Rx: 4 to 6 cardio 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 weight training twice a week, 8 to 12 repetitions of each exercise, or 15 to 20 using lighter weights. Always stretch afterward.
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, what Peeke calls the menopot. 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."
The classic shoulder slump from years of hunching over a desk or computer "will really age you," says Smith, who suggests this stretch: Clasp your hands behind your back at the level of your butt and squeeze your shoulder blades together, pinching your spine. Try, with straight arms, to stretch your fingertips toward the floor until you notice a tug between your ears and shoulders, then lift your hands as high as you can, feeling the stretch in your chest.
"If you haven't started weight training, you must," says Smith, "although if you're a beginner, I really recommend guidance. Women in their 70s have doubled their strength in nine weeks. If you feel intimidated going to a gym, you can rent videos to do at home. You want to hit all the major muscle groups, and you can do the whole cycle in 15 minutes if you keep some dumbbells around."
Yoga—along with tai chi, dance, and the Bosu ball (a soft half-dome used for standing and sitting exercises)—is great for balance, which will become an increasingly important issue. While the physical changes this decade brings may be hard to take at first, ultimately, says Smith, "you shift into an acceptance mode. You change what you can, and live with what you can't. It's a gentler way."