In one sentence, describe what the following article is about:

Swimming helps you lose weight because it is great cardio that helps you burn calorieswhich, in turn, burns fat. When you first start swimming with the hopes of getting skinnier thighs, you need to be realistic about your swimming level. It is very, very hard to jump in a pool and swim laps for 30 straight minutes. Your lungs and muscles have to adjust before you can perform at that kind of level. To begin your workout regimen, start by swimming four lengths of the pool at an easy effort. Stop at the ends of the pool to catch your breath if you need to. After your four lengths, rest for 30 seconds. Repeat 5-10 times. Try doing this 3 times a week to build up your swimming muscles. Not only will this help you burn more calories, which will make you skinnier, but, it will also keep you entertained. Doing the same motion for 30 minutes, 3 times a week will get very mundane. Keep yourself looking forward to working out by switching up the strokes. Freestyle is great because it's easy to learn and burns a ton of calories. The backstroke, with your eyes looking straight up, will help improve your posture. The breaststroke engages your hip and inner-thigh muscles. These are often missed in other workouts and will help you get the most out of your swim.

Summary:
Start with realistic expectations. Use starter workouts. Attempt different strokes.