Twelve minutes of swimming can burn well over 100 calories. Swimming is a full body exercise that also helps to strengthen nearly every muscle in your body. Swimming is a great way to get your cardio in with no stress on your joints.
If your goal is to burn the most amount of calories every day you need to get up and move. Do extra things around the house, take the stairs instead of the elevator and walk instead of driving. Do not be a slave to the cardio machine, think outside the box and burn those calories.