Joining the wait staff...where's my tip?

3 rounds for time:
100m right arm 50# db waiters walk
30 GHD sit ups
100m left arm 50# db waiters walk
30 back extensions

Time: 17:14
round times: 5:07, 5:54, 6:13

Nice WOD.  I found the waiter's walk to be harder with my right arm than my left.  GHD sit ups touch floor to touch bracket between feet.  I did back extensions done a little further up the machine than usual, had mid-calf on the pad, giving my a bend at my lower waist, rather than the hips...felt like I was using my back a lot more than my glutes and hammies.

I rode my bike to the Depot for this one.  The ride home was not fun...lower back was tiiiiiight!