The Polar F55™ provides you with the ultimate fitness experience. Because cardiovascular exercise, strength training, and relaxation are essential to maximum well being, the Polar F55™ gives the modern fitness enthusiast a complete exercise session by adding new features like Body Workout and OwnRelax. Body Workout, a muscular strength-training guide can be adjusted according to the exerciser's progress, provides basic guidance for strength training. The new OwnRelax feature, checks the body's state of relaxation, and helps exercisers "listen" to their bodies, an essential component of fitness.