Last year Samsung launched its health-tracking app S Health, and the company has a new version that takes advantage of some specialized sensors in the Galaxy S4. The phone features a built-in pedometer for tracking the number of steps you take — or run — during the day, much like Fitbit's line of devices. However, sensors in the phone also allow it to measure the ambient temperature and humidity of the room you're, all of which feeds into the S Health app itself. Diet tracking is integrated as well, with the app pulling able to pull caloric information from a database of common food items.

Like earlier versions of the app, the new S Health can also sync with third-party blood pressure monitors and glucose meters — all over Bluetooth — providing a comprehensive look at your overall health trends. Samsung is going a step further for fitness fans, however, with several new accessories. The S Band is a pedometer bracelet, meant to track your steps when you don't want to carry the 5-inch Galaxy S4 around with you; users then sync the data from their run or particular activity back to the phone when they're done. Samsung also showed brief glimpses of its own Body Scale and heart-rate monitoring bands that will work with the S Health system.

The fitness-tracking market has blown up lately, with the likes of Fitbit, Basis, and Jawbone all announcing new devices in the past few months — to say nothing of the prospect that Apple's much-rumored watch could include similar functionality. In any case, it seems clear that Samsung hopes to sidestep any competition by providing a wide range of functionality in its own ecosystem of products.

Check out our Galaxy S4 event live blog for the latest updates!