F or years, the focus of strength-

training science was almost en-

tirely on building bulk. But the

latest research shows that you can’t reach

optimal size unless you bring other factors

into play. Organizing your workouts around

movement patterns, a concept we’ll talk

about throughout this book, is one key

factor. Another is developing the network of nerve fibers that thread through

muscles and eventually snake back to the brain. Every time you lift, the body

releases chemicals that thicken individual muscle fibers so they contract with

more force. Lifting increases the supply of capillaries, the tiny networks of

blood vessels that carry in nutrients and cart away

wastes. At the same time, the endless repetition of

lifting conditions nerve fibers and improves their ef-

ficiency at firing muscles into action. That’s why a

tall, lean man who lifts smart and develops a finely

honed nervous system might be stronger than the

stocky man with tree-trunk legs and a barrel chest.

What you want, of course, is to bring all these

factors into play. Even if you lift for practical rea-

sons—to protect your back, say, or build endurance

for weekend sports—there’s a lot to be said for de-

veloping a physique that not only works well, but

gets noticed. That’s what this book is all about.

B R E A K ’ E M D O W N , B U I L D ’ E M U PEvery man has a mix of slow-twitch and fast-twitch

muscle fibers. Fast-twitch fibers are the ones that

contract powerfully and give pure strength. They fa-

tigue quickly, which is why you might be able to curl

a 50-pound dumbbell just a few times. The slow-

twitch fibers are made for endurance. They can’t

propel the kinds of force generated by fast-twitch

fibers, but they can go just about forever.

Each of your skeletal muscles is made up of

water, protein, fat, and carbohydrates, along with

glycogen (the stored form of blood sugar) and a host

of amino acids and chemical compounds. All of the

usual lifestyle factors—good nutrition, good sleep,

adequate rest between workouts, and so on—are

critically important in any lifting plan. Men who op-

timize these factors while maintaining a tough

workout regimen can achieve steroidlike results

without ever touching those noxious drugs.

There’s another factor, not related to lifestyle,

that can take you from merely fit to built. It’s called

muscle damage. We’re not talking about pain or

H O W M U S C L E S G R O W 3

1HOW MUSCLES

GROW

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post-workout soreness, though those are pretty good

indicators of what’s happening beneath the surface.

At the level of individual muscle fibers, damage and

destruction are your best friends.

Strip away all the scientific jargon. Weight lifting

boils down to what trainers call the progressive

overload of skeletal muscles—in other words,

pushing those muscles harder than they’re accus-

tomed to working.

Every time you lift, you produce tiny tears in

the muscle fibers. Depending on your level of fit-

ness and how hard you work, the tears can be as

small as just a few molecules across, or large

enough to affect entire muscle cells (along with the

supporting connective tissue). The body then re-

sponds to tears in muscle fibers by making bigger

proteins as well as more proteins, which translates

into bigger muscles.

You obviously don’t want to lift yourself into

traction. But you need some damage, and that

means pushing yourself. A man who never taxes his

muscles to their uppermost limits can lift every day

for years without gaining appreciably in size.

Conversely, the man who overloads his muscles the

right way will get bigger much faster.

The process of tearing down and rebuilding

muscle is incredibly complex. Basically, here’s what

happens.

• When you lift, damaged muscle tissues release

signaling factors, substances that attract neu-

trophils, macrophages, and other immune cells

to the damaged site.

• The immune cells trigger inflammation. This

process is designed to remove damaged tissue

from around the torn fibers. If you’ve overdone

it, the inflammation might be painful. If you’re

lifting smart, however, you’ll just feel a pleasant

tightness.

• The immune cells release substances that stim-

ulate the production of cells called satellite cells.

The satellite cells, stimulated by hormones and

other anabolic chemicals, then merge with the

muscle cells as part of the repair process.

At the end of the process, the muscle tear is repaired.

But the muscle itself isn’t quite the same one you had

before because it’s gained additional and larger cells.

It’s like nailing a 2-by-4 to a shaky gate. The struc-

ture is stronger—and bulkier—than it was before.

The traditional thinking was that muscles in-

4 T H E S C I E N C E O F S I Z E

NOKIDDING? M O R E R E P S O R M O R E W E I G H T ?

It’s probably the oldest locker room debate, and still the most common: Do you get optimal results using the heav-

iest possible weight, even if you can only finish 1 repetition? Or is it better to stack up the reps using lower weights?

The definitive answer: It depends.

If your goal is to boost endurance, higher reps at lower weights make sense. But most men want to gain muscle

and definition. To do that, you need to push serious iron.

A recent report compared the effects of different training loads on strength and muscular hypertrophy (increased

size). Men who lifted 80 percent to 95 percent of their 1 repetition maximum—the heaviest weight they could lift

once at full-out exertion—had greater increases in size than those who stuck with lower weights.

001-018_MaxMuscle_01PREP 10/4/05 8:16 AM Page 4

takes work, a lot of it. But the initial “quick jumps”

in strength when you start lifting, or bump up your

workouts another notch, have relatively little to do

with muscle size. They’re mainly due to neural fac-

tors—alterations in the nervous system that increase

force and power in an astonishingly short time.

Think of these gains as confidence builders. You’ll

move up in weights very quickly. The heavier

weights take you further into the realm of muscle

overload, and that’s the secret to size.

Nothing increases muscle mass faster than

lifting, not even steroids. In a 10-week study that di-

rectly compared weight lifting with steroids for

muscle gain, guys on a lifting program increased

their bench weight by 22 pounds, compared to the

19-pound gain among men taking steroids. The

lifters increased their squat poundage 55 pounds,

compared to a scant 28 pounds in the steroid group.

Nor will combining aerobic exercise and strength

training increase your muscle gains. Aerobic work-

outs can get the heart and lungs working like a bass

variably reached the point at which increases in size

basically stop. New research suggests that doesn’t

happen. It’s possible that once muscle fibers reach

a certain size, they split like twigs on a tree, creating

more muscle fibers. Each of these new fibers will

grow until it reaches maximum size, then it will split

again. This could mean that every man can keep get-

ting bigger, no matter how long he’s been lifting.

B I G G E R , F A S T E RThe ripped physiques and hard-core musculatures

that most men would kill to have don’t come

quickly. But you can get there a lot faster than you

probably think. Scientists have known for almost 50

years that muscular strength increases rapidly when

men start a lifting program. Gains in maximal force

of up to 15 percent have been measured after a

single training session.

Obviously, no one becomes Schwarzeneggeresque

in a few days—or a few months. That kind of build

H O W M U S C L E S G R O W 5

T H E “ T E R M I N A T O R ” G E N EMen are undergoing record numbers of appearance-enhancing procedures these days, but at some point, we might

look back on hair replacement and chest implants as relics from the Dark Ages. On the horizon: the ability to ma-

nipulate a man’s genetic material to create massive size without a hint of sweat.

Scientists have discovered some of the genes that control muscle growth. Some genes limit size; others enhance

it—sometimes to a startling degree. When scientists blocked the myostatin gene, mice and cows developed double

the usual amount of muscle. Other genetic pathways, such as the Akt/p70S6 kinase protein synthesis pathway, may

cause an increase in muscle growth and an accelerated rate of fat burning.

Leaner and bigger without lifting a finger, let alone lifting weights? It’s a tantalizing possibility, though light-years

from reality at this point. The studies have been done on animals, not humans. And genetic tinkering is always risky.

It’s impossible to predict what might happen when genes are artificially switched on or off. The genes that control

muscle growth might turn out to control other things, as well.

So, don’t give up your gym membership yet. Even if it were possible today to get that genetic edge, the men who

work out hard would still be a step ahead.

001-018_MaxMuscle_01PREP 10/4/05 8:16 AM Page 5

drum. Aerobic exercise also boosts endurance, burns

more fat calories, reduces the risk of dozens of dis-

eases, and generally makes you healthier. What it

won’t do is make you bigger. In fact, it has just the

opposite effect.

Researchers looked at gains in strength and

muscle size in three groups of men: those who lifted,

those who did endurance workouts, and those who

combined both. Men in the strength-training group

showed greater muscle gains than those in either of

the other groups. Endurance training actually lim-

ited increases in strength and muscle size.

This is because skeletal muscle can’t adapt to

both strength and endurance training simultane-

ously. Put another way, the muscle changes that you

experience when you run, for example, are the op-

posite of the changes needed for maximum size. The

muscles simply can’t adapt to both activities simul-

taneously. Running before a weight-lifting session

produces muscle fatigue that makes it impossible to

generate the necessary muscle tension to reach peak

power.

This doesn’t mean you should blow off running,

swimming, or other endurance sports. They’re

good for you. But if your primary goal is to get

bigger, focus on the weights first. To keep the heart

rate up and the calories burning, keep moving

when you lift, with nonstop motion from one ex-

ercise to another.

L I F E L O N G P O W E RMost men will never compete on the bodybuilding

circuit or line up to be the year’s top male model.

Guys lift because it makes them look and feel better.

They’re stronger generally, which makes the ho-

hum, practical details of living, like hoisting a 50-

pound bag of dog food out of the car, a little easier.

If you keep lifting—not just this week or next

year, but over the decades—you’ll see payoffs such

as a much lower risk of obesity, diabetes, high blood

pressure, and heart disease. You’ll also have a

physique that other men will envy. The sad truth is

that most men lose a lot of muscle as they age.

Weight lifting is by far the best way to reverse

muscle declines. Older men who lift just a few times

a week don’t lose muscle at all. They gain mass as

well as strength.

Most of us aren’t satisfied with the status quo.

We want more—bigger arms, a stronger chest, that

elusive washboard gut. You can have all this and

more. But there’s no lazy way out. Remember the

term progressive overload. Push your muscles hard,

and push them often. We’ll show you how.

6 T H E S C I E N C E O F S I Z E

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