Have you ever seen a fat sprinter? Not me. And without mentioning any names, have you ever seen a fat aerobicizer? I see them daily. More people perform aerobic exercise than any other fitness activity, yet many of them remain, at various levels, basically unfit. Why this is and what can be done about it? I will answer shortly, but first, let’s look into the basic “science” of aerobics.
Aerobic exercise presents itself in many forms. First, you have walking, followed by maybe jogging, then running. To get you off your feet, you can ride a bike, tug on a rowing machine, or jump into one of those fancy machines you see advertised on TV. Whatever the activity is, if you continue it long enough, you’ll obtain aerobic conditioning. Remember though, exercise should be enjoyable and refreshing. Forget that “No Pain, No Gain” mentality; it’s simply not true for the life-extension enthusiast. You should start your aerobic exercise at a pace that’s comfortable with your beginning level of condition, then gradually accelerate the tempo and frequency of your workouts as you adapt to your new lifestyle. In a short time, you’ll begin to recognize many health benefits.
What is Aerobic Exercise?
Depending on the activity or task at hand, the body innately selects any one of two basic energy sources as fuel. For powerful and explosive tasks that are interrupted with rest intervals; like that in weight lifting, football, etc., the body preferentially chooses carbohydrates as the dominant fuel source; this is called “Anaerobic Metabolism”. For long sustained uninterrupted activities, performed at submaximal efforts, the body will utilize oxygen and fat as fuel sources; this is referred to as “Aerobic Metabolism”.
Sustained activities are better fueled with fat and oxygen as these two energy sources are the most dense and abundant fuels–you never have to worry about running out.1 In contrast however, running out of carbohydrate fuel [in the form of glucose or glycogen] can happen within seconds of an intense power burst.
The analogy I use when teaching the body’s energy system is that of a rocket ship. As we know, rockets are launched into outer space with several power, or fuel, boosters. The first booster is used to explode the rocket–and it’s massive weight–up off the ground. Once that booster is depleted of its fuel, it disengages and the second booster propels that rocket even further into the sky. Once the final booster is reached, the rocket is dependent on a fuel source that will carry it throughout the rest of its mission, which is a very long time in comparison to the duration of the previous boosters.
Like the rocket ship, your body acts in a similar manner. At first, when activity begins, your body relies on immediate and fast burning fuel sources–the carbohydrates. If you repeat an explosive burst after taking a replenishing rest, the body will again select carbohydrates as fuel for that chore. However, when activity persists for a long duration, like that in most aerobic workouts, your carbohydrate stores deplete and/or are bypassed early in the routine and the body automatically shifts to a fuel mixture of oxygen and fat in the wake of the carbohydrates.
Generally speaking, the duration of aerobic exercise should expend no less than 20 minutes with sessions exceeding 30 minutes being ideal. During this time, the cardio-respiratory systems are forced to function above a resting level and at submaximal levels; this is referred to as the “Aerobic Threshold” or “Aerobic Range”. Authorities claim that 60% – 85% of Maximum Heart Rate (MHR) is the range for which best aerobic benefits are obtained–I’ll explain more later.
In general, scientific data indicates that the amount of energy expended after an aerobic workout tends to be very small.2 The number of calories burned during the recovery is dependent upon the intensity of the workout.3 Conventional aerobic exercise is very effective at burning body fat only during the activity itself. So for those needing to lose excess body fat, and only use aerobics to accomplish this objective, training frequency must increase. But, here’s the twist which I’m going to let you in on–a secret I discovered in 1974 that experts today are just now claiming to be the breakthrough in aerobic science. Lets now look at the real differences between the sprinter and the aerobicizer as mentioned at the onset of this article.
A sprinter’s training and competition requires a series of explosive performances–the 100 meter dash record for instance is less than 10 seconds, and these athletes are lean, muscular and healthy. In training, a sprinter will perform a sprint drill, rest, conduct another sprint drill, followed with another rest period, and repeat that cycle until the workout requirements have been fulfilled for that day. In comparison, an aerobic athlete may train for the same time period as the sprinter [or anaerobic athlete] but instead of having plenty of non-active time, aerobic workouts are continuous, with no rest intervals.
But if aerobicizers train nonstop throughout the entire duration of their workouts; supposedly burning calories without hesitation, why do so many of them have difficulty retaining lean muscle tissue and keeping fatty storages under control?
To answer and explain, conventional aerobics do not stress the muscular system; primary stress is to the heart and lungs. Energy is used (or burned up) to perform the workout but little is needed in post recovery as the body is not traumatized to the degree of the anaerobics.
Anaerobic activities (like the sprinter example) emphasize the muscular system to a high degree. Intensity percentages begin at 75% and escalate to 100%. The bulk of true anaerobic training lies between 75% – 90% of Maximum ability; this is “The Anaerobic Range”. Training for anaerobics utilizes carbohydrates as fuel, mostly ignoring oxygen and fat during the workout itself. During anaerobic training micro traumas are experienced to the muscles as anaerobic, or explosive movements, tear tissue on a microscopic level. The body’s own defense mechanism to these types of injuries repairs the damage to rebuild and strengthen the lean tissue compartments of the body.
However; here’s the amazing breakthrough, the post-workout reparation of damaged tissues that have been inflicted by anaerobics stimulates metabolism for several days after each workout utilizing many energy sources, including fat, to fuel tissue remodeling! This is how the sprinter has an easier time staying leaner than his aerobic cousin. Additionally, lean tissue is metabolically active meaning it burns more calories, even at rest. So those who strive to attain a higher degree of quality lean tissue will have an easier time keeping fat off their body’s.
Here’s my secret: To get the best of both worlds; the aerobic conditioning for your heart and lungs, and the anaerobic development of quality lean tissue, I suggest that many of your aerobic sessions be conducted with interval intensities. For instance, if you are walking, begin your workout with a comfortable pace then, after you feel warmed up, accelerate to a power walk or even a slow jog or run until you have difficulty breathing. Maintain that [accelerated] pace until you’ve had enough then decelerate back to a pace you can endure comfortably. Continue these comfortable/explosive intervals until the duration of your workout has expired. In essence, you’ll be fluctuating in and out of both the aerobic and anaerobic ranges all within the same workout.
The thing to understand about conventional aerobics is that on the days you’re doing your aerobics, you’re benefiting, but on the days you’re resting, not much is being accomplished. This is why so many overload the frequency of their aerobic workouts. Personally, I believe no more than five aerobic workouts should be conducted each week, any more is excessive. Each workout itself might fluctuate between 30 – 60 minutes with occasional 90 – 120 minute sessions; like afternoon walks or bike rides. Overtraining sets in when one tries to rely on aerobics for total body conditioning reaching up to 7 workout days each week with excessively long sessions. At first, overloading the body with this volume of training might seem to be manageable, but if the body is not completely recovered before commencing your next workout, your recuperative needs will compound themselves over time and your results will stagnate and might even regress. This is when you know you’re overtraining.
On the other hand, if you try my suggestion of interval aerobics, on the days you’re exercising, you’re benefiting and, on the days you’re resting, you’re still receiving results! Interval aerobics will condition the heart and lungs while, at the same time, create the muscular trauma needed to ignite post workout metabolism building the lean tissue you need. Isn’t that amazing? It’s like making a great investment and enjoying the interest. Plus, you don’t have to exercise as often or as long.
Interval aerobics can be applied to walking, biking, running, stair climbing, rowing, and all other forms of this activity–the list is as long as the number of activities you can select from. You can also try alternating up hills then back to flat land while walking, biking, or running. Some of the new aerobic machines even have preset computer interval courses which make interval aerobics easy to apply.
Getting Back to the “Why’s” of Aerobics
Aerobic exercise produces benefits you simply cannot live without. Getting a regular dose of aerobic exercise contributes to vibrant health and can extend mean life span. Specifically it benefits:
As with any activity, voluntary or involuntary, the brain is the master controller of the human body. Those who are sedentary don’t spend enough time thinking about, or doing things for, their bodies. They also don’t engage in physically challenging activities which require specialized skills to perform.
On the other hand, those who engage in exercise regularly are like pilots in the cockpit behind the controls of a sophisticated machine. Exercise requires billions of psychophysiological actions that only the brain can pilot. As we condition ourselves, we have the ability to communicate with the various systems of our bodies and, in many ways, control the destiny of our health. Once a satisfactory level of conditioning is achieved, the body, and its various systems, begin to operate in efficient harmony, largely due to improved brain function.
Conditioning the heart is probably the number one reason why most commit to aerobics, and aerobic exercise indeed targets the heart and its vascular system. The heart is a pump that, with each contraction, forces the circulation of blood throughout the body. With each heart beat our cells receive the nourishment needed to survive as oxygen and other vital nutrients are pumped into these cites through our vascular system.
Thinking of the heart as a muscle, the stronger your heart is the easier it can circulate the blood we need to live a healthy life. Inside the human body, we have approximately 60,000 miles of blood vessels which act as pathways to oxygenate the body’s tissues and unburden them of waste.4 If the heart is weak it has to work overtime to accomplish these tasks while a conditioned heart can force more blood throughout the body than weaker hearts.
At rest, strong hearts don’t need to beat as fast due to the fact that each beat is more forceful, whereas the weaker heart needs to pump quicker and more often to maintain adequate blood flow, one reason for an elevated blood pressure.
A normal heart rate is about 72 beats per minute (bpm). For those who exercise, that figure can reduce to below 60 bpm; (I’ve measured 48 – 54 bpm in a few of my students). If you’re doing the math, that means a well-conditioned person can save a minimum of 12 heart beats each minute, 720 beats each hour, 17,280 beats each day, 518,400 beats each month, and 6,307,200 beats each year.
Now you don’t have to be a mathematician to figure out that if you save over six million heart beats each year, you’re bound to prevent the normal wear and tear that plagues so many people in our aging population; plus you simply have a much higher chance of living a more productive life. Try flexing your biceps six million times and see how that muscle feels; now relate that sensation to your heart muscle.
As heart rate accelerates during exercise an internal cleansing is taking place. The analogy I use to simply explain how we cleanse our body’s with aerobic exercise is that of the plumbing system in house. When water is forced to flow through the plumbing on a regular basis; like running the facets of the sinks, tubs and showers, flushing the toilets, and watering the garden with the hose, the inner linings of those tubal pathways (the pipes and hoses) remain relatively clean. As the water surges through the pipes and hoses on a regular basis waste materials are more easily eliminated. They same holds true for the human body. With each aerobic workout, accelerated heart rate forces more blood, at faster speeds, throughout the body, not only carrying the nutrients we need to survive, but removing the toxins at the same time. A sedentary lifestyle is like abandoning your home for a long winter only to return several months later to a gooey mess when the facets are turned back on again. The accumulation of waste particles that cling to the inner lining of the pipes and hoses have no way to exit and will coalesce, and sit their doing their corrosive damage.
The Respiratory System
Another target system emphasized during aerobic exercise is your respiratory system; the system that allows you to inhale air, absorb vital oxygen, and exhale toxic gases like carbon dioxide. The lungs are the primary organs of the respiratory system. The lining of your two lungs are made up of spongy tissue that contains millions of tiny holes called alveoli. The alveoli enlarge as we inhale, and the lungs expand. As we exhale the alveoli shrink, and the lungs constrict.
With each inhale, oxygen is taken into the body and penetrates the lungs which eventually seeps into the circulatory system. The lungs are responsible for supplying the blood stream with oxygen which is then transported to the tissues via the circulatory system. Human life is dependent on oxygen. Going without oxygen for just a few minutes will end a life. And even though we might receive just enough oxygen to allow us to function on a day-to-day basis, being deprived of adequate supplies inevitably guarantees a road that’s filled with maladies.
It’s wise then to condition the system that provides the most vital element of life. Aerobic exercise is one great means to accomplish this objective. With literally thousands of deep breaths accumulating during each aerobic session, the lungs, and its respiratory system strengthens just like any other muscle attaining an enhanced ability to supply an abundance of oxygen to all body cells. Even at rest, the well-conditioned respiratory system will provide greater oxygenation. Those who engage in regular aerobic training will feel fresher, clear headed, and more cognitive no matter what they’re doing.
So for those who succumb to a sedentary lifestyle, headaches, memory loss, fatigue, and lack of concentration are just a few conditions they can alleviate (and even cure) with some aerobic exercise.
Observing the myology of the human body, we basically have two fiber types, 1) Fast Twitch muscle fibers (FT) and, 2) Slow Twitch muscle fibers (ST). The FT fibers are used for short bursts of energy, are very powerful, require carbohydrates as fuel, and fatigue very easily. ST fibers are used for sustained activity, are weak in comparison to the FT fibers, utilize oxygen and fat as fuel, and are resistant to fatigue. Let me provide another analogy; If I told you to walk 100 meters, at the end of that walk you’d be breathing relatively easy, would be able to carry on a conversation, and could continue walking indefinitely. On the other hand, if I told you to perform an all out sprint for the same distance, by the time you crossed the finish line you’d be gasping for air, would need a lot of time to rest before proceeding on doing any other activity, and would knock me on the head for making such a suggestion. It’s obvious by the outcome of each that the body uses two very different and distinct systems to carry out each task.
Training and developing both the FT and ST muscle fibers is the ideal protocol for optimum health, appearance, and performance. As we age, we naturally use less of the FT fibers. Consequently, these fibers atrophy. This seems logical as strength, energy and the ability to perform quick movements usually diminishes with each passing year.
The concept of interval aerobics works perfectly well for enhancing the integrity of both the ST and FT muscle fibers. I’m convinced that this methodology will contribute greatly to developing leaner physiques of impressive muscular tone and symmetry with more stamina and better overall health.
Target Heart Range: Attaining and Maintaining the Aerobic Threshold;
As stated, according to many fitness experts, the target intensity range to perform aerobic activity lies between 60% – 85%. This is the rate at which the heart is beating during exercise which is calculated from your Maximum Heart Rate (MHR).
We know that at rest our hearts should beat between 60 – 72 times each minute.
Once we begin to exercise that rate increases. When heart attains a beating pace between 60% – 85% of its MHR (see formula), authorities suggest that this is the intensity, or pace, that should be sustained until that workout time expires.
My method of interval aerobics fluctuates your heart rate in and out of the conventional range of 60% – 85%. By performing your workouts in this fashion, you’ll avoid a one-sided energy source and burn carbohydrates, oxygen and fat.
You’ll also train both the anaerobic and aerobic systems of the body conditioning the heart and lungs and muscles.
If you calculate the fluctuations of your HR throughout an interval aerobic session, you’ll discover that your average HR, or overall intensity, measures well within the range needed to provide excellent results.
To determine your heart rate percentages follow this formula:
- 220 minus your Age equals your Maximum Heart Rate (MHR) or Heart Beats Per Minute (BPM).
- Multiply MHR by 60%, then by 85%; this is your aerobic range and the intensity you should succumb during the duration of the aerobic time period.
Here’s an example for an individual 50 years of age; (figures are rounded)
As long as this 50 year old aerobic participant performs his/her workouts maintaining a heart rate (or average BPM) between 100 to 145, results are guaranteed. Interval aerobics may increase BPM above 85% and plummet BPM below 60% during the bursts of power and relaxation phases respectably. Don’t worry, as stated, your training heart rate will average out and you’ll attain aerobic conditioning.
* Swimming may impose high impact shock to the shoulder apparatus.
(NOTE: High-Impact and Low-Impact aerobics refers to the shock, or pounding, experienced during the activity)
To begin an aerobic program, I suggest the usual check up from your physician to obtain the “green light” to proceed. After that, it’s wise to make a selection of the activities you’ll perform, then set your schedule–days and times.
I suggest a frequency of 3-5 aerobic workouts each week. If you’re a beginner, start with 10-15 minute workouts, then add 5 minutes every other workout until you reach 30 minutes; you can go as high as 60 minutes. If you’re going to try my interval aerobics, I suggest that you first endure a conventional aerobic program for at least one month to condition yourself. At the same time, you should include some weight training which isolates the FT fibers of the muscles you’ll stress most with your activity. For instance, if you walk, jog, or run, it’s wise to strength train the knees, ankles, and lower back. If you swim, cross-country ski, or use a rowing machine, perform some upper body resistance exercises to strengthen and prepare the upper body muscles.
During your interval aerobic workout session, I suggest shorter durations as compared to a conventional session. A time reduction of 25% is average. For example, if you’re normally performing 60 minute aerobic workouts, reduce your time down to 45 minutes with the intervals. Cutting your workout time with interval aerobics should in no way make you feel guilty. Interval aerobics burn more calories during a shorter period of time than conventional aerobics; plus, you’ll burn more calories even at rest.
If you use wise judgment, and listen to your body, you shouldn’t have problems with overtraining, and should experience year-round progress. Aerobics are terrific, but I sincerely feel my little twist with the inclusion of intervals will help you achieve better results faster. If you have any questions about training or nutrition, please write me here at Fitness For Longevity (FFL) and I’ll try my best to address your needs. See you next issue!
1. Michael Colgan, Ph. D., Optimum Sports Nutrition, Chapter 9, Page 95.
2, 3, 4. James A. Peterson, Ph.D.. Muscular Development, “Aerobic Training”. 10/94, p. 32. 8/94, p. 32.