I agree with some of the pp about walking/jogging/running. Spend some money on a good pair of shoes, which would still be less than a personal trainer of gym membership.
I bought some good shoes last year and started walking, then worked my way up to jogging, I have not lost a lot of pounds, but my body looks completely different. I've lost inches.
We use the stroller, go on family walks, etc.
I also put my running shoes on when I am housecleaning. Somehow...