Pounding chicken (or pork, or veal), tenderizes the meat and decreases the cooking time because the pieces are thin. Thinner pieces of meat also help with portion control. It looks like you're eating more when you're really eating about the right amount.
To pound meat, for this example we're using chicken, arrange a couple chicken breast halves between two pieces of plastic wrap. With a mallet or rolling pin, pound chicken to an even thickness of 1/4 inch.