The Genius of Weights

By Adam Campbell
Oprah.com   |   April 23, 2010

Could lifting dumbbells actually make you smarter? Adam Campbell, fitness director of Women's Health and author of The Women's Health Big Book of Exercises has 20 ways lifting can transform your life, body and mind.

"You don't look like you lift weights."

I've heard this phrase more than once in my life, and it's always delivered by a burly guy in a sleeveless shirt who most certainly does look like he lifts weights. And who's no doubt basing his observation on the standards of a typical musclehead.

That's just it, though: Like most of you, I've never aspired to be a musclehead. Or a powerlifter. Or a strongman competitor. (All of which are fine pursuits, for sure.) So do I look like any of those? Of course not.

But do I look like I lift weights? Absolutely. I'm lean and fit, and my muscles are well-defined, even if they're not busting out of my shirt.

You see, lifting weights isn't just about building 20-inch biceps. In fact, for most women, it's not about that at all, since resistance training may be the single most effective way to lose fat and look great in a swimsuit. What's more, the benefits of lifting extend into nearly every aspect of your health and well-being. So much so that after nearly 12 years of reporting in the field of health and fitness, I've come to one rock-solid conclusion: You'd have to be crazy not to lift weights—even if bigger biceps are the last thing you want. And that's why I wrote The Women's Health Big Book of Exercises.

The truth is, lifting weights gives every woman an edge. Over belly fat. Over stress. Over heart disease, diabetes, and cancer. Lifting even makes you smarter and happier.

Want proof? Here are 20 reasons you shouldn't live another day without lifting.

1. You'll Lose 40 Percent More Fat
This might be the biggest secret in fat loss. While you've no doubt been told that aerobic exercise is the key to losing belly flab, weight training is actually far more valuable. Case in point: Penn State University researchers put overweight people on a reduced-calorie diet, and divided them into three groups—one that didn't exercise, another that performed aerobic exercise 3 days a week, and a third that did both aerobic exercise and weight training 3 days a week.

The results: Each of the groups lost nearly the same amount of weight—about 21 pounds. But the lifters shed about 6 more pounds of fat than did those who didn't pump iron. Why? Because their weight loss was almost pure fat, while the other two groups lost just 15 pounds of lard, along with several pounds of muscle. Do the math and you'll see that weights led to 40 percent greater fat loss.

This isn't a one-time finding. Research on non-lifting dieters shows that, on average, 75 percent of their weight loss is from fat, and 25 percent is muscle. That 25 percent may reduce your scale weight, but it doesn't do a lot for your reflection in the mirror. It also makes you more likely to gain back the flab you lost. However, if you weight train as you diet, you'll protect your hard-earned muscle and burn more fat instead.

Think of it in terms of liposuction: The whole point is to simply remove unattractive flab, right? That's exactly what you should demand from your workout.

2. You'll Burn More Calories
Lifting increases the calories you burn while you're sitting on the couch. One reason: Your muscles need energy to repair and upgrade your muscle fibers after each resistance training workout. For instance, a University of Wisconsin study found that when people performed a total-body workout comprised of just three exercises, their metabolisms were elevated for 39 hours afterward. What's more, they also burned a greater percentage of their calories from fat during this time, compared with those who didn't lift.
But what about during your workout? After all, it's considered common knowledge that jogging burns more calories than weight training. Turns out, when Christopher Scott, Ph.D., an exercise physiologist at the University of Southern Maine, began using an advanced method to estimate energy expenditure during exercise, his data indicated that weight training burns more calories than originally thought—up to 71 percent more. Based on these findings, it's estimated that performing just one circuit of eight exercises—which takes about 8 minutes—can expend 159 to 231 calories. That's about the same as running at a 6-minute-mile pace for the same duration.

3. Your Clothes Will Fit Better
If you don't lift weights, you can say goodbye to your biceps. Research shows that between the ages of 30 and 50, you're likely to lose 10 percent of the total muscle on your body. And that number will double by the time you're 60.

Worse yet, it's likely that lost muscle is replaced by fat over time, according to a study in the American Journal of Clinical Nutrition. The scientists found that even people who maintained their body weight for up to 38 years lost three pounds of muscle and added three pounds of fat every decade. Not only does that make you look flabby, it increases your waist size. That's because one pound of fat takes up 18 percent more space on your body than one pound of muscle. Thankfully, regular resistance training can prevent this fate. Just remember this muscle motto: Use it, so you don't lose it. After all, nothing good comes of that.

4. You'll Keep Your Body Young
It's not just the quantity of the muscle you lose that's important, it's the quality. Research shows that your fast-twitch muscle fibers are reduced up to 50 percent as you age, while slow-twitch fibers decrease less than 25 percent. That's important because your fast-twitch fibers are the muscles largely responsible for generating power, a combined measure of strength and speed. While this attribute is key to peak sports performance, it's also the reason you can rise from your living room chair. Ever notice how the elderly often have trouble standing up? Blame fast-twitch muscles that are under-used and wasting away.

The secret to turning back the clock: Pumping iron, of course. Heavy strength training is especially effective, as is lifting light weights really fast. (Hint: Any exercise with the word "explosive" or "jump" in its name is ideal for working your fast-twitch muscle fibers.)

5. You'll Build Stronger Bones
Just like muscle, you lose bone mass as you age, too. This increases the likelihood you'll one day suffer a debilitating fracture in your hips or vertebrae. That's even worse than it sounds, since U.K. researchers found that among older women who break a hip during a fall, more than 50 percent will never walk again. In addition, significant bone loss in your spine can result in the dreaded "Dowager's hump," a condition that leaves you with a hunchback. The good news: A study in the Journal of Applied Physiology found that 16 weeks of resistance training increased subjects' hip bone density, and elevated their blood levels of osteocalcin—a marker of bone growth—by 19 percent.

Another bone-related benefit: Researchers in Georgia found that osteoarthritis sufferers who performed leg exercises through a full range of motion three times a week reduced knee pain by up to 58 percent.

6. You'll Be More Flexible
Over time, your flexibility can decrease by up to 50 percent. This makes it harder to squat down, bend over, and reach behind you. But in a study published in the International Journal of Sports Medicine, scientists found that three full-body workouts a week for 16 weeks increased flexibility of the hips and shoulders, while improving sit-and-reach test scores by 11 percent. Not convinced that weight training doesn't leave you "muscle-bound?" Research shows that Olympic weightlifters rate only second to gymnasts in overall flexibility.

7. Your Heart Will Be Healthier
Pumping iron really does get your blood flowing. Researchers at the University of Michigan found that people who performed three total-body weight workouts per week for two months decreased their diastolic blood pressure (the bottom number) by an average of eight points. That's enough to reduce the risk of a stroke by 40 percent, and the risk of a heart attack by 15 percent.

8. You'll Derail Diabetes
Call it muscle medication. In a 4-month study, Austrian scientists found that people with type 2 diabetes who started strength training significantly lowered their blood sugar levels, improving their condition. Just as important, lifting may be one of the best ways to prevent diabetes in the first place. That's because it not only fights the fat that puts you at an increased risk for the disease, it also improves your sensitivity to the hormone insulin. The end result: Your body has an easier time moving sugar from your blood stream into your muscles cells. This helps keep your blood sugar under control, reducing the likelihood you'll develop diabetes.

9. You'll Cut Your Cancer Risk
Don't settle for an ounce of prevention; weights may offer it by the pound. A University of Florida study found that people who performed three resistance training workouts three times a week for 6 months experienced significantly less oxidative cell damage than nonlifters. That's important since damaged cells can lead to cancer and other diseases. And in a study published in Medicine and Science in Sports and Exercise scientists discovered that resistance training speeds the rate at which food is moved through your large intestine by up to 56 percent, an effect that's thought to reduce the risk for colon cancer.

10. Your Diet Will Improve
Lifting weights provides a double dose of fat-loss fuel: On top of burning calories, exercise helps your brain stick to a diet. University of Pittsburgh researchers studied 169 overweight adults for 2 years and found that the participants who didn't follow a 3-hour-a-week training plan ate more than their allotted 1,500 calories per day. The reverse was also true—sneaking snacks sabotaged their workouts. The study authors say that it's likely both actions act as a reminder to stay on track, reinforcing your weight-loss goal and drive.

11. You'll Handle Stress Better
Break a sweat in the weight room and you'll stay cool under pressure. Texas A&M University scientists determined that the fittest people exhibited lower levels of stress hormones than those who were the least fit. And in another study, researchers at the Medical College of Georgia found that the blood pressure levels of people with the most muscle returned to normal the fastest after a stressful situation, compared to those who had the least muscle.

12. You'll Shrug Off Jet Lag
Next time you travel overseas, hit the hotel gym before you unpack. When researchers at Northwestern University and the University of California at San Francisco studied muscle biopsies from people who had performed resistance exercise, they discovered changes in the proteins that regulate circadian rhythms. The researchers' conclusion? Strength training helps your body adjust faster to a change in time zones or work shifts.

13. You'll Be Happier
Yoga isn't the only exercise that's soothing. Researchers at the University of Alabama-Birmingham discovered that people who performed three weight workouts a week for six months significantly improved their scores on measures of anger and overall mood.

14. You'll Sleep Better
Lifting hard helps you rest easier. Australian researchers observed that patients who performed three total-body weight workouts a week for 8 weeks experienced a 23 percent improvement in sleep quality. In fact, the study participants were able to fall asleep faster and slept longer than before they started lifting weights.

15. You'll Get in Shape Faster
The term "cardio" shouldn't just describe aerobic exercise. A study at the University of Hawaii found that circuit training with weights raises your heart rate 15 beats per minute higher than running at about 60 percent to 70 percent of your maximum heart rate. According to the researchers, this approach not only strengthens your muscles, it provides cardiovascular benefits similar to those of aerobic exercise. So you save time without sacrificing results.

16. You'll Lift Your Spirits
Squats may be the new Prozac. Scientists at the University of Sydney found that regularly lifting weights significantly reduces symptoms of major depression. In fact, the researchers report that a meaningful improvement was seen in 60 percent of clinically diagnosed patients, similar to the response rate from antidepressants—but without the negative side effects.

17. You'll Be More Productive
Invest in dumbbells—it could help you land a raise. U.K. researchers found that workers were 15 percent more productive on the days they made time to exercise compared to days they skipped their workout. They were also 15 percent more tolerant of their co-workers. Now consider for a moment what these numbers mean to you: On days you exercise, you can—theoretically at least—accomplish in an eight-hour day what normally would take you nine hours and 12 minutes. Or you'd still work nine hours, but get more done, leaving you feeling less stressed and happier with your job, another perk that the workers reported on the days they exercised. Think a busy schedule is a good excuse not to lift? Think again.

18. You'll Add Years to Your Life
Get strong to live long. University of South Carolina researchers determined that total-body strength was linked to lower risks of death from cardiovascular disease, cancer, and all causes. Similarly, University of Hawaii scientists found that being strong at middle age was associated with "exceptional survival"—defined as living until 85 years of age without developing a major disease.

19. You'll Stay Sharp
Never forget how important it is to pump iron. University of Virginia scientists discovered that when men and women lifted weights 3 times a week for 6 months, the study participants significantly decreased their blood levels of homoscysteine, a protein that's linked to the development of dementia and Alzheimer's disease.

20. You'll Even Be Smarter
Talk about a mind-muscle connection: Brazilian researchers found that 6 months of resistance training enhanced lifters' cognitive function. In fact, the workouts resulted in better short- and long-term memory, improved verbal reasoning, and a longer attention span.