NEW YORK (Reuters Life!) - Strength training for women is a weighty issue.
Despite building stronger bones and providing a metabolic boost that burns fat for hours after a workout, experts say too many women resist it because of a misplaced fear of morphing into the Incredible Hulk.
"People who lift weights are generally leaner," said Lou Schuler, a strength and conditioning expert. "This idea that pounds of muscle are suddenly going to appear on a woman's body because she lifts weights is just a delusion."
Unlike body building, in which the goal is aesthetic, the goal of strength training is to get stronger.
Schuler, the author of the book "New Rules of Lifting for Women," says for most women getting huge is simply not in the genetic cards. But you need a bit of muscle on those bones.
"To get definition you need the muscles a little bigger and you need the leanness," he said. "Women have to lift weights big enough to have an effect on muscle mass and strength. You want to get progressively stronger with heavier weights, fewer repetitions."
According to the National Center for Health Statistics, only 21 percent of women strength train, despite government guidelines that call for adults to do resistance, or strength training, two or more days a week.
Jessica Matthews, of the American Council on Exercise, said getting women to the weight room is still an uphill battle.
"Most women are really looking for the toned look. That's just general muscle fitness," she said.
Body building, by contrast, works muscles in isolation.
"A well-rounded strength training program is functional and a great way for women to build and maintain lean body mass. It will not lead to that bulky appearance."
For most women, Matthews suggests eight to 10 or 12 to 15 repetitions using a moderate weight to gain muscle strength.
"The muscle worked should be fatigued at the end of that last repetition," she said. "If we wanted to develop muscle size, we'd be training at higher weight, with fewer repetitions."
By stressing the bones strength training increases bone density and reduces the risk of osteoporosis, which the National Osteoporosis Foundation says afflicts an estimated nine million women over age 50 in the United States.
But Matthews said what sells weight training to the young women she has worked with is the afterburn.
"Strength training makes the body more efficient at burning fat," she explained. "It enhances your metabolism even while you're sitting at your desk."
The exact number of additional calories burned varies from one study to another.
"I've seen anywhere from seven to 10 calories a day," she said, adding that form is crucial in strength training, for safety and to ensure that you're working the same muscle you're targeting.
"Even in a lunge. If you want a great butt, a smaller step forward will work those glutes, but a larger step will work the quadriceps," she added.