What is the best exercise to lose belly fat?

According to CNN, it is not possible to reduce fat on specific body parts; weight loss is proportional to how the body is already shaped. About.com states that cardiovascular exercise, such as running, bicycling and swimming, is effective for weight loss when performed within the user's target heart rate zone.

CNN elaborates that large stores of fat within the abdomen are believed to be more dangerous than similar quantities stored in the lower body. This visceral fat can negatively affect the surrounding vital organs and is metabolically active. Toxic biochemicals can be released from visceral fat, heightening the chances of heart attack, stroke, and joint and muscle pain.