As you build your heart healthy regimen, think like a kid and bring your bike into play. Cycling is a rewarding form of physical activity, because of the workout it gives your heart and the de-stressing that’s associated with changes of scenery. There’s nothing like the fresh air that fills your lungs and oxygenated blood that pumps through your body while cycling. That’s especially true if you have a mountain bike and forest trails nearby. Cycling is also extremely practical: Many of us can get our share of exercise in simply by riding our bikes to work.