"So, you started exercising to lose weight? You're doing aerobics right? Stair stepper or maybe a class? Right? That's what everyone does you know," said the curious woman.
Is she right? Does aerobic exercise help you burn fat? Since it is the gold standard in weight loss exercise, you would think so. But, is it?
Aerobic exercise had its genesis in the late 60's and early 70's. Dr. Kenneth Cooper is widely regarded as the father of aerobics and published his first book of the same name Aerobics in 1968. The concept of "jogging" evolved and before long, the streets were peppered with early morning runners. Dr. Cooper's thirty years of research clearly demonstrates the benefits of aerobic exercise on the cardiovascular and pulmonary systems. Walking two miles in thirty minutes three days per week reduces your risk of heart attack by 58%. But, aerobics was never intended as the best method for improving your body's ability to burn fat. In fact, twenty five years of research proves that aerobic exercise and diet are not much better than diet alone on burning fat. While it is true that aerobic exercise will help you lose fat, it is not an efficient method.
The problem with using aerobic exercise as a fat loss tool is two fold. First, to burn fat during aerobic exercise, the intensity and duration of the exercise has to be just right. If the intensity is too high, you burn very little fat and if it is too low, you burn very little fat. The reason is that fat burning takes time. Fat must be converted through a series of enzymes into a substance that your body can use. The second reason that aerobic exercise burns little fat is that with aerobic exercise you burn very few calories after you stop exercising. This is called Post Exercise Oxygen Consumption (EPOC). EPOC is a physiologic payment of oxygen debt. Aerobic exercise creates a small oxygen debt and therefore, you spend few calories once the exercise has stopped. So, in order to burn fat with aerobic exercise you must exercise a long time and very frequently.
Here is a common story. You get up early in the morning, don your running gear, and head out the door for your daily run. As you jog, your body feels heavy. Your joints are stiff. Your breathing becomes labored. Everything feels difficult to do. This goes on for about 10-20 minutes and then suddenly you feel really, really good. Your steps are effortless. Your joints are loose, breathing is easier and you feel as if you could run forever. The first twenty minutes of your run is the phase where your body is burning mostly carbohydrate and is converting fat. When you hit the phase of feeling really good, you are now burning mostly fat. If your run is a total of 40 minutes, you spent about half of the run burning fat and half burning mostly carbohydrate.
If you are very fit and highly conditioned, you will shift into fat burning quickly. This is because the enzymes you need increase in supply in response to your training. The more you burn fat, the more you burn fat. But, to get there, you must train often, understand when you switch from fat to carbohydrate and be prepared to put in the time.
You might be wondering that if what I am saying is true, how does someone like Lance Armstrong maintain such a trim, lean body? Isn't his exercise regimen aerobic? The answer is that a cyclist like Lance has a very high energy flux. He consumes a lot of calories in a day but then burns them with hours of cycling (not 45 minutes like many of us would do). If he were to cycle only an hour per day and continue to consume a high number of calories, he would likely gain weight over the course of several months.
Aerobic exercise is an important component of your overall fitness program and if you would like to use it to supplement your fat burning fitness, here are our suggestions:
1. Identify your optimal aerobic fat burning intensity. Start walking at a brisk pace and pump your arms. After about five minutes, try saying this, "I am testing my heart and lungs and finding the best intensity to burn fat." If you can say this sentence easily, try singing Row Row Your Boat (or another song of your choice). If you can talk and sing, increase your intensity. If you cannot talk easily (and therefore you will not be able to sing either), you are exercising too hard (this is referred to as the Talk-Sing Test).
The optimal level of intensity is one where, after about 5 minutes, you can talk but cannot sing. You would then maintain this level of intensity for 30 minutes periodically testing yourself. As soon as you have difficulty talking, you should reduce the intensity to maximize the fat burning effect. The less trained you are, the longer it will take for you to reach a fat burning mode. Lower your intensity until you find the right blend. I have worked with people who, when first starting this test, must stop and rest periodically. It doesn't matter whether you have to rest or not; the effect on your body will be just as good.
2. Plan on exercising at least 30 minutes three days per week. The form of exercise is not as important as the intensity (see #1 above) and duration. You could cycle, walk, jog, use an elliptical machine, stair stepping machine or treadmill. There are a number of options at local gyms and health clubs.
3. Increase your intensity and duration each week for six weeks then take one week off. Your body needs brief periods of recovery. The benefit of exercise is the rest. During the rest period, your body replenishes its energy reserves and prepares itself for the next and more demanding sessions. And, by taking a few days off each six weeks, you reduce the chances of being bored with your routine.
Always include some form of aerobic exercise in your fat burning fitness plan for its cardiovascular and pulmonary benefits and remember to do the Talk-Sing Test to adjust your pace. By doing this, you maximize the benefits for your heart, lungs and burn as much fat as possible.
Make today count.
Doug Kelsey
Author. Teacher. Therapist.
PS- If you would like to learn more about fat burning, consider our Fat Burning 101 on DVD. You get nearly sixty minutes of detailed information and the Fat Busting Four Drills for about the cost of a large pizza.
