Mp3 Player Used For Exercise?

Well im 16 and im a weight lifter, i lift about 8 hours a week. And i wana get a mp3 player that is dependable,dont mess up when i run or something, and cant cost to much and gots to have bluetooth, well bluetooth can be optional. But i need a mp3 player that i can bring to a gym and not have to worry about it skippin or something goin wrong.