We're supposed to get at least 30 minutes of physical activity a day to ward off heart disease and weight gain, but sometimes just living life feels like exercise. So what counts and what doesn't? Here are the facts according to Robert Stoner, president of the American Health and Fitness Association: * Let's start with shopping at the mall. Is it exercise? Yes! Mall walking, even when you stop to browse, adds up to a surprisingly solid exercise session. You can burn 100 calories per half hour - more if you're carrying bags. * So what about trying on clothes? Yes, it's exercise. There's a reason fitting rooms make you sweat. You're doing leg lifts, arm stretches, twists, and walking in place. That can burn 100 calories in half an hour, too. * If you decide to take the stairs everywhere you go, that's definitely exercise. Stair workouts burn more calories than walking - up to 100 calories in 15 minutes. So 10 trips up and down between floors in your own house counts as part of your daily exercise requirement. So what doesn't count? * Carrying your baby. It may leave your arms sore, but hoisting a baby - or even a toddler - doesn't rate as a workout in the health sense, because it doesn't engage your cardiovascular system. Plus, studies show that when people are carrying their children, they slow down - which prevents you from burning as many calories as you would walking on your own, or pushing a stroller briskly. * Finally, physical relations with your partner does not count as exercise. It doesn't raise your heart rate enough and only burns an extra 50 calories per half hour.