Exercise: a lot versus a little

The study, published in the Archives of Internal Medicine, included 246 women over 65 who were randomly assigned to either an exercise program or a wellness program for 18 months. The exercise program consisted of two 60-minute supervised exercise sessions and two 20-minute home exercise sessions per week. The exercises included stretching, balance and strength training, and aerobics, and exercise intensity was increased over time. The wellness program consisted of ten-week blocks of once-a-week, one-hour, low-intensity exercise sessions alternating with ten-week blocks of rest.

More exercise leads to more bone mineralization

• Exercise improved:
• Overall cardiovascular risk
• High blood pressure
• Cholesterol profiles
• Bone mineral density in the lumbar spine and hip
• Balance (lessoning the likelihood that a participant might fall and fracture a bone)

The wellness program improved:

• Overall cardiovascular risk
• High blood pressure

Bone mineral density did not change in the lumbar spine and decreased in the hip in this group, and the wellness program did not improve participants' chances of falling. The fall rate was 41% lower in the exercise group than the wellness group at the end of the study, and there were twice as many fractures due to falls in the wellness group compared to the exercise group, although this difference was not statistically significant.

"Our exercise program clearly demonstrated positive effects on the most relevant risk factors for elderly women: fracture and coronary heart disease risk factors," said lead study author Dr. Wolfgang Kemmler of the Institute of Medical Physics in Erlangen, Germany. "These findings add to the evidence that a regular high-intensity exercise program designed for the elderly improves overall fitness, maintains bone health, and reduces fall and heart disease risk."

Building healthy bones

If you plan to add exercise to your bone-loss prevention program, consider including the following elements:

• High-impact weight-bearing exercise. Thirty minutes of weight-bearing exercises help preserve bone. Walking will work, though high-impact exercises, such as jogging, tennis, and jumping rope, have the best effect.
• Resistance exercise. Studies have shown that resistance exercises with free weights, exercise machines, resistance bands, and so on, two or three times per week can stimulate bone formation and increase bone mineral density.
• Postural and balance exercises. Practices such as yoga and tai chi promote good posture and balance awareness, which reduce risk of falling and fracture.
• Remember to start with easy exercises and gradually increase the duration and intensity of your program. It's always a good idea to discuss a new exercise program with your doctor, and essential if you are under treatment for any medical conditions.

(Arch Intern Med 2010;170:179-85)