NHLBI Communications Office
(301) 496- 4236
Just 3 hours of advice and counseling by doctors and other health care professionals over 2 years can boost sedentary adults' physical fitness, according to a new study sponsored by the National Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health.
The study compared three types of education and counseling, which differed in intensity. Results showed that doctor advice and behavioral counseling worked better than advice alone in increasing sedentary women's physical fitness. However, the added help had no increased effect on sedentary men's physical fitness.
All three methods worked equally well in significantly increasing women's and men's physical activity.
The 2-year, multi-center study is the first controlled trial to compare several methods of education and counseling by physicians and other health care providers for their long-term effects on physical fitness and activity.
Results of the study, "A Randomized Trial of Physical Activity Counseling in Primary Care for Inactive Adult Patients: Results for the Activity Counseling Trial" (ACT), appear in the August 8, 2001, issue of the Journal of the American Medical Association.
"The study shows that doctors and their medical staff can help their patients, especially women, increase their physical fitness and that such an effort doesn't take much time," said NHLBI Director Dr. Claude Lenfant. "For women, such counseling could make a crucial difference because national surveys show they are less likely to be physically active than men."
Physical inactivity is a major risk factor for heart disease and high blood pressure, and contributes to overweight and obesity. Federal recommendations call for adults to engage in at least 30 minutes of moderate-intensity physical activity, such as brisk walking, on five or more days of the week. But, according to the 1996 Surgeon General's Report, Physical Activity and Health, 26.9 percent of women and 21.4 percent of men age 18 or older engage in no leisure-time physical activity.
"If the ACT results could be translated to the general population, then many more American adults would be physically active, and that would be a major public health gain," said Steve Blair, a researcher at the Cooper Institute for Aerobics Research in Dallas, TX, and the ACT study chair.
ACT was conducted at 11 primary care facilities, which were affiliated with three clinical research centers. The centers were: Stanford University in Palo Alto, CA; The University of Tennessee-Memphis; and the Cooper Institute for Aerobics Research in conjunction with The University of Texas Southwestern Medical Center in Dallas. The ACT coordinating center was Wake Forest University School of Medicine in Winston-Salem, NC.
The study involved 874 men and women, ages 35 to 75, who were inactive at the start of the trial and had no clinical cardiovascular disease. Forty-five percent of participants were women and 55 percent men. About 33 percent were minorities.
About 85 percent of the participants had one or more cardiovascular risk factors in addition to physical inactivity. The most common risk factor was overweight or obesity. About 72 percent of women and 75 percent of men were overweight or obese. Additionally, about 33 percent of participants had high blood pressure; about 20 percent had high blood cholesterol; about 10 percent had diabetes; and about 10 percent smoked cigarettes.
Participants were randomly assigned to one of three groups, which received "advice," "assistance," or "counseling." The first group had 2-4 minutes of advice from the doctor about physical activity and were referred to an on-site health educator for more information, which included educational materials on the topic. The assistance group received the same recommendations, plus behavioral counseling by a health educator, one follow-up telephone contact, a monthly interactive newsletter, and an electronic step-counter and calendar. The counseling group got everything the other two groups got plus regular counseling by telephone from a health educator and weekly classes on behavioral skills to help them adopt and maintain their physical activity.
Over 2 years, the interventions amounted to an average of 3 contacts (or 18 minutes of interaction) for both men and women in the advice group, 22 contacts (or almost 3 hours of interaction) for both men and women in the assistance group, and 44 contacts (or 9 hours of interaction) for women and 38 contacts (or 5.5 hours) for men in the counseling group.
Cardiovascular fitness was measured by oxygen uptake during a maximal treadmill test and physical activity levels by a recall questionnaire.
Researchers assessed changes in physical activity and cardiorespiratory fitness for each group and compared the results. The comparisons were done separately for men and women, because investigators felt they might respond differently to the interventions.
After 2 years, when compared with women in the advice group, women in the counseling group had 80 ml/minute and women in the assistance group had 74 ml/minute higher oxygen uptakes (a measure of fitness)–both equaling about a 5 percent improvement. The interventions worked equally well in their effect on reported physical activity.
"The surprise was that the two more intensive interventions worked equally well," said Dr. Denise Simons-Morton, Leader of the NHLBI Prevention Scientific Research Group and NHLBI Project Officer for ACT. "We had thought it would take the more intensive counseling interventions to boost physical fitness. This is a positive message. With fitness, a little help yields an important improvement."
For men, after 2 years, neither of the more intense interventions produced greater cardiorespiratory fitness or physical activity than physician advice alone.
Finally, all of the interventions resulted in similar gains in women's and men's physical activity: At the start of ACT, only about 1 percent of those who volunteered to participate in the study met Federally recommended levels of 30 minutes of moderate-intensity physical activity on five or more days of the week; at the end of the study, 20 percent had achieved those levels.
To interview Simons-Morton, contact the NHLBI Communications Office at (301) 496-4236. To interview Blair, contact Sarah Tollett at the Cooper Institute Communications Office at (972) 716-7092.
Information about physical activity and other heart health-related materials is available online at www.nhlbi.nih.gov/index.htm.