The Fitness Markers That May Matter Most for a Longer Life

A 2026 study published in JAMA Network Open followed 13,423 adults aged 65 and older.

Rather than relying only on questionnaires about how active people believed they were, the researchers used objective assessments of physical fitness.

Participants completed measured tests of cardiovascular fitness, muscular strength, flexibility, balance, and agility.

Those results were then compared with how participants fared over roughly seven years of follow-up.

Higher overall physical fitness was associated with lower all-cause mortality during the follow-up period.

Several components stood out as having particularly strong associations:

• balance and agility
• lower-body strength
• cardiovascular fitness

One important caveat matters here. This was an observational study.

It shows an association between fitness and longevity. It does not prove that improving a test score directly causes a longer life.

People who score well on these assessments may also differ in health status, medical history, and daily habits.

Even so, the pattern is consistent with a large body of earlier research and is worth paying attention to.

Balance, agility, and lower-body strength are not just gym qualities. They are the abilities that carry us through ordinary days.

They determine whether you can rise from a low chair, climb a flight of stairs, step off a curb, carry groceries, catch yourself when you stumble, or get down on the floor with a grandchild and get back up again.

As those abilities decline, the risk of falls and injury rises, and activity often decreases along with them. Less activity then tends to accelerate further loss of strength and confidence.

Cardiovascular fitness plays a related role. It reflects how well the heart, lungs, and circulation support sustained effort, and it influences how much of life you can comfortably take part in.

Viewed this way, fitness is a reasonable stand-in for functional capacity, independence, and resilience.

Fitness is often framed as appearance or athletic performance. This research points somewhere different.

The qualities most closely linked with longevity here were practical ones, not aesthetic ones.

That is encouraging news, because these abilities respond to training at nearly any age and starting point.

You do not have to be an athlete. You do not have to train hard every day.

You simply need to keep asking your body to do the things you want it to keep being able to do.

Start where you are today, not where you wish you were. Consider:

• regular walking, building gradually in time or pace
• appropriate resistance training two or three days per week
• chair stands, sitting and standing without using your hands when it is safe to do so
• step-ups onto a low, stable step, with support nearby
• balance practice, such as standing near a counter on one foot or narrowing your stance
• heel raises and gentle single-leg work for lower-leg strength
• carrying something moderately heavy for short distances
• mobility and gentle stretching to maintain range of motion

Every one of these can be adapted to your present ability.

Hold a counter for balance work. Use a higher chair for chair stands. Shorten the walk. Lighten the load.

Consistency over months matters far more than intensity in any single session.

In this study, older adults with higher measured fitness, especially balance and agility, lower-body strength, and cardiovascular fitness, were less likely to die during the follow-up period.

It is an association, not proof of cause.

But it reinforces a practical idea worth acting on: fitness is about function, and function can be built.

If you have a medical condition, balance problems, pain, or a history of falls, speak with your physician or an appropriate healthcare professional before beginning a new exercise program.