When the world gets you down, go for a walk and make your heart happy. Physical activity is one of the best ways to manage stress and boost your mood, while reducing your risk for heart disease and stroke, according to the American Heart Association (AHA). The AHA recommends at least 150 minutes of moderate-intensity aerobic activity each week—or about 30 minutes a day, five days a week. And the minutes don’t have to be consecutive to bring benefits. “Walking is a great way to improve your health and your mental outlook, and it doesn’t take a lot of expensive sporting equipment to do it. Put on a good pair of shoes and grab a water bottle and you’re ready to go,” said Donna Arnett, a past president of the AHA and a dean at the University of Kentucky College of Public Health, in Lexington. “It doesn’t matter how fast or how far …