What is Cardiovascular Fitness???

Using the same large muscle group, rhythmically, for a period of 15 to 20 minutes or longer while maintaining 60-80% of your maximum heart rate.

Think of aerobic activity as being long in duration yet low in intensity. Aerobic activities include: walking, biking, jogging, swimming, aerobic classes and cross-country skiing. Anaerobic activity is short in duration and high in intensity. Anaerobic activities include: racquetball, downhill skiing, weight lifting, sprinting, softball, soccer and football.

Aerobic means with air or oxygen. You should be able to carry on a short conversation while doing aerobic exercise. If you are gasping for air while talking, you are probably working anaerobically. When you work anaerobically, you will tire faster and are more likely to experience sore muscles after exercise is over.

 

Benefits of Cardiovascular Exercise:

Aerobic exercise conditions the heart and lungs by increasing the oxygen available to the body and by enabling the heart to use oxygen more efficiently. Exercise alone cannot prevent or cure heart disease. It is only one factor in a total program of risk reduction; examples of other factors are high blood pressure, cigarette smoking and high cholesterol level.

In addition to cardiovascular benefits, other benefits of aerobic exercise include:

[Back]

 

A. Physiological Measures Related to Cardiovascular Fitness

Heart Size

Stroke Volume

Heart Rate

Cardiac Output

Blood Flow

Blood Pressure

Blood Volume

 

[Back]

 

B. Chronic and Acute Responses

Acute Responses

1. There is only an increase in sheart rate during exercise because the heart needs to pump more blood to the different muscles. This increase is directly proportional to the increase of intensity of exercise.
- Average heart rate is 60-70 beats per minute, and during exercise it increases to 165-190 beats per minute

2. Stroke volume increases with intensity of work
- Affected by body position and supine position (have to fight gravity)

3. Cardiac output increases with exercise from the normal 5 Liters per minute to 20-40 L per minute
- Major purpose: meet muscles' demand for oxygen

4. Metabolic waste products accumulate
- Caused by increase in Hydrogen ion concentration, increase in acidity

5. Heat builds up in the body
- Increase in skin and deep body temp
- How heat is dissipated from the body

6. Redirection of blood flow
- Flow of blood to essential areas

7. Blood pressure increases for systolic
 
8. Blood volume
- Decreases because of water loss:perspiration

9. Oxygen consumption increases
- Arterial venous oxygen difference
- Oxygen intake from blood

10. Muscle activity
-fatigues

11. More common responses
- Chest pains
- dizziness, fainting, nausea, cold sweat, lightheadedness
- palpitating, fluttering and missed heart beats- irregular heart beats
- sudden burst and slowing of rapid pulse.

 

Chronic Responses

1. Heart Structure
- Heart hypertrophy
- Heart weight, volume, ventricle's wall thickness, chamber size

2. Heart Rate
- Resting heart rate, maximal heart rate, steady heart rate are substantially lowered
- More efficient heart because it can pump needed amount of blood at lower rate

3. Heart rate recovery is shorter and faster
 
4. Stroke volume shows an overall increase
- Amount of stroke volume is substantially higher than an untrained individual

5. Cardiac output increases in a greater amount that acute response
 
6. Increase in blood flow, caused by the ff:
- Increase in capillirization of trained muscles
- Increased opening in existing capilliaries
- More effective blood distribution

7. Blood pressure
- Resting blood pressure lowers for trained individuals because stroke volume is greater for slower heart rate

8. Blood volume increases with more intense level of training
 
9. Blood volume can also decrease due to sweating: Hemoconcentration
 
10. Respiratory rate is lowered because of a decrease in the amount of energy used to move air into and out of the lungs.
 
11. Pulmonary diffusion increases during maximal exercise
 
12. Cells have greater ability to utilize oxygen thus the use of anaerobic system is lowered
- Better efficiency with the use of aerobic system

13. The body can exercise longer without feeling fatigue because heart is stronger
 
14. Exercise lowers risk and incidence of heart disease
 
15. Exercise reduces emotional stress

 

[Back]
 

C. Factors Influencing Cardiovascular Fitness


It is medically proven that people have different cardiovascular responses to numerous exercises. This is due to the different factors that have an effect to their cardiovascular fitness. The four widely accepted and acknowledged factors are: (1) heredity, (2) age, (3) sex, (4) individual's physical reponse to the exercise or his potential for fitness.

1. Heredity
According to medical research and studies, maximum oxygen consumption of an individual can be inherited by their offspring. the amount of oxygen an individual's body can hold miust be taken into consideration because it serves as the measure of his aerobic capacity. This criterion is used to regulate the amount of activity a person should do.
 
Hypertension is one of the diseases that can be inherited. Due to the prolonged constriction or plaque formations (arteriosclerosis) of the arterioles, there is an increased resistance to the flow of blood and this in turn causes hypertension. In order to adapt to this situation, the heart has to beat harder in order to pump the blood. The heart's walls thicken in time due to the hypertension. And if this persists for a long time, the heart, being a pump starts to fail leading to what is called heart failure.

Thus hereditary traits really could affect the cardiovascular fitness of a person.

2. Age
Age is an important factor in cardiovascular fitness. Due to the passing years, human being's bodies undergo certain changes that can affect their health as well as their capability to perform aerobic activities. However, there is a decrease in aerobic capacity of about 10% per decade. This is due to the aging process in which other bodily functions start to weaken.

Due to the weakening of the body as it ages, a person could suffer from different heart ailments. hypertension is one of the heart ailments that could trouble old people.

3. Sex
A person's gender can also influence their cardiovascular fitness. The variations between the male and female genetic make-up bring about differences in the cardiovascular fitness of people. Basically, males have more muscles thatn females so it can be said that they are physically stronger than their female counterparts. Thus it can also be concluded that they would be able to perform more vigorous activities. However, scientific studies have proven that male human beings are more prone to heart disease than femals.

4. Potential for fitness
The variations in reponse to training could be due to individual differences. There are two categories that an individual can fall under in this particular factor. A person could either be a responder or non-responder. A responder is someone who undergoes a large or notable improvement upon peforming cardiovascular exercises and activities. A non-responder on the other hand has little improvement or does not improve at all. A person's responsiveness, or lask thereof, could also be hereditary.
 

 

[Back]
 

 

D. FITT Principles

The FITT Principle of Exercise is an easy way to remember the key components of exercise prescription for body fat loss.

Frequency
The experts say that cardiovascular endurance exercise (such as: WALKAEROBICS) should be done at a frequency of 3 to 6 days a week. Beginners should start with 3 times a week, skipping at least a day in between. This is generally agreed upon by experts, but our Walkaerobics study has shown that even less exercise will be effective for a deconditioned, "couch potato." Even if you start out exercising only twice a week, you can reap benefits. In fact, exercising too much can cause more problems than too little, due to problems of fatigue and the increased chances of an overuse injury. As you get adapted to the exercise you can add additional days, if you wish. But don't overdo it. Rest one whole day for every three or four days of exercise. Once injured, we don't return to exercise for a long time, if ever.
 
 
Intensity
- amount of physiological stress or overload placed on the body during exercise

Maximum Heart Rate
100% is the level of your heart rate at its maximum intensity. It is your survival heart rate. For example; if there was a fire and you had to gather your belongings, flee a building, and get out to your car, by the time you reached your car, your pounding heart would probably have reached its maximum heart rate, its 100%. It is your "fight or flight" heart rate. You won't die at that heart rate, but, you only have 9 seconds of energy at that intensity. The fuel our bodies uses during emergencies such as this is glucose or "sugar" (carbohydrate), not body fat. Our bodies store a small amount of "sugar" in our muscles (called glycogen) and there is glucose traveling around in our blood. Glucose is the only fuel our brain uses, so when we use up this blood sugar during a high impact aerobics class, we feel fatigued, hungry, and sometimes dizzy during or afterwards.

We should never exercise at that maximum intensity (100% of your maximum heart rate equals 220 minus Your Age ). In addition to exhausting us for many hours afterward and increasing our appetite, high intensity activity can easily cause an injury, which stops our exercise program temporarily or even permanently, and besides, we're not even burning body fat.

Sports Heart Rate
80% is our sports heart rate. We get to this high an intensity for a few minutes at a time playing tennis or running bases in a softball game. Athletes use short spurts of energy at 80% in a football game or running the 50 yard dash. However, most "no pain, no gain" aerobics exercise classes have you exercise at 80% heart rates. This is wrong and dangerous! 80% is very close to 100% and much too intense for a sustained exercise session, especially for some one who is overfat. The more recent studies show that at 80% intensities the injury rate is very high and not worth the risk. In other words the wrong exercise might be worse than no exercise. Besides, the high intensity of the exercise causes the body to think it's in a "fight or flight" situation so the fuel the body uses is primarily glucose not fat.

Optimal Heart Rate - for Burning Body Fat
60% is our optimal heart rate during exercise. The studies that looked at exercise intensities at 80% compared these rigorous activities with more moderate exercise, like walking, stationary biking, and Walkaerobics, which get heart rates up to 60%. They found that the cardiovascular improvements were similar in 60% and 80%, but the injury rate was substantially lower at 60%. They also found that the moderate intensities burned more body fat as fuel.

Most enlightened exercise specialists now agree with the ACSM that the optimal heart rates during exercise should reach an intensity of 60% or less.

Time
The time or duration of the aerobic portion of the exercise session should be between 12 minutes and 60 minutes.The less fit you are, the shorter the duration and the more often you should exercise. As you become leaner and fitter, you will need to exercise for a longer duration, more intensely, and less often.

When you start your exercise program you may decide to walk around your local high school track. You might be able to do it for only 5 minutes before feeling tired. You might find walking takes a tremendous effort and you can't go very fast. Your heart rate may reach your 60% or may not. Your extra fat may hamper you from walking fast to raise your heart rate very much. On the other hand, if you have a strong, healthy heart, your legs, feet, ankles, or lungs , may tire before your heart has to work at all. Your heart may only get up to its 40% or 50%, but you are still burning calories (one mile consumes approximately 300 kcals).

Or the opposite might happen. Your extra fat pounds and couch potato life-style may make walking even a short distance stress your cardiovascular system and heart, raising your heart rate higher than 60%, and possibly as high as 70% or 80%.

In both cases you should try to achieve a comfortable, moderate pace and if you return to the track 3 to 5 times a week, you will find that in a period of time you can walk longer and more briskly. When you can walk for 30 minutes without stopping and you can sustain a heart rate of 50% to .60%, then 3 times per week is enough.

Type
Any exercise induced net calorie deficit can result in fat loss.Weight lifting, however, may lead to a gain in lean body weight and therefore a discouraging gain in overall weight.Whereas aerobic exercise, such as walking and Walkaerobics, usually results in a maintenance of lean body weight. Both types can contribute to a loss of body fat.

The Most Effective Fat Burning Activities are:

[Back]