Exercise Capacity, the Most Important Health Risk Factor

Exercise capacity is closely related to both aging and to health. Exercise capacity declines with age, and people with low exercise capacity have higher health risks. In fact, exercise capacity is the most important health risk factor. Fortunately there’s some good news that means that older people can robustly increase their exercise capacity.

Exercise capacity and health

Exercise capacity is exactly what it sounds like, the amount of exercise someone is capable of doing. It’s closely related to VO2max, the maximum oxygen uptake while doing exercise.

A study published in the New England Journal of Medicine of men who were referred for exercise testing divided the men according to quintiles (fifths) of exercise capacity, and then followed them over time.

“Exercise capacity is a more powerful predictor of mortality among men than other established risk factors for cardiovascular disease.” See chart below.


In normal men without cardiovascular disease, those with the lowest exercise capacity were 4.5 times as likely to die within the follow-up time than those with the highest exercise capacity.

If exercise were a pill, doctors would prescribe it to everyone. There’s no drug or supplement as powerful as exercise in promoting health.

Exercise capacity declines with age

If aging is an increasing tendency toward breakdown of biological systems and increasing tendency to ill health – which it is – then it stands to reason that exercise capacity declines with age – which it does. We could expect that declining exercise capacity and the tendency to ill health would be closely related, and they are.

A study of several hundred people in the Baltimore Longitudinal Study of Aging found not only a strong decline in exercise capacity with age, but that decline also accelerates with age. This held true even when adjusted for lean body mass, which also declines with age. See chart below.

This decline in exercise capacity is a disaster for health. I know a man in his late seventies who gets winded from walking, and that may be typical for the average man that age who doesn’t exercise and is overweight.

But is it inevitable?

Older people robustly respond to exercise

It’s been thought that older people would not be able to respond to exercise training with as great an increase in exercise capacity as younger people. Turns out, that’s not true, at least in the case of high-intensity interval training (HIIT).

A study done in Norway took 94 people, aged 20 to 83, and put them through a high-intensity interval training program. Against their hypothesis, age was not related to the amount of improvement in fitness.

Initial training status, which would be better formulated as initial fitness level, or initial exercise capacity, was related to improvement. In other words, those with the lowest level of fitness improved the most. Not surprising – newbie gains.

In this study, the older groups even showed a tendency towards higher maximum heart rates, which decline with age.

Therefore, the declining level of fitness seen in aging may be at least partly due to decreased physical activity, not an inevitable consequence of aging. To be sure, an older athlete can never compete at the highest levels with a younger one, so aging does intrinsically affect our biology in a way that makes for lower maximum exercise capacity.

Exercise capacity, the most powerful determinant of health and longevity?

Men who have low exercise capacity have nearly a five-fold higher risk of death per period of time than men with a high exercise capacity. (See first chart above.)

I can’t think of any other factor among nominally healthy people that shows such a large difference between low and high levels. Not cholesterol, LDL, or HDL. Not blood pressure. To be sure, these are related to exercise.

In fact, in men aged 75, exercise capacity was the most powerful predictor of survival until age 90. (Source. For women, it was low white blood cell count.) See chart below.

The most interesting finding, especially among men, was the strong association between survival and results from the exercise test, including high exercise capacity as measured by MET, high HRR after 4 minutes recovery, and high systolic BP rise during exercise. The prognostic importance of these factors greatly exceeded that of common prevalent diseases such as diabetes, hypertension, asthma, and angina pectoris/previous MI as well as that of conventional risk factors such as smoking, high BP, high level of TC, low level of HDL-c and obesity. [Emphasis added]


Exercise capacity is the most powerful health risk marker for men.

To get and remain healthy and to live a long life, exercise is a must. The higher your exercise capacity, the greater the odds of long life.

Exercise also gives you the best odds of feeling well, both mentally and physically.

Exercise should be a lifelong pursuit.

PS: For a great exercise program, including strength training and HIIT, see my book, Muscle Up.

PPS: Check out my Supplements Buying Guide for Men.


Leave a Comment:

Stephen Moreton says November 13, 2017

Excellent article. I really agree that exercise capacity is hugely important when it comes to maintaining and improving health and performance. It is definitely something that many coaches should look further into when programming training for their clients.

    P. D. Mangan says November 13, 2017

    Thanks, Stephen.

paul rivas md says November 13, 2017

Great article
Th exercise stress test is a total of 4 stages of increasing intensity while hooked up to an EKG machine . We monitor the patient for symptoms and for any evidence of cardiac ischemia ( on the EKG) while exercising. There was an interesting study done in the 80’s that remarkably showed that if you ignore all findings of the test and just evaluate how long the patient was able to continue the test, we found that the prognosis was good with completing stage 3, but it was excellent if you made it through all 4 stages, regardless of the EKG results. Exercise capacity trumped all of the other findings.

    P. D. Mangan says November 13, 2017

    Thanks, Paul, means a lot coming from you.

JP says November 13, 2017

“For women, it was low white blood cell count.”

So what does that mean? Should women strive to lower WBC, or is that just a byproduct of an otherwise healthy lifestyle? Is it also good for men to have a low WBC?

    Paul Rivas says November 13, 2017

    Was wondering that myself. A low WBC can be reflective of a lower mTOR. In my case my WBC dropped 10% on rapamycin due to a hematologic stem cell effect. Maybe this is representative of a group of women with a naturally lower TOR content , whereas a male’s could never get low enough on its own to lower the white count. Just a guess.

Ole says November 13, 2017

It was quite surprising to me, what a dramatic impact menopause has on lung capacity in women.
In fact it is the equivalent of having smoked 20 cigarettes a day for 10 years! Aging sucks, but for women, this is especially true.


bigmyc says November 13, 2017

Not boasting, because I’m sure that this site alone is brimming with people like me, but I feel that my capacity to exercise is actually a slight detriment, at least in the short run. Don’t get me wrong, I’m very fortunate to have a seemingly unlimited energy on most workout days, but I pay the price dearly after many of them. I will feel great all day, through any number of activities and later that evening while at rest but if I overdo it, that next day might just bring hell. I don’t mean the basic delayed onset muscle soreness. I’m talking about hard to shake fogginess and a dearth of energy that matches my drive to do anything. It can get so pronounced that it affects my outlook. A large problem is that I have a couple of days in a week to get out doors and exercise at the gym so I blow it all out in that smallish window.

    P. D. Mangan says November 13, 2017

    I hear you. Same here. I’ve had to learn the hard way so many times that I need to limit my workout sessions, otherwise I’m barely functional the next day. By trial and error I’ve largely figured it out, and spend no more than 40 minutes in the gym, twice a week. More than that and I’m half dead.

      Nick says November 15, 2017

      I’ve not had a miserable recovery day since going to a Naimanese style approach in October. 10 minutes or so every day of pullups, chinups, pushups, squats, overhead presses, front shoulder lifts, and forearm work. Also whatever we call rowing when you do it from rings lying on the ground.

      https://sendvid.com/v8fz4kxn .

Shaq says November 14, 2017

As someone a bit under age 75, I chuckled a bit about the two stage process (if you get to 75, then here’s how you get to 90). It reminded me of the Steve Martin routine of how to be a millionaire and not pay taxes: first, get a million bucks….

Is the exercise stress test common across all studies? If I ask my doc will he plug me into the “best practices” stress test?

Good stuff, as always. Thanks for sharing.

    P. D. Mangan says November 15, 2017

    Hi Shaq – an exercise stress test is one in which you’re hooked up to an EKG so they can monitor your heart, and unless you’re being referred specifically for that, may not be necessary. You can get your VO2max tested at various locations, or you may be able to get one from a local cardiac center. Another way is to find out how many METs of exercise you can do via self-testing, thenm compare it to the chart above of mortality vs quintiles of METs. That should give you a rough and ready idea of where you stand.

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