Jan. 5, 2011 -- Edward Gerjouy can walk briskly on an inclined treadmill for more than half an hour without too much trouble. This wouldn't be so remarkable, but for the fact that he is 92 years old.

A study in the Journal of the American Medical Association (JAMA) demonstrates that seniors like Gerjouy who can still hoof it at a relatively speedy pace have a good chance of living to an even riper old age.

When researchers at the University of Pittsburgh pooled the data from nine large studies that involved more than 34,000 seniors, they were able to correlate walking speed in people 65 or older with expected longevity.

At the beginning of each study, subjects were timed at their normal, comfortable walking pace for about 13 feet and periodically retested for up to 21 years. Anyone who could ambulate, even if they used a cane or walker, was included.

The faster an older person can walk, the longer they can expect to live and, according to the researchers, walking with some pep in your step appears to be a better predictor of who survives than simply looking at someone's age and sex.

"It's a real part of the human experience to see that when someone slows down with age, they may not be doing as well as they once were," said lead researcher Dr. Stephanie Studenski. "One of the major goals of this study was to quantify this experience for practical and clinical purposes."

Studenski notes that the act of placing one foot in front of the other requires the cooperation of many body systems including the heart, lungs, blood, bones, muscles, joints, nerves and brain -- and all of these systems synchronize, coordinate and integrate in a way that allows each individual to choose their own ideal walking speed, a speed that remains remarkably constant throughout life unless it's affected by medical issues.

For this reason, scientists consider how quickly a person walks, when correlated with age and sex, a reflection of their underlying health.

Someone like Gerjouy, for example, who at his age still strolls comfortably at about 3 miles per hour, can expect to enjoy another seven years of life. In contrast, a 75-year-old man who barely shuffles along at less than 1.0 mile per hour may not make it to his 80th birthday; and a 75-year-old woman who can keep pace with Gerjouy may look forward to celebrating another 18 birthdays.

"In fact, speed of movement seems to be linear, with each increase correlating with an increased prediction for years of life," Studenski said.

Walking Speed Tests Could Guide Doctor Advice

Administering a simple timed walking test could prove useful for helping doctors make more individualized healthcare recommendations. For instance, prostate cancer screening is generally considered a waste of time for men over 70 because it is widely accepted that elderly men who develop prostate cancer will most likely die of another disease or natural causes.

But if an energetic walker in his seventies can reasonably presume to live another decade in good health, he could benefit from the screening. "Functional predictions like this give doctors an opportunity to do individual life planning for healthy older people where we ought to treat them like they are going to be around for a good long time," Studenski said.

Identifying the slowpokes might help identify at-risk seniors too, so they can be targeted for interventions to help improve their health. Clinicians could even monitor speed over time as a safe and inexpensive way to red-flag slowdowns associated with developing health problems.

One caveat Studenski makes is that longevity charts are not good predictors for natural slow walkers; some healthy people simply prefer to move at a more leisurely pace.

There's little evidence to show that revving things up means living longer either, though in one previous study Studenski's team did show that people who improved walking speed over a one-year period had a better chance of survival over the following eight years compared to people who didn't speed up. And even though Studenski says there's more proof needed before it can be said that cultivating a livelier step translates to additional years, she still thinks that working on physical fitness as you age is a good idea.

"Working with your doctor, a physical therapist or some other healthcare professional to help maintain your health and your walking speed certainly can't hurt and can only help in most cases," she said.

Steps for Healthy Walking

Gerjouy jokingly attributes his good health and quick stride to a daily ration of Jell-O. Jiggly desserts aside, there are some real steps you can take to ensure you maintain mobility into your golden years. John R. Martinez a licensed physical therapist and president of Therapy Experts in New York City, offers the following tips for optimal walking.

Stay Flexible. Maintaining your flexibility, particularly in your hips, sustains your ability to move. You can stretch your hips daily by leaning forward towards your kitchen counter (usually a perfect height for this stretch) with your legs straddled a stride's distance apart. Hold for 30 seconds as you feel the stretch spread up the back of your leg into your hip. Repeat to other side.

Improve Balance. Balance is a bigger component of walking than most people realize; it's what keeps you from stumbling or tripping over your feet. For a simple daily challenge, stand on one leg while you brush your teeth. Start by hanging onto the sink with your extra hand, progress to no hands, and then to doing it with your eyes closed.

Build Endurance and Strength. As you rack up birthdays, endurance and power can diminish unless you focus on maintaining them. One way to keep up stamina is to do the very activity you are trying to preserve: Walking. This is also likely to strengthen the walking muscles too. You can mix this with lower impact endurance activities like riding a stationary bike or water exercise.

Care for Your Feet. Taking good care of your feet will ensure they remain in walk-worthy condition. Wear comfortable shoes, maintain good hygiene and visit a podiatrist periodically for a foot checkup. One easy daily foot strengthening exercise involves placing a small towel under your bare foot and scrunching it up and straightening it out with your toes. Repeat three to five times with each foot.

Lose Weight. Carrying excess weight strains your body, especially your knees, which can slow you down and prevent you from being more active. Watch your diet and do what you can to burn calories. Even a 5 percent reduction in weight can make a tremendous difference in your mobility.