Like minded peopleI do, on a Monday evening, about a 75 minute session. I don't know what type though.
I'm still waiting for it's benefit in climbing hills, but i'm aware of engaging my core when riding. Or lifting anything heavy, changing gear in the car it even climbing the stairs. We use our core more than we think we do.I've suffered from back problems for years (disc related).
Pilates is an excellent way of building up abdominal core muscles. I used to do it quite a bit, although sadly have got out of the habit.
It also benefits cycling as i find when cycling up hills, engaging the core muscles improves the efficiency of getting leg power into the pedals and you get a burst of speed.