An 80-year-old woman has an elite VO2 max. She's as healthy as a 60-year-old thanks to a simple routine.

"I have always seen myself as a very ordinary person with no real athletic ability," said Linda Kelly.

Still, at 80, she has completed multiple half-marathons and routinely hikes, bikes, and runs around her part-time home in Anchorage, Alaska.

Kelly is as fit as someone decades earlier, with the lab results to prove it. Her son, cardiologist Dr. Jake Kelly, put Kelly to the test on a treadmill and found she had an exceptionally high VO₂ max, the gold standard of cardio fitness.

The metric measures your body's ability to use oxygen during exercise, and research links higher levels to a longer life.

Kelly told Business Insider she's never followed any extreme exercise plan or strict longevity routine. Instead, it's the result of tiny yet consistent movements that accumulated over her lifetime.

Some people think staying fit into old age requires intense training, but research suggests consistency matters more. And Kelly is living proof of how powerful it can be to invest in simple, sustainable habits: walking every day, running when you can, and making time for yourself.

"It's what every ordinary person can do, and who knew it would turn out to have such great benefits," Kelly said.

Exercise over the years

From a young age, Kelly said she loved every opportunity to exercise, from high school gym class and volleyball practice to long runs or bike rides.

As she got older, life got busy as she started a career and a family. Still, Kelly found ways to move every day, logging "probably a million miles" by just walking with her twin baby boys in a stroller, or pedaling on a DIY stationary bike. Her husband helped her build it by mounting a bike frame and some cinder blocks.

She also got plenty of steps in at work as a teacher, preferring to interact with students rather than stay behind a desk.

"I never liked sitting still," she said. "My goal was [to] achieve one interaction of eyeball-to-eyeball with every kid … every day."

Kelly retired in 2013. She had lived in several states — Texas, Colorado, and Louisiana — before moving to Anchorage, where her son, Jake, lives.

Throughout her life, her philosophy has been to embrace the joy of movement for its own sake.

"You don't have to be talented to move. That's the beauty of it. You don't have to have the grace of a ballerina to feel the joy of moving," Kelly said. "That's sustained me all my life."

Why VO₂ max matters

VO₂ max has become an incredibly hot topic (and a point of pride) as growing research suggests it's a key predictor of a longer, healthier life.

While Kelly may not have set out to be a star athlete, her stats would be the envy of gym bros and longevity nerds alike. Her son Jake measured Kelly's health data with a Garmin fitness watch, a portable VO₂ max analyzer, and a treadmill test.

She scored 30.7 ml/kg/min, a strong result for someone in their 50s. For her age group, it's elite.

A higher VO₂ max number indicates better fitness, trainers previously told Business Insider. And a good VO₂ max for a woman in her 50s is 24.6 ml/kg/min, according to the Cleveland Clinic. For a woman in her 40s, around 27.7 is considered good.

Kelly's score was higher than both benchmarks and off the charts for her age group. Research suggests that VO₂ max tends to decline steadily over time, often dipping well below 30 ml/kg/min in women by age 80.

Still, Jake said he sees a high VO₂ max as a reflection of a simpler longevity metric: how durable a person is over time. Kelly is a textbook example of how to set yourself up for longevity because she wasn't chasing a specific fitness metric, but instead focusing on her overall ability to keep moving, her son said.

"Later in life, if you have the capacity to walk faster, to go upstairs, to lift your suitcase, then you have physiologic reserves," he said. "That means your heart, lungs, liver, muscles, mitochondria are all working and you have capacity to do things."

Jake, 45 years old and an endurance athlete himself, wasn't surprised by the results. He always knew his mom was exceptional. "She's the one who taught me," he said.

A daily movement routine

Kelly hasn't slowed down at 80.

These days, she splits her time between Alaska, where she moved to be closer to Jake, and a farming town in rural Texas. There, she takes care of her own housework, yard work, and enjoys running and biking on the country roads.

She and her husband travel extensively, preferring to live like locals when possible by renting apartments in the places they visit rather than staying in resorts.

No matter where she is in the world, Kelly said exercise is still a key part of her day. She starts her mornings with a dynamic yoga-inspired routine, alternating between poses and counter-poses. It takes 20 to 30 minutes, can be done with limited space and equipment, and leaves her feeling spry.

"I don't do well in a yoga class holding a pose for three minutes going 'ommmm' because it's too slow for me," she said, adding that by the time she finishes her specialized routine, "I don't have much pain or stiffness."

She takes daily walks with her 13-year-old giant schnauzer. "He has the heart of a much younger dog. Exercise works for your dog, too," Kelly said.

Along with the exercise, she keeps a busy social life thanks to fitness groups and her community. Spending time with friends is linked to longer life, and can also help people stay more active, research suggests.

In Anchorage, Kelly is part of a hiking group led by an 89-year-old marathon runner, with the youngest member being 55. In the winter, she stays active with water aerobics at the local fitness center three to four times a week.

Kelly isn't a fan of the treadmill and doesn't think working out should feel like a chore. "You don't have to get up at 4 in the morning to run on the treadmill for an hour and a half. Go outside and walk for 10 minutes," she said.

The takeaway

As a cardiologist, Jake said we can all learn from his mom's longevity-boosting routine, incorporating habits accessible to almost anyone, even if you have a busy schedule or can't make it to the gym.

First, start walking. Getting your steps in every day is the foundation of a healthy heart.

From there, add a little intensity, aiming for Zone 2 effort, a comfortably hard pace. Try walking on an incline or picking up the pace, so you're sweating but not so out of breath that you can't hold a conversation.

As you build fitness, increase the intensity for short bursts that challenge you. Then, incorporate strength training. Even small amounts of resistance exercise can support healthy muscles and bones, promoting longevity.

Finally, stay consistent, Jake said. Exercise only works if you keep it up for the long term, and small, daily movements add up to big benefits.

"What I learned from my mom is that fitness stacks over time. She had many years where she didn't go to the gym or anything, but she walked her dog," he said. "If you do that for 80 years…you're going to do great."