At the humane society near my home, they're always looking for volunteers. Since I have such a soft spot in my heart for animals, like my pal PetSugar, I was checking out ways to help out and saw the perfect job.
You and your significant other can volunteer as dog walkers. You usually have to have some kind of orientation first, but then after that you can show up and take the dogs that are waiting to be adopted for a walk whenever you want. It gives you both some exercise, and it also helps the dogs feel more at ease when socializing with humans.
Animal shelters appreciate your help, and the dogs appreciate getting out of their tiny stall and into the fresh air where they can run around. It'll have a huge impact on the dogs you walk, and you'll feel good getting outside and running around, too.
Fit's Tips: Some shelters are closed on Sundays so call ahead to find out when they're open.