Memorial Day has always been the unofficial start, but summer officially begins June 21. From then until Labor Day, we'll be spending more time outdoors.

Maybe you'll head to the beach. Beaches are America’s top tourist destination, generating more than $640 billion a year for the U.S. economy.  

You don't have to swim in the ocean or lake to get exercise. Running is a good work out. Some like to run on sand because it feels softer. Fitness experts say it is actually better to run on wet sand first then ease into the softer sand. Men's Health offers a 15-minute lower-body workout.  Prevention.com offers ideas for a "beach-body" workout that targets the "bathing suit" muscles.

Finally, just where are the best beaches? Scientist Stephen P. Leatherman (also known as Dr. Beach) likes those in Hawaii, Florida, and New York. See his complete list here.