Pilates is a form of exercise which combines flexibility and strength training with body awareness, breathing and relaxation. The exercises are based on certain movement patterns performed with your tummy and pelvic floor muscules -- known in Pilates as the "stable core" or base. These muscles are also known as deep stabilizing muscles. Because Pilates targets the tummy and pelvic floor muscles and these muscles can weaken during pregnancy, Pilates exercises can be useful