Roll some golf balls under your arches. — Illustration by Juliette Borda

9. Grab some golf balls. Sore heels and arches are common in older exercisers and can result in full-blown plantar fasciitis, an inflammation of the connective tissue in the foot that can take months to heal. Prevent the problem by loosening the arch and tissues in your feet. "Roll a golf ball over your arches," Wright says. Or keep a golf ball in the bathroom "and roll your bare foot over it while you brush your teeth."

Don't have weights? Try lifting your laundry. — Illustration by Juliette Borda

10. Do the laundry lift. Strength training increases muscle mass — and also helps to stabilize and protect your joints. Studies show that 14 weeks of strength training lengthened older adults' muscle fibers by 10 percent and stiffened their tendons by an impressive 64 percent. You don't have to lift heavy weights — light ones are also effective. Can't get to the gym? Lift your laundry instead.

Try stretching before bed. — Illustration by Juliette Borda

11. Stretch strategically. First, we were told to stretch before exercise. Then we were told to stretch after our workouts. The latest news? Stretching might actually decrease muscle power, thus contributing to injuries if done while muscles are cold. "Stretching is important," Wright stresses. But stretch at some other time during the day, perhaps while watching TV or right before bed.

Take a day off each week to recover. — Illustration by Juliette Borda

12. Take a load off. Days off are more important as you get older. "It's hard for some people to accept, but we do not recover as quickly after age 40 or 50 as when we're 20 or 30," Wright says. So take at least one day off every week or, at most, go for a gentle walk. If you're still fatigued or achy the next day, take another day off. "Life is a long race," she adds. "You can and should take it easy sometimes."

Remember to go to the AARP home page every day for tips on keeping healthy and sharp, and great deals.