Go read a book, it's good for your back.

When I was in law school, I suffered from that exceptionally common ailment, lower back pain.  There was a lovely gym with all sorts of brand new equipment with exciting names waiting for me to try it out, so I systematically gave pretty much every device a shot, from the rowing machines to the ellipical something or others.  Nothing worked.  My back still ached.  And ached.

Finally, one day, I said, "Enough!" and stopped with the exercise at the gym, though I did walk a fair amount, as it was unavoidable.  Bingo!  Back pain gone!

My single sample has now been proven scientifically.  Exercise does not help lower back pain.  Read about it here.