Do Fitter People Live Longer? Why VO2 Max is Important for Longevity.
Many people look for strategies to age better, but your aerobic fitness may be one of the best predictors of how well and how long you might live.
Our fear of aging inevitably stems from what aging brings — disease, wrinkles, and physical and mental decline are among the maladies we experience as we get older. Nobody wants to age because nobody wants to act or feel old. It’s not the number that’s scary, but the acceptance that we may become inferior to our younger selves in brain and brawn.
Aging (or technically, anti-aging) is a hot topic. Researchers are currently looking for ways to “cure aging” or to reverse it completely.
Presumably, finding the “fountain of youth” in the lab would allow humans to live longer in the real world. Many aging scientists seek — if not immortality itself — to extend maximal human lifespan a decade or two. Getting humans to live to 130 or 140 would be quite the achievement.
The promises of a longer life currently reside in interventions like calorie restriction (CR) — which has been shown to extend average and maximum lifespan in organisms like flies, worms, and even primates. In addition — molecular compounds like metformin, resveratrol, and rapamycin are showing promise in the lab (in mice) for lifespan and healthspan enhancement, though some of this research is receiving a bit of scrutiny as of late.
There is a wealth of new-age science to explore on the frontiers of aging research. But sometimes it’s valuable to consider that simple interventions can produce potent outcomes. That brings us to exercise, and its (potential) impact on lifespan.
Get active to live longer
I won’t belabor the point that exercise is a necessity for (super)successful aging. We know that exercise is efficacious for treating or preventing diseases — including the disease of “getting old.” Given that physical function declines with age (we lose about 5–10% of our aerobic capacity per decade after about age 30), exercise is a counterattack against the time-driven process of muscular, cardiovascular, and cognitive decline.
The robust effects of exercise on physical function throughout life and during old age could perhaps translate to a longer life by reducing the rate of aging or increasing our capacity for “stress resistance” in old age.
For instance, a meta-analysis (a “study of studies”) indicated that getting adequate exercise could be associated with an additional 1–2 years of extra life, and that regular physical activity reduces the risk for all-cause mortality (death from any cause) and death from cardiovascular disease (CVD). Even more, this is a dose-response relationship — more exercise corresponds to a longer life, though there may be a point of diminishing returns.
Other studies have estimated that the risk of death is about 25–30% lower in physically active vs. inactive individuals — which might translate into an extra 3.5–4 years of life gained, on average.
In fact, nearly every single study that compares active to inactive people reports that the exercisers live longer! On top of this, people in those studies who are current and former athletes also live longer, suggesting that chronic regular exercise gives you an extra leg up.
Does how much you exercise matter? Yep — and so does how hard.
HIIT for successful aging?
In a follow-up study of Harvard alumni (men) from 1966 to 1988, there was an inverse relationship between vigorous intensity physical activity and mortality — meaning that more energy expended during the week through physical activity yielded greater benefits for longevity. Another analysis of the same study found that low- and moderate-intensity exercise had little relation to mortality, but vigorous-intensity exercise noted a clear benefit. High-intensity interval training might just be the new longevity drug.
The above studies provide some compelling examples that exercise is a lifespan enhancer. But these types of associations come with their limitations. Association studies of physical activity commonly use self-report measures and are prospective — meaning that the participants fill out an activity questionnaire at one time point (to estimate how much they exercise) and are then followed up for a certain amount of years with the outcome (dying, for example) tracked and reported.
While we can observe a positive correlation of physical activity and lifespan, we can’t claim that exercise causes the increased lifespan. Indeed — people who exercise are more likely to engage in other positive lifestyle habits like eating a healthy diet, not smoking, using less alcohol, and (maybe) having a higher socioeconomic status.
In research, this is known as the “healthy user bias.” Positive lifestyle behaviors tend to cluster in individuals. Since all of these factors also influence longevity, they make it impossible to isolate the influence of exercise on lifespan.
Fortunately, we can look for an association of longevity with a physiological outcome that is tightly related to physical activity — aerobic fitness. Direct measures of fitness could provide even more robust data for the association of exercise and longevity, since it tells us more about the “status” of the body than a physical activity questionnaire does.
Fitter people live longer
A recent study in the Journal of the American Medical Association (JAMA) found evidence that a greater cardiorespiratory fitness predicted a lower risk of death.
With access to exercise treadmill tests — or VO2 max tests — they were able to gather data on over 120,000 individuals on whom they also had access to death records (all-cause mortality was the primary outcome).
Not only did higher aerobic fitness predict a reduced death risk, but those who were categorized as “elite performers” (who had VO2 max levels >2 standard deviations above the average for their age) had the lowest risk of death in the entire study.
In fact, there appeared to be no “upper limit” for the mortality benefit gained from increasing aerobic fitness levels. The fitter the participants were, the greater benefit to longevity they received.
This finding was “surprising” amid some newer published data that indicates “extreme” endurance exercise may have cardiovascular consequences. That’s not exactly what this particular study says, though it’s hard to determine if any participants in this study meet the definition of “extreme exercisers.” All we know is that they had a higher aerobic capacity — whether they exercised more or not is unknown. This is important to point out since a good portion of VO2 max is genetic — i.e. influenced by genes more so than lifestyle. This is why if you want to be an elite endurance athlete, you should choose your parents wisely.
As for why exercise might increase lifespan, we have plenty of studies in humans that tell us exercise improves cardiovascular health and function, increases skeletal muscle mass and performance, reduces risk factors for disease, and improves cognitive function.
It is likely that synergistic effects of exercise at a whole-system level combine to reduce disease risk, maintain physiological function, and increase lifespan as a result.
I don’t think exercise gets enough of the spotlight when it comes to healthspan and lifespan extension. Much of the focus (especially recently) has been on diet and, to a lesser extent, potential lifespan-enhancing pharmacological agents and nutraceuticals.
This is not to downplay diet, as what we eat has an enormous role to play in living a healthy and long life.
As far as pharmacological agents go — these too may have their place in a future where lifespan enhancement is a strategy available to all. Lots of studies in animal models show promise. Perhaps one day we will pop a lifespan pill to boost our chances of being a centenarian.
But exercise is a time-honored strategy to not only reduce disease, but enhance health above and beyond wherever you’re currently at. The best part is, it’s completely free (well, not a Peloton membership).
Exercise is the ultimate biohack, and it doesn’t get enough credit.
As we search for the evasive fountain of youth or to create the ultimate cocktail of longevity drugs, let’s not forget that if we feed our evolutionary roots by moving like we were meant to, we can maintain our health—perhaps for a long, long time.
Do you know your VO2 max? Many wearable fitness trackers can provide this data through estimation equations. If you find yours, I’d love to see you post it below along with you age, and what you’re doing to maintain (or improve!) your VO2 max!
Studies cited
Reimers CD, Knapp G, Reimers AK. Does physical activity increase life expectancy? A review of the literature. J Aging Res. 2012;2012:243958.
Gremeaux V, Gayda M, Lepers R, Sosner P, Juneau M, Nigam A. Exercise and longevity. Maturitas. 2012;73(4):312–7.
Lee IM, Paffenbarger RS. Associations of light, moderate, and vigorous intensity physical activity with longevity. The Harvard Alumni Health Study. Am J Epidemiol. 2000;151(3):293–9.
Mandsager K, Harb S, Cremer P, Phelan D, Nissen SE, Jaber W. Association of Cardiorespiratory Fitness With Long-term Mortality Among Adults Undergoing Exercise Treadmill Testing. JAMA Netw Open. 2018;1(6):e183605.
Lee I, Hsieh C, Paffenbarger RS. Exercise Intensity and Longevity in Men: The Harvard Alumni Health Study. JAMA. 1995;273(15):1179–1184. doi:10.1001/jama.1995.03520390039030
According to Garmin, my VO2Max is 45, putting me in the top 5% of my age group. I am 50. I try to run 4x each week, 2 longer, steady state runs and 2 shorter, more intense Interval runs. I also play tennis 4x each week.