Britt McDermott has no trouble picking up her 7-year-old, 53-pound son. Carrying loads of groceries for her four children isn't a big deal either. Running up hills is easier than it used to be, too.

The reason is simple: muscles.

Not big, bulging ones, but strong, supple muscles that she's developed through a regular routine of strength training.

She doesn't fit the stereotypical image of a husky male weight-trainer trying to bulk up. McDermott is a 38-year-old Carmel, Ind., mother of four and a certified public accountant who has kept in good cardio shape through running.

But she does fit the profile of a growing number of women getting into strength training — using anything from free weights and machines to resistance bands, stability balls and weight bars. Men, too, seek health benefits, in addition to being motivated by six-pack abs.

Trainers now are pushing so-called "functional" strength training, developing and toning muscles for day-to-day activities — going up steps, carrying groceries and kids, golfing. It also helps maintain balance to prevent falls, lower body fat or prevent increases, curtail bone loss, boost metabolism and even lower blood pressure.

"It has made a huge difference in how I feel and how my clothes fit," says McDermott. "I wasn't muscular when I started. My upper body was weak. Now, I get comments on my shoulders all the time. They ask, 'Do you work out?' " she says.

But it doesn't take a lot of time to get results, say personal trainers. Two or three times a week, 25 to 40 minutes, is plenty. And people of any age, even in their 70s, can start and benefit from strength training, given no other health issues.

Since January 2005, McDermott has done an hour of strength training twice a week at Better Bodies in Zionsville, Ind., with owner Mitch Schroder.

She's among the 17.5 percent of women who do at least twice-a-week workouts, according to a federal study by the U.S. Centers for Disease Control and Prevention. That 2004 figure is up from 14.5 percent in 1998.

The study, tracking strength training among more than 30,000 adults nationally, showed nearly one out of five U.S. adults do it, including 22 percent of men. Their rate has held fairly steady.

What's holding back more?

"There are still a lot of people who look at strength training as something that men do who want to get big and bulky," says Brian Holdsworth, personal trainer and owner of Anytime Fitness in Zionsville. "They don't look at the health benefits of strength training."

For women, the fear of getting bulky is unfounded because they don't have enough of the hormone testosterone, he says.

When you build muscle through strength training, Schroder says, the added muscle burns more calories daily, which can help you lose weight or maintain weight loss.

Exercise like walking does not stave off the loss of muscle that often accompanies aging — about 7 pounds per decade for men, 5 pounds per decade for women, according to the American Association of Retired Persons. This slows down resting metabolism.

Much of that decline in muscle mass can be halted, and even reversed, by strength training, which is typically recommended along with cardio and flexibility exercises.

For Victoria Wesseler, 53, all she has to do is look in the mirror for motivation to continue strength training. At age 50, she gained about 12 pounds, despite spending an hour a day on the treadmill.

"It was frightening," says Wesseler, who is winding down her consulting firm on business ethics and compliance. "I wanted to lose the weight, but I wanted to be stronger, too."

So she enlisted Jason Stuckey, co-owner of PUSH Fitness for Women, to set up a strength-training program she could do in her basement with free weights and resistance bands three days a week, followed by a treadmill workout. She started taking Pilates and changed her diet, eliminating all refined sugar, flour, alcohol and processed foods.

"I feel the best I've ever felt in my life. I can see my biceps. My arms are getting firmer."

And she can do 30 regular push-ups, not the kind balancing on your knees. "That was my tah-dah moment. I could do a real push-up. There's a real feeling of power."

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Women in the weight room