aight I started doing a new Ab routine....15 lb weight behind my head, 3 sets of 15, then 10 lb weight doing 3 x 10 of russian twists....Last week I had no problem doing it, and it felt great after each set, really good burn...however, this week my abs feel really different...i feel like im working em, but it's almost like im hurting them more, i don't feel the same burn I had a week ago, and it was a little harder for me to do this week so far....any ideas? I appreciate any help....thanks