The S5 includes a built-in heart rate monitor, pedometer and fitness tracker, though I'm not sure how useful they actually are. For instance, to check your heart rate, you hold your finger over a sensor on the back of the phone _ something I can't imagine doing in the middle of a jog.
Fitness aside, the S5 phone includes some other significant upgrades from its predecessor.
Some of the biggest changes are in its camera. Its 16 megapixels make it sharper than the S4, which had just 13. It's also designed to focus faster and lets you blur the foreground or background of an image to emphasize a subject.