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VO2 Max and Longevity: The Data, and a Plan to Raise Yours

11 min read

In a Cleveland Clinic study of 122,007 adults referred for a treadmill test, the least fit group had about five times the adjusted death risk of the fittest over a median of 8.4 years. The authors judged the risk tied to low fitness comparable to or greater than smoking or diabetes. Fitness also responds to training within weeks, and the trials below show which training moved it most.

13%
Lower risk of death from any cause for each 1-MET higher fitness level, in healthy men and women
Kodama et al. 2009, JAMA meta-analysis of 33 cohort studies
1.41
Adjusted death risk ratio for below-average versus above-average fitness, the same as for smoking
Mandsager et al. 2018, JAMA Network Open
53%
Lower all-cause death risk with the highest versus the lowest fitness, across 34 cohort studies
Han et al. 2022, British Journal of Sports Medicine
+7.2%
VO2 max gain in the 4x4 interval group after 8 weeks, three days a week, in a trial of 40 moderately trained men
Helgerud et al. 2007
+5.5
mL/kg/min average VO2 max gain with interval training against no exercise
Milanovic et al. 2015, 28 trials, healthy adults 18 to 45
Sources: Kodama et al. 2009, JAMA. Mandsager et al. 2018, JAMA Network Open. Han et al. 2022, British Journal of Sports Medicine. Helgerud et al. 2007, Medicine and Science in Sports and Exercise. Milanovic et al. 2015, Sports Medicine.

What VO2 max measures

VO2 max is the most oxygen your body can take in and use during hard exercise. It is usually reported in millilitres of oxygen per kilogram of body weight per minute, written mL/kg/min. Clinics often estimate fitness from a treadmill test instead and report it in METs, or metabolic equivalents, where 1 MET is the energy you use at rest. In the 2009 JAMA meta-analysis led by Satoru Kodama, a 1-MET higher fitness level corresponded to running or jogging about 1 km/h faster.

Fitness and death risk: the Cleveland Clinic data

Kyle Mandsager and colleagues studied 122,007 adults, average age 53, who were referred for a symptom-limited treadmill test at the Cleveland Clinic between 1991 and 2014. Over a median of 8.4 years, 13,637 of them died. The team grouped people by fitness for their age and sex, from low (the bottom quarter) to elite (the top 2.3%).

The results are given as hazard ratios: a ratio of 2 means twice the risk of death over the follow-up, and 1.0 means no difference. After adjustment for other risk factors, the low-fitness group had 5.04 times the death risk of the elite group. That compares the two extreme groups. A narrower contrast, below-average against above-average fitness, gave a ratio of 1.41. The study's adjusted ratios for clinical risk factors were 1.41 for smoking, 1.40 for diabetes and 1.29 for coronary artery disease. The authors concluded that the risk tied to reduced fitness was comparable to or greater than these traditional risk factors.

Adjusted death risk, by factor Hazard ratio for death from any cause. 1.0 means no added risk. 1.0 5.04 1.41 1.40 1.29 Low vs elite fitness Smoking Diabetes Coronary artery disease
Source: Mandsager et al. 2018, JAMA Network Open, 122,007 adults referred for treadmill testing at the Cleveland Clinic. The fitness ratio compares the low and elite groups. The other three are the study's adjusted ratios for each clinical risk factor.

Elite performers also had a lower adjusted death risk than the high-fitness group, and the authors observed no upper limit of benefit.

This was an observational study of people referred for a treadmill test at one US hospital. It shows an association, not proof that fitness alone caused the difference, and fitter people may differ in ways the adjustment did not capture.

What the meta-analyses show

A meta-analysis pools the results of many studies. The Kodama meta-analysis pooled 33 cohort studies, which follow groups of people over time, of healthy men and women, with 102,980 people in the death analysis. Each 1-MET higher fitness level was linked to a 13% lower risk of death from any cause and a 15% lower risk of coronary heart disease or cardiovascular events. People below 7.9 METs had a 70% higher risk of death than those at 10.9 METs or more.

A 2022 dose-response meta-analysis in the British Journal of Sports Medicine, led by Minghui Han, pooled 34 cohort studies in healthy populations. Each 1-MET higher fitness level was linked to a 12% lower risk of death from all causes, 13% lower from cardiovascular disease and 7% lower from cancer. Compared with the lowest fitness level, the highest was linked to a 53% lower risk of death from any cause.

Much of the gap sat at the bottom. In the Han analysis, intermediate fitness was already linked to a 33% lower all-cause death risk than the lowest level. All of these were cohort studies comparing people at different fitness levels. None tested whether raising your own fitness through training lowers your death risk.

Which training raised VO2 max most

A 2015 meta-analysis led by Zoran Milanovic pooled 28 controlled trials with 723 healthy adults aged 18 to 45, average age 25. Compared with no exercise, continuous endurance training raised VO2 max by 4.9 mL/kg/min on average and high-intensity interval training (HIIT) by 5.5 mL/kg/min. Against continuous training, HIIT gave what the authors called a possibly small extra gain of 1.2 mL/kg/min. Longer programmes tended to bring larger gains.

In adults with high blood pressure, a 2020 meta-analysis led by Juliana Leal found larger gaps. HIIT raised VO2 max by 4.9 mL/kg/min against control groups and continuous training by 1.3 mL/kg/min, and HIIT came out ahead by 2.5 mL/kg/min in direct comparisons. VO2 max was a secondary outcome in that analysis, which focused on blood pressure.

VO2 max gain against control groups Average gain in mL/kg/min, by training type Continuous training Interval training (HIIT) 4.9 5.5 1.3 4.9 Healthy adults, 18 to 45 Adults with hypertension
Sources: Milanovic et al. 2015, Sports Medicine, 28 controlled trials, 723 healthy adults. Leal et al. 2020, Current Hypertension Reports, randomised trials in adults with hypertension. The two analyses pooled different trials and populations, so compare within each group, not across. Milanovic compared against no-exercise groups.

The 4x4 protocol comes from a 2007 trial led by Jan Helgerud at the Norwegian University of Science and Technology. It randomised 40 healthy, non-smoking, moderately trained men to four programmes matched for total work, done 3 days a week for 8 weeks. The two interval programmes raised VO2 max more than long slow running or lactate threshold running. In the 4x4 group, each session was 4 rounds of 4 minutes at around 90 to 95% of maximum heart rate, each followed by 3 minutes of active rest at 70%. The authors reported a 7.2% rise in VO2 max for that group. These were moderately trained men, so the size of the gain may differ for you.

In a women-only meta-analysis, led by Robert Lindner at RMIT University in 2023, moderate to vigorous continuous training and HIIT showed no statistical difference. Both raised VO2 max from baseline by similar amounts, and women who did more sessions saw bigger gains in both formats. Those gains were measured from baseline, not against a no-exercise group, so they are not directly comparable with the figures above.

Across these analyses, both continuous and interval training raised VO2 max, with intervals adding a little more in some groups. Most training trials studied younger adults. Our reading: a base of steady work plus one or two interval sessions a week suits most people.

A weekly plan

The plan below is our coaching suggestion, built on the trials above and NHS guidance. The NHS asks adults to do at least 150 minutes of moderate intensity activity or 75 minutes of vigorous intensity activity a week, plus strengthening activities on at least 2 days. It advises speaking to your GP first if you have not exercised for some time, or if you have medical conditions or concerns.

  • Build a base first. Our suggestion is several weeks of regular moderate cardio before you add hard intervals. One NHS check for moderate intensity is that you can still talk, but not sing. Brisk walking, riding a bike and dancing all count.
  • Check with your GP before hard intervals if you have not exercised for some time, or have a medical condition or concerns, as the NHS advises. In our view that includes a heart condition, heart symptoms, high blood pressure, recent illness or injury, pregnancy, and medicines that affect your heart rate.
  • Then add one or two interval sessions a week. Our scaled 4x4 for most people: warm up, then 4 rounds of 4 minutes hard, at a pace where you can say only a few words without pausing for breath, each followed by 3 minutes of steady, lighter jogging or walking. Cool down afterwards. If you train with a heart rate monitor, the trial used around 90 to 95% of maximum heart rate for the hard rounds and 70% for recovery, three times a week in moderately trained men, so build up from one session.
  • A sample week, as our suggestion: three moderate cardio sessions, one interval session and two strength sessions, with at least one rest day.
  • Keep strengthening activities on at least 2 days a week, in line with the NHS guideline.
  • Treat 8 weeks as one training block and judge it at the end. The Helgerud trial measured its gains at 8 weeks, and longer programmes tended to bring larger gains in the Milanovic analysis.
  • Log one repeatable test every 4 weeks, such as your time for a fixed route at the same effort, and compare at the end of the block. This is our suggestion for tracking progress, not a lab measure of VO2 max.
  • Our advice: stop a session if you feel dizzy, unwell, unusually breathless for the effort, or get palpitations or chest discomfort. The NHS says to call 999 if you get sudden chest pain or discomfort that does not go away, pain that spreads to your arm, neck, jaw, stomach or back, or chest pain with sweating, sickness, light-headedness or shortness of breath. It advises seeing a GP if chest pain comes and goes.

Common mistakes

  • Making every session hard. Continuous training raised VO2 max in all three training meta-analyses above (Milanovic, Leal and Lindner), and in our experience steady work is easier to repeat week after week.
  • Skipping intervals altogether once you have built a base and any GP check you need is done. In healthy adults, HIIT added a small extra gain over continuous training in the Milanovic analysis.

Frequently asked questions

What fitness level was linked to lower risk?
Fitness norms depend on age and sex, so the Cleveland Clinic study compared people within their own age and sex group. In the Kodama meta-analysis, people at 7.9 METs or more had lower rates of death and cardiovascular events than those below it. Your own trend over time is a useful guide.
Is HIIT better than steady cardio for VO2 max?
In healthy adults aged 18 to 45, HIIT gave a small extra gain over continuous training in the Milanovic analysis. In women, the Lindner analysis found no statistical difference between the two. Both raised VO2 max.
Do older adults still benefit?
In the Cleveland Clinic data, the authors reported a survival edge for elite over high fitness in people aged 70 or older. Most of the training trials in this article studied younger adults, so they say less about how much older adults gain. The NHS asks adults aged 65 and over to stay active every day and to add strength, balance and flexibility work.
Is fitness linked to cancer death risk?
In the 2022 Han meta-analysis, each 1-MET higher fitness level was linked to a 7% lower risk of cancer death. These were observational cohort studies, so they show an association.

The bottom line

In large cohort studies, higher fitness was linked to lower risk of death from all causes, cardiovascular disease and cancer. In trials, both continuous and interval training raised VO2 max within weeks. Build a base, add one or two interval sessions a week, keep strength work on 2 days, and check with your GP first if you have a medical condition or have not exercised for some time.

Build your fitness with a coach
DT Fitness London coaches one-to-one conditioning and strength training, with interval work set to your current fitness.
Book a consultation at dtfitnesslondon.com

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