Rescue me.

That could be what your muscles are screaming if you're not already doing strength training several times a week. You don't have to bench-press 100 pounds at the gym to rescue your muscles from being small and lax. Free weights, resistance bands and everyday activities -- climbing stairs, cleaning the house, lifting your toddler or grandchild and vigorous yard work -- all help strengthen, tone and preserve muscle.

That's good, because with age muscle mass declines -- something you may have noticed the last time you tried to sling your carry-on bag into the overheard compartment on a plane.

Depending on activity levels, even twenty-somethings can lose small amounts of muscle. But this natural aging process picks up speed in the thirties, forties and fifties and accelerates even more quickly in the sixties, when "muscle mass makes a dramatic drop," said William Kraemer, an exercise physiologist at the University of Connecticut's Human Performance Laboratory in Storrs, Conn.

Weight training won't return the typical 60-year-old to the vitality and function of a 30-year-old. But numerous studies show it is possible to rescue and build "muscle at just about any age," Kraemer said. "Muscle does respond [to training] over the course of a lifetime."

That's why the U.S. Dietary Guidelines, the National Institute on Aging and other groups including the American College of Sports Medicine and the American Council on Exercise underscore the importance of strength training for people of all ages -- even those in nursing homes.

If you expect more muscle mass to give a big boost to your daily metabolism, as is often claimed, think again. "Add two pounds of muscle, and you burn about 24 calories of extra metabolism per day," said David Nieman, director of the Human Performance Laboratory at Appalachian State University in Boone, N.C. "If it's four pounds of muscle, you get on the order of an extra 50 calories burned per day."

That adds up to 350 calories in a week -- or about the energy contained in a tenth of a pound of fat. "You would have to go for 70 days . . . before that would translate to [burning] a pound of fat," Nieman said. Sure, over the course of a year, Nieman said, these calories could add up. "But keep it in context with everything else," including other daily activities and a healthy diet.

Here are some other myths about strength training:

* Added protein is needed to build muscle. Most Americans already eat about 90 grams of protein per day, "enough protein to meet the needs of a [professional] bodybuilder," Nieman said. "To take in a protein supplement is just crazy. . . . It's not needed."

* Pumping iron burns a lot of calories. It feels like weight training should translate to a big calorie burn, but brisk walking eats up far more calories than weight training sessions. Even heavy lifting generally burns "just 15 to 55 calories per workout," said Kraemer. "It's very low when you calculate it. . . . People do a lot of resting between sets, and the sets are usually very short." Circuit training, where you rev your heart rate by moving rapidly from weight machine to weight machine, could help burn a few more calories.

* Dietary supplements can help build muscle. Creatine and L-carnitine are two popular dietary supplements purported to help build muscle. In healthy, high-functioning athletes, creatine, which is made by muscle cells, will bulk muscle a little, "but it's primarily due to water retention," Nieman said. Creatine may help elite athletes do a few more reps in weight training, he said, but "it's not for the average person." As for L-carnitine, "there's no good data there to support" the claim that it builds muscle in anyone, Nieman said.

* Muscles bulk up fast. Studies show that it takes a minimum of 12 to 15 weeks to build muscle, provided that you do three to four sessions per week. The typical workout is six to 15 repetitions--or sets--of eight to 12 different exercises. Few people stick with the regimen long enough to build significant muscle. Those who do typically gain "only on the order of three to five pounds of fat-free muscle mass and water," Nieman said.

* Using heavy weight provides the most benefit. Too much, too soon is a recipe for injury. "Start small," said registered dietitian Leslie Bonci, Director of Sports Nutrition at the University of Pittsburgh Medical Center. "Spend the money to learn the technique. Not everyone does well with an instructional video. . . . The goal is not to do one rep with maximum weight."

Better to pick free weights or a piece of weight equipment at the gym "where you can do the exercises comfortably, you're not in agony and you like it enough that you can go back" to do it again, she said. Progress slowly and expect modest gains.

"Unfortunately," said Kraemer, "that's not something that the public wants to hear."

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