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|All About Cardio|
|Written by Jeff Behar, MS, MBA|
What Is Cardio or Aerobic Exercise?
Cardio (or aerobic exercise) refers to exercise that involves or improves oxygen consumption by the body.
Aerobic means "with oxygen", and refers to the use of oxygen in the body's metabolic or energy-generating process. (Note: For the sake of simplification, I will use the term aerobic and cardiovascular interchangeably).
Many types of exercise are aerobic, and by definition are performed at
moderate levels of intensity for extended periods of time. For example,
running a long distance at a moderate pace is an aerobic exercise, but
sprinting is not. Playing singles tennis, with near-continuous motion,
is generally considered aerobic activity, while golf or doubles tennis,
with brief bursts of activity punctuated by more frequent breaks, may
not be predominantly aerobic. Some sports are thus inherently
"aerobic", while other aerobic exercises, such as aerobic dance
classes, are designed specifically to improve aerobic capacity and
fitness. Generally speaking however, cardio/aerobic exercise is any
exercise that uses large muscle movement over a sustained period of
time keeping your heart rate to at least 50% of its maximum level.
Cardiovascular System. Your cardiovascular system is composed of your heart, blood & blood vessels.
High-impact Aerobics - meaning that both feet regularly lose contact with the floor, as with running, jumping and hopping.
Low-impact, meaning that at least one foot retains contact
with the floor throughout the workout session.
Maximum Heart Rate. Your maximum heart rate (HR max) is the theoretical number of beats per minute that your heart is capable of producing.
Aerobic / Cardio History
Both the term and the specific exercise method were developed by Kenneth H. Cooper, M.D., an exercise physiologist, and Col. Pauline Potts, a physical therapist, working at the San Antonio Air Force Hospital in Texas. Cooper, an avowed exercise enthusiast, was personally and professionally puzzled about why some people with excellent muscular strength were still prone to poor performance at tasks such as long-distance running, swimming, and bicycling. He began measuring systematic human performance using a bicycle ergometer, and began measuring sustained performance in terms of the ability to utilize oxygen.
Cooper’s groundbreaking book, Aerobics, was published in 1968, and became a best seller. Cooper's data provided the scientific baseline for almost all modern aerobics programs, most of which are based on oxygen-consumption equivalency.
How it is Done
Generally, cardio training involves exercising
for 30 – 45 minutes at a continuous pace, or intensity… Continuity is a
key feature of cardio training, and hence this makes cardio training
completely different from weight training, which is intermittent in
nature, involving stops and starts.
The No. 1 benefit of following an aerobic
exercise plan is the change in your cardiovascular fitness that results
from this kind of training regimen. Cardiovascular or Aerobic Training
is aimed at improving your heart muscle and cardiovascular system. Your
heart is a muscle. Like any muscle, it becomes stronger with exercise
and can pump blood more efficiently. Regular aerobic exercise causes
your lungs to process more oxygen with less effort; your heart to pump
more blood with fewer beats; and the blood supply directed to your
muscles to increase. As a result, by performing cardiovascular
exercises, you are increasing your body's endurance and efficiency. At
the same time, exercise also improves the performance of the muscles in
the rest of your body.
Cardiovascular training, no matter what the exercise, is categorized based on duration and intensity. When you are choosing which type of cardio to do, keep your goals in mind.
Regardless of what cardiovascular activities that you do, the following guidelines should form guide you on what form of exercise to do.
your goal is to improve your general cardiovascular fitness, do
moderate intensity work where you are starting to breathe deeply and
you can feel that you are working.
From a health perspective, you want the heart to be stressed but yet at the same time not over-stressed. Over-stressing the heart has certain advantages and disadvantages. If you are young and training for competitive event, it is not unusual for the heart to be stressed to the maximum, especially during integral training, stressing the heart at maximum target heart rate would allow peak performance especially in sprint-type event where powerful burst of energy is required.To measure aerobic exercise intensity, percentage of HR max (%HR max) is often used. If you want to exercise at 60% of your HR max, your heart rate should be, using the example above, around 108 beats per minute.
Your heart rate is your guide for cardiovascular exercise intensity.
Intensity (Target Heart Rate)
The target heart rate is the range of heartbeats per minute at which you should work at in order to best achieve aerobic fitness. Your Target Heart Rate is used to gauge intensity. The intensity of an activity can vary. Most health and fitness experts are in agreement that between 60% and 80% of one’s maximum heart rate is a good, reliable index of intensity. The bottom end of the scale is best for low intensity training while the top end is for high intensity training.
So, using the maximum heart rate example. If you are 30 years old, then your maximum heart rate is 220-30=190 beats per minute. If you take 70% of this then you arrive at 133, 80% of 170 equals 152. Therefore if you exercise in an aerobic capacity, which enhances your cardiovascular fitness, your exercise target heart rate should be between 133 and 152. This is of course a very general formula and does not apply to those who are training for competitive sports. As your cardio-fitness increases, your ability to train closer to your maximum cardiac heart rate level will also improved automatically.
Taking Your Heart Rate
An electronic heart rate monitor that is strapped to your chest or on a watch can also be used to keep track of your heart rate (the chest strap style is usually more accurate, being much closer to your heart).
There are also some cardio machines that have touch sensitive pads on the handlebars that can take your pulse by counting the electrical signals of your heartbeat. These are typically not very accurate, but then can give you an “idea” or baseline to gage your intensity. Make sure the pads are clean and dry and grip them firmly.
Taking Your Heart Rate (manually)
The first is on the inside of the wrist below your thumb. Use your forefinger and middle finger to feel the pulse (this is known as palpation).
The second site is on the carotid artery on the neck (either side). Place your fingers on the side of your windpipe, just below the jaw.
Count the beats for 10 seconds then multiply by six to get beats per minute. This count can last for 10 seconds, 15 seconds, 20 seconds, 30 seconds or a full minute. Multiply by 6, 4, 3, and 2 respectively to get beats per minute.
How Much Cardio is Needed?
The answer to this will depend on your goals. If you lead a fairly inactive or sedentary life, any increase in aerobic activity is good for you. Typically for most people, in order to gain the benefits of cardiovascular training, one must do this sustained activity of the large muscle groups for a minimum of twenty to thirty minutes at least three times per week.
show that a brisk walk for even one to two hours a week (30 minutes a
day) reduces your risk of having a heart attack or stroke, developing
diabetes, or premature death. The U.S. Surgeon General, along with the
Centers for Disease Control and Prevention and the American College of
Sports Medicine, recommend getting a minimum of 30 minutes of
moderate-intensity physical activity on most days of the week.
For health purposes the goal is to keep the heart in healthy condition but not to over-stress the cardio muscles. For that reason, you should adjust your exercise in such a way that your heart rate is no more than between 60-80% of your maximum heart rate. At this level, 85% of your calories burnt are fat, 5% are protein and 10% are carbohydrates. If you are training at 70-80% of your maximum heart rate, you are increasing your endurance capacity. In this zone, your functional capacity will greatly improve and you can expect to increase the number and size of the blood vessels, as well as increase in aerobic capacity and respiratory rate. At this level, 50% of your calories burnt are from carbohydrates and 50% are from fat and less than 1% is from protein.
If you are training at 80-90% of your heart rate, then you have entered into another zone. In this zone, the exercise intensity is high, more calories are burnt. 85% of the calories burnt are from carbohydrates, 15% from fat and less than 1% is from protein. For anti-aging purposes, it is not recommended that you enter into this zone for a prolonged period of time. A burst of exercise within this zone just to stimulate the heart and to challenge the heart to meet adverse conditions on an intermittent basis is acceptable, however.
Training at 90% -100% of your maximum heart rate is not recommended for anti-aging purposes or fat reduction purposes. In this zone, the highest number of calories are burnt and the lowest percentage of fat calories. Almost 90% of calories burnt here are carbohydrates, only 10% are fat and less than 1% are protein. Very few people can last within this zone for more than a few minutes. Additionally, intensive and strenuous exercising increases cell metabolism, which causes an increase in the production of oxidized products known as free radical. Free radicals are damaging to the cells and are a leading cause of aging and age related diseases.
As a general guideline, if your goal is to look good and increase your level of health exercise “moderately” at 50 – 70 % of ones capacity for 30 – 45 minutes, 3-5 days a week, for best results. This is generally the pace at which one gets slightly out of breath. One way to gauge moderate activity is with the "talk test" - exercising hard enough to break a sweat but not so hard you can't comfortably carry on a conversation.Brisk walking is an ideal moderate-intensity activity. For the average person, a brisk walk means walking 3-4 miles an hour, or about as fast as you'd walk if you were late for a meeting.
Start conservatively if you are just starting training, e.g. three times per week, 20 minutes per session.
Working Out Safely
To safely undergo an aerobic exercise program, it is necessary to include at least 3 phases: warm up, work out, and cool down. Each phase has its particular purpose.
The warm up phase usually includes stretching and breathing exercises. This may last 5-10 minutes with the purpose of increasing the body temperature, loosening the joints and legs to prevent any undo strain or soreness. A slight elevation of heart rate is also a benefit of the warm up phase and gets the heart muscles ready for the work out phase. You should be at 50-60% of your target heart rate during this phase.The main portion of your workout should lasts from 15-50 minutes. As discussed earlier this should be performed at 50 – 70 % of your max heart rate.
The final phase of your workout should be a cool down phase that lasts from 5-10 minutes. The cool down phase is designed to bring the physiological system back to its resting level at a gradual pace. This gradual cool down gives the heart time to get used to the decrease in blood flow and decrease in oxygenation and gives it time to rest. Slow walking is cooling down exercise.
Measuring Progress and Performance If improving your appearance is your primary motivation for cardiovascular exercise other than anti-aging, then your mirror is your best gauge. The scale, unfortunately, is not a good indicator because we could be gaining muscles and losing fat and that will not show up on the scale. The measurement of a lean body mass as well as a percentage of body fat is a good indicator as it gives you a good gauge of how your body composition is changing. Ideally, with a good cardiovascular and weight training exercise, you should be losing fat and gaining lean muscle mass. Your body composition should change accordingly.
You can also measure your progress by duration and intensity of your cardiovascular exercise routine. If you are able to increase your exercise duration or find that you are making the same progress but with less effort, then your cardiac health is improving. The simplest way is to jog continuously for one mile at a comfortable pace and measure the time it takes. You know you are in excellent cardiac shape if your time is less than 8 minutes. If you can do it within 11-13 minutes, you’ve achieved anti-aging benefits.
Ultimately, your progress is best measured by how you feel. When you are consistent in your cardiovascular program, chances are you will feel better, have more energy and a better outlook in life. This may take a few weeks, but it will come. You will realize that your daily tasks have become easier and that the activities and sports you enjoy will not only become easier but also become more enjoyable. Your friends will notice the significant change in you after you have been consistently on the program. Anti-aging is a life-long process and that does not yield immediate results. Many of the benefits will only be apparent years later.
Cardiovascular exercises benefit any age group. The benefits are many, raging from improved health and well being, to anti-aging properties and improved longevity. However, any exercise of aerobic capacity should be structured properly, with physician guidance and should be scaled moderately to fit the particular needs and health of each person.
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