You are already familiar with the statistics--and likely see the results of inactivity in countless patients walking through your office doors. In spite of the fact that higher levels of physical activity are associated with better physical and mental health, more than half of Americans do not get enough exercise.¹ Furthermore, 60 percent of those over age 65 do not exercise sufficiently to maintain good health.²

Fortunately, evidence shows a relatively simple device can make a measurable difference. In fact, studies show people who use pedometers, inexpensive devices that count the number of steps a patient walks, exercise more, lower their blood pressure and decrease their risk of diseases associated with inactivity.

Weighing the Evidence

A systematic review of 26 pedometer interventions published in The Journal of the American Medical Association (JAMA) found that pedometer users took about 2,000 more steps or walked about one additional mile per day compared with a control group.³ Furthermore, pedometer users decreased their systolic blood pressure almost 4 mmHg, which is similar to findings in other studies of physical activity and blood pressure.^3,4 This small decrease is significant: Among middle-aged adults without any history of cardiovascular disease, a decrease in systolic blood pressure of 2 mmHg is associated with a 10 percent decrease in death from stroke. A reduction of 10 mmHg decreases death from stroke by 40 percent.⁵

Helping Patients with a Plan

Research suggests that ambulatory people who are relatively inactive benefit the most from a pedometer-based exercise program.³ I recommend pedometers to sedentary people who do not have an exercise plan, especially if they are overweight or have hypertension. People who already exercise may still find a pedometer useful to motivate them to walk more during their daily routine.

To get the most out of a pedometer, I advise patients to identify a daily step goal and keep track of the number of steps taken. By monitoring their steps, patients can change their routine to achieve their goals. If at the end of the day they have not reached their step goal, they can take an extra walk around the block. Pedometer research has shown that people who do not have a step goal do not increase their physical activity.³ So having a goal is essential to reaping the benefits of using a pedometer.

Pedometer users may create an individualized step goal based on their current activity or use a standard goal, such as 10,000 steps per day. For the individualized goal, users simply add 2,000 steps to 2,500 steps per day to their baseline physical activity. Patients can calculate average baseline physical activity by wearing the pedometer for seven days and adding the cumulative amount of steps counts and dividing that number by seven.

Note that epidemiological studies indicate that people who get at least 10,000 steps per day have a healthier weight and lower blood pressure.^6,7 Thus, many experts recommend this goal. However, both the individualized goal and the 10,000-step goal seem to be equally effective at motivating people to exercise more.³

The most important point is to have a goal and keep track of it in a daily planner or a notebook. With more expensive pedometers, exercisers can upload step counts and keep track of their progress on their computer, personal digital assistant (PDA) or even cell phone.

Purchasing a Pedometer

Buying a pedometer is easy. Have patients to look for one with an internal spring coil device, cover, belt clip and security leash. Most devices costing at least $15 to $30 will have these features. An internal spring coil will last longer than the "hairspring" coil. A cover on the device is important so that you don't accidentally reset it to zero during the day. The security leash attaches to your clothing to prevent the device from hitting the floor and breaking in the event that the pedometer slips off.

Patients can check pedometer accuracy by counting their steps and comparing this to the device's count. The device may be off a little from the patient's count as some pedometers consistently under count or over count steps.⁸ If this is the case, have the patient mentally make an adjustment to the steps counted by the pedometer or exchange the pedometer for a new one.

If the patient has a large round belly, the pedometer may slip down and tip forward, making the step count less accurate. Clipping the pedometer to a sturdy belt can minimize this problem.

Tackle Obesity One Step at a Time

Physicians recommend physical activity in the treatment of multiple conditions including hypertension, coronary artery disease, obesity, diabetes, mild depression and osteoporosis.⁹

National guidelines recommend at least 30 minutes per day of moderate-intensity physical activity, most days of the week.¹⁰  However, for overweight or obese people trying to lose a significant amount of weight (five to 10 percent of body weight), experts recommend dietary changes and 60 minutes to 90 minutes of physical activity daily. ¹¹  Hence, a physical activity program to increase steps per day by 2,000 (or 30 minutes of walking) will not be enough to achieve these weight-loss goals.

People wanting to lose a significant amount of weight will need more exercise. Pedometer users on average lose about 0.38 kg/m² over the course of four-and-a-half months, the average length of the pedometer intervention studies.³ Pedometer users were obese with an average body mass index (BMI) of 30.3 kg/m². This translates to a 2.3-pound weight loss for a woman with a BMI of 30.3. BMI is calculated using height and weight. For example, a 5-foot-5-inch woman weighing 182 pounds would be classified as obese with a BMI of 30.3. (Check out this BMI calculator from National Heart, Lung and Blood Institute Obesity Initiative: www.nhlbisupport.com/bmi/)

Remind patients not to center on achieving the "perfect weight." This is especially important to note because patients may become frustrated by how difficult it is to lose weight and tempted to give up and stop exercising. Even if they are overweight or obese, patients can still see significant health benefits from regular exercise.

By being active, they can lower their blood pressure independent of whether they lose weight, thereby reducing their risk of death or disability from cardiovascular disease.³ Physical activity after the age of 50, 60, 70 years and beyond has been shown to decrease disability among older people and increase the number of years of healthy living. ¹²

And pedometers may provide one more tool to bring patients closer to that goal.

Crystal Smith-Spangler, MD, is a general internist and research fellow at the Center for Health Policy at Stanford University.

References

1. CDC Division of Nutrition, Physical Activity and Obesity. U.S. Physical Activity Statistics, 2007. Accessed September 2, 2008, at http://www.cdc.gov/nccdphp/dnpa/physical/everyone/index.htm

2. Centers for Disease Control Division of Nutrition, Physical Activity, and Obesity, National Center for Chronic Disease Prevention and Health Promotion, National Average: Recommended Physical Activity by Age, 2007. Accessed September 8, 2008, at http://apps.nccd.cdc.gov/PASurveillance/DemoComparev.asp

3. Bravata, D.M., Smith-Spangler, C.M. et al. Using pedometers to increase physical activity and improve health: A systematic review. (2007). JAMA. 298(19):2296-2304.

4. Whelton, S.P., Chin, A., Xin, X., He, J. Effect of aerobic exercise on blood pressure: a meta-analysis of randomized, controlled trials. Ann Intern Med. 2002. 136(7):493-503.

and Kelley, G.A., Kelley, K.S., Tran, Z.V. Walking and resting blood pressure in adults: a meta-analysis. Prev Med. 2001. 33(2 pt 1):120-127.

and Halbert, J.A., Silagy, C.A., Finucane, P., Withers, R.T., Hamdorf, P.A., Andrews GR. The effectiveness of exercise training in lowering blood pressure: a meta-analysis of randomized controlled trials of 4 weeks or longer. J Hum Hypertens. 1997. 11(10):641-649.

5. Lewington, S., Clarke, R., Qizilbash, N., Peto, R., Collins, R. Age-specific relevance of usual blood pressure to vascular mortality: a meta-analysis of individual data for one million adults in 61 prospective studies. Lancet. 2002. 360(9349):1903-1913.

6. Tudor-Locke, C., Bassett, D.R. Jr. How many steps/day are enough? preliminary pedometer indices for public health. Sports Med. 2004. 34(1):1-8.

7. Iwane, M., Arita, M., Tomimoto, S., Satani, O., Matsumoto, M., Miyashita, K., & Nishio, I. (2000). Walking 10,000 steps a day or more reduces blood pressure and sympathetic nerve activity in mild essential hypertension. Hypertension Research, 23, 573-580.

8. Schneider, P. L., S. E. Crouter, O. Lukajic, and D. R. Bassett, Jr. (2003). Accuracy and Reliability of 10 Pedometers for Measuring Steps over a 400-m Walk. Medicine and Science in Sports and Exercise, 35 (10), 1779-1784.

9. Alevizos, A., Lentzas, J., Kokkoris, S., Mariolis, A., Korantzopoulos, P. Physical activity and stroke risk. Int J Clin Pract. 2005. 59(8):922-930.

and Miller, T.D., Balady, G.J., Fletcher, G.F. Exercise and its role in the prevention and rehabilitation of cardiovascular disease. Ann Behav Med. 1997. 19(3):220-229.

10. Department of Health and Human Services, Centers for Disease Control and Prevention. Physical Activity for Everyone: How Much Exercise Do you Need? Accessed September 8, 2008, at http://www.cdc.gov/nccdphp/dnpa/physical/everyone/recommendations/index.htm

11. Department of Health and Human Services, Centers for Disease Control and Prevention. Healthy Weight: Losing Weight. Accessed September 8, 2008, at  http://www.cdc.gov/nccdphp/dnpa/healthyweight/losing_weight/index.htm

12. Chakravarty, E.F., Hubert, H.B., Lingala, V.B., Fries, J.F. Reduced disability and mortality among aging runners: a 21-year longitudinal study. Arch Intern Med. 2008. Aug 11;168(15):1638-46.