Swimming is a classic type of good-for-you, heart-rate-raising exercise. No matter your experience level or how many strokes you may or may not know, understand this: Swimming is one of the best overall workouts you can do. It affects your whole body. It benefits your heart, your lung function, your flexibility, your muscle tone and strength -- it's also low-impact and burns as many as 500 to 650 calories in an hour [source: Weil].
If you don't already know how to swim, or you're just feeling out of practice, check out your local gym, fitness center or YMCA to learn the strokes or brush up on your technique before diving in.