How do I change the email address associated with my ipod nano (6th generation)

I am trying to upload my workout info to Nike+ from my ipod nano 6th generation but I recently changed my apple id. The email address on my ipod for Nike+ does not match my new email address on my apple id, so my information is not being updated on Nike+. I do not have access to my previous email and I do not know how to change the email address associated with my ipod nano.