Below are the Professional Organizations I recommend for quality information on physical activity and lifestyle changes:
American College of Sports Medicine http://www.acsm.org/
American Council on Exercise
https://www.acefitness.org/acefit
National Physical Activity
Plan http://www.physicalactivityplan.org
America Association of Cardiovascular https://www.aacvpr.org/Default.aspx
and Pulmonary Rehabilitation
IDEA Health and Fitness Association http://www.ideafit.com/
National Strength & Conditioning
http://www.nsca.com/Home/
Association
American Heart Association http://www.heart.org/HEARTORG/
American Lung Association
http://www.lung.org/#
American Cancer Society
http://www.cancer.org/
American Diabetes Association
http://www.diabetes.org/
USDA-Choose My Plate
http://www.choosemyplate.gov/
Live Well Colorado http://livewellcolorado.org/healthy
Tobacco Free Colorado http://www.tobaccofreeco.org/home
Centers for Disease Control http://www.cdc.gov/HealthyLiving