I hate the way key words can be used in marketing to label things without really communicating the specifics. Core indicates central area says nothing abut the different muscles involved, the need for many exercises and stretches, the link with balace via the psoas or the need for stretching as well as strengthening.

There's an add on TV here at the moment for a vacuum broom thingy that works without electricty. They say it has "quad brush technology" when really they just mean four brushes .

IMO They use these words to make you think there's something mystical about how things work that you'll never be able to understand or to generalize something they may not even understand.

A personal trainer could tell me he'll teach me to strengthen my core and just get me doing 300 crunches a day without really understanding the way different muscles effect your core and how things need to be balaced and trained for specific movements etc.

If I didn't read a lot I'd think he'd put me onto a good thing. Many people who don't have a lot of time for their own research who will automatically trust that a personal trainer knows everything they need so the word 'core' will sell with them.

I do think that among people who do their research the evidence for needing good pelvic stability etc is out there though. I don't see a lot of genuine experts though.

I think it too complicated for most personal trainers to learn just during their course - you just about need to be a physiotherapist and/or in the business for a very, very long time with an open, questioning mind.