All it takes is half an hour of brisk walking a day, and you're set. Of course, you have to eat right and get plenty of rest, but as far as doing all kinds of vigorous exercising, no need to.
A study by Duke University suggests that walking at least 30 minutes a day will work your body hard enough to burn enough calories to maintain your weight.
"There's many different ways you can get your 30 minutes of exercise in a day, whether it's walking to the store, or making a choice to walk to the other side of the building, or to use stairs instead of an elevator," says Kurt Swenson of the Woodson YMCA. "Take the long way walking when you come in from a parking spot."
On average, Americans gain about a pound of fat each year from age 25 to 55.