Working out at a gym can improve your health. In addition to helping you to burn fat and calories, cardiovascular exercise also helps to strengthen your heart and prevent against risky medical conditions like heart disease, high blood pressure, high cholesterol, stroke, some cancers, type 2 diabetes and obesity. Cardio exercise can also help you sleep through the night more soundly, relieve stress, have a more positive attitude and increase energy levels. Gyms offer a wide variety of cardio choices through both machines, like the treadmill, elliptical trainer and stationary bike, and group exercise classes, such as cardio kickboxing, aerobic dance and group indoor cycling. At a gym, you can also enlist the help of a personal trainer, who can guide you on the best methods and techniques in order to reach your fitness goals.