How often do you walk your dog?

I, too, don't walk Gigi as often as I should. It's been over 90 degrees or higher here for the last 3-4 weeks, too uncomfortable for both of us. Plus, I don't live in the best of neighborhoods. The people who do walk their dogs here walk Pitbulls and big dogs that, quite literally, scard the heck out of me. They looks as if Gigi would make a tasty snack for them. lol But we do have a huge backyard that I let Gigi run around in and play with her back there for 20-30 minutes at a time. Wouldn't this be enough exercise for her?