Improper exercise is not only a waste of your valuable time, but can cause significant harm to your body, possibly even shortening your lifespan. I have been preaching for years to my patients that aerobic exercise on a prolonged basis is harmful. Now Al Sears, MD, an internationally known expert in the field of fitness and exercise has written a book advocating an entirely new way to exercise that not only is free of the dangers of the aerobics fad, but strengthens muscles, including the heart, increases endurance and adds lean muscle mass to your body while reducing body fat; all in a fraction of the time most people think is required to accomplish these goals; while not causing the significant harm that protracted aerobic exercise causes.
The remainder of this article is not original work, but rather a synopsis of Dr. Al Sears most recent book “PACE- The 12 Minute Fitness Revolution”. (PACE stands for “Progressively Accelerating Cardio-Pulmonary Exertion”). If you are currently spending hours each week at the gym, you would be doing yourself a huge favor by reading the complete book.
Until recent times, human exercise has consisted of running as fast as one can to either catch food or to escape being food. Weight lifting was limited to actual performance of a task at hand. Since the Industrial Revolution, we have become progressively more sedentary, especially since the advent of television and computers. Sixty-six percent of Americans are overweight and out of shape. Previously, people enjoyed “Native Fitness” which was a natural consequence of survival of Darwinian Evolution- survival of the fittest. Current exercise programs are attempts to substitute for this native fitness with unnatural methods. Until recently- no human jogged or performed aerobic exercise for hours on end. Native exercise caused the body to: increase lung volume, improve heart capacity, keep excess fat off, increase metabolic rate, improve muscle mass and bone strength. The trigger for this was NOT long-term AEROBIC exercise; rather it was short bursts of INTENSE exercise, which is ANAEROBIC. Beginning this exercise program slowly and progressively increasing various exercise parameters recreates challenges we used to face in our historical environment.
Aerobic exercise does not significantly increase your lung volume. Anaerobic exercise rapidly increases lung volume. Does this matter? YES! The chances of dying from any and all causes increase with decreasing lung volume. This is worth reiterating- YOUR LUNGS ARE THE NUMBER ONE PREDICTOR OF DEATH! The Framington Heart Study followed over 5,000 people over 18 years. They showed that congestive heart failure increases up to 1000% as lung volume decreases, even in people with no history of heart disease. Lung capacity decreases 9-27% each decade over 30 years old. Studies show that even MODERATELY impaired lung capacity increases risk of death. Every doctor should perform a pulmonary function test. Has yours?
Here are some other studies showing the link between decreased lung capacity and disease:
Higher levels of C-Reactive Protein , a marker of inflammation and cardiovascular risk factor
Obesity restricts lung capacity 20-30%
Lower lung capacity increases hostility in older men
Even a moderate loss of lung capacity doubles risk of dying from cardiovascular disease in a 7 year study of over 7,000 people.
What is the difference between aerobic and anaerobic exercise? Aerobic means that you are using oxygen to help create energy. As long as stores of glycogen last (which is how the body stores carbohydrate or sugar), and assuming that you aren’t exercising harder than your body can use oxygen, you are exercising in an aerobic zone where sugar is converted completely to water and carbon dioxide with the help of oxygen. If the amount of energy you produce exceeds your ability to take in and circulate oxygen, you will be exercising anaerobically. Sugar can’t convert to CO2 and gets stored as lactic acid. With aerobic exercise, you can continue for a prolonged period of time as long as you are in the “aerobic zone” where O2 intake equal usage. Anaerobic exercise on the other hand can only be performed in brief bursts of very high intensity before the oxygen debt exceeds your ability to continue accumulating lactic acid. It is this oxygen debt that triggers the expansion of your lungs, cardiovascular system and skeletal muscles. If you don’t believe it, just compare the pictures of the sprinter and long-distance runner and ask yourself “Who looks healthier?”
It is the stimulus of the oxygen debt that signals the body to create an “Adaptive Response”, causing the increases in lung volume, maximum stroke volume of the heart and growth of skeletal muscle- which does not occur in people who perform endurance or aerobic conditioning. Strength and endurance are two separate things induced by two different types of exercise. Aerobic exercise in fact creates a condition that mimics the effects of long term stress, creating a cortisol response, causing you to be in “Fight or Flight” mode for too long. For a myriad of reasons beyond the scope of this article, it is highly undesirable to have excess cortisol. One of the negative effects of too much cortisol is clearly visible in photos above of the endurance runner- the loss of muscle mass. A prolonged stress response causes a reduction of the body’s ability to handle other stressful situations should they arise. Thus your ability to ward off disease and degenerative conditions is decreased by excessive aerobic exercise. On the other hand anaerobic exercise increases your ability to deal with stressful situations.
Where is the proof of this, you may ask? Two Harvard studies in 1995 and 2003 including over 24,000 men clearly showed a decrease in death rate among those who performed vigorous exercise versus aerobic. Here is the logical reason why: Endurance exercise trains your lungs and heart to become SMALLER in order to conserve energy and increase efficiency at low intensity. This is the body’s Adaptive Response to low intensity, aerobic conditioning. Again, current research bears this out. Multiple studies in the past 10 years have shown that endurance training causes:
An increase in pro-inflammatory blood markers, including: C-Reactive protein, vWF, D-Dimer, fibrinogen, BUN, and increased blood coagulation.
The rate of heart artery calcification (arteriosclerosis) is significantly higher in marathon runners than age matched controls.
Post- marathon runners show huge increases of a blood marker that people who have just had a heart attack exhibit, and also have abnormal echocardiograms.
More than 4 days post-race, marathon runners have elevated levels of the “Bad Cholesterol” LDL. Not only is LDL higher but even worse- it is in the dangerous oxidized form.
An inverse relationship between bone mass and running exists; so long distance running may contribute to osteoporosis.
7,037 men whose average age was 66 were followed for 5 years, during which time 482 developed heart disease. Aerobic exercise was not superior to vigorous exercise in conferring protection.
Increased intensity exercise in a large study group was significantly associated with: lower blood pressure, lower body fat, higher HDL cholesterol and smaller waist.
Leg muscle mass was compared by biopsy after 13 weeks of marathon training, which resulted in a decrease in both slow and fast-twitch fibers (i.e.- less muscle).
Levels of the beneficial Growth Hormone are higher after anaerobic vs. aerobic exercise (which is one reason anaerobic exercise causes a gain in lean muscle mass).
In a study of exercise-related fat loss, participants were assigned to either an aerobic or an anaerobic exercise group. The anaerobic exercisers lost nine times (that’s 900%) more subcutaneous fat than did the aerobic group (and took much less time doing it)
People with Metabolic Syndrome (The precursor to diabetes), were assigned to either a low or a high intensity exercise program. The anaerobic (high intensity) program caused significantly greater improvements in endothelial (blood vessel) function, insulin sensitivity, skeletal muscle mass increase, reduced blood sugar and fat storage.
Aerobic exercise can only increase endurance while anaerobic exercise increases both endurance and strength.
Hopefully you are now convinced that spending hours on end walking or jogging on a treadmill, elliptical, stair-climber, or bike is not only a huge waste of time but, if continued long enough, is detrimental to your health. Would you rather spend hours each week on boring, low intensity exercise that causes increased oxidative and free- radical damage, reduces muscle mass, causes a chronic stress response, decreases immune function, and increases risk of chronic inflammatory disease; or would you rather spend minutes a day doing the following:
Sprint interval training increases Krebs Cycle activity (your ability to produce energy), glycogen (energy) storage, and endurance (yes-aerobic) capacity.
High intensity interval training increases peak oxygen consumption, lowers heart rate, increases burning of fat compared to sugar, and increases enzymes related to energy production.
Obese, diabetic males on interval training showed: increased muscle mass and maximum work load, decreased blood pressure, blood sugar, ketones, and need for insulin.
Improves times even in highly conditioned aerobic bicyclists.
Increases heart stroke volume and total lung forced expiratory volume (lung capacity).
Let’s summarize aerobic vs. anaerobic exercise then you choose the one right for you:
AEROBIC EXERCISE ANAEROBIC EXERCISE
Burns Muscle Burns fat while building muscle
Decreases lung capacity Increases lung capacity
Reduces secondary sexual characteristics Builds an attractive physique for both men and women
High Rate of Injury Low Injury Potential
Lowers metabolic rate Increases metabolic Rate
Takes 60-90 minutes 5 times a week Takes 12-20 minutes 3 times a week
Hard to stick with Easy to stick with
Skipping all the esoteric stuff discussed above, let’s cut to the chase and talk about what most people care about- losing weight (or more specifically losing fat while preserving or increasing lean muscle mass) and looking young. So let’s conclude by unequivocally stating that anaerobic, intense interval training that progressively increases (The PACE program), wins hands down. When you exercise you burn sugar, fat, or protein for energy. You DON’T want to burn protein (which is what aerobic exercise does- see above photo). For the first few minutes of any exercise you burn stored sugar (glycogen). It’s what happens thereafter that is critical. If you continue exercising, it must by nature be aerobic as it is impossible to maintain anaerobic exercise beyond a few minutes at most. You will then switch to burning fat and protein. Burning fat is good, protein bad. Continued long enough you look like the long distance runner in the photo. However, when you burn fat to generate energy, the body in its wisdom, thinks you need more fat because you are starving and sends signals to make more fat- which is contra-productive. It becomes very efficient at burning fat to preserve it (since fat is the most concentrated form of stored energy). Remember, the body thinks that it is in a prolonged stressful situation and it reacts accordingly- one of the downsides of too much cortisol. It sacrifices muscle protein to preserve fat-absolutely not what you want to do. To make matters worse, if you stop your aerobic training, there will be a rebound rapid increase in fat as the body tries to recover from what it thinks is starvation!
With the high intensity exercise we evolved to do; only sugar is burned as an energy source. The exercise stops before you start burning fat and protein. So how can you lose fat and increase lean muscle mass if you don’t burn fat? The answer is that this occurs after you stop exercising. Because you have depleted your stored glycogen during exercise, your body switches to using slow burning fat for energy. Despite burning fewer calories during exercise, you burn up to nine times more fat after exercise, while preserving protein. In conclusion here is what research shows occurs when you do a PACE type of program:
Increase Growth Hormone levels.
Increase Resting Metabolic Rate- thereby burning more fat.
Strengthen and enlarge larger muscle fibers.
Have a bigger, stronger heart.
Increase lung capacity.
Have a leaner, more attractive physique rather than looking like a prune.
Live longer and healthier.
Hopefully the information provided has convinced you that a program of progressively increasing anaerobic exercise will benefit you to a significantly greater degree than will an aerobic program. To learn more about implementing the PACE program, please read Dr. Sear’s book, or feel free to ask me.