Since having kids, my wife and I have really let ourselves go. How can we get healthier and improve our bond?

We've both gained weight (especially me I look awful!). We've just kind of lost that spark in our relationship. It seems like we're not really that attracted to each other anymore. We don't really do anything like we used to (for example exercise together, go on trips, etc). It's like we're old frumpy dumpy's and we're only in our early 30's. It's like we're just together for the kids now. Any helpful advice?