One in two men and one in three women 40 and under will develop coronary heart disease. After age 40 the odds only improve by about 30 percent. The major risk factor for heart disease and other illness is simply the lack of physical activity.
While one in four US adults are actually sedentary, two in four are not active enough to reach a healthy level of fitness. Most medical practitioners recommend adults get at least 30 minutes of moderately intense physical activity most days of the week. We often procrastinate, however, citing lack of time, social support, access to exercise facilities, bad weather, and a general dislike of vigorous exercise.
To find an effective way around such barriers, researchers at Cooper Institute for Aerobics Research in Dallas, Texas enrolled 237 men and women ages 35 to 60 in Project Active. All participants were originally sedentary. None had existing cardiovascular disease, but most were moderately overweight.
Participants were randomly assigned. In the life style group, 122 participants learned behavioral skills to help them gradually increase physical activity in their daily routines. In the structured group, 115 participants used a fitness center for vigorous forms of exercise such as aerobics, swimming, stair climbing, and walking.
Both groups learned behavioral skills to help them be physically active. Participants in the lifestyle group, however, received more individualized help to tailor physical activity changes to daily routines. The lifestyle group learned to keep track of inactivity and activity such as time spent sitting, minutes of moderate-intensity physical activity accumulated in a day, and, how many steps they took in a day. Examples of their lifestyle changes included: taking longer walks on the way to office meetings; walking around airports while waiting for a plane; walking around the field at children’s games; and forming a walking club.
After 6 months, the structured exercise group had improved their cardiorespiratory fitness more than the lifestyle group. Then, they underwent a measurable decline in fitness.
After 2 years, both groups had significantly increased their physical activity and improved their cardiorespiratory fitness and blood pressure. Furthermore, most participants maintained their improvements.
According to Dr. Andrea Dunn, Project Director and lead author of the study: “The results show physical activity doesn’t require a fitness center and high-intensity workouts. People have more opportunities to add physical activity to their daily life than they might think. Anyone can sit down and think about what he or she does in the course of a day, then see how to work in more activity through a simple change or two.”
Dr. Claude Lenfant, Director of the sponsoring National Heart, Lung, and Blood Institute (NHLB I), noted the recommended 30 minutes of moderate-intensity activity do not have to be done at once, but can be divided into periods of at least 10 minutes each. “The study shows how effective small changes in lifestyle can be, especially for those who have been sedentary. This is great news for the millions of Americans who are not getting enough physical activity.”
These findings appear in the January 27, 1999 issue of the Journal of the American Medical Association. NHLBI is part of the National Institutes of Health.
