34% of the population in North America is considered obese and 59% are inactive. Obesity contributes to an estimated 120 000 preventable deaths in North America each year. Other obese related health risks include high blood pressure, dyslipidemia, type 2 diabetes, coronary artery disease, and stroke. Because of the link of obesity and physical inactivity, adults are recommended to engage in at least 150 minutes of moderate-intensity physical activity per week. But how effective is increased physical exercise as the single intervention for weight reduction?