Exercise with your pet: An owner's manual

A brisk walk is arguably the best form of overall exercise for both dogs and their owners. For older and less active dogs, begin fetch games indoors with a favorite plush toy. Canine athletes can participate in organized sports for dogs, including those that also burn up people calories, like "agility" (an obstacle course for pooches, where people instruct their dogs by running alongside them) and "freestyle" (dancing with your dog). Others, like "canine disc" and "flyball" (doggy relay races), aren't as calorie-intensive for people but are great workouts for dogs.

Cats
Most well-fed cats come when they're called -- it's just that they respond to the call of what really motivates them: the electric can opener or refrigerator door. If you say "Muffin, come" as you simultaneously use the can opener or open the fridge, soon he'll associate his name with dinner. Once you've got that down, hide in another room and call your cat for a game of kitty hide and seek. Play "chase me" with a feathered fishing pole-type toy, and race Kitty from room to room.

Use a laser light to give a high-impact workout to cats that already are in good shape. (Don't allow children to do this unsupervised; shining the light in the cat's eyes or their own can be dangerous.) Never make the game impossible by sweeping the light up the wall and onto the ceiling. To avoid frustrating your kitty, drop a treat on the light several times during the game so he can sometimes "catch" that little red bug.

Horses
You burn almost 120 calories per half-hour riding at a trot, but you can increase the exercise by matching the horse's workout. Nicole McCorkle of 'Humble R' Ranch in Aubrey, Texas, actually runs with her horses: "I take my horse out on lead into the sand arena and run with him at my side for 20 minutes. Sometimes I sprint, and he trots faster with me. I've even taken him on cross-country runs."

Other pets
If you have an overweight bird and can let it out safely, perch it on your arm and move the arm up and down. You'll get toned arms, and the bird will get a workout from flapping his wings to keep his balance. You can even exercise a lizard or a frog by moving its food dish from place to place and periodically rearranging the rocks and plants in its home. The animal, naturally curious, will happily investigate the new floor plan.