Alternatives

I think from the quality of the photo it's obvious I didn't have much choice...so this is an image of a friend showing me alternatives to a sit up, all on zoom! I'm into my 10th week of five HIT classes a week and while progressively I'm getting stronger/fitter, my stomach muscles don't seen to be getting much better. Maybe I'm just doing the exercises all wrong or maybe three kids later they just don't work so well anymore!