What’s Your Fitness Age and Why Does It Matter?

Turns out that you may not be as old as you think—in fitness years, at least.

Returning to the gym after a months-long hiatus may make your body feel older than it really is. It turns out this isn’t just in your head; you can have a “fitness age” that greatly differs from your actual age.

A fitness age can predict longevity perhaps even better than your chronological age can, and can give you a sense of how well your body is running. But, what exactly is a fitness age and how do you find out what yours is?

Here’s what you need to know.

What is a fitness age?

Health researchers at the Norwegian University of Science and Technology are behind the concept of a fitness age. The university’s Cardiac Exercise Research Group (CERG) has spent years researching physical activity and how it relates to lifespan, and have found that a person’s fitness age is an important marker of health.

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Unlike your actual age, your fitness age is largely determined by your VO2 max—a measurement that determines how well your body uses oxygen, says Alex Boross-Harmer, a registered kinesiologist at Toronto’s MOVE Fitness Club.

Boross-Harmer explains that when you inhale oxygen, it enters the bloodstream and is used by your muscles. The more efficient your body is at that process, the higher your VO2 max is, and the “fitter” you are, she says. In other words, your VO2 max indicates your cardiovascular endurance.

“Because aerobic exercise —like running, rowing, biking, or anything where you get your heart rate up for a sustained duration—use oxygen to keep the movement going, these are typically the best ways to test just how much oxygen you can use,” Boross-Harmer says.

Unlike your actual age, your fitness age can decrease. This means that you can be 35 years old and have a fitness age of 25 because your VO2 max is higher. On the flipside, you can be 50 years old and have a fitness age of 70, because your cardiovascular endurance is not as strong.

How do you calculate your fitness age?

Boross-Harmer says calculating your precise fitness age requires “specific equipment, personnel, time, and knowledge,” making it largely inaccessible for most folks. That’s why the CERG researchers made calculating your approximate fitness age easy—and doable from the comfort of your couch.

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They developed a Fitness Calculator that determines your VO2 max based on an algorithm that uses individual information including age, weight, gender, resting heart rate, and physical activity level. Once you input all your data, the Fitness Calculator will give you an estimated fitness age. It also will let you know if your fitness age is on par with others in your age bracket.

What does your fitness age mean?

If your fitness age is higher than your actual age, it may be a good time to look at some of your lifestyle habits and see where you can make improvements. Your fitness age can help predict your risk of heart disease and longevity, among other things.

The Norwegian team behind fitness age research published a study in 2014 that found those with fitness ages higher than their actual age had an increased risk of dying prematurely compared to those with a fitness age lower or on par with their actual age. Another 2011 study found that people with higher VO2 max had better heart health than those with lower VO2 max.

What’s more, CERG researchers found that those with lower fitness ages have better lung function and are less likely to experience headaches and inflammation. Being in good physical health has plenty of other benefits, too, Boross-Harmer says. The better we take care of our well-being, the higher quality of life we experience.

“There aren’t just physical benefits to exercise, but psychological and social, as well,” she says. “Exercise helps improve mental health, clarity, long-term memory, and ability to focus. It also can give you the opportunity to create new friend groups or do new activities with friends.”

How can you improve your fitness age?

Exercise is an important factor in lowering your fitness age—and that’s something that happens over time.

“VO2 max doesn’t improve with a one-off bout of fitness, but a long, sustainable, active lifestyle,” says Boross-Harmer. “The general rule of thumb is if you are fairly active and get your heart rate up a few times a week, your VO2 max will improve, which will give you a lower ‘fitness age’ in the long run.”

While exercise is an important aspect of aging well, genetics affect your fitness age, too. Boross-Harmer says that everyone ages differently, and the reality is that our bodies will change as we get older. “A 25-year-old will still always likely be literally and physically younger than a 75-year-old,” she adds.

There are also lifestyle factors that affect how fit you are. Boross-Harmer says that a healthy, balanced diet is key to well-being, as is hydration and proper sleep. She says a lack of sleep will negatively affect your fitness age—no matter how much you work out.

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“If you can find a balanced lifestyle that works for you where you get a quality night’s sleep, hit the gym regularly, do a combo of strength and cardio work, generally eat balanced, healthy snacks and meals, and drink enough water, your fitness age will decrease,” Boross-Harmer says.

The important thing to remember is that you are never too old—fitness age or actual age—to exercise. Too often people think once they hit a certain age they are unable to maintain a fitness routine, but Boross-Harmer says this is simply not true. You also don’t need to be “in shape” before starting at a gym; trainers are there to help you.

“It’s important to note that fitness age can decrease no matter what your actual age is. So whether you start at 15 or 75, you’re going to see positive effects,” Boross-Harmer says. “If you are nervous about trying something new…find a friend to go with you.”

Bottom Line

Fitness ages can be good indicators of health, and give us a good reminder of why exercise is important if we’ve fallen off the bandwagon. Regularly exercising not only makes us stronger, it can help us live longer, too.

“When in doubt, grab a friend, pick a sweaty thing, and no matter how old you are, start,” Boross-Harmer says. “Regular exercise equals a happier, healthier, higher-quality life.”



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