Patients need to feel confident that they are receiving accurate guidance about physical activity from their health-care providers. Tailoring exercise recommendations to meet the unique needs of each patient gives those patients a better chance of meeting the fitness goals they have set with you. Also, by helping patients understand that there are many different ways to measure success—weight loss, health improvement, and enhanced quality of life (for example, increased mobility, self-esteem, and productivity)—you can empower them to take control and become more active, even in the face of obstacles. Unfortunately, exercise guidelines appear inconsistent.

In 2001, the Surgeon General recommended 30 minutes of moderate-intensity exercise on most days of the week to maintain health and manage weight (www.surgeongeneral.gov/topics/obesity, accessed December 15, 2008). Last October, the Department of Health and Human Services made available the “2008 Physical Activity Guidelines for Americans.” This document focuses on the overall health benefits of physical activity and generally recommends 2.5 hours per week of moderate physical activity coupled with increasing the activity that is accumulated throughout daily life.

Unfortunately, both these standard guidelines tend to overlook the 30% of the population now considered obese. As reported by Schoeller and colleagues (Am J Clin Nutr. 1997;66:551-556) and Weinsier et al (Am J Clin Nutr. 2002;75:499-504), obese people ultimately may need as much as 70-80 minutes per day of moderate activity (e.g., brisk walking) or 35 minutes per day of vigorous activity (e.g., running or cycling) over the long term to maintain weight loss. According to the National Weight Control Registry, adults who lost >30 lb and maintained the loss for at least one year reported the equivalent of walking about four miles per day (Am J Clin Nutr. 1997;66:239-246). Taken together, these and other studies suggest that those who have lost weight may need to be more active than the current public-health recommendations suggest in order to maintain a healthy weight.

So how should you advise your obese patients, particularly those who are severely obese and sedentary? Simply start with what the patient is doing now and build on that, keeping in mind that even small increases in activity can yield benefits beyond weight loss. Our own recent Duke Diet and Fitness Center study of 1,220 severely obese individuals revealed that even moderate amounts of exercise (60 minutes per week) were associated with better quality of life (Obesity. 2008;16[suppl 1]:s200-s201).