A new body of work. Linda gets tough in T2.

She looks like a sweet young thing in her sundress and straw hat complete with chin strap, with long, high school-style hair pouring over her shoulders. But don't be fooled. Linda Hamilton can bench-press 85 pounds as easily as she swings her Evian bottle. She can pump-load a 12-gauge shotgun with one arm and run eight miles before lighting up a Camel. The 5-foot-5 1/ 2-inch, 112-pounder in the white anklets and tennis shoes can hold her own against both man and machine when it comes to super-strenuousness in T2.

In a summer of machisma movie madness, Hamilton's Sarah Connor makes Thelma and Louise look like Ethel and Lucy. In reprising her role as the mother of the boy who's supposed to save mankind, Hamilton may have found the launching pad of her career. She has metamorphosed into a fierce, humorless commando. And she has transformed her softly feminine physique, best remembered from the 1987-89 CBS series Beauty and the Beast, into a hardbody even a five-time Mr. Universe can admire. "All last summer I couldn't wait to take my clothes off," says Hamilton of her new musculature: bulging biceps and delineated shoulders, a washboard stomach and marathoner's legs. "I'd pull my little crop top up -I had a running bra on - for anyone who wanted to see. It's just wonderful when you fall in love with your body. Arnold was low-key at first, but then when he saw how strong I was, he was thrilled." He even let her loose in the gym he sets up on locations and taught her how to pose with her best bicep forward.

Hamilton, 34, was a recent mother (her son, Dalton Abbott, is now 20 months old) with a few pounds of baby fat left when personal trainer Anthony Cortes began working with her last summer, 13 weeks before T2 shooting started. They trained for three hours a day, six days a week, usually in the garage of the actress' Santa Monica home. Hamilton also shed 12 pounds on a nonfat diet that revolved around cereal with skim milk, chicken, and dry salads. The regimen continued throughout the grueling six-month shoot. Her drills included aerobic exercise (running, biking, swimming, or stair-climbing) followed by free weights interspersed with mini-trampoline work-and, for dessert, walking lunges or an abdominal series.

On top of all that, Hamilton says, an Israeli commando, Uzi Gal, primed her for action scenes with "judo and heavy-duty military training. I learned to load clips, change mags, check out a room upon entry, verify kills. It was very vicious stuff. And it was sheer hell." She went through the training "because Sarah would have," but she did set limits. "He would have liked to have had me swimming in the ocean at dawn with a 50-pound pack," she says. "But I have a son who needed me too." In fact, Dalton was often on the set, and he makes his screen debut as Hamilton's young film son in a school-yard dream sequence.

Another family member also appears briefly in the film: Hamilton's identical twin sister, Leslie Gearren, a nurse and the mother of three in New Jersey, was tapped to play a cyborg Sarah Connor (she's the one standing farthest from the camera, wearing hair extensions, in a dramatic scene near the film's end). "They were going to use a process shot for the double," Hamilton says, "but they flew Leslie in and were delighted." The experience was a far cry from the sisters' community-theater days growing up in Salisbury, Md. "We were shooting in freezing temperatures in a steel mill, and they had to wet us down," Hamilton says. "Leslie got a glimpse of how tough it can be to do this stuff."

Although she claims that "anything that scares me I want to do," Hamilton would like to move away from action-adventure into "stylish, sophisticated comedy, like Grace Kelly or Audrey Hepburn." She knows that T2 is not exactly a showcase for her comedic talent. "People aren't going to look at this character and think, 'Wow, she's so funny!'" she says. "But I have a very good sense of humor. It's the only way to get through life."

Recently divorced from Dalton's father, Bruce Abbott (TV's Dillinger), Hamilton has been through six nannies and says she slept an average of four hours a night during the shoot. "Sometimes I'd get home at dawn and Dalton would just be getting up. You can't look at your child and say, 'Sorry, Mommy's tired, she's going to bed.'" Rumors now link her with T2 director Cameron (who is married to Point Break director Kathryn Bigelow), but the actress deflects queries with an exhalation of cigarette smoke.

So how's that body doing? "I want to feminize it a little," says Hamilton. "I've relaxed the fat thing, and I'm down to five workouts a week-if I'm lucky. I'm not panicking about it. I still look good." And she's set her sights on some other new goals besides becoming the next Grace Kelly. "I'd like to sleep for eight hours one night," she says. "And I'd like to stop smoking."