Occupational therapist Cathy Barnett, 52, of Fort Lauderdale, Fla., folds her petite frame into yoga poses several times a week to improve her flexibility and strengthen her bones. She hopes the exercise routine reduces her risk of developing the bone-weakening disease osteoporosis.
"A few years ago my family practitioner told me that I had to start exercising to preserve my bone strength," she recalls. "Now I walk on the treadmill a few times each week and do yoga at least three times a week."
Barnett feels better and has more energy since she began exercising. "My doctor also said my bone-density scan looks better," she says, referring to a simple test that doctors use to detect bone loss.
Barnett clearly is doing right by her bones, and millions of Americans could benefit by following her example. "Bones become stronger and denser the more we place demands on them with regular exercise," says Dr. Felicia Cosman, an osteoporosis specialist at Helen Hayes Hospital in West Haverstraw, N.Y., and clinical director of the National Osteoporosis Foundation. About 10 million Americans—mainly women and men over age 50—have osteoporosis. Another 34 million are believed to have low bone mass, which puts them at higher risk for the disease and potentially debilitating fractures that can occur when bones are weak.
Women account for 80 percent of osteoporosis cases; they can lose up to 20 percent of their bone mass in the first five to seven years after menopause.
Prescription for strong bones
About 85 to 90 percent of adult bone mass is acquired by age 18 in women and by age 20 in men. "Exercising during our youth will help enhance the peak amount of bone mass, but after that we are exercising to keep our bone mass stable," Cosman explains.
Bones constantly are being broken down and rebuilt. With osteoporosis, bone deteriorates faster than it is rebuilt, and bones become porous and more prone to breaking.
Weight-bearing and strength-training exercises are needed to help maintain bone strength, Cosman says. Weight-bearing exercises include walking, cross-country skiing, jogging, dancing and racquet sports.
"Aim for about 30 minutes of weight-bearing exercise a day, three times week," Cosman says. "It's also a good idea to vary your choices and keep it relatively interesting," she adds. "If you use a treadmill two times a week, do something else for your third day."
Strength training involves the use of resistance to build muscle mass. Examples are weight-lifting exercises with free weights or weight machines, and yoga and pilates, which use the body's own weight as resistance.
"Try to engage in strength-training exercises at least twice a week," Cosman says. This can be done on the same day as weight-bearing exercise or on a different day of the week.
Recommendations about exercise are different for people who are frail or who have already sustained a fracture due to brittle bones. "Talk to your doctor before starting an exercise program," says Dr. Nancy E. Lane, director of the University of California Davis Center for Healthy Aging in Sacramento. "If you are at risk of falling, we don't suggest doing any upright exercising. Instead, try yoga or sitting down and doing leg lifts."
In addition to exercise, consuming enough calcium through diet and/or supplements also is important to maintain bone health. "Some studies have shown that there is a synergy between nutrition and exercise and that you will get even more benefit if you do both," Cosman says.
The National Osteoporosis Foundation recommends that adults age 50 and older get 1,200 milligrams of calcium and 800 to 1,000 units of vitamin D3 daily. Vitamin D helps the body absorb calcium.
"Not smoking and avoiding excess alcohol also helps keep bones strong," Cosman says. "I take calcium and vitamin D supplements every day and really try to make healthy choices about what I eat and drink."
Osteoporosis isn't an inevitable part of aging. Engaging in regular exercise and making other healthy lifestyle choices can help keep your bones healthy and strong.