Aqua aerobics, also referred to as water aerobics, is one of the most effective and safe ways to get you into shape. Basically, these are exercises done in a swimming pool using the support and resistance of water. Usually, an instructor stands on the deck of the pool, demonstrating various arm, leg and core exercises, which a class of exercisers, standing in chest deep water, follows. These exercises are usually done to rhythmic music. Weights can also be included in the workout. Each workout session runs for about 45-60 minutes. It begins with a warm-up session, which incorporates slow cardio and stretching exercises to get the muscles ready for the increased activity to follow, and ends with a cool-down, where the limbs and other parts of the body are stretched and relaxed. According to estimations, about 500-700 calories are burned in a whole session.