Being "old" just got younger, according to a new study in Medicine & Science in Sports & Exercise—that is if you hit the gym regularly.

After administering fitness tests to 4,500 volunteers ages 20 to 90, scientists reported that the fitness levels/indicators of active middle-aged participants were nearly identical to that of inactive 20-year-olds.

During the study, conducted by the Norwegian University of Science and Technology, each participant warmed up by walking on treadmills for eight to ten minutes. Then researchers increased the machine's speed and incline every 30 seconds until the participant quit.

At that point, fitness levels were assessed by measuring the volunteer's peak or maximum oxygen uptake. Peak oxygen uptake (or VO2peak) is a measurement of the body's capacity to use oxygen during exercise and is considered the most accurate measure of cardiovascular health—an indication of fitness.

Surprisingly, the peak oxygen uptake levels of middle agers who work out regularly were the same as the sedentary youngsters.

Exercise intensity—rather than duration—determines peak oxygen uptake and researchers confirmed that with this study. "Many studies indicate that physical fitness is very important for longevity and health, but there have been no studies describing the expected VO2peak levels in a healthy adult population," said study author Stian Thoresen Aspenes on the university's website. "We wanted to look at the relationship between VO2peak, conventional cardiovascular risk factors and physical exercise."

It turns out that exercising in a manner that increases your heart rate-along with following a healthy diet—keeps blood pressure and blood sugar stable and decreases your risk of heart disease and diabetes. In other words, being fit is the best way to keep your heart behaving like a blood-pumping organ nearly half its age!

"Inactivity at any age is dangerous to your health," said Aspenes who recommends high-intensity interval training at least three times a week.

Speeding the body up—or exercising with high intensity—gets the heart pumping and burns more calories. Alternating periods of sprinting with jogging and rest is a formula that keeps the body burning calories post workout as well. If you're not a fan of pounding the pavement (or running on a treadmill), you can accomplish interval training on a bike, in a pool, or at the gym with an elliptical trainer. Jumping jacks or using a jump rope can also provide a challenging cardiovascular workout. The key is stopping and starting over a period of time.

Being sedentary is linked to heart disease, obesity, diabetes, high blood pressure, and osteoporosis. If that's not reason enough to get moving, consider your mind. Several studies have shown that exercise can actually slow cognitive decline. So, don't just sit there!

If you haven't been active in a while be sure to speak with your doctor before starting any kind of regimen. Fitness instructors at the health club should also be aware of any medications you're taking as some can cause fatigue, muscles aches, or other issues that could be mistakenly confused with exercise.

But joining a gym isn't necessary. Walking is a wonderful and safe way to start (and power walking can get your heart rate up). It's also possible to work out in the privacy of your own home with fitness videos and exercise programs on TV. Finally, don't overlook fitness options available right in your own town. The local library likely has exercise videos you can borrow or check out classes at the community center.




The American Council on Exercise

The Centers for Disease Control and Prevention
Growing Stronger: Strength Training for Older Adults

National Institutes of Health
Exercise and Physical Activity for Older Adults