VO2 Max and Aging: Why Cardiorespiratory Fitness Is a Key Longevity Marker

What VO2 max actually is

VO2 max, sometimes called maximal oxygen uptake, is the highest rate at which your body can consume oxygen during intense exercise. It is usually expressed in milliliters of oxygen per kilogram of body weight per minute (mL/kg/min). Think of it as the ceiling on your aerobic engine: the more oxygen you can pull in through your lungs, pump through your circulation, and burn inside your working muscles, the more sustained power you can produce before you hit a wall.

What makes VO2 max such a useful marker is that it is not one system, it is the whole chain working together. Your lungs have to move air. Your heart has to pump oxygen-rich blood. Your blood vessels have to deliver it. And, critically, your muscle cells and their mitochondria have to extract that oxygen and turn it into usable energy. A weak link anywhere in that chain lowers the number. That is exactly why it captures overall cardiorespiratory fitness so well, and why it tends to move with how capable and energetic you feel day to day.

You do not need a lab to care about it. The same qualities that produce a high VO2 max, an efficient heart and dense, healthy mitochondria, are the qualities that let you climb stairs without thinking about it, keep up on a hike, or carry groceries up from the car at 60 the way you did at 40.

Why VO2 max matters for longevity and healthy aging

Among fitness markers, cardiorespiratory fitness stands out in the exercise-science literature for how strongly it associates with healthy, functional aging. Large observational studies of cardiorespiratory fitness have repeatedly found that people with higher measured fitness tend to enjoy better long-term health outcomes and greater physical capability into older age. The relationship is graded, meaning that moving from low fitness toward even moderate fitness is associated with meaningful benefit, and there is no sharp point where more fitness stops mattering.

It helps to reframe VO2 max as a functional reserve rather than an athletic vanity stat. Daily life for a healthy 45-year-old rarely demands anything close to maximal effort. But as VO2 max declines with age, ordinary activities start to take up a larger share of your available capacity. When your ceiling is high, walking, gardening, playing with grandkids, and travel all sit comfortably below it. When your ceiling drops, those same activities feel harder, and that is often what people describe as simply "getting old."

This is why fitness professionals increasingly treat cardiorespiratory fitness as a longevity marker worth tracking alongside things like grip strength. Both are windows into how well your body is holding up, and both respond to the choices you make now. Protecting your aerobic capacity is one of the most direct ways to protect your independence in the decades ahead.

How VO2 max declines with age, and why

Starting in the early thirties, the average sedentary adult loses somewhere in the neighborhood of 10% of their VO2 max per decade, and that rate of loss tends to accelerate later in life. But the phrase "average sedentary adult" is doing a lot of work in that sentence. A large portion of what looks like inevitable age-related decline is actually the compounding effect of reduced activity year after year.

Two things drive the drop. The first is central: maximum heart rate and the volume of blood the heart pumps per beat both tend to decrease with age, which limits oxygen delivery. The second is peripheral, and this is where it gets interesting for anyone thinking about longevity. Inside your muscles, both the number and the quality of mitochondria, the tiny structures that actually consume oxygen to make energy, tend to decline with age and inactivity. Fewer, less efficient mitochondria mean less oxygen extraction, which pulls VO2 max down.

Mitochondrial function is a recurring theme in aging biology precisely because it sits at this crossroads. When mitochondrial density and efficiency fade, your cells' ability to produce energy on demand fades with them, and aerobic capacity is one of the first places you feel it. The encouraging flip side is that mitochondria are remarkably responsive. Endurance training is one of the most powerful known stimuli for building new mitochondria and improving the ones you have, which is a big part of why consistent aerobic exercise can dramatically slow, and partly reverse, the expected decline.

How to support and improve your VO2 max

The good news is that VO2 max is trainable at 45, 55, and 65, not just at 25. The evidence-based approach blends a few complementary types of training. None of it requires being an athlete, and consistency matters far more than intensity or novelty. Always talk with your healthcare provider before beginning a new exercise program, especially if you have been inactive or have any existing health considerations.

Training type	What it does	Practical starting point
Zone 2 aerobic base	Builds mitochondrial density and aerobic efficiency; the foundation of VO2 max	Conversational-pace effort (you can talk but not sing), 30 to 60 minutes, 2 to 4 times per week
Higher-intensity intervals	Directly stresses the oxygen-delivery system and pushes the ceiling upward	Short, hard efforts such as 4 rounds of 3 to 4 minutes near your limit, once or twice weekly
Strength training	Preserves muscle mass and mitochondria-rich tissue that support oxygen use and function	2 sessions per week covering major movement patterns
Daily movement	Reduces the inactivity that drives much age-related decline	Regular walking, taking stairs, standing breaks throughout the day

If you take one idea from this section, make it this: build a large aerobic base first. Zone 2 work is the unglamorous foundation that makes everything else productive, and it is where much of the mitochondrial adaptation happens. Layer in one or two interval sessions per week to raise the ceiling, keep strength training in the rotation to protect muscle, and stay generally active the rest of the time. That combination, repeated month after month, is what moves the number.

Recovery, sleep, and nutrition all feed into the same engine, because a body that cannot recover cannot adapt. Weaving these habits into a sustainable weekly rhythm tends to work far better than heroic bursts followed by burnout. If you want a framework for that, our guide to a healthy aging daily routine walks through how to structure movement, recovery, and consistency over time.

Where mitochondrial-support ingredients like Urolithin A fit

Because VO2 max ultimately depends on how efficiently your muscle mitochondria use oxygen, mitochondrial health is a natural place for curiosity about nutrition and supplementation. Urolithin A is one of the more genuinely studied compounds in this space, and it is worth being precise about what the research has and has not shown, rather than overstating it.

Urolithin A is a metabolite your gut bacteria can produce from certain ellagitannins found in foods like pomegranates and walnuts, though many people produce little of it on their own. In a randomized, placebo-controlled trial published in Nature Metabolism (2019), Urolithin A supplementation was shown to influence markers of mitochondrial gene expression in older adults, supporting the biological rationale for interest in it. A later trial in Cell Reports Medicine (2022) found that in middle-aged adults, several months of Urolithin A supplementation was associated with improvements in measures of muscle endurance and strength compared with placebo.

Here is the honest framing that compliance and good science both demand: those human trials looked primarily at muscle endurance, strength, and mitochondrial markers. They did not establish Urolithin A as something that raises VO2 max on its own, and no supplement should be thought of as a shortcut around training. VO2 max is built by what you do, not by what you take. What Urolithin A represents is a studied way to support the mitochondrial and muscular systems that your training depends on, as a complement to consistent exercise rather than a replacement for it.

That is the role a product like SOMA Urolithin A gummies is designed to play: a simple way to support mitochondrial and muscle health alongside a smart training routine. For a deeper look at the endurance and muscle research specifically, see our breakdowns of Urolithin A and endurance and Urolithin A and muscle strength. As always, talk with your healthcare provider before starting any new supplement, particularly if you take medications or have existing health conditions.

Frequently asked questions

What is a good VO2 max for my age?

Reference ranges vary by age and sex, and they generally step down each decade, so a "good" number for a 55-year-old looks different from a "good" number for a 35-year-old. Rather than fixating on hitting an elite value, the more useful goal for most people is to be in a higher fitness category for your age group and, more importantly, to keep your own number stable or trending up over time. Progress relative to yourself is what matters most.

Can I improve my VO2 max after 50?

Yes. Aerobic capacity remains trainable well into later life. Older adults who begin structured aerobic and interval training routinely improve their measured fitness, and much of the decline once assumed to be purely age-related turns out to reflect years of reduced activity. It is rarely too late to build meaningful improvement, though you should start gradually and with guidance from your provider.

How do I measure my VO2 max without a lab?

A true VO2 max test uses a mask and treadmill or bike in a lab, but you do not need one to track progress. Many fitness watches now estimate VO2 max from heart-rate and pace data, and while those estimates are approximate, they are useful for spotting trends over months. Simple field tests, like a timed brisk walk or run, can also give you a repeatable benchmark to measure yourself against.

Is zone 2 or high-intensity training better for VO2 max?

They do different jobs, and the best results come from using both. Zone 2 training builds the aerobic base and mitochondrial density that underpin your capacity, while higher-intensity intervals directly stress the oxygen-delivery system and push the ceiling higher. For most people in midlife, a large base of easy aerobic work plus one or two weekly interval sessions is a well-balanced, sustainable approach.

Does Urolithin A improve VO2 max?

The published human trials on Urolithin A focused on muscle endurance, strength, and mitochondrial markers rather than establishing an increase in VO2 max itself. It is best understood as a studied way to support the mitochondrial and muscle health that your training relies on, not as something that raises aerobic capacity on its own. Training remains the driver of VO2 max; supplements can only play a supporting role. Check with your healthcare provider before starting any supplement.