Your Guide to Exercising Through the Ages

What's the golden ticket to living well into your golden years? A lifelong exercise program, says Pamela Peeke, assistant professor of medicine at the University of Maryland School of Medicine. Specifically, a program that adapts to your physiological needs as you age. "Exercise is age-specific," says Peeke, author of Fit to Live and Body-for-LIFE for Women. "And you want to start as young as possible."

If you wait until age 65 to start exercising, you'll still benefit somewhat: Research has shown that you can, indeed, take steps to reverse the effects of inactivity later in life, and with considerable success. But why take the hard route? Fitness is like retirement savings, Peeke suggests: Wait until later to start socking away "body currency," and you'll get much less bang for your buck. You'll be trying to amass strength and endurance just as your energy and lean muscle mass have dwindled.

But start with a simple, well-rounded fitness plan now, and modest upkeep can take you spryly into your 60s, 70s, 80s and beyond. All you have to do is stay consistent. "I've seen 100-year-olds who are more active than some 20-year-olds," Peeke says. However, most people neglect their fitness regimens as they get older: Only 30 percent of people ages 45 to 64, 25 percent of 65- to 74-year-olds, and 11 percent of people 85 and older say they exercise regularly, according to a recent study by the National Institutes of Health (NIH).

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Ready to turn aging on its head, then? This guide will lead the way.

20s: Build your fitness base. Your 20s may seem like a "freebie" decade when you can skip exercise without significant weight gain. But it's really the perfect time to start building your fitness foundation. "As we get older, we lose muscle strength and our bones become less strong," Peeke says. Start a strength-training routine now and keep it up two to three times a week and you'll be able to afford losing some lean muscle mass and bone density later, "no sweat."

Your strength-training regimen should consist of lifting weights or doing exercises that use your body weight for resistance, such as pushups and lunges, for 30 minutes. Aim for a load you can comfortably perform at least eight reps with, but no more than 12, Peeke says. Intersperse strength-training sessions with cardio workouts and you'll reap additional benefits for tomorrow: Exercising one to three hours per week can reduce a woman's risk of breast cancer by 20 to 30 percent, Peeke says in her book; four or more hours can drop the risk by almost 60 percent. For both sexes, regular cardio--at least 30 minutes of activity three to five days per week--can cut your risk of colon cancer by 30 to 40 percent, research suggests.

Your 20s are also a good time to learn what Peeke calls "positive coping skills." The sooner you can deal with life's stressors healthfully--say, by meditating or going for a jog instead of plunking down on the couch with a bottle of wine--the easier it will be to stick to your exercise blueprint long-term.

30s: Diversify. If you focused on one sport or activity throughout your 20s, now is the time to round out your exercise program, says Karl Knopf, coordinator of the Adaptive Fitness Program at Foothill College in Los Altos Hills, Calif. Swimmers who "just swim," for example, can run into posture troubles down the road, such as hunching over due to chronically tight neck, chest, and shoulder muscles.

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Cross-training is a great way to prevent imbalance and overuse injuries, says Knopf, author of Kettlebells for 50+. A swimmer might add cycling and running to the lineup, which will ensure a good mix of upper and lower body workouts. It's critical that your fitness regimen also include balance and flexibility exercises to loosen tight muscles, preserve range of motion, and prevent falls--which is important now and as you age, says the National Institute on Aging. Stretching is a simple way to maintain flexibility, and exercises such as heel-to-toe walks and standing on one foot will boost your balance. Activities like yoga, tai chi, or dancing are also good options.

40s: Preserve strength, fight belly fat. Done raising young kids and settled into jobs with extended desk time, many 40-somethings stop lifting weights (or kids) just when it should be the opposite. Peeke explains that at 40, a man's testosterone starts to drop, and with it roughly 5 to 8 percent of his muscle mass per decade. Women also begin losing muscle more rapidly in their 40s. To keep your metabolic rate high and continue burning calories optimally, you need to work to preserve that lean muscle mass.

Another biological disadvantage to watch for is "stress fat," which burrows deep inside around the organs, putting you at risk of heart disease, diabetes, and cancer. "Up to the age of 40, sex hormones tend to protect you from getting too much fat inside the belly," Peeke explains. "A woman's estrogen will keep fat in the hips, thighs, and buttock, while a man's fat typically goes outside the belly, not deep in." But at 40, all bets are off. Chronic stress can also lower sex hormones and elevate the stress hormone cortisol, both of which lead to the buildup of this so-called "visceral" fat. Be very careful, Peeke says: "You can stay the same size but with fat redistribution" and not realize you're packing the pounds deeper. A consistent exercise regimen will help you keep fat gain, stress, and stress-eating in check.

50s: Protect your heart and core. No matter how active you've been, aches and pains will start to crop up now, Peeke says, and you'll have to adapt your exercise regimen around them. Sore knees? Stop running and find a pool, she says.

You'll also have to fight your body's tendency to curve forward in your 50s, which can cause chronic back pain and give you a "dowager's hump." Peeke recommends yoga and pilates for strengthening your abs and back, or "core." And don't slouch while you're walking--extend your body. This simple change can make a big difference in your spinal alignment.

The American Heart Association (AHA) recommends 30 minutes of aerobic activity five times per week to preserve heart health as you age. Since you'll start to need more recovery time from vigorous workouts in your 50s, Knopf suggests exercising with mild to moderate exertion instead. It's just as effective, he says, and you can do it every day of the week because you won't be sidelined by extreme fatigue or muscle soreness.

60s: Focus on prevention. Are you exercising regularly? Good--you're less likely to die prematurely from a chronic condition such as diabetes or heart disease, the AHA says. Staying strong through your 60s will also improve your odds of surviving a fall, which the Centers for Disease Control and Prevention pegs as a high risk once you hit 65. Recent research found that women in their 60s and 70s face as much as five times the risk of death within a year of suffering a hip fracture. Strong muscles and bones and good balance can help you avoid taking a tumble.

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You should be lifting weights at least once, but ideally two to three times per week for 30 minutes, alternating sessions of upper body exercises and lower body exercises. A simple resistance regimen can be enough to keep you from "the slippery slope of frailty," from which there's no coming back, Peeke says.

However Peeke doesn't recommend going it alone. In your 60s, your bones become more fragile and "your tendons and ligaments are drier," so she strongly advises working with a certified fitness professional specializing in geriatric exercise to help you avoid getting hurt. IDEA Fitness Connect, an extensive online database of certified fitness professionals, can help you find one near you.

Better yet, join a group fitness class; many gyms and community centers offer a variety of group classes geared toward seniors, such as Zumba and water aerobics. The supervision makes it safe and you may find working out with others more enjoyable, Peeke says.

70s+: Sustain strength and flexibility. Walking isn't the only activity that's safe for seniors 70 and up. To continue performing daily functions independently, Knopf says you must also continue to work on strength, flexibility, and balance.

No rigorous workouts or gyms are required, however. In Knopf's classes, his elderly students incorporate all of these elements into simple activities done on or around a chair. The routine might consist of arm raises with resistance bands and leg lifts. Next, they move on to aerobics around the chair, followed by stretching.

You're never too old to reap benefits from exercise, according the NIH. The key to exercising safely is easing into your workouts. "Don't just run it out of the stall," Knopf says. You can avoid clicking and clunking--not to mention cracking--by taking inventory during your warm-up to see how you feel. If you're tired, take it slowly. If you experience pain (different from discomfort), check that you're using correct form in your movements, he suggests. If the pain persists, stop and consult your doctor to determine how to proceed with your exercise regimen.

If a lifetime of exercise sounds overwhelming, remember that the most important aspect of your exercise regimen at any age is not a particular fitness benefit--it's fun! "Health has to be carried on, on a daily basis, for a lifetime," Knopf says. The best way to keep your drive to exercise from burning out is to find the activities you love enough to do every day.