I took a core fitness class for almost a year with the mantra to keep my core engaged all through the class. I got nowhere. Unless the work I'm doing actually requires my core be engaged, just trying to engage it doesn't happen.
Okay, so I do squats, presses, deadlifts. That's supposed to engage my core, right? I must be a genius at being able to do things without any core strength because I never felt like I was working very hard on my core but hey, I'm lifting the weight so my core must be engaged. Then I was shown how to do an overhead squat with a 25lb bar. Holy crap. So THAT'S what the core does? I have no core strength at all.
If I want core strength I have to actually force my core to work. I still haven't found a good way to do that.
Female, 5'3", 50, Max squat: 202.5lbs. Max deadlift: 225 x 3.