Take your age. Now add 20 years. That’s the effect that an oversized gut has on your health, according to a UCLA study. Which means that the quest for a lean midsection, through diet and exercise, isn’t a shallow pursuit; it’s the only natural way to increase your lifespan. Or at the very least, ensure that you live up to your full potential.
It’s important to understand that belly fat isn’t just lifeless tissue that only serves to make you cringe at the idea of taking your shirt off in public. Fat can actually act like an endocrine organ, secreting numerous hormone and hormone-like substances—called adipokines—into your bloodstream. In fact, scientists have identified more than 50 different kinds of adipokines, many of which are harmful. One is called resistin, a hormone that leads to high blood sugar, an independent risk factor for heart disease and diabetes. There’s also angiotensinogen, a compound that raises blood pressure, and interleukin-6, a chemical that causes arterial inflammation. What’s more, a landmark discovery was the finding that an adipokine called retinol-binding protein 4 (RBP4) caused insulin resistance and diabetes. While drug companies are now racing to find methods to lower RBP4, we showed in a recent study that a low-carbohydrate diet reduced levels by more than 20 percent. In the same study, we found that a low-fat, high-carb diet increased RBP4.
Your body actually houses two main types of fat: subcutaneous and visceral. Although displeasing to the eye, subcutaneous fat, which is located just under the skin and in front of your abdominal muscles, appears to be the less harmful of the two. This is the fat that you can pinch—or the kind that jiggles. Visceral fat, on the other hand, lurks behind your abdominal muscles, and surrounds your internal organs. Even though it’s the less aesthetically harmful of the two fats (it doesn’t jiggle, although it does push your belly out), scientists have concluded it’s far more active than subcutaneous fat, making it markedly more dangerous to your health. You might liken the difference between subcutaneous and visceral fat to that of a dormant volcano compared to one that’s constantly erupting. The latter is spewing out nasty stuff all the time; the other—subcutaneous fat—is just part of the landscape.
Worse, unlike other endocrine organs such as your pancreas, fat has the unique ability to expand. This potential is especially problematic where visceral fat is concerned. The larger visceral fat cells grow, the more dysfunctional—and dangerous—they become.
If your belly is bulging with visceral fat, it’s likely that you are, or will soon be, insulin resistant. As discussed earlier, insulin is a hormone whose primary function is moving glucose out of your bloodstream and into your cells. This process helps you maintain normal, healthy blood sugar levels. Problems arise, however, when, often due to weight gain, your cells start to become resistant to the effects of insulin (it knocks, no one answers). As a result, more insulin is required to dispose of the same amount of glucose (the knock becomes a loud banging). This condition, called insulin resistance, is the first stage in type 2 diabetes. (Once you develop diabetes, you’ll be able to predict the future: There’s an 80 percent chance your cause of death will be heart disease.) If you think this doesn’t apply to you, there’s nearly a one in two chance you’re wrong. Currently, it’s estimated that at least 43 percent of American men are insulin resistant. That number is staggering, especially when you consider it includes all men—even very lean ones—making the prevalence of the condition even greater among those with the high-risk waistlines. The bottom line: If your gut is growing larger, you’re probably on your way toward insulin resistance—even if your belly jiggles, since there’s probably plenty of visceral fat underneath it.
What’s more, without treatment, insulin resistance worsens over time. As a result, your pancreas has to pump out enormous amounts of insulin to force glucose into your cells (hey, let’s use a sledgehammer!). This is called hyper-insulinemia. As this dysfunction intensifies, and even large amounts of insulin can no longer maintain glucose levels, you enter into a period where blood sugar is moderately elevated at all times—a condition known as impaired glucose tolerance. Over one-third of adults in the United States suffer from glucose intolerance according to a recent National Institutes of Health study. Eventually, your pancreas has trouble keeping up, leaving you with chronic high blood sugar, the defining marker of diabetes and the root cause of the calamities—heart disease, kidney failure, blindness, gangrene—that arise from it. Alas, it only gets worse from there: If the resistance continues to mount, some of the insulin-producing beta cells inside your pancreas can “burn out” and stop working altogether. Once this happens, you’re looking at a lifetime of daily insulin injections.
Keep in mind, insulin resistance progresses over time. Long before being diagnosed with diabetes, other symptoms appear, all of which seem to be related. So much so, in fact, that some scientists have termed it metabolic syndrome. Metabolic syndrome describes a condition in which a person is inflicted with a cluster of heart disease risk factors. You are an unlucky qualifier if you have any three of the following five markers: a 40-inch (or greater) waist, high triglycerides (a type of fat in your bloodstream), high blood sugar, low HDL (good) cholesterol, and high blood pressure. This murderer’s row of maladies is lethal. It increases the likelihood you’ll develop diabetes by 500 percent, have a heart attack by 300 percent, and die of a heart attack by 200 percent. All of which is why the pharmaceutical industry has created drugs like rimonabant—branded under the name Acomplia—to treat the markers of metabolic syndrome, including obesity. These drugs, though, have limited success and are not without side effects.
Thankfully, there’s a far more effective therapy than medication: low-carbohydrate diets. Research from our lab and many others has shown that simply restricting carbohydrates improves all of the markers of metabolic syndrome. In fact, the opposite approach—eating a low-fat, high-carb diet—will actually make metabolic syndrome worse unless you also lose weight and exercise more.
But unlike any other approach, low-carb diets decrease your risk of metabolic syndrome and its deadly consequences even if you don’t lose weight and exercise. So from day one, you can put yourself at less risk when you follow the TNT Diet. Start shedding some pounds and hitting the gym, and you’re going to be even better off. This is an important point because the conventional view is that low-carbohydrate diets improve metabolic markers only because people lose weight. The truth is that the low-carb approach directly improves metabolic syndrome because of the way it impacts your glycogen and insulin levels. Sure, weight loss generally does occur, and in fact, to a greater extent than low-fat diets in most studies. But again the point is that weight loss is not necessary to see metabolic improvement, whereas with low-fat diets it is.
In a recent study, we compared a low-carb, high-fat diet to a low-fat, high-carb diet for 12 weeks. We measured several markers of disease risk, including those of metabolic syndrome. The results were amazing. The low-carb approach far outperformed the low-fat diet. For example, the guys who followed a low-carb diet experienced a 50 percent greater reduction in belly fat than those who ate a low-fat diet. More impressive, though, were the effects seen on the study participants’ underlying health.
When you start a diet, everyone has an opinion on it—your co-workers, your buddy, even your 90-year-old grandmother. That’s why it’s important that you know all the facts. After all, we wouldn’t want you to start doubting the TNT Diet due to a conversation with a misinformed relative. Throughout this chapter and this book, we’ve shown that unlike once thought, low-carb diets are fantastic for reducing your heart disease risk, and that eating fat doesn’t make you fat. But here are three more low-carb myths that are still being perpetuated—on morning talk shows, in office break rooms, and at family get-togethers across America.
When you reduce your carbohydrate intake significantly—typically to less than 50 to 75 grams a day—you enter a metabolic state known as ketosis. Ketosis is a term used to describe the normal process of using ketones for energy. Ketones aren’t bad. They’re actually a fat breakdown product. That is, whenever fat is burned, ketones are created. So they’re always present in the body.
On a high-carb diet, your body uses glucose, the simplest form of carbohydrates, as its primary fuel. But when glucose isn’t readily available to your body for energy—such as when you’re in the Fat-Burning Time Zone—your body begins burning fat at an accelerated rate, producing more ketones. These ketones are really just storage units, holding the excess energy that’s produced from the rapid breakdown of fat so that it can be later used as fuel. As ketone levels rise, your body’s reliance on glucose decreases.
In the simplest terms, ketosis is just a shift from using carbohydrates (glucose) as the body’s main energy source, to using fat (ketones). It’s not a dangerous condition; it’s simply your body adjusting to your diet so that it’s using the most efficient form of fuel.
Unfortunately, many health professionals believe ketosis to be a dangerous metabolic condition. Why? Because over a hundred years ago, physicians discovered an overabundance of ketones in the urine of diabetics who were unable to control their disease. Naturally, the association of high levels of ketones with poorly controlled diabetes led to negative views of ketones. The high level of ketones in diabetics was given the name diabetic hyperketoacidosis (now known simply as diabetic ketoacidosis).
Diabetic ketoacidosis, which represents extremely high levels of ketones, is a life-threatening state that can occur in type 1 diabetics who aren’t treating their condition appropriately. While diabetic ketoacidosis is serious, the mere presence of ketones is not. The point here is that sometimes a lot of something causes problems, but a little can be advantageous. Sort of like your heart beating 300 times a minute might be bad, but your heart beating 60 times a minute is ideal—and certainly better than not at all. Now consider: The ketone levels in people with diabetic ketoacidosis are 8 times higher than those following a low-carb diet.
Interestingly, ketones have many benefits. In fact, they may be the perfect fuel for dieters. Since ketones spare the use of carbohydrates for energy, they prevent the protein from your muscles from being broken down and converted to glucose. And that ensures that the calories you’re burning are far more likely to be fat, compared to typical diets where muscle loss almost always accompanies fat loss. Ketones also suppress your appetite. Research shows that increased levels of a compound called beta-hydroxybutyrate—the primary ketone in the blood—act as a satiety signal, meaning it tells your brain that you’re full.
Of course, the other knock on ketosis is that even if it burns fat faster, it deprives your brain of glucose, reducing your mental capacity. However, your brain only requires a small amount of glucose, which can be met through gluconeogenesis, the process of converting protein to glucose. Although not high in protein, by its nature a low-carb diet provides ample incoming protein. So there’s plenty available for the small amount of glucose that your brain needs, without having to break down muscle. In addition, encouraging new research from National Institutes of Health scientist Richard Veech, MD, PhD, has found that ketones may help both your brain and heart run 25 percent more efficiently.
We hear this one a lot. The first flaw is that this claim is based on the assumption that low-carb diets are excessively high in protein, which some experts say forces your kidneys to work harder. (We’ll address that point in a minute.) Unless you’re consciously trying to down lots of protein by drinking several protein shakes a day, more than likely just 20 to 30 percent of your calories will come from protein. That’s more than what the average American eats, but certainly not at a level that’s going to strain healthy kidneys. In fact, most Americans probably don’t eat enough protein. And of course, you need even more than the average person because you’ll be hitting the weights hard 3 days a week. Research shows that guys who pump iron need almost twice as much protein as those who don’t exercise. For reference, about a gram of protein each day per pound of lean body mass (your body weight minus the amount of body fat you have) seems to be about right—and certainly not excessive.
All that said, the idea that high-protein diets overstrain your kidneys seems to be perpetuated by people unfamiliar with the research. Read the scientific papers and you’ll see that what’s been found is that higher protein intake causes an increase in glomerular filtration rate, or GFR. Think of GFR as a measure of how much blood your kidneys are filtering per minute. This has been erroneously interpreted as an adverse effect when, in fact, it should be considered a normal physiologic adaptation to higher protein intakes. Consider an analogy with the heart: Exercise causes the heart to enlarge. Why? Because the heart muscles grow larger in order to push more blood throughout the body with less effort. Although an enlarged heart is also a consequence of heart disease, a bigger heart from exercise is not viewed as pathological, but rather, a positive physiological adaptation. It’s a similar effect with protein and GFR. If you have kidney disease, you may have an elevated GFR. However, an elevated GFR doesn’t mean that you have kidney disease—just like an enlarged heart from exercise doesn’t mean that you have cardiovascular disease. Still, it’s really a moot point when it comes to low-carb diets, such as the TNT Diet, which don’t provide excessive amounts of protein anyway.
In contrast to the scientific evidence, another common criticism of diets low in carbohydrates, and again, high in protein, is bone loss. This concern seems to be based on a misunderstanding of basic metabolism. Critics claim that low-carbohydrate diets, and diets rich in animal protein, increase the acidity of your blood, which causes calcium to be leached from your bones. The theory is that because calcium is alkaline—the opposite of acidic—it’s used by the body to buffer the higher acid levels, bringing blood pH levels back to normal. To support this notion, these critics cite evidence that higher protein intakes are associated with acute increases in the amount of calcium excreted in the urine. This, they say, is an indicator of calcium loss from the bones. Over time, this is suggested to cause actual bone loss.
However, this mechanism of bone loss is not substantiated by clinical data or long-term epidemiologic studies. In fact, the published research shows the opposite. A critical review published in the Journal of the American College of Nutrition actually concluded that low-protein diets have adverse effects on bone, whereas higher protein intakes have a positive impact. It turns out that the increased calcium in the urine—with higher protein intake—is due to increased absorption of calcium from the intestines. So protein causes more of the calcium you eat to be absorbed, resulting in more calcium available for your bones. Some of this additional calcium may not be needed by your bones, though, and so it’s simply excreted, accounting for the mysterious increase in urine calcium on a higher protein diet. It’s important to remember, though, that low-carb diets such as TNT are actually high-fat diets, not high-protein.
As far as low-carbohydrate diets specifically, though, a 2006 study conducted at South Florida University determined that a strict low-carb diet—40 grams or less a day—had absolutely no effect on the markers of bone loss or bone formation over a 3-month period. In fact, the low-carb dieters didn’t differ in either of these measurements from study participants who consumed a typical American diet.
Because everyone is different, we can’t guarantee your results will be as dramatic as those of our participants. But we know that our own lab work as well as the available science shows that by adopting a low-carb diet like TNT, you can quickly battle many of the health problems that are slowly killing millions of Americans every year.
The right diet should, of course, improve your health. And we believe that will happen for most people when they adhere to the guidelines of TNT. There’s no doubt that individual results vary, so not everyone will experience the same degree of blood work improvements. But following the TNT Diet, on average, you should anticipate that you will …
This is the most consistent response to a low-carb diet. Triglycerides are the chemical name for the form most fat takes in your body. In recent years, the level of blood triglycerides has been shown to be an increasingly important independent risk factor for heart disease. For instance, in a 40-year study, University of Hawaii researchers found that middle-aged men with the lowest triglycerides were the most likely to have “exceptional survival rates.” This was defined as living until 85 years of age without suffering from any of six major diseases: coronary heart disease, stroke, cancer, chronic obstructive pulmonary disease, Parkinson’s disease, and diabetes.
Of course, you might think that consuming a high amount of fats would boost the amount of fat circulating in your blood. But it turns out that the opposite is true. Remarkably, carbohydrates are more likely to be responsible for dangerously high levels of triglycerides in your bloodstream. Remember how your body converts excess blood sugar to fat in your liver? That fat is triglycerides, which are then transported back into your bloodstream. So by limiting carbohydrates, except for when your glycogen levels are low, you’ll automatically lower your triglycerides. In fact, the reduction in blood levels of triglycerides on a low-carb diet are even greater than triglyceride-lowering drugs can achieve.
Cholesterol is a well-known factor in cardiovascular disease risk. You’re probably familiar with three measurements: LDL, or “bad” cholesterol; HDL, or “good” cholesterol; and total cholesterol, which is roughly the total amount of bad and good cholesterol combined. Most doctors will tell you that it’s best to keep your bad cholesterol low and your good cholesterol high. Here’s why: LDL cholesterol is believed to lay down plaque in your arteries, while HDL removes plaque.
However, for years, the emphasis in the health-care community has been primarily on lowering both total and LDL cholesterol levels. Why? Because except for exercise, physicians couldn’t figure out how to raise the good HDL. So the idea was to treat the risk factors that you can improve. And it turns out, in addition to losing weight and taking drugs such as statins, you can decrease total and LDL cholesterol by eating a low-fat diet. Seems like a sensible solution, right? Wrong.
The reason: Along with lowering total and LDL cholesterol, low-fat diets also decrease HDL cholesterol and tend to increase triglycerides (since they’re high in carbs). Which brings us back to low-carb diets. As we noted in a recent study, the low-carb approach increases HDL cholesterol by 13 percent and almost always significantly reduces triglycerides. Of course, that leads to the question, What happens to the bad LDL? The answer to that is variable: some people see increases, some observe decreases, and some experience no change. But regardless, because HDL increases significantly more than LDL, your risk of heart disease goes down.
A 2006 study, published in the American Journal of Cardiology, reported that your levels of LDL cholesterol only matter in relation to your levels of HDL. For example, let’s say your LDL is 100 and your HDL is 30 compared to another guy whose LDL is 150 and HDL is 80. Which one of you has the lowest risk for heart disease? The answer is that it’s the other guy, since his ratio of LDL to HDL is far smaller, or better. (To do the calculation yourself, just divide LDL by HDL.) The same math applies to the ratio of total cholesterol to HDL—the lower the number, the lower your risk. It’s important to note that this data was derived from the famous Framingham Study. Started in 1948, the Framingham Study is still going strong and is credited with providing most of the knowledge we have today about heart disease risk.
All that said, physicians have been trained to raise their eyebrows in concern when LDL rises even just a little—regardless of any positive change in HDL. It’s important in understanding the TNT Diet that we delve a little deeper into the complexity of cholesterol. And that means understanding that not all LDL cholesterol is created equal. Case in point: LDL particle size, which we’ll cover next.
Contrary to popular opinion, not all LDL cholesterol is bad. Doctors have known for many years that LDL comes in different sizes. There’s pattern A, which are large, “fluffy” particles, and pattern B, which are small, dense particles. Back in 1997, Canadian researchers reported for the first time that men with the greatest number of small, dense particles had a nearly four times greater risk for developing heart disease than those with the least number. As they followed these men over the next several years, they confirmed this finding. They also determined that large, fluffy particles of LDL were not even associated with heart disease. So it’s not just how much LDL cholesterol you have, it’s the type of LDL cholesterol that matters. Bottom line: Small LDL particles have been shown over and over to be associated with increased cardiovascular disease.
Can you guess the number one factor determining LDL size? It turns out it’s the carbohydrate content of your diet. You know how enthusiastic we are about low-carbohydrate diets, so you won’t be surprised to find out that they change the LDL particles from small to large—that is, from harmful to harmless. Even though total LDL cholesterol may stay the same or even increase slightly with the TNT Diet, the size of those LDL particles increases. As a result, the amount of the small, dense, artery-clogging particles floating around in your bloodstream is reduced, which significantly decreases your risk of heart disease. For example, the low-carb dieters in our lab experienced a 10 percent reduction in small LDL particles. Thus, even if you are one of the people who experiences an increase in LDL cholesterol levels, this is likely due to an increase in the nonthreatening large, fluffy LDL particles. At the same time, you probably also increased HDL cholesterol and reduced your triglycerides—a finding you should share with your doctors should they ever raise their eyebrows at your LDL numbers.
The trouble with asking your doctor to check your LDL particle size is that few will accommodate you—at least not if you’re paying with insurance. That’s because insurance companies are behind the times when it comes to covering charges for some of the emerging risk factors. But you can probably figure it out for yourself, by calculating your ratio of triglycerides to HDL. To do so, simply divide your triglycerides by your HDL cholesterol reading. Researchers at the Albert Einstein College of Medicine determined that this ratio is inversely related to LDL particle size. That means the lower your ratio, the larger and fluff ier your LDL particles. For instance, scientists found that 83 percent of people whose ratio was 3.8 or greater had a predominance of small, dense LDL particles, compared with just 11 percent of those whose ratio was lower. Let’s walk through an example. Suppose your triglycerides are 125, and your HDL cholesterol is 50. You’d divide 125 by 50, for a triglyceride-HDL ratio of 2.5. Congratulations: Your LDL particles are as big and fluffy as the Stay-Puft Marshmallow Man.
In addition, the triglyceride-HDL ratio is also strongly correlated with insulin resistance, according to Stanford University researchers. The scientists found that people with the highest ratio have eight times the risk for a heart attack than those with the lowest. Thankfully, we’ve found that low-carb diets lower this ratio by an average of 54 percent.
A person has normal blood sugar when his fasting glucose—the most common gauge—is between 70 and 100 milligrams per deciliter (mg/dl). He’s considered diabetic when that number reaches 126 mg/dl. In between the two is what’s known as impaired fasting glucose, or prediabetes. Prediabetes is such an accurate predictor of future diabetes that 95 percent of people in this category end up with the disease.
High blood sugar, also called hyperglycemia, has been shown to damage both the small blood vessels of your eyes and kidneys—which is why diabetes is linked to blindness and renal failure—as well as the larger vessels that deliver blood to your heart. The latter helps explain the connection between diabetes and heart disease. In fact, Johns Hopkins researchers determined that high blood sugar is now an independent risk for heart disease. It’s also an indicator of insulin resistance. But here’s the good news: In a recent study, we found that a low-carb diet, like TNT, lowers blood sugar by 12 percent in 12 weeks. This is a huge health benefit to someone who has high blood sugar. That’s because it can help a guy with prediabetes quickly restore his blood sugar to normal levels, which instantly reduces his risk of heart disease, diabetes, and kidney disease.
When you consider that insulin resistance results in high insulin levels, it’s not hard to understand why lower insulin levels are an indicator of improved health. Don’t misunderstand: Insulin isn’t bad—it’s necessary for life. And as we’ve shown, it can be used at certain times to effectively build muscle. The trouble comes when insulin is chronically elevated. Doctors determine this by measuring insulin after you’ve fasted for at least 8 hours. Since you’ve had no food—such as carbohydrates—insulin shouldn’t be elevated. When it is, this is a sign of insulin resistance, as well as future heart disease and diabetes. Of course, chronically elevated insulin levels also keep your body in a perpetual fat-storing mode, leading to larger visceral fat cells, which can cause even more health problems. However, low-carb diets are extremely effective at reducing fasting insulin levels—cutting them almost in half.
Over the last few years, it’s been determined that inflammation may be one of the best indicators of future heart disease and many other afflictions, such as cancer. One of the most recognized and well-studied markers of inflammation is a blood compound known as C-reactive protein (CRP). In fact, scientists now believe that elevated levels of CRP are highly predictive of looming heart disease. That’s why we measured it in a recent low-carb study at our lab. The result: Men eating a low-carb diet experienced a 55 percent reduction in CRP. In addition, we measured several other markers of inflammation, all of which decreased when people cut back on carbs. Clearly, low-carb diets such as TNT are naturally anti-inflammatory. Which means they offer protection from many diseases.
Indulge us for a moment and flex your right arm. Assuming you have an average build, you’re looking at about 6 pounds of muscle. That hard figure might sound disappointing, but it’s hardly minuscule; it represents about 10 percent of the total muscle on your body.
Now imagine that muscle gone. No biceps, no triceps, no wrist flexors—only a jiggly mass of skin and fat covering your bones from your shoulder down to your fingertips. Simply put, you’d be a mess. But consider this: As we noted earlier, that 6 pounds of muscle is the same amount most men lose between the ages of 30 and 50. And that number doubles by time they’re 60. In fact, once a man passes the half-century mark, he can expect to lose 1 percent of his muscle each year for the rest of his life.
Carrying around extra fat only makes this worse. Researchers at the National Institutes of Health found that some of the adipokines that fat cells secrete signal your body to break down muscle tissue. Specifically, interleukin-6, an inflammatory agent that’s been linked to a decline in strength and mobility, particularly in people with high amounts of visceral fat. Although the scientists aren’t sure why interleukin-6 may cause muscle loss, they speculate that it could be because it inhibits muscle-building hormones. It’s also thought that high levels of interleukin-6 may cause insulin resistance, which means your muscles won’t respond to the effects of insulin. That’s critical, you’ll remember, because insulin helps to ensure your muscles aren’t broken down and used for energy.
If all of this doesn’t scare the hell out of you, it should. Life without muscle is miserable and short. That’s because the natural erosion of muscle as you age, and the loss of strength that accompanies it, lead directly to weak bones, stiff joints, and poor posture. Muscle loss also increases your risk for heart disease and diabetes, and makes it less likely that you’ll recover from a serious disease, such as cancer. Your once-strong, healthy body is transformed into that of a frail—and soon to be dead—old man.
To know whether or not you suffer from metabolic syndrome, you’ll need to have a blood test done by your family doctor. If you meet at least three out of the five criteria listed below, then you meet the definition of metabolic syndrome. That said, if any of these markers are not in the normal range, you should monitor them closely throughout the TNT program. We recommend having your blood retested every 8 to 12 weeks.
| RISK FACTOR | DEFINING LEVEL |
| Abdominal Obesity (waist circumference) | |
| Men | >40 in |
| Women | >35 in |
| HDL Cholesterol | |
| Men | <40 mg/dl |
| Women | <50 mg/dl |
| Triglycerides | ≥150 mg/dl |
| Glucose | ≥100 mg/dl |
| Blood Pressure | |
| Systolic (top number) | ≥130 mmHg |
| Diastolic (bottom number) | ≥85 mmHg |
But you don’t have to accept that fate. Instead of helplessly letting your muscle—and your life—waste away, you can defend both from the ravages of time with help from the best anti-aging weapon in any man’s arsenal: resistance training. Regularly lifting weights signals your body to fight for your muscle. That means a longer, healthier life. And besides making you fit and strong, the actual process of training your muscles with weights provides many benefits. This is one of the many reasons we’ve made weight training a key component in the TNT plan. Without it, you’d be shortchanging your body, and shortchanging your health. In fact, doing three total-body workouts a week—like the ones found in Chapter 11—will help you:
Keep your heart healthy. Researchers at the University of Michigan found that men who performed three total-body weight workouts per week for 2 months lowered 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.
Build stronger bones. Just like muscle, you lose bone mass as you age, too, increasing the likelihood you’ll one day suffer a debilitating fracture in your hips or vertebrae. That’s even worse than it sounds, since Mayo Clinic researchers found that 30 percent of men die within 1 year of breaking a hip. In addition, significant bone loss in your spine can result in perpetually rounded shoulders and the dreaded “dowager’s hump,” a condition that literally transforms you into a 21st-century Quasimodo. The good news: A study in the Journal of Applied Physiology found that 16 weeks of resistance training increased hip bone density in men, and elevated blood levels of osteocalcin—a marker of bone growth—by 19 percent.
Increase your flexibility. Between the ages of 30 and 70, flexibility decreases 20 to 50 percent. That results in an inability for you to move through a joint’s full range of motion. For example, if you can’t squat down until the back of your thighs touch your calves (most men can’t), you have tight hip flexors, which limits your movement at the knee joint. In a study published in the International Journal of Sports Medicine, researchers found that three full-body workouts a week for 16 weeks increased flexibility of the hips and shoulders by more than 30 percent, 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 weight lifters rate only second to gymnasts in overall flexibility.
Reduce diabetes risk. Every time you eat sugary foods or processed carbohydrates such as white bread, rice, and potatoes, your levels of insulin rise dramatically. That’s a problem because consistently elevated insulin increases your risk for diabetes and heart disease. But weights can help: Researchers at the University of Massachusetts found that men who added two full-body weight workouts a week to their existing aerobic exercise program had 25 percent lower insulin levels after a sugary meal than men who performed the same aerobic exercise program, but didn’t lift weights.
Stay in the game. 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 by up to 50 percent as you age, while slow-twitch fibers decrease less than 25 percent. It’s important because fast-twitch fibers are the muscles largely responsible for generating strength and power. These muscles hold the key to peak sports performance when you’re young and help you easily get out of a chair when you’re old. Another benefit: Researchers in Georgia found that men with osteoarthritis who performed leg exercises through a full range of motion three times a week reduced knee pain by up to 58 percent.
Fight cancer. High levels of visceral fat increase your risk for both prostate and colon cancer. However, researchers in Spain found that men who simply participated in a twice-weekly weight-training program for 4 months decreased visceral fat stores by 10 percent, reducing disease risk. And in a study published in Medicine and Science in Sports and Exercise, scientists found 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.
Tracking your waist circumference is an easy way to gauge your progress—and your risk for heart disease. Here’s how to do it: Wrap a measuring tape around your abdomen—or better yet, have someone help you—so that the bottom of the tape touches the tops of your hip bones. (Your belly button moves as you lose fat, but your hip bones don’t; so this method ensures that you always take the measurement at the exact same location.) The tape should be snug, but shouldn’t compress the skin, and should be parallel to the floor. If the tape measures 36 inches or greater, you need to take action. Today.
Lead a happier life. In a 2004 study at the University of Alabama-Birmingham, researchers found that older men who performed three weight workouts a week for 6 months improved their scores on measures of confusion, tension, anger, and overall mood. Although unsure of the mechanism, study author Gary Hunter, PhD, suggests, “It could simply be a feeling of accomplishment from having become fit and more confident in themselves.” Makes sense: The study participants reversed a decade of age-related muscle loss and fat gain, by adding 4 pounds of muscle and dropping 3 pounds of fat, while increasing strength by an average of 42 percent. Those results would improve anyone’s mood.