Q: Do I Need To Worry About My Cat Getting Exercise?

A: Yes. Indoor cats (which is what we're exclusively talking about here) will not, despite a common myth, find a way to get enough exercise on their own by chasing shadows and attacking shoelaces.

Cats, as we know, sleep a lot -- around 14 hours a day -- and in an indoor environment with no prey, people, or other cats around, they have a tendency to become sedentary, much like ourselves. Now, inactivity is natural for cats; in the wild, their behavior includes lots of downtime. But the domestic cat is fed by its owner, taking away that healthful and instinctive hunting activity. So do you need to, in part, assume the role of personal trainer? "Absolutely," says Dr. Elizabeth Colleran, former president of the American Association of Feline Practitioners and the owner of two west coast veterinary clinics focused on cats.

Without it, two big problems can arise, according to Colleran: Obesity and boredom.

A short list of potential effects of feline obesity, from a 2006 article in the Journal of Nutrition: Orthopedic disease, diabetes mellitus, abnormalities in circulating lipid profiles, cardiorespiratory disease, urinary disorders, reproductive disorders, neoplasia (mammary tumors, transitional cell carcinoma), dermatological diseases, and anesthetic complications.Then there's arthritis. Says the Cornell Feline Health Center: "Older cats frequently become less agile as arthritis develops and muscles begin to atrophy." They recommend "regular moderate play" to stave off arthritis.

Bored cats, meanwhile, "act out other behaviors that are considered inappropriate, like chewing on things, or scratching on inappropriate surfaces," says Colleran. "Sometimes they just plain sleep all the time, and that's no life to have."

So how do you make sure your cat gets enough exercise? Different breeds, and even different cats, have different needs. Some breeds, like the Savannah and Cornish Rex, are naturally energetic, while others, like the Scottish Fold and Persian, are less inclined to exercise. Young cats and kittens have much more energy to burn off, so need more playtime than older cats. So when do you know if your cat has had enough exercise? "When they quit!" says Colleran. How much time that will take, of course, will vary; Jackson Galaxy, cat behaviorist and host of "My Cat From Hell," recommends at least 15 minutes of intense playtime per day.

There's also a right and a wrong way to play. Cat behaviorist and author Pam Johnson-Bennett writes that "Cats are sprinters and they don't hunt by chasing to exhaustion. Because of their smaller lungs, they rely on their stealth to inch closer and closer to their prey. Once they're within ambush distance, they execute a well-timed pounce."

"Having your cat racing around until his sides are heaving," she writes, "isn't beneficial physically or mentally for him."

The key is to stimulate your cat's natural hunting instinct. Toys that simulate real-life animals are often best, like a few feathers on the end of a stick, or the very cheap, and ever-popular Cat Dancer. Heather O'Steen, of the American Association of Feline Practitioners, also recommends toys that involve food. "Food puzzles and food balls are also a great way to stimulate your cat and provide a more natural eating behavior," she writes. These are often ball-shaped hollow toys with a small hole, into which you put dry food. When the cat knocks the ball around, small amounts of food falls out of the hole, bit by bit. That encourages the cat to "hunt" for its food--and exercise while it does.

Having another cat around may also help -- if the two cats get along. (Says Colleran: "Two siblings from the same litter can keep each other amused while people are away at work.") But getting a companion cat is not an easy solution -- and will backfire quickly if the two cats don't get along. As we know, cats, notorious loners that they are, can be extremely picky about the company they keep.