All exercise burns calories. But there are good exercises and bad exercises.
The good exercises burn mostly fat calories.
The bad exercises don’t.
That’s why you need to know something about exercise physiology. What works best. What doesn’t. Why. And how much.
This section explains.
Everyone knows exercise directly burns Calories. But that's only it's most obvious and least useful effect.
Exercise directly burns Calories, and if those Calories happen to come out of your excess fat stores, it's a good thing. But there's no guarantee that this will happen -- unless you know how to make it happen.
This is because although all exercise burns Calories, not all exercise burns fat Calories. For example, hard, fast, "power aerobics" type exercise is the kind of exercise that burns mostly glucose. (Glucose is a carbohydrate, not a fat.) Therefore, this kind of exercise doesn't help you lose much fat -- and it tends to make you hungry afterward.
These are just two of the exercise problems that defeat dieters who don't understand how exercise really works.
But don't give up on exercise. Because used properly, it's one of your most valuable tools for staying on a diet long enough to lose all the weight you want.
There is a clear, proven, cause-and-effect relationship between a healthier diet and increased physical activity. A large number of medical experiments have demonstrated that deficiencies of various vitamins and minerals will degrade both physical performance and endurance—which means energy production—not just during the exercise but also in ordinary life.
In other words, if you mismanage the nutritional Vital Factors discussed earlier, you will suffer from continuous low energy output—and turn into a couch potato. If this happens, the homeostatic phenomenon called hunger will also be constantly trying to make you eat more in order to try to get more of whichever of these Vital Factor(s) you lack. (So you become a couch potato layered with sour cream.
This means that when you get the other Vital Factors balanced, you won’t have low-energy problems anymore and exercise will begin to feel good again. Until you have the other Vital Factors balanced, it won’t. When you have them balanced, you can gain the benefits of exercise for weight loss. Until you have them balanced, you can't.
Therefore, before beginning a weight-loss exercise program, your first objective should be to put your attention onto mastering the process of getting (and keeping) the other Vital Factors balanced.
When you’ve gotten good at that, it becomes worthwhile to “push yourself” a little to see if you’ve reached the stage where exercise can directly help you lose weight. You’ll know when this happens because that’s when exercise will begin to feel “not so bad” and “sort of refreshing” and “almost kind of fun”. (Wow! ).
When you reach this stage, your hunger will no longer be “worried” about how it’s going to take care of your body’s essential needs for EFAs, protein, minerals, etc. Then it’ll “lighten up” on letting you be more active because it’ll no longer have any need to suppress your desire to be active. That’s when you’ll almost unknowingly start to do more and be more active and start burning more fat and losing more weight (assuming, of course, that you haven’t put yourself on some version of the Liar’s Diet).
This also means that one of the greatest benefits of exercise is as an “early warning system”. When you exercise, and it feels good, you know you’ve got the other Vital Factors balanced properly. When it doesn’t feel good, you should suspect that one of them needs some attention, and you should start thinking about which one that might be—so you can fix it before hunger strikes and tries to fix it for you.
To summarize, exercise feels good when you’ve gotten yourself ready for it. Before this, any exercise program is just obnoxious drudgery with a very short life expectancy—much like the other aspects of those “"Heroic" Diets.
At this point, if you’re not completely clear on the other Vital Factors, you should re-read at least Part One. In the rest of this chapter I assume you already understand how to handle the other Vital Factors and I go on to discuss the metabolic effect of exercise on the fat-burning process and—more importantly—what you should do to maximize that effect.
As a preview, I’ll tell you that some types of exercise burn very little fat and are also likely to make you eat more. Other types of exercise burn almost nothing but fat and additionally tend to keep your body burning fat even after you stop exercising. (As a bonus, this latter type doesn’t even increase your appetite.)
There are at least two decades of solid science demonstrating these facts. But exercising will be a waste of your time and energy if you don’t understand the differences between these two types.
When was the last time you took the stairs two at a time—just because you felt like it? When was the last time doing a dozen knee bends actually felt good? Well, if you’re like most, chances are it was a very long time ago—if ever. But if (perchance) you can remember the feeling, wouldn’t you like to get it back?
Feeling good is what “quality-of-life” is all about—and also what losing weight is all about.
For exercise physiologists, exercise is mainly about techniques to increase the body’s ability to produce energy for moving around. For dieters, it is additionally about how to make sure that this increased energy production results in less bodyfat. Dieters have learned (usually the hard way) that simpleminded exercising doesn’t reduce bodyfat, except by accident and rarely for long.
As with everything else on the diet, turning exercise into less bodyfat involves making sure you do certain things and don’t do other things.
As we discussed earlier in more on… energy metabolism & storage, the muscles have “favorite fuels” which depend primarily on the intensity and duration of what they’re doing.
Basically, these fuels are:
Carbohydrate (which is stored as glycogen) is the body’s most efficient fuel in terms of oxygen consumption. This means that the heart and lungs don’t have to deliver as much oxygen in order to get it burned for energy—a situation which has obvious physical advantages. On the other hand, the body can’t store very much glycogen, so glycogen tends to be conserved until it’s really needed (like for climbing trees faster than saber-teeth tigers. )
Keeping glycogen storage capacity minimal also has some physiological advantages, because storing energy in glycogen form takes up a lot more space than storing energy as fat.. If you stored the same amount of energy in glycogen form as you do in fat form, you would be about five times as heavy as you are now. (The saber-teeth tigers wouldn’t even have to run to catch their dinners. )
In any case, at low-to-moderate exercise-intensity levels, when the heart and lungs have lots of excess capacity to deliver oxygen, the muscles will use fat for fuel and can go on using it for long periods. Conversely, at very high exercise-intensity levels, when the heart and lungs may have difficulty keeping up with the oxygen demand, the muscles switch over to using mostly carbohydrate, but run out of it fairly quickly. Naturally, we dieters want to keep our exercising in the “fat-burning” low-to-moderate intensity range. (We thank God and evolution for these small favors. )
All exercise burns Calories. (Well duhh!!J) But since you already know that, I won’t waste your time blathering about the science of how and why. For weight loss purposes the only important thing you probably don’t know about it is the actual numbers of Calories that various activities will burn. You can look this up in Table 25: Calories Expended in Various Activities. For now let’s just continue to discuss what kind of calories various exercises burn—because obviously, we would like to make sure they are mostly fat calories.
Physiologists consider a measurement called “VO2 max” to be the most accurate single measure of “aerobic fitness” (which is the body’s ability to produce energy by “burning” fuel). The more oxygen your body is capable of using (when needed), the better your level of aerobic fitness is, and the higher your “VO2 max” will be. You don’t really need to know anything about VO2 max except that it’s easily and routinely measured and is a good scientific measure of how much energy is being produced and whether the energy is coming from fat or glycogen or protein.
“VO2” means the volume (V) of oxygen (O2) in liters that the body consumes per minute per kilogram of body weight. VO2 “max” means the maximum amount of oxygen your body is capable of using. This amount depends on your fitness level. The couch potatoes have a much lower VO2 max than highly trained athletes. However, even though your VO2 max is probably pitiful compared to Michael Jordan’s, this is not the most important issue in weight-loss exercising (fortunately). The important issue is the relative intensity level you exercise at.
To put this in somewhat more useful terms:
Obviously, to lose fat, we want to exercise in the low-to-moderate intensity range of exertion since this is where the most fat is being burned (relative to total energy expenditure).
But WAIT! There’s MORE!!
Although low-intensity exercise directly burns fat, and this is great, it has a potentially even more useful metabolic effect.
Even low-intensity exercise does burn a small amount of glucose. Therefore, it tends to slowly push your blood glucose levels down toward the low end of the “normal” range. As we found out in more on… energy metabolism & storage, a low-normal blood glucose level lowers your blood insulin level, which in turn allows your fat cells to release more fatty acids into your bloodstream to be used for energy by the rest of your body. This low–normal blood insulin level will persist even after you stop exercising (unless you go eat a lot of carbohydrate). Low-intensity exercise therefore tends to promote fat-burning even after you stop exercising. This is obviously a good thing for dieters!
Of course, it is theoretically possible to maintain this low-normal blood glucose level even without exercise by making sure you routinely eat only low-glycemic-index carbohydrate and only just enough of it to keep your brain and nervous system happy. However, you will find that you have better control by using both the Exercise Factor and the Carbohydrate Factor to manage this insulin issue. (See more on… carbohydrate.)
It is also obviously “rather easy” to eat too much carbohydrate at any given meal (or snack ). This shuts off fat burning until the excess carbohydrate has been used up (See more on… energy metabolism & storage). So if you think you may have done this, it’s a good idea to take a brisk walk around the block once or twice (or more) to “burn it off” so your fat-burning can resume. (Of course, you must also stay off the Liar’s Diet—you’d have to walk for hours to burn off a slice or two of chocolate cheesecake. )
In other words, one of the best uses of exercise is to help control blood glucose and insulin levels so that fat burning can take place both during and after the exercise. This is also a reason to make sure your exercise is of the low-intensity “lite” variety. Intense exercise can lower blood glucose too far because it forces your muscles to use a lot of stored glucose for energy. When levels of blood glucose go too low the brain and nervous system don't have enough for their needs and they naturally make you hungry to make you go eat.
As you know by now, your body makes you hungry when you start to run low on something it needs to keep you healthy. When it does this, it’s really trying to get you to replenish whatever you’ve run low on. So if you get hungry after exercising it’s safe to assume you’ve run low on glycogen. Of course, since exercise uses both fat and glycogen for energy, it could (in theory) deplete your stores of either fat or glycogen. But as a practical matter, exercise is not likely to make you run out of fat anytime soon,J so we can assume that any post-exercise hunger you may feel is caused by a shortage of glucose, not fat.
As we found out in more on… energy metabolism & storage even without exercising, your body maintains only smallish stores of glycogen—usually only about 12–15 hours worth of normal requirements are available in the liver. Exercising even at low intensities will use up some of this small supply, and may push your glycogen reserve below the “desired” level (depending on its level when you start—which is hard to determine).
Not only that, but since your body knows that your blood cells, brain, and nervous system need a constant supply of glucose, it “watches” your reserves of glycogen very carefully.
So if you get hungry after exercising, what should you eat? Chocolate cheesecake? No-o-o-o! You should eat a smallish amount of some zero-fat, medium-to-high glycemic index carbohydrate food, which will get into your blood fairly quickly and shut off the hunger. (However, the higher it is on the glycemic index the less of it you should eat.)
Eating carbohydrate after exercising requires striking a balance between eating too much, thereby shutting off fat-burning, and eating too little, thereby making your body unhappy. Unfortunately, I know of no practical substitute for plain old trial-and-error to find out your personal patterns and to learn how much will be enough for you.
My above comment about “chocolate cheesecake” was actually not completely frivolous. The reason is that there are some older but still well known “Heroic Diets” that imply (or even state outright) that if you eat very little carbohydrate (in order to control glucose/insulin), then it’s OK to stuff yourself with fat because it’ll just get burned or otherwise wasted.
More recent information indicates this is not so! The part about controlling glucose and insulin is absolutely correct, of course. But your body can only get rid of fat by burning it, and it can only burn so much fat in a day. Obviously, if your body is busy burning the fat you just ate, then it’s not burning the fat you’ve got stored, and that’s no way to get thinner.
The proper way to control glucose and insulin is by using the Exercise Factor and the Carbohydrate Factor. The proper way to control fat is by using Exercise Factor and the Essential Oil Factor. (See more on… carbohydrate and more on… essential oil.)
Maintaining these balances keeps hunger at bay, and that lets your body burn stored fat, which is “the name of the game” in weight loss. Plan to eat smallish amounts of low-G.I. carbohydrate and as little fat as possible while at the same time making sure you still get your RDIs of EFAs.
Exercise can have another seriously useful effect for dieters. This is that it helps preserve muscle mass. As we’ve been discussing, muscle burns fat, so the more muscle you have—and keep—the faster the weight goes away.
Practically speaking, what does this mean?
First, you probably don’t know that even when you gain weight by “overeating” (as opposed to weight lifting), every pound you gain consists of about three-quarters of a pound of fat and one-quarter of a pound of muscle. The probable reason for this is the body needs the extra muscle to support and move the extra fat—so it builds what it needs. (Most of this extra muscle probably forms in your hips and legs, since those are the parts that do most of the additional heavy lifting.)
When you diet and lose the extra fat, your body re-absorbs this extra muscle that it no longer needs. (It recycles the proteins and macrominerals from the muscle to re-use elsewhere in the body.) However, since muscle burns fat even when at rest, this re-absorption results in less muscle to burn your remaining fat—which means your rate of weight loss slows down as you lose weight. This is one cause of the infamous “diet-slowdown” that creates the infamous “last five pounds” which are so difficult to get rid of and so dreaded in the fashion modeling profession.
What can be done about this?
Obviously, if there were some way to lose the fat but keep the muscle, we could avoid much of this “diet-slowdown” problem.
The right type of exercise provides the only known way to do this. Now having just read that, some people (not you, of course) are probably thinking, “Great! I’m doing a lot of low-intensity walking every day anyway so I’ve got no problem.” Good logic! Wrong, but logical. (I cheated, I haven’t given you all the facts yet.J)
The problem is this: If you need (say) 40 lbs of muscle to move your 160 lb body across the room, you don’t need any more muscle to move that same 160 lbs around the block. You do need more energy (Calories) and more time to do this—but not more muscle. The reason is that walking around the block is merely continually re-using the same muscle you used to move across the room. A rough analogy might be to point out that driving your car to the next state doesn’t require a bigger engine than driving it to the corner store, just more fuel and more time. In other words, you will not preserve otherwise unneeded muscle mass with low intensity, repetitive, endurance-type exercise. To preserve muscle you will need strength exercises like lifting and supporting weight (which is what you do every time you stand up).
I’m sure you already see where I’m going with this. In order to preserve that fabulous, firm, fat-fighting fitness and rid yourself of foul, flabby fat, you should also do some strength exercises—push-ups, sit-ups, knee-bends, or even use resistance exercise equipment (weights). This tends to “make up” for the resistance formerly provided by the weight you’re losing.
However, for those who cringe at the mere thought of push-ups (yuck, ptooeyL), I’ll point out that, like low-intensity endurance exercise, resistance exercise actually feels good—when you’ve got the other seven Vital Factors balanced properly. When you don’t, it doesn’t. (And as you recall, feeling good is a good way to verify that you’ve got the other vital factors balanced.)
“Hundreds of pushups a day, right?”
No, (shudder). That’s unnecessary. Exercise physiologists point out that when you can do about 20 repetitions of a strength exercise at any given resistance level, you have reached the point where further repetitions merely convert the strength exercise into an endurance exercise. The additional reps will burn Calories and increase your ability keep going without fatigue—but they won't build or preserve any more muscle. To build or preserve muscle, you will have to increase the resistance in some way.
How Does All This Affect dieters?
For dieters, exercise is a technique, not a goal, so there isn’t any “RDI” amount. You should do as much exercise (both endurance and strength) as is comfortable for you. Obviously, if you get into serious bodybuilding or endurance running, you will really lose weight fast (provided you manage the other Vital Factors properly). But if you’re not into doing these things, you should do what is comfortable.
If you try to force yourself beyond what is comfortable, your motivation will probably start to evaporate—and there is nothing worse than that for weight-loss. To give you a personal example, I can tell you that I personally am as much of a couch potato as anyone. I have found that for resistance exercise, I’m comfortable with 20 pushups and 20 knee bends a day because any higher resistance would probably require some sort of equipment. I also often do 20 minutes of slow indoor jogging. This helps control blood glucose and also preserves a portion (but probably not all) of the muscle I had when I was fat. In theory, I could do more and get better results. In practice, this is good enough for me.
|
Calories Burned in Various Activities |
||
|---|---|---|
| Activity | Calories per minute |
Calories per hour |
| Sleeping | 1.2 | 72 |
| Bedrest | 1.3 | 78 |
| Sitting quietly | 1.3 | 78 |
| Sitting, reading | 1.3 | 78 |
| Sitting, eating | 1.5 | 90 |
| Standing | 1.5 | 90 |
| Conversing | 1.8 | 108 |
| Sitting, writing | 2.6 | 156 |
| Standing, light activity |
2.6 | 156 |
| Driving car | 2.8 | 168 |
| Walking indoors | 3.1 | 186 |
| Showering | 3.4 | 204 |
| Walking outdoors | 5.6 - 7.0 | 336 - 420 |
| Jogging (5 mph) | 10.0 | 600 |
These figures apply to people weighing 150 lbs (70 kg).
For each 15 lb over (or under) this, add (or subtract) 10%
Note that by the above table, a 150-lb person walking at a comfortable speed for one hour burns about 360 Calories. Therefore, if you’re eating only 1500 Calories a day, this will burn one quarter of your total daily energy intake—which “ain’t bad” for an easy one-hour walk. (If you’ve successfully used the other Vital Factors to get The Beast under control, it’s also not difficult.)