Deflating the myths about pumping up

Strength training has built up a strong set of preconceptions. They include:

It will make you bulk up.

False. In fact, it's a moot point for women, said Jennifer Menk, senior director of fitness for the YMCA of the Greater Twin Cities. "Testosterone is what makes a muscle bulk up, and women don't have enough of this hormone to build big, bulky muscles," she said.

Even men don't turn into Mr. Universe types simply by working out a couple of times a week. "Body builders train intensely for decades to build muscle," said Phil Martens, founder and fitness director at 501Fit in downtown Minneapolis.

Weightlifting decreases flexibility.

False — if you do it right, said Lindsay Marie Ogden, group training coordinator for Life Time Fitness.

"It technically shortens the muscles, but it doesn't have to," she said. "Lifting weights won't result in a loss of flexibility if you perform each exercise through your full range of motion and include stretching during and after your workout."

Muscle turns to fat when you quit lifting.

False. "It is physiologically impossible," Martens said. Adding 5 pounds of muscle burns an extra 200 calories a day, he said. When people quit training, they lose on two fronts: They no longer burn off calories working out, and they lose the muscle mass that has been burning additional calories.

"The doughnut one may get away with at work while lifting regularly now turns to fat when they stop," he said.

Weightlifting is bad for joints.

False. Just the opposite is true, Menk said. "Strength training builds muscle, which helps absorb shock and actually protect the joints," she said. "With proper form and load, women who strength train can actually avoid pain by preventing potential injuries with the strong muscles they build to support their body."

Weightlifting causes high blood pressure.

Temporarily, yes. The act of lifting a weight makes your blood pressure rise, especially if you hold your breath while doing so. "Any exercise of any kind performed while holding the breath will increase blood pressure dramatically," Martens said. "So smooth breathing is paramount."

But long-term, the statement is false. "Strength training can actually have positive effects on blood pressure, much like aerobic exercise," Menk said. "When a woman participates in moderate strength training two or three times per week, both systolic and diastolic blood pressure can be reduced significantly."

All the experts said that people with high blood pressure should check with a doctor before starting any exercise program.

You need to eat more protein when weight training.

You don't need to do strength training if you participate in an endurance sport such as running.

False. It helps everyone, Ogden said. "I've known many runners to cut back on the running and increase the cross training — strength work — and achieve personal bests on races," she said.

Martens agreed. Even non-athletes can benefit, he said.

"Having a little extra muscle on the body in adulthood is like having a little extra money in a retirement account," he said. "You will need it later."