Most people have a rough sense of what shortens a life.
Smoking. Diabetes. Heart disease. High blood pressure. Those are the risk factors everyone knows, and they are the ones doctors screen for.
Here is one that rarely gets mentioned, and that turns out to sit right alongside them.
How fit you are.
Not how much you weigh. Not how much you exercise according to your own estimate. Your actual, measured cardiorespiratory fitness.
And the data behind this is considerably stronger than most people realize.
The Study Worth Knowing About
In 2018, researchers at the Cleveland Clinic published an analysis in JAMA Network Open covering 122,007 consecutive patients who had undergone exercise treadmill testing between 1991 and 2014.
This was not a survey asking people how active they felt. It was an objective measurement of fitness, taken on a treadmill, followed by long term mortality tracking.
The findings were striking.
Cardiorespiratory fitness was inversely associated with all cause mortality, and the relationship held across the entire range. The fitter you were, the lower your risk.
People with elite level fitness had roughly an 80 percent lower risk of dying over the follow up period compared with people in the lowest fitness group.
And there was no observed upper limit of benefit. This is the part that surprised people. There has been a long running debate about whether extreme amounts of exercise might eventually become harmful. In this analysis, every incremental increase in fitness was associated with further improvement. Even the people classed as “high” fitness did measurably worse than the people classed as “elite.”
The Comparison That Should Get More Attention
Here is the finding that reframes how seriously to take this.
The authors found that participants with below average fitness, compared with above average fitness, had around 41 percent decreased odds of survival.
They noted that the increase in all cause mortality associated with reduced cardiorespiratory fitness was comparable to or greater than traditional clinical risk factors, including coronary artery disease, smoking and diabetes.
For context, coronary artery disease in the same analysis was associated with a 29 percent increased risk of all cause mortality.
So being unfit carried a risk on par with smoking. That is not a sentence most people have ever had said to them, and it deserves more weight than it gets.
Why This Matters More, Not Less, With Age
A lot of people assume this kind of finding applies mainly to younger people, and that by 70 the ship has largely sailed.
The subgroup analysis says otherwise.
The survival benefit of elite fitness over merely high fitness was most notable in patients older than 70. In that age group, elite performers had close to a 30 percent reduced mortality risk compared with high performers.
In other words, the advantage of being fitter rather than just adequately fit was larger in the over 70s, not smaller.
Which turns the usual assumption on its head. Fitness does not stop mattering as you get older. By several measures it starts mattering more.
What Fitness Actually Means Here
Cardiorespiratory fitness is your body’s ability to take in oxygen, deliver it to working muscle, and use it. In the study it was measured by how hard and how long people could work on a treadmill.
It is not the same as being thin. Plenty of lean people have poor fitness and plenty of larger people have good fitness.
It is not the same as being young.
And it is not the same as thinking of yourself as active. The researchers specifically noted that their study differed from many earlier ones because it used an objective measure rather than self reported activity, and self reports in this area are notoriously generous.
It is, however, modifiable. The authors describe it as a modifiable indicator of long term mortality and conclude that healthcare professionals should encourage people to achieve and maintain high levels of fitness.
One honest caveat: some of your fitness is inherited. Estimates suggest somewhere in the region of 15 to 30 percent of cardiorespiratory fitness may be genetic. So people start from different places. The remaining majority is yours to work with.
How You Actually Build It
The good news is that this responds to ordinary, unglamorous work.
Aerobic activity, done regularly. Walking, cycling, swimming, rowing, anything that raises your breathing and heart rate and that you will keep doing.
Start where you are. If you are currently doing very little, the biggest proportional gains in this whole picture come from moving out of the lowest fitness category. You do not need to chase elite. Going from low to moderate is the single largest step available to most people.
Build duration before intensity. Twenty minutes becoming thirty becoming forty, at a comfortable effort, before worrying about going harder.
Then add some harder work. Once you have a base, intervals of slightly harder effort, with recovery between, are an efficient way to push fitness higher.
Three to five days a week is a reasonable target for most people.
And accept that it takes months. Cardiorespiratory fitness improves over weeks to months, and the gains are real but gradual.
The Practical Problem Nobody Addresses
Here is where a lot of this advice falls down for the people who most need it.
If walking hurts, you will not walk.
If your knee complains after ten minutes, if your back tightens up, if your hip aches on hills, if your feet burn, or if you are worried about falling on uneven ground, then “do more aerobic exercise” is not actionable advice. It is a wish.
This is the gap we spend most of our time closing.
The musculoskeletal problems that limit activity are, for a large number of people, the reason their fitness has declined in the first place. They did not decide to become less fit. They became less able to do the things that kept them fit, and the fitness followed.
Which means the useful sequence is frequently:
Address what hurts. Then restore the capacity to move comfortably. Then build the aerobic fitness that the evidence above says matters so much.
Skipping to step three rarely works when step one has not been dealt with.
Before You Start
Speak with your physician before beginning a new exercise program, particularly if you have cardiovascular risk factors, existing heart or lung conditions, diabetes, or you have been largely inactive for a long period.
Stop and seek urgent medical care for chest pain or pressure, unusual breathlessness, dizziness, fainting, or pain spreading into the jaw, neck or arm during exertion.
And if you have been avoiding activity because of pain, that is worth getting assessed rather than working around.
The Honest Summary
Cardiorespiratory fitness is one of the strongest modifiable predictors of how long you live that anybody has measured, the benefit appears to have no ceiling, and the advantage of being fitter is if anything larger after 70 than before it.
It is also one of the few health markers that responds directly and reliably to something entirely within your control.
The barrier, for most people, is not motivation. It is that moving comfortably has become difficult. That part is addressable.
Let Us Remove What Is Stopping You
If pain, stiffness or unsteadiness is the reason your activity has dropped off, the fitness conversation starts there.
Morgain Physical Therapy offers a Free Discovery Visit at no cost and no obligation. You will get an assessment of your strength, movement and current capacity here in Grand Forks, an honest explanation of what is limiting you, and a plan to get you moving comfortably enough that building fitness becomes realistic.
Book your Free Discovery Visit today. Or call us on (701) 599-3848.