Welcome to the forum
I know what u mean about exercise with a 4 year old, I have a 4 year old boy and its really hard to exercise with him, his little legs dont go too fast and get worn out quickly
So, we still go for walks, but slower ones, they are great for you and the kids, just getting out of the house into the fresh air... Even if u dont like them (and I used to HATE them!) exercise dvds can be fantastic...and Im sure your 4 year old will join in with you (mine does and has a ball!
) Good luck with the weight loss