Grant: Randomized Controlled Trials

The worldwide prevalence of abdominal obesity and associated disease and death among adults is increasing at alarming rates and requires immediate attention. Physical inactivity is a major determinant of obesity. Approximately 60% of adult Canadians are inactive; a factor that contributes to the rising prevalence of overweight that now exceeds 60%. The specific exercise strategy required to achieve optimal benefit for reduction of obesity and associated disease continues to be the source of considerable uncertainty and debate. At present health professionals know little about the specific type, amount and intensity of exercise that provides optimal or even measurable health benefit. This represents a major gap in knowledge with direct practical and clinical implications. In response, we propose to perform a rigorously controlled randomized trial inherent to which are four key characteristics. First, the use of waist circumference as opposed to BMI as the principal obesity-related outcome variable. Second, the prescription of exercise without a reduction in caloric intake, thereby isolating the effect of exercise on the primary outcomes. Third, precise control for exercise dose (how much) and intensity (how hard) with continual adjustment for improvement in fitness throughout the study. Fourth, recruitment of abdominally obese men and women at elevated health risk. These key features highlight our response to the limitations of prior investigations and will help resolve uncertainties regarding the utility of exercise as a means of reducing abdominal obesity and related health risk which impair the development of strategies for the promotion of obesity reduction in public health, clinical and community settings. This is timely as the number of Canadians at increased obesity-related health risk is high and increasing and hence, the development of efficacious lifestyle-based strategies designed to reduce obesity and related health risk is of paramount importance.