Agreed - i always attempt Flexibility 1st - which a lot of time involves Foam rolling or certain exercises that stretch and work the knott out followed by stretching.
Once decent movement is in place - then we add ab work.
I didnt know that about the x-trainer - but it does make sense, i can see how that would cause an issue thinking about it. Thanks for that.
On a related NOTE - i just got off the phone with a Physio - she is coming in today to see i do for a guy - who when he was 35 (now 50) started developing what called, Adult Onset Spacidity. Basically his nerves to his Legs are becoming Useless, and so he cannot walk very well.
He has been coming in for 2x months now. Only last session we touched on Abs.
He can now stand up out of chairs or seats without effort - before he used to fall, or use his entire body to get up. We work on Strength AND not stability.
The physio wants to see how we do things - hopefully open her eyes a bit?