Physical Activity for Your 20’s: The great thing about being in your 20s is that your body is so strong; you can get away with abusing it. The bad thing is that you often do, punishing it with late nights and bad eating habits. And you routinely fail to appreciate what you have. This is the decade of anxiety — frantic exercise, fad diets, the mad pursuit of pinup perfection and self-hatred when you fail to meet it. The fitness challenge of these years: Get over it. Lots of cardio is great, but mix it up so you really push the body. But it is strength training that builds muscle definition, not to mention bone density, which will be crucial for staying active later on and preventing osteoporosis. 30 minutes of strength training followed by 30 minutes of endurance 3x a week, plus 45 to 60 minutes of straight endurance 3x a week. One day of rest.

Physical Activity for Your 30’s: With the 30s, you start noticing that weight doesn’t come off quite as easily as it used to. This is because after age 20, your basal metabolism drops by 1 to 2 percent every decade, and as lean muscle decreases and body fat increases, you don’t need as many calories to sustain yourself. One hour of circuit training (endurance and strength), 4x a week, plus at least one day of endurance for 45 to 60 minutes at a high intensity. Take one day off.

Physical Activity for Your 40’s: This is the decade of the triple whammy: gravity, hormones, and slowing of metabolism as lean muscle mass continues to decrease and body fat increases. Even women who don’t put on a pound may expand, according to Pamela Peeke, M.D., author of “Body for Life for Women.” After 40 and certainly after 50, you may find that you gain fat more easily in the torso, below the bra, through the triceps area, on the back, and in the belly. The reason for this is because your body composition is changing. One hour of strength training 3 days a week (if you do your whole body at once), 4 days for half an hour, if you split it up, plus 45 minutes of endurance 5 days a week. Take one day off.

Physical Activity for Your 50’s: If your metabolism feels like it’s slowing to a crawl, it’s not in your mind. Researchers at the University of Pittsburgh studying 541 midlife women found an average gain of 12 pounds eight years after menopause. We also tend to gain a little potbelly. And other places begin to droop noticeably. “At this point, loss of muscle mass and tone really shows,” says longtime fitness expert Kathy Smith, 54. “It can actually start to change your posture.” Rx: 4 to 6 endurance sessions a week, 20 to 40 minutes each, with an intensity that lets you answer a simple question but not chat, plus half an hour of strength training twice a week, 8 to 12 repetitions of each exercise if using weights, or 15 to 20 without weights.

Physical Activity for Your 60’s: In the 60s, problems like arthritis, bad knees, and spinal stenosis (a narrowing of the spaces between bones that can put painful pressure on the spinal cord) become common. Aches and pains are not an excuse for giving up exercise. Make changes so that exercise doesn’t jar and stress the joints — for example, replace long runs with jogging. Maybe, jogging in a pool, swimming, or riding a stationary bicycle is a good exchange. (Women with bad backs may need to use a recumbent bicycle.) Walking three to five miles a day offers both cardio and bone-strengthening benefits. Stretching and balance are absolute musts. If you don’t stretch now, “by the time you’re in your 80s, your joints will have lost their flexibility. If you haven’t been physically active, start slowly: • Do strength exercises 1 – 3 times, and build up slowly • Do endurance exercise (brisk walking, for example) for 5 – 10 minutes each day and slowly build up to 30 minutes • If you are out of breath and it is hard to talk, slow down or do less • Stretch slowly and you will become more flexible after a while 3 days a week of challenging but not exhausting endurance, such as a brisk walk, plus 3 days of strength training, use light resistance and slower, more controlled movements combined with slow, sustained stretching. Walk whenever possible, and do daily balance exercises.

Physical Activity for your 70’s and 80’s: Is Physical Activity Safe for Me? Yes! Physical activity is good, and not harmful, for most. Not being physically active is much less safe. Those of you who have arthritis, diabetes or osteoporosis (bone loss) can safely do physical activity to improve your health and fitness. Physical activity will make your joints work better and can reduce the pain of arthritis. Physical activity has the potential to change the way we age. It provides physical, mental and social benefits and helps keep you mobile and independent. Much loss of function that was thought to be “normal” aging is actually the result of not being physically active. Despite these important benefits, older adults are too inactive. By age 75, one in two women and one in three men get no physical activity at all. Given that 88% of older adults over 65 have at least one chronic condition, physical inactivity is a public-health issue, not just a personal problem. Why don’t you get more exercise? Multiple barriers confront you as you age, including the physical environment (lack of transportation), the social environment (family members who disapprove), the intrapersonal environment within ourselves (fear of looking foolish). Brainstorming solutions can be a creative and motivating process. (American Society on Aging Live Well, Live Long: Steps to Better Health Series, 2005.)