Lite Makes 'Right'

It's no secret that the majority of Americans are physically inactive, despite persistent efforts to change this pattern. In the past several years, however, there has been a shift in strategy by health promotion organizations such as the American College of Sports Medicine and other groups to reach out to sedentary individuals. The thinking is that older guidelines for physical activity were seen as unattainable and unrealistic, not to mention unappealing in an overly prescriptive way (i.e. needing to exercise at 50-85 percent of your maximum oxygen uptake for 20-60 minutes, three to five times per week). The emphasis was on fitness, strength and endurance, which for most people were about as relevant and appealing as having weekly root canal surgery.

More recent guidelines reflect a different approach that emphasizes health-protective benefits of being physically active, rather than fitness. The distinction is important, because being healthy simply does not require the level or duration of physical exertion required to be highly physically fit. Going from being a couch potato to a healthy level of physical activity is a huge step, whereas anything beyond that is a matter of progressive refinement, one that requires increasing effort and dedication for diminishing returns. People who are highly health-conscious may be willing to accept the latter challenge, but they are in the minority. In practical terms, evidence suggests that by following the new "lifestyle" guidelines, you can lower your risk of common chronic medical conditions (diabetes, heart disease, obesity, cancer) and experience modest gains in endurance and strength sufficient for relevant activities of daily life.

Current guidelines are more user-friendly and less intimidating. For example, rather than indexing exercise intensity to oxygen uptake (What is that, anyhow?), moderate intensity physical activity is advocated, enough to elevate your heart rate and keep it there for a few minutes. Does 30 minutes on a treadmill seem frightfully boring? How about a brisk 15-minute walk with friends in the morning and then later in the day planting those shrubs that have been sitting behind the garage for the past week? The idea is to link the basic benefits of exercise to functional, everyday activities.

So how effective are the new guidelines at promoting health and reducing disease risk? Evidence is accumulating that this is a valid approach. A good example of this comes from a study published in the Journal of the American Medical Association in 1999 by Andrea Dunn and her colleagues at the Cooper Institute in Dallas, Texas. Two hundred thirty five previously sedentary women and men participated in either of two activity programs, one based on traditional, prescriptive guidelines, the other emphasizing the newer, lifestyle-behavior changes.  Each involved six months of intensive intervention, followed by an 18-month maintenance program. For the traditional program, this consisted of up to five weekly, supervised training sessions using fitness equipment in a state-of-the-art facility. Participants in the "lifestyle" group focused more on developing flexible, individualized activity programs, with a goal of 30 minutes of moderate-intensity activity most days of the week.

Results? Participants in both programs showed significant improvements in both physical activity and cardio respiratory fitness. Systolic and diastolic blood pressure decreased, as did body fat. Average physical activity increased, along with caloric energy expenditure. Fitness levels declined somewhat after 24 months, but - and this is really interesting - more so in the structured exercise program.

The bottom line? Physical activity has enhancing and protective benefits for your health, whether you're a dedicated "gym rat" or prefer a less structured, individualized approach. Either way, get moving and stay active!

Paul Salmon, Ph.D., M.S., is an associate professor of clinical psychology at the University of Louisville and an ACSM-Certified Health Fitness Instructor. Paul is a member of the Kentuckiana HealthFitness Advisory Board . You can contact him via email at psalmon@louisville.edu.