H2O Audio has teamed up with iTrain and Olympic gold medalist Natalie Coughlin for a power-coached MP3 swim workout. Check out other MP3 workouts like iSWIM, iTREAD and iCIRCUIT at iTrain.com. Or simply clip your iPod shuffle into the iSH2, a waterproof headset. Hook it to your goggles and rock out underwater!

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