work those abs without ruining it back

First aback indeed it is far from established dogma on the abs again and again doing crunches that ruins your back.
Here we base this on fairly wacky but some exercises to work the deep muscle and not just the visible part of the iceberg.
The book is divided into more level that for people like me a little overloaded we'll start with an easy program that will awaken our amnesiac muscle without being overwhelming. so no need to be an athlete to meter and if we will be able to level up and who knows maybe one day achieve level 3 in large sports book.
there for everyone and all levels plus the fact of the deep muscle work is really good and I almost forgot respecting our posture, our morphology