Go exercising, drink green tea (green tea burns your calories, no kidding), do sit-ups, swim, etc.
It depends on how fast you swim and how much you exert yourself. You can burn about 900 calories an hour just sitting/walking around in the pool so if you take a long time doing laps you'll burn a lot more.
The breast stroke
The most common stroke is freestyle. This is based on during practice and in swimming events. Its because nobody wants to swim a 1650 butterfly.
I depends on the context but the default swim for most people is definitely the freestyle. It is the first form a swimming taught to children. It was originally called the front crawl but after it's dominance in freestyle swim competitions (competitions where any stroke could be used) it eventually became known as freestyle swimming. It became popular in the middle of the 19th century and before that the breast stroke was the most used stroke.
crawl
The average person burns about 200 calories walking 2 miles. To burn 200 calories swimming, you would need to swim about 15 to 20 minutes depending how you are swimming.
Most people burn calories because of the body's attempt to maintain its temperature while scuba diving. Rescue divers burn additional calories while doing more strenuous movement underwater. You can burn a great deal of calories if you had to swim against a strong current or in a medium current for a long time. Estimates show that an average person burns 600-1000 calories per hour while diving.
About 580 - 600 calories
There are four strokes; Breast stroke, Butterfly, Freestyle and Back Stroke
Swimming definitely you lose 6 calories in 1 minute, so if you swim for 1 hour, you burn about 360 calories.
The oldest is believed to be the breaststroke.