Fact vs. Fiction

The guy lifting beside you looks like he should write the book on muscle. Talks like it, too. He's worked out since the seventh grade, he played D-1 football, and he's big. But that doesn't mean he knows what he's talking about. Starting now, ignore him.

The gym is infested with bad information. Lies that start with well-intentioned gym teachers trickle down to students who become coaches, trainers, or know-it-all gym-rat preachers. Lies morph into myths that endure because we don't ask questions, for fear of looking stupid.

Scientists, on the other hand, gladly look stupid--that's why they're so darn smart. Plus, they have cool human-performance laboratories where they can prove or disprove theories and myths. Here's what top exercise scientists and expert trainers have to say about the crap that's passed around in gyms. Listen up and learn. Then go ahead, question it.

Myth #1
Lifting incredibly slowly builds incredibly big muscles.

Lifting super slowly produces superlong workouts--and that's it. University of Alabama researchers recently studied two groups of lifters doing a 29-minute workout. One group performed exercises using a 5-second up phase and a 10-second down phase, the other a more traditional approach of 1 second up and 1 second down. The faster group burned 71 percent more calories and lifted 250 percent more weight than the superslow lifters.

Myth #2
If you eat more protein, you'll build more muscle.

To a point, sure. But put down the shake for a sec. protein promotes the muscle-building process, called protein synthesis, "but you don't need exorbitant amounts to do this," says John Ivy, Ph.D., coauthor of Nutrient Timing. If you're working out hard, consuming more than 0.9 to 1.25 grams of protein per pound of body weight is a waste. Excess protein breaks down into amino acids and nitrogen, which are either excreted or converted into carbohydrates and stored.

Find out what the real expert says!

Myth #3
Leg extensions are safer for your knees than squats.

And cotton swabs are dangerous when you push them too far into your ears. It's a matter of knowing what you're doing. A recent study in Medicine & Science in Sports & Exercise found that "open-chain" exercises--those in which a single joint is activated, such as the leg extension--are potentially more dangerous than closed-chain moves--those that engage multiple joints, such as the squat and the leg press. The study found that leg extensions activate your quadriceps muscles slightly independently of each other, and just a 5-millisecond difference in activation causes uneven compression between the patella (kneecap) and thighbone, says Anki Stensdotter, the lead study author.

Find out what the real expert says!

Myth #4
Never exercise a sore muscle.

Before you skip that workout, determine how sore you really are. "If your muscle is sore to the touch or the soreness limits your range of motion, it's best that you give the muscle at least another day of rest," says Alan Mikesky, Ph.D., director of the human performance and biomechanics laboratory at Indiana University?Purdue University at Indianapolis. In less severe instances, an "active rest" involving light aerobic activity and stretching, and even light lifting, can help alleviate some of the soreness. "Light activity stimulates bloodflow through the muscles, which removes waste products to help in the repair process," says David Docherty, Ph.D., a professor of exercise science at the University of Victoria in Canada.

Myth #5
Stretching prevents injuries.

Maybe if you're a figure skater. Researchers at the Centers for Disease Control and Prevention reviewed more than 350 studies and articles examining the relationship between stretching and injuries and concluded that stretching during a warmup has little effect on injury prevention. "Stretching increases flexibility, but most injuries occur within the normal range of motion," says Julie Gilchrist, M.D., one of the study's researchers. "Stretching and warming up have just gone together for decades. It's simply what's done, and it hasn't been approached through rigorous science."

Find out what the real expert says!

Myth #6
You need a Swiss ball to build a stronger chest and shoulders.

Don't abandon your trusty bench for exercises like the chest press and shoulder press if your goal is strength and size. "The reason people are using the ball and getting gains is because they're weak as kittens to begin with," says Craig Ballantyne, C.S.C.S. You have to reduce the weight in order to press on a Swiss ball, and this means you get less out of the exercise, he says.

Myth #7
Always work out with free weights.

Sometimes machines can build muscle better--for instance, when you need to isolate specific muscles after an injury, or when you're too inexperienced to perform a free-weight exercise. If you can't complete a pullup, you won't build your back muscles. So do lat pulldowns to develop strength in this range of motion, says Greg Haff, Ph.D., director of the strength research laboratory at Midwestern State University in Wichita Falls, Texas.

How Strong Are You?

The truth is trickier than you think

When exercise experts look at strength, they look beyond the bench press and squat, which measure only absolute strength--the amount of force you can exert. But a bench-pressing behemoth with an injured shoulder is not strong. "The essence of strength is being able to use the right muscle at the right time with the right amount of force to accomplish your goal," says Mike Clark, president of the National Academy of Sports Medicine.

His definition of a strong man: a guy who can perform any exercise or daily task without pain or injury. This starts with understanding that your muscular system comprises two systems, one for movement and one for stabilization. The movement system produces force by using big muscles like your pecs and lats. The stabilizing system controls your joints and utilizes smaller muscles like your lower trapezius, your posterior deltoids, and the muscles of the rotator cuff.

"Most injuries occur because the stabilization system is not strong and the movement system is overly dominant," says Clark. You need to build both equally to avoid injury and perform better.

Alternate strength and stabilization exercises to enhance your endurance. For instance, do Swiss-ball pushups immediately after you bench-press; perform a squat followed immediately by a single-leg squat. If your stabilizing muscles are obviously weak--your shoulders are rounded, for instance--then begin your workouts with stabilizing exercises.

Aim to improve posture, flexibility, and power as well. You can follow strength exercises with power moves such as the medicine-ball chest pass, plyometric pushup, and jump squat. Incorporate core and flexibility moves to round out your routine.