Gertrude McDermott already knows what she wants for Christmas: Wii Sports. She loves the Red Sox — especially Kevin Youkilis — and fell in love with Wii Baseball after her first inning.

If she's lucky, maybe her grandchildren will buy it for her.

That's right. This 72-year-old Hampstead, N.H., grandmother is part of a rapidly growing segment of the Silent Generation who can't get enough of Wii, Nintendo's interactive video game system, which allows players to simulate the physical motions of sports like bowling, baseball and golf with a wireless controller.

The game system, which launched in November 2006, offers low-impact exercise to those who aren't likely to participate in the actual sport at their late stage in life.

"I like this better than the real thing," said Jeanne Cooke, 85, also of Hampstead. "It's not at all heavy, so it's easier on your knees."

The Friends of the Hampstead Public Library purchased a Nintendo Wii video game system last spring to entertain kids at the library. But a few times this summer, a tight-knit crew of senior women, including McDermott and Cooke, have participated in Wii tournaments, playing virtual bowling, golf and baseball.

It's the interactive aspects of Wii that appeal to these senior women in ways that other video games didn't.

"I'm not about to sit all day and click, click, click," Cooke said while tapping her two thumbs on an invisible gaming console. "I'm too active for that. I'd rather get out and garden."

Seniors around the region appear to agree. Haverhill High School students are teaching seniors how to play at the Citizens Center in Haverhill. The North Andover Senior Center has a Wii, as does the Merrimac Senior Center and the Ingram Senior Center in Salem, N.H.

Just don't ask these aging gamers the name of the popular program.

"What is it called — W-2?" Cooke asked as she picked up the remote during a recent two-hour Wii marathon at the Hampstead Public Library.

"I keep wanting to call it 'Why' instead of 'Wee,'" said Louise Pryor of Hampstead, who said she is "well over 70."

Increasingly, physical therapists are also turning to Wii to help seniors with functional endurance, balance and attention to task. For those who have suffered strokes or neurological damage, the game can help patients with their cognizant-physical connection by having to press a button or move their arm to play the game at hand, said Glenn Fogg, a recreational therapist at Northeast Rehabilitation Hospital in Salem, N.H.

Therapists at Northeast Rehab started using Wii a year ago, and it's already created a real sensation with patients of all ages. Fogg used the game with five patients in just two days last week.

"It's not too scary that some older adults and seniors would be scared to touch the remote," Fogg said. "It's unique in a way that folks can enjoy the activity, and there's a level playing field for everyone to enjoy the technology. Some seniors, once they have a little experience with it, tell us, 'We're going to get that for home.' It's a new way to promote therapy and social values, because the game does allow people to be together and host an afternoon of virtual bowling."

Bowling seems to be the most popular game. Most seniors have fond memories from the bowling alley during their teenage years. Plus, Wii Bowling can be played from a wheelchair or more actively by taking a few steps down the virtual alley, Fogg noted.

Hampstead resident Cay Robbins, 89, has only tried Wii Bowling. She grinned and giggled whether she rolled a strike or threw a gutter ball.

"My father would take us bowling when I was a child. I just loved it," she said. "When you really bowl, your hand is flat. This is hard because you have to get used to holding something in your hand."

Massachusetts General Hospital's Physical Therapy Inpatient Service Department has a Wii on order, and plans to use it with multiple patient groups, including their older adult patients.

Katharine Teele, now a staff physical therapist at MGH Inpatient Service, observed seniors' visible display of fun playing the Wii at a previous therapy center.

"It works fantastically well," she said. "They participated in groups, and there was competition and interaction and diversity with the activities. It was surprising to them how easy it was for them to use, and you would hear them all say, 'I used to bowl when I was younger,' or 'I haven't played baseball in 60 years. I almost feel young again.' They really looked forward to it."

Glenna Dowling, a professor of physiological nursing at the University of California, San Francisco, is working on a new Wii therapeutic game to improve gait and balance among patients with Parkinson's disease.

"We did some trial access testing in a classroom program where patients came once a week. The research did suggest that in a number of gait and balance exercises that, in part, it can benefit the patient," said Dowling, who is also the director of the Institute on Aging Research Center in San Francisco. "We've identified gestures that we want to translate into a video game platform. It's really done with some gestures and three basic games we're writing."

For seniors who are relatively stable, Dowling thinks Wii allows them to keep fit and moving. But not everybody would like to see it replace supervised care.

"I don't support in-house therapy at all because it can't be corrected if the person is doing something wrong," said Bob Worden, founder and president of Pinnacle Physical Therapy in Plaistow, N.H. "Plus, there are plenty of things that are not safe, with coffee table corners, slippery rugs. I like it when seniors are doing their exercises in a safe area with the supervision of an exercise group."

The Hampstead women did find it a little tricky to get the hang of pressing the A button with their thumb, doing the arm motion of bowling and then pressing the B button with their index finger to release the virtual ball.

But Ellen Edwards, director of the Hampstead Senior Drop-In Center — who is several decades younger than her Wii competitors — also struggled to get the timing down.

"Just a little twist of the wrist can make all the difference between a strike and just a few down," Robbins said.

Cooke excelled at the golf competition, noting that she "played golf before they had carts." And Pryor strongly encouraged the group to step up its endurance and try Wii Baseball.

"Bowling was the easiest because I'm so used to it," said Pryor. "I would like to try baseball again, just to see if I could get a hit."

Maybe at the next Wii party.