I sat there glued to the TV, trying to imitate the model on the video, who was cheerily flexing her zygomaticus muscles - which run from the cheekbone to the corners of the lips - and keeping the rest of her face relaxed.

Not so easy. Then she worked her levator labii superioris, raising her lips up into a sneer. Then she attacked her chin, working the depressor labialis.

We should be doing these exercises 10 to 15 minutes a day, six days a week, according to the narrator, a 71-year-old British lady named Eva Fraser, who's about to launch in this country the "facial fitness" program she's promoted for years in England.

On the video, Fraser, who looks closer to 50, spoke through clenched teeth, her face barely moving. Were her muscles so exhausted from all her facial workouts that she could no longer move them?

No, she was not her usual animated self in the video, she explained in a telephone interview, because she was trying to keep still so the microphone didn't pick up extra noise.

In any case, her take-home message seemed to make sense: Weak muscles, sagging face; strong muscles, a young, vibrant one.

Too bad it's not true.

The real problem when faces droop with age, it turns out, is loss of collagen in the skin, the pull of gravity on fascia (that gristly tissue that lies between muscles and skin), and the loosening of facial ligaments.

And, sadly enough, exercise is useless for collapsing collagen, falling fascia and lax ligaments.

That means, at least as doctors see it, that not only won't facial fitness do you much good, neither will those mouth-stretching gadgets called Facial Flex, advertised in magazines and the Internet, or electrical stimulation devices like those also touted on the Net by Boulder, Colo., esthetician Kay Young.

Now, you could take the cynical - or is it the hopeful? - view that dermatologists and plastic surgeons would naturally dump on exercise and other do-it-yourself tricks because they can make a fortune doing chemical peels, facelifts, and other nips and tucks that may hide the ravages of age.

But the doctors make a pretty good case against facial workouts.

Exercising may "work partly," concedes Dr. Jessica Fewkes, a dermatologist at the Massachusetts Eye and Ear Infirmary in Boston. "It can work on the part of the face that is due to just sagging muscles. . . . But a lot of our drooping skin isn't necessarily due to muscles; a lot of it is due to photoaging."

Photoaging is caused by exposure to sunlight. The ultraviolet light destroys the elastic fibers in skin that hold it together, causing the collagen to become much thinner.

"When you pinch a baby's cheek," Fewkes says, "it has a nice, solid feel to it. When you pinch your mother's skin, it's thin. It's missing that layer. That's not muscle we've lost, it's collagen."

That's why "the number-one thing for looking good is sun protection," she adds. Indeed, people with darker skin, like blacks and Asians, "tend to look younger longer because they have so much pigment in their skin they don't get the same radiation damage."

Exercising facial muscles "really won't do anything for the sagging face," says Dr. Devinder Mangat, a Cincinnati plastic surgeon and president of the American Academy of Facial, Plastic and Reconstructive Surgeons.

Jowls, for instance, which often run in families, are caused "almost 100 percent by displacement of the `SMAS' [or superficial muscular aponeurotic system] layer of fascia," says Dr. Mack Cheney, director of facial and cosmetic surgery at Mass. Eye and Ear.

In a face lift by plastic surgery, it's this layer of tissue that is "redraped" over bone and muscle to tighten sagging cheeks, says Cheney.

And facial exercises could make some problems worse.

Horizontal lines in the forehead are caused by the frontalis muscle. "The stronger this muscle gets, the deeper the creases," says Cheney. "So strengthening the frontalis muscle is a negative thing. It will make furrows deeper."

Short of a face lift, what may help for forehead furrows, including vertical ones in the corrugator muscles between the eyebrows, is botox, or botulism toxin. While botulism is fatal if injected in high doses, in the tiny doses injected cosmetically, it can paralyze the frown muscles for a few months without causing harm.

Puffy eyes aren't caused by muscle weakness, either, even though the eyes are surrounded by the orbicularis oculi muscle.

The problem with droopy eyelids - upper and lower - lies with a ligament-like structure called the orbital septum, which lies just below the muscles, and stretches with time.

"Exercises wouldn't help that," he says. "It's not muscle that's holding the orbital fat, which produces the puffiness. It's this ligament-like structure."

And what of those Facial Flex gadgets that you put in your mouth to exercise muscles in the lower face? The ads tout research suggesting these gadgets can increase muscle strength by 250 percent.

Sorry, they can't. "If you're trying to get improvement in skin and fascia, a stronger muscle won't do that," says Cheney.

And electrical stimulation to tone the face? "That is unlikely to help, either," he says.

The bottom line is simple. Forget facial workouts. You'll have to love the face you've got - unless you choose to go under the knife.

Judy Foreman is a member of the Globe staff. Her e-mail address is: foreman@globe.com.

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