adults aged 18+, aerobic activity | 2024 | 48.0% |
| Adults aged 18+, aerobic activity baseline | 2020 | 47.9% |
| Adults aged 18+, national policy target | 2030 target | 52.9% |
The 2024 result and the 2020 baseline come from the Healthy People 2030 PA-02 measure; the 52.9% figure is a policy target, not an observed prevalence (Increase the proportion of adults who do enough aerobic physical activity for substantial health benefits — PA-02).
The CDC’s 2020 NHIS analysis found substantial geographic differences in self-reported leisure-time activity. In nonmetropolitan counties, 38.2% of adults met the aerobic guideline, 21.1% met the muscle-strengthening guideline, and 16.1% met both.
In the West Census region, 52.1% met the aerobic guideline, 35.3% met the muscle-strengthening guideline, and 28.5% met both. No analyzed rural-urban or regional subgroup exceeded 28% for meeting both guidelines (Prevalence of Meeting Aerobic, Muscle-Strengthening, and Combined Physical Activity Guidelines During Leisure Time Among Adults, by Rural-Urban Classification and Region — United States, 2020).
The same analysis reported adjusted odds ratios of 0.68–0.89 for adults in the most rural category versus more urban categories across the three guideline measures. Adults in the Northeast, Midwest and South had adjusted odds ratios of 0.75–0.82 versus the West; these are associational comparisons, not causal effects.
Global Physical Inactivity Trends Linked to Lower Fitness
The World Health Organization’s global activity estimates describe insufficient physical activity, a behavioral proxy rather than direct CRF testing. In 2022, about 31% of adults worldwide—approximately 1.8 billion people—did not meet activity recommendations, and global adult inactivity had increased by about 5 percentage points from 2010 to 2022.
| Population or region | Year | Estimated inactivity |
|---|---|---|
| Worldwide adults | 2022 | 31% |
| High-income Asia Pacific adults | 2022 | 48% |
| South Asian adults | 2022 | 45% |
| High-income Western-country adults | 2022 | 28% |
| Oceania adults | 2022 | 14% |
In 2022, inactivity was estimated at 34% among women worldwide versus 29% among men. If current trends continue, global adult inactivity is projected to reach 35% by 2030; the projection assumes continuation of the observed trend (Nearly 1.8 billion adults at risk of disease from not doing enough physical activity).
The WHO also identified 22 countries as likely to reach the 15% reduction target by 2030 if their trends continued. This forecast concerns insufficient activity, not a forecast of measured VO₂max.
Cardiorespiratory Fitness Statistics and Mortality Outcomes
CRF has been studied as a risk marker in large observational cohorts. A meta-analysis of 37 cohorts through December 2021 included 2,258,029 participants and 108,613 all-cause deaths (Objectively Assessed Cardiorespiratory Fitness and All-Cause Mortality Risk: An Updated Meta-analysis of 37 Cohort Studies Involving 2,258,029 Participants).
- Top versus bottom CRF tertiles had pooled all-cause mortality relative risk of 0.55, with a 95% confidence interval of 0.50–0.61.
- When CRF was expressed in METs, top versus bottom tertiles had pooled all-cause mortality relative risk of 0.56, with a 95% confidence interval of 0.50–0.62.
- Each 1-MET higher CRF was associated with all-cause mortality relative risk of 0.89, with a 95% confidence interval of 0.86–0.92.
An overview of meta-analyses published from 2002 through March 2024 found high versus low CRF associated with an all-cause mortality hazard ratio of 0.47. The same overview found each 1-MET higher CRF associated with 11%–17% lower all-cause mortality, although evidence certainty ranged from very low to moderate (Cardiorespiratory fitness is a strong and consistent predictor of morbidity and mortality among adults).
A meta-analysis of estimated rather than directly tested CRF found each 1-MET increase associated with cardiovascular mortality HR 0.83, 95% CI 0.80–0.86, and all-cause mortality HR 0.83, 95% CI 0.78–0.88 (Is estimated cardiorespiratory fitness an effective predictor for cardiovascular and all-cause mortality? A meta-analysis).
In a UK Biobank analysis using risk-stratified exercise testing, each 1-MET higher estimated CRF was associated with 8% lower all-cause mortality and 9% lower cardiovascular mortality. The study included 79,981 participants, with 2,670 deaths and 854 cardiovascular deaths; the estimates were observational (Cardiorespiratory fitness assessment using risk-stratified exercise testing and dose-response relationships with disease outcomes).
Cardiorespiratory Fitness Data for Cardiovascular Disease and Cancer
The overview of meta-analyses found high versus low CRF associated with heart-failure incidence HR 0.31, 95% CI 0.19–0.49. Each 1-MET higher CRF was associated with 18% lower heart-failure incidence, corresponding to HR 0.82 and 95% CI 0.79–0.84 (Cardiorespiratory fitness is a strong and consistent predictor of morbidity and mortality among adults).
Among adults living with cardiovascular disease, high versus low CRF was associated with cardiovascular mortality HR 0.27, 95% CI 0.16–0.48. These pooled estimates come from observational patient-population evidence and should not be read as proof that changing CRF alone produces the entire risk difference.
| Population and comparison | Period or evidence scope | Association |
|---|---|---|
| Post-diagnosis cancer patients, each 1-MET higher fitness, all-cause mortality | Post-diagnosis follow-up | HR 0.74 |
| Post-diagnosis cancer patients, each 1-MET higher fitness, cardiovascular mortality | Post-diagnosis follow-up | HR 0.86 |
| Post-diagnosis cancer patients, each 1-MET higher fitness, cancer mortality | Post-diagnosis follow-up | HR 0.75 |
The cancer estimates came from an observational exercise-test cohort, with adjusted 95% confidence intervals of 0.70–0.79 for all-cause mortality, 0.76–0.97 for cardiovascular mortality and 0.69–0.80 for cancer mortality (Association of post-diagnosis cardiorespiratory fitness with cause-specific mortality in cancer).
A systematic review of 20 prospective cohort articles published from 1980 through February 2023 examined BMI and CRF jointly. Relative to normal-weight fit adults, CVD mortality HR was 2.04 for normal-weight unfit adults, 2.58 for overweight-unfit adults and 3.35 for obese-unfit adults; the respective 95% confidence intervals were 1.32–3.14, 1.48–4.52 and 1.17–9.61 (Cardiorespiratory fitness, body mass index and mortality: a systematic review and meta-analysis).
Cardiorespiratory Fitness in Older Adults and Clinical Populations
The Generation 100 study measured 1,537 adults aged 70–77, including 769 women. It reported direct peak oxygen uptake and peak ventilation values in an older-adult study cohort rather than a national prevalence survey (Cardiorespiratory Reference Data in Older Adults: The Generation 100 Study).
| Generation 100 group | Mean peak oxygen uptake | Mean peak ventilation |
|---|---|---|
| Men aged 70–77 | 31.3 mL O₂/min/kg | 96.2 L/min |
| Women aged 70–77 | 26.2 mL O₂/min/kg | 61.1 L/min |
Compared with healthy peers in the same study, men aged 70–77 with cardiovascular disease had 19% lower peak oxygen uptake, while women with cardiovascular disease had 14% lower peak oxygen uptake. Their 1-minute heart-rate recovery was also 16% lower for men and 12% lower for women; heart-rate recovery is related to CRF but is not VO₂peak itself.
A systematic review of cardiopulmonary exercise-testing studies in adults with cardiovascular disease found high versus low CRF associated with all-cause mortality HR 0.42, 95% CI 0.28–0.61, with high heterogeneity. The same review found cardiovascular mortality HR 0.27, 95% CI 0.16–0.48 (Cardiorespiratory fitness measured with cardiopulmonary exercise testing and mortality in patients with cardiovascular disease: a systematic review and meta-analysis).
Among people with coronary artery disease, each 1-MET higher CRF was associated with all-cause mortality HR 0.83, 95% CI 0.76–0.91; heterogeneity was I² 77.1%. Among people with heart failure, each 1-MET higher CRF was not statistically associated with all-cause mortality: HR 0.69, 95% CI 0.36–1.32, with heterogeneity of I² 83.3%.
These clinical findings illustrate why population activity statistics, direct exercise-test reference values and disease-outcome associations should remain separate. Each uses a different population, measurement method and evidentiary scope.