Most people exercise in order to lose weight faster. Actually, their goal is to lose to excess body fat faster. Well, here is some sad news. Losing body fat is a slow, long process. Frankly, to lose more than one pound of fat a week is a difficult task. Fortunately, there are plenty of other reasons why you want to be incorporating exercise into your daily life regardless of the fat loss benefits.

Let’s start with strength training first. The primary benefit is maintaining muscle mass while you age, and in the process maintaining your immune function as you age. Between ages twenty and forty, you will lose about 40 percent of your muscle mass, and then about 1 percent every year thereafter. The good news is that your body maintains the ability to synthesize new muscle as you age. You have the same ability to build new muscle up through your seventies and eighties as you did in your twenties and thirties. Although we maintain the ability to synthesize new muscle mass as we age, we have to combat the increase in the rate of degradation of muscle that occurs with aging. The most likely reason behind this muscle loss is an increased level of cortisol, which rapidly tears down existing muscle mass and converts it into glucose. This also happens if you follow a very low glycemic-load diet, like the Atkins diet.

Thus, you are going to naturally lose muscle mass if you take no steps to maintain it. You have to continually do strength training to keep a constant stimulus to induce the cascade of events that leads to the synthesis of new muscle mass. If a lifetime of strength training doesn’t seem to be your cup of tea, then consider that without enough muscle, you’ll get sicker more often. The reason? Your body stores all its amino acid reserves in your muscle cells including the amino acid glutamine—a critical component for certain immune cells called macrophages and neutrophils. During times of acute stress, such as an infection, your body secretes excess cortisol in order to break down muscle cells to supply adequate levels of glutamine to your immune system.

If you don’t have adequate amounts of muscle, then you’re not going to have adequate levels of glutamine in a crisis, and your immune system is going to suffer. This is one reason that so many elderly people die from infections shortly after bone fractures. When they have a major injury such as a bone fracture, their body breaks down what little muscle it has to release enough glutamine to help repair the bone. This leaves practically no glutamine reserves to fend off infections. Thus, these patients are far more susceptible to pneumonia, staph, and other infections that run rampant in the nursing homes and hospitals where they are often recovering. Strength training at any age becomes a great defense to ensure the adequate levels glutamine reserves you need for maximum immunity and for reducing silent inflammation. The result is maintenance of wellness for as long as possible.

Just as the unexpected benefit of strength training is maintaining proper immune function, the unexpected benefit of aerobic exercise is that it builds your brain. Aerobic exercise can improve your overall brain function by activating a hormone called brain-derived neurotrophic factor (BDNF) to repair and potentially trigger the development of new nerve cells in the brain. Just as muscle cells need amino acids from protein-rich foods to repair themselves and grow, nerve cells in the brain require a very specialized type of long-chain omega-3 fatty acid as a fuel source. This fatty acid, docosahexaeonic acid (DHA), is found in rich amounts in fish oil. The DHA in fish oil works hand in hand with BDNF to keep your neurons and brainpower primed over time.

For years it was thought that the brain couldn’t regenerate nerve cells. Now we know that under the right conditions, it can be done. The stimulus for that nerve growth is BDNF. Aerobic exercise stimulates the release of BDNF. BDNF is like a master mason, but in order to build the structure, he needs some bricks. The bricks for the building of new nerves come from having adequate levels of DHA in the diet. So if you want to remain sharp as a tack as you age, do daily aerobic exercise and take your fish oil.

To burn fat, you have to lower insulin levels, since insulin inhibits the release of stored fat from the adipose tissue. This is true as you exercise, but it is also true as you watch TV. Exercise just speeds up the fat-burning process. All exercise burns the same number of calories, but not necessarily the same amount of fat. Let’s look at running. If you increase your running pace from, say, 5.5 miles per hour to 6.5 miles per hour, you will burn both more fat and more calories if you cover the same distance. However, if you then increase your pace from 6.5 miles per hour to 7.5 miles per hour, you’ll actually burn less fat in proportion to the total calories burned. That’s because your muscles need adequate amounts of oxygen to metabolize fat to chemical energy (adenosine triphosphate or ATP) needed for muscle contractions. As you go beyond a certain exercise intensity, this growing lack of oxygen transfer to the muscle cells makes them more dependent on burning stored glucose for ATP production. You are still burning calories, but more of these are coming from a low-octane fuel (glucose) and less is coming from a high-octane fuel (fat). The combination of the Zone Diet plus high-dose fish oil increases your oxygen transfer capacity so that you can keep using high-octane fat for ATP production at increasingly higher exercise intensities.

Furthermore, doing high-intensity aerobic exercise in an effort to burn fat faster can set you up for muscle injury due to the excess impact on your joints.

Every time you lift both feet off the ground (as you do when you run), each foot transmits three times your weight through your ankles, legs, knees, and hips as it hits the surface. This is why brisk walking is recommended over running to minimize potential damage to your joints and minimize increased inflammation.

Strength training, on the other hand, uses primarily glucose for ATP production. Therefore you will always burn less fat during a strength-training workout than an aerobic workout. However, this is more than compensated by increased muscle mass that can extract excess glucose from the blood throughout the day. This effectively lowers the need for extra insulin secretion and thus allows more effective burning of fat throughout the day.

Realize that 80 percent of your insulin-lowering ability will come from your diet, and only 20 percent from exercise. The amount of fat burning from exercise drops even further if you are following a high glycemic-load diet. This is because excess insulin produced by a high glycemic-load diet blocks the release of stored fat for its potential use as energy. This explains why many people who spend an extraordinary number of hours in the gym have very little to show for their efforts. However, following the Zone Diet maximizes the fat-burning benefits of exercise.

By now, you should be convinced that there is more to exercise than simply fat loss, and that you have to exercise on a lifetime basis. You have to treat exercise like a drug to be taken at the right dose and at the right time. Here is your Zone exercise prescription:

• Exercise aerobically six days a week.

• Do strength training three days a week.

• On the three days you don’t do strength training, do stretching.

Although stretching won’t help you lose fat, build muscle, or decrease silent Inflammation, it will prevent the nagging injuries that can keep you from exercising. As you age, your tendons and ligaments become shorter, thus limiting your range of motion, especially as you strength train. Consider stretching to be a cheap insurance policy against exercise-induced inflammation.

A SAMPLE WEEKLY WORKOUT PLAN

Here’s what a typical Zone exercise routine should look like on any given week. You can see that you have a great amount of flexibility in choosing your weight-training or stretching exercises. Just try to make sure that you do at least one of each exercise during the course of a week.

Day 1

Day 2

Day 3

Day 4

Day 5

Day 6

Day 7

3 minutes weight training

3 minutes stretching

3 minutes weight training

Rest Day

3 minutes stretching

3 minutes weight training

3 minutes stretching

11 minutes walking in place

11 minutes step aerobics

11 minutes walking in place

11 minutes walking in place

11 minutes step aerobics

11 minutes walking in place

3 minutes weight training

3 minutes stretching

3 minutes weight training

3 minutes stretching

3 minutes weight training

3 minutes stretching

11 minutes walking in place

11 minutes step aerobics

11 minutes walking in place

11 minutes step aerobics

11 minutes walking in place

11 minutes step aerobics

3 minutes weight training

3 minutes stretching

3 minutes weight training

3 minutes stretching

3 minutes weight training

3 minutes stretching

Every time you engage in physical activity, you put a certain amount of stress on your body. In aerobic activities, this means working out to a point where you begin to break a sweat. This usually happens when you get your heart up to 70 percent of its maximum limit for a reasonable period of time. Once this occurs, things are happening at the molecular level; in particular, you are making your cells more responsive to taking up blood glucose, thereby decreasing the amount of insulin needed to be secreted by the pancreas. If you are overweight or out of shape, then it won’t take you very long to begin to increase your core temperature and break into a sweat. That’s a good point to stop exercising that day. With time and consistent exercise, you will have to work out longer or with more intensity to reach the same point of exertion.

Strength training works very differently from aerobic exercise to reduce insulin levels. By building more muscle mass, your body will have an easier time extracting glucose from the bloodstream and your need for insulin will drop. Regardless of your form of exercise (aerobic versus strength), the long-term outcome is the same: reduction of excess insulin.

However, there are other hormonal changes that take place with strength training that do not occur with aerobic training. When you exercise your muscles to exhaustion, a certain level of trauma occurs. This triggers a pro-inflammatory response to treat the micro-tears in your muscles.

If the pro-inflammatory response is not too severe, there will be a corresponding anti-inflammatory response to repair the muscle damage and increase muscle strength for the next bout of exercise. Part of that anti-inflammatory response is the release of growth hormone from the pituitary gland to rebuild the damaged tissue and make it stronger. This is why strength athletes are much more muscular than endurance athletes, although both have low levels of fasting insulin.

Moderate strength training should provide you with just enough micro-trauma to allow you to sufficiently recover from your workouts to repair and rebuild your muscles before your next strength workout. As you age, the time for this repair process increases. This is why young athletes can do intense two-a-day workouts, whereas older athletes should do moderate strength training every other day. The amount of recovery time ultimately depends on your innate anti-inflammatory responses, which can be enhanced by following the Zone Wellness Pyramid. However, no matter how good your dietary program, excessive exercise increases inflammation to such an extent that it overwhelms the body’s ability to produce sufficient levels of anti-inflammatory eicosanoids needed for recovery. The end result is you’re still sore and weak from your last workout on the day of your next workout.

The most important thing is to listen to your body. If it’s still sore from your last workout when you’re about to begin your next one, you’ve probably pushed it too hard and your body is still churning our inflammatory mediators. Rest some more, and cut back a bit on your next workout.

Getting physically fit isn’t necessarily about losing weight. It all boils down to your ability to control insulin resistance and therefore silent inflammation. If your body maintains an appropriate zone of insulin, you can still be overweight and healthy. On the other hand, if your body has to pump out greater and greater amounts of insulin due to insulin resistance in your cells, then your excess body weight is generating silent inflammation around the clock, setting you on a fast track for type 2 diabetes and heart disease.

For example, in one recent study in which overweight individuals lost weight on a calorie-restricted diet, it was only those with insulin resistance who had any decrease in their blood levels of CRP when they lost weight. This helps to explain why some overweight people have perfectly normal cholesterol levels and are at relatively little risk for heart disease. They manage to maintain their insulin levels in a healthy zone. Their weight is a cosmetic problem due to eating too many calories, but not a medical problem. Research by Stephen Blair at the Cooper Clinic in Dallas, Texas, confirms this seemingly paradoxical situation. Individuals who were physically fit but overweight were significantly less likely to develop heart disease then those who were of normal weight but less physically fit. Of course, those who were of normal weight and physically fit had even lower levels of cardiovascular risk.

How is it that some people can be healthy and overweight while others are not? It all boils down to the levels of visceral fat. Decrease this type of fat, and levels of CRP are also lowered. It is visceral fat that is mobilized by exercise. Unfortunately, exercise has a much smaller impact on subcutaneous fat, the unsightly but relatively safe fat that collects on the hips, thighs, and buttocks.

Obviously, the best course of action is to be physically fit and at a normal weight. But don’t use loss of body weight as a fitness goal. First of all, you might gain a few pounds of muscle while you’re reducing fat—which is a great thing, though your scale won’t tell you this. This is why your body fat percentage is a far better indicator of fat loss and why it is considered to be a biomarker (although a weak one) of wellness. Second, from a health standpoint, getting active will help reduce silent inflammation regardless of whether you lose any inches from your hips and thighs.