The first thing to realize is how much exercise is needed to burn calories. Don’t get discouraged but it takes a lot of time. See: Lighten Up and Get Moving! | The Calorie Control Council

Physical activity patterns and prevention of weigh…[Int J Obes (Lond). 2009] – PubMed Result

Pedometer-based walking programs show modest weight loss A meta-analysis of pedometer-based walking interve…[Ann Fam Med. 2008 Jan-Feb] – PubMed Result

Using pedometers to increase physical activity and…[JAMA. 2007] – PubMed Result

Exercise alone of minimum use Effects of a popular exercise and weight loss prog…[Nutr Metab (Lond). 2009] – PubMed Result, especially it would seem, among women Exercise is not an effective weight loss modality …[J Am Coll Nutr. 1993] – PubMed Result

Exercise in weight management of obesity. [Cardiol Clin. 2001] – PubMed Result

American College of Sports Medicine position stand…[Med Sci Sports Exerc. 2001] – PubMed Result

Treatment and prevention of obesity: what is the r…[Nutr Rev. 2006] – PubMed Result

Physical activity considerations for the treatment…[Am J Clin Nutr. 2005] – PubMed Result

Exercise for overweight or obesity. [Cochrane Database Syst Rev. 2006] – PubMed Result

Regular exercise trumps metabolic drive to regain after weight loss Regular Exercise Attenuates the Metabolic Drive to…[Am J Physiol Regul Integr Comp Physiol. 2009] – PubMed Result

US self-reported physical activity Prevalence of Self-Reported Physically Active Adults — United States, 2007

Prevalence of adult physical activity Prevalence of Regular Physical Activity Among Adults — United States, 2001 and 2005

Physical activity may matter a lot less than you thought. Study compares energy expenditure between Chicago and Nigerian women Energy expenditure does not predict weight change …[Am J Clin Nutr. 2009] – PubMed Result

Physical activity is associated with risk factors …[J Am Diet Assoc. 2008] – PubMed Result

Physical activity decreases cardiovascular disease…[Am J Prev Med. 2004] – PubMed Result

Active Commuting Active commuting and cardiovascular disease risk: …[Arch Intern Med. 2009] – PubMed Result

Physical activity, obesity and cardiovascular dise…[Handb Exp Pharmacol. 2005] – PubMed Result