CHAPTER
3
Principles of Exercise Training to Improve Physical Fitness
Chapter 3 - Principles of Exercise Training to Improve Physical Fitness ________________________________________________________________________________________________
Did You Know That… Forty three percent of the nation’s physical education instructors are classified as being in “poor” physical shape. Sixty three percent of commercial gym instructors and/or trainers do not understand the basic concepts of physical fitness. Eighty one percent of the individuals who workout in a commercial gym do not understand the basic concepts of physical fitness. Research indicates that individuals who exercise have fewer wrinkles, experience less stress and are generally healthier than people who don’t exercise. Men and women should train for fitness in exactly the same manner. Longevity has more to do with your physical fitness than with your genetics. Research in the field of health science has consistently revealed that the more knowledge an individual has about fitness and nutrition, the greater his fitness level. Isometric exercises do not develop the muscles through a full range of motion. A muscle that is loaded isokinetically can be exercised through the full range of motion with high level resistance.
After reading this chapter you should be able to answer the following questions What is isometric exercise? What are several advantages and disadvantages of isometric exercise? What is isotonic exercise? What are the advantages of using isotonic exercise? Are there any disadvantages of isotonics? What is isokinetic exercise? What is the difference between a muscle that is loaded isotonically and one that is loaded isokinetically? What advantages are there to using isokinetic exercise? Are there disadvantages associated with isokinetic exercises? What are aerobic exercises? What are the best aerobic exercises? What are anaerobic exercises?
Key Terms Isotonics Isometrics Isokinetics Specificity Isoscale Aerobic Anaerobic Concentric
Chapter 3 - Principles of Exercise Training to Improve Physical Fitness ________________________________________________________________________________________________
Introduction ________________________________________________
Here is something that might surprise you. Physical fitness training has been around longer than M.T.V. …even longer than Soul Train. In fact, it started with the Greeks in about, oh, the fourth century B.C. From there, fitness training caught on like jock itch. Today, everyone is exercising. Some people are even exercising the right way. Unfortunately, the majority of people don’t have a clue as to what physical fitness is or how to develop it. Well, we have good news for you. After you finish reading this chapter you will know more about fitness than Plato or Socrates ever thought about knowing. Heck, you will know more about fitness than the “body shapers” on ESPN, even more than Richard Simmons. In short, we are going to “pump up” your brain as well as your body. For starters, you will need to get a general understanding as to what this fitness stuff is all about. So let’s begin at the beginning with Physical Fitness. Physical fitness can be defined in terms of the degree of cardiovascular endurance, muscular endurance and muscular strength. Most physiologists, however, define physical fitness in terms of cardiovascular endurance, which is the ability of the heart and respiratory system to supply the tissues of the body with oxygen. Now here is something you may not know. Each of the aforementioned components of fitness is quite independent. In fact, there is very little relationship between them. For instance, a long distance runner would have superb cardiovascular fitness, but may possess very little strength. Conversely, a weightlifter would have extraordinary strength, but have relatively little cardiovascular endurance or muscular endurance. This brings up an important point. If you want to develop all three components of physical fitness… cardiovascular endurance, muscular endurance and muscular strength…you will have to work on each component separately.
Chapter 3 - Principles of Exercise Training to Improve Physical Fitness ________________________________________________________________________________________________
The question arises. Which component of fitness is most important? Actually, it depends on your objectives. For example, different sports make some fitness components more important than others. If you were an Olympic lifter or powerlifter, then muscular strength would have the greatest value (as far as your career was concerned). In fact, few weightlifters have good cardiovascular fitness…unless they have also trained for this component of fitness. Some sports such as wrestling requires the development of all three components, whereas with other sports such as swimming or running, the nature of the event will determine the importance of a fitness component. In a sprint, muscular strength is the key, whereas cardiovascular endurance is more important in long distance events…you know…like marathon sex. As you might have guessed, most physiologists believe that cardiovascular fitness is most important because there is a possibility that this may increase longevity. If this yet unproved benefit does result, then many nonexercisers will want to know if the increase in longevity is of sufficient magnitude to justify the time and effort involved in training. In other words, is it worth spending forty years of your life engaged in intense cardiovascular training to increase your life span five years? Still, being fit often greatly improves the quality of one’s life, and whether or not it increases its duration may be less important. It might be noted here that there is a prolific amount of research which indicates that exercise helps increase the length of life as well as the quality of life. Just a few of the health benefits of regular exercise as follows: 1. A delay in the aging process. 2. Improved physical appearance. 3. Increased cardiovascular fitness. 4. Increased muscular strength and endurance. 5. Reduced risk of cardiovascular diseases. 6. Reduced anxiety and stress. 7. Maintenance of proper body weight. 8. Naturally induced fatigue and relaxation. 9. Improved sex life. With the tremendous benefits that can be derived from exercise, it would seem foolish not to lace up your Air Jordans and get started. Instead of sitting around and getting high (on life of course) and watching MTV, get up and get down. Open your mind to exercise, don’t just sit there…do something. Run the Boston marathon, walk around the block, chase a squirrel… you see, the possibilities are endless. The important thing is to do something. Set a goal, pick out exercises you enjoy, start out slowly and before you know it, you’ll be charging people to breathe. They’ll probably be old and feeble, but hey, it’s money.
Types of Exercise _________________________________________________________
The first thing you learn in education is to use big fancy words to impress your friends with and to confuse the hell out of your students. Well, we are not going to disappoint you. We have some real fancy words for the plain old exercises that people have been doing for years. For instance, when you are finished with this chapter and someone asks you, “Hey, what are you doing over there? A bench press?” You’ll be able to respond, “No! I’m not doing bench presses. I’m doing an isotonic supine press.” Now, doesn’t that sound impressive? What is an isotonic supine press? A bench press by another name! Isn’t that great? Like we said, words you can use to impress your friends with, and we have them all in this chapter. Not only that, but we are also going to tell you what they mean. That puts us one up on most educators. Okay here we go.
- Isometrics Your first new word is isometric exercise. Now, is that a scientific word or what? An isometric
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exercise is an exercise in which a force is applied against an immovable object. The muscles attempt to contract but are unable to overcome the resistance being used. An example would be if you stood in a doorway and pushed against the sides of the door with your hands…provided of course, you don’t move the walls! During such an exercise, the muscles involved are statically contracted (iso-same; metric-measure). Research indicates that when exercising in this manner, best results are obtained by contracting the muscle with maximum force for a duration of five to eight seconds. A main advantage of isometric training is that it is the most efficient type of training for strength in terms of time spent exercising. Another major advantage is application in orthopedics where strength assessment or rehabilitation is necessary for joints that are incapacitated. Unfortunately, isometric exercises have a number of disadvantages. First of all, isometrics can only be used to develop muscular strength. Research has indicated that because of the nature of the exercise, muscular endurance and cardiovascular fitness cannot be developed. Perhaps the greatest drawback is that the muscles are not developed through a full range of motion. Since strength is only developed at the angle at which the force is being applied, there is little, if any, transfer of strength to other joint angles. Thus, strength developed isometrically at specific angles cannot be utilized to advantage in exercises or movements that require a full range of motion. This problem can be alleviated by isometrically exercising the muscle at various angles, but this would require a considerable amount of time…like forever or longer. Another disadvantage of isometric training is that it is difficult to determine the effectiveness of each repetition without specialized equipment (tensiometer, isoscales). Since there is almost no movement during the exercises, it is difficult to determine whether or not strength is increasing from one training period to another, or if an overload force is being exerted. This lack of feedback generally causes motivational problems for the individual who relies on isometric methods of training. Of course we don’t have to tell you how important motivation is to peak performance. Okay, we will. Motivation is about as important as Spanish Fly or Viagra at a Hugh Hefner get together. It’s that important…really.
- Isotonic exercise Here is another good word for you…isotonics. Notice how isotonics sounds like isometrics. Educators live for words like these. They are perfect for adding chaos to confusion. So pay attention so that you can become the enlightened rather than the perplexed. Isotonics are exercises in which force is applied against a moveable resistance. During this type of exercise, the muscle is either concentrically contracted (shortened) such as when you curl a weight with your arm, or eccentrically contracted (lengthened) as when you slowly lower the weight. The use of the term isotonic (iso = same; tonos = tension) is somewhat misleading because as a weight is moved, the tension is not really constant, but varies with the joint angle or position of the weight. The angle where movement of the weight is most difficult is referred to by weightlifters as the sticking point. Probably, the greatest advantage is that isotonic exercises develop the muscle through a full range of motion, thus eliminating the problem of specificity associated with isometric exercises. Also, unlike isometrics, isotonics can be used to develop muscular endurance and cardiovascular fitness as well as strength. Another advantage of isotonic exercises is that the trainee is constantly receiving feedback about the work being done. This knowledge of results is not only important for evaluation, but is often rewarding to the individual and helps create and sustain motivation. Nothing’s perfect though…except Bo Derrick…not even isotonics. Like isometrics, there are a few disadvantages associated with using isotonics. Generally speaking, some type of equipment is required in order to do isotonic exercises. If equipment is necessary, you’ll need money to buy it and a place to put it…a
Chapter 3 - Principles of Exercise Training to Improve Physical Fitness ________________________________________________________________________________________________
blinding flash of the obvious...right? There is also the possibility of being injured when using equipment. For instance, we’ve seen more than one lifter get his head buried in his crotch under a heavy squat. Of course the risk of injury varies with different types of equipment and types of exercises. Nevertheless, weightlifting is one of the safest sports. When using heavy free weights, especially when the weights are above the body as in the bench press, the lifter should have an assistant or spotter. In fact, it’s not a good idea to train by yourself if you are using isotonics. Such safety requirements might also be considered a drawback, unless of course, you can get Tyra Banks to spot you.
- Isokinetic Exercises Isokinetics…now is that a great word or what? It makes us intellectually erect just thinking about it. Can you imagine what a word like this does to the Dean of Education? And he probably wouldn’t even know what it means. But you’re going to know before we get finished here. Technically speaking, isokinetic exercises (iso=same; kinetic=movement) are simply a variation of isotonic exercises. The difference is that the resistance used in isokinetic exercises is such that the speed of movement is constant throughout the entire exercise. This enables the individual to place maximum resistance on the muscle at every point throughout the range of motion. In isotonic exercises, no matter how much (or how little) force is generated, the resistance continues to move at a constant speed. Thus, a muscle that is loaded isokinetically can be exercised throughout the full range of motion with maximum resistance…provided that the individual exerts maximum force. Practically the same advantages that were mentioned for isotonics are inherent to isokinetics. However, as previously stated, unlike isotonics, isokinetics have the advantage of putting the muscle under maximum tension at every point in the range of motion. Since isokinetic exercises are always performed with the use of machines, isokinetics can be somewhat safer than isotonics. Some machines are inexpensive and can be used safely without the assistance of others. In general though, isokinetic machines are more expensive than isotonic equipment.
- Aerobic Exercise If you’re one of those people who lie down every time you feel like running until the feeling goes away, you probably won’t like the word aerobics. Let us give you a hint. It’s a Jane Fonda word. Aerobic
Chapter 3 - Principles of Exercise Training to Improve Physical Fitness ________________________________________________________________________________________________
exercises are activities that require oxygen, such as sustained running, bicycling, swimming, some types of dancing, etc. Often, the intent is to do these types of exercises with sufficient intensity to produce increased cardiovascular fitness through a training effect. A training effect can be achieved by sufficiently elevating the heart rate (or pulse) and keeping it at that level for a minimum of about ten minutes. The minimum heart rate necessary for achieving a training effect varies with the age of the individual. Older individuals do not have to elevate their heart rate as much. For example, individuals under 30 require about 140 beats/minute, individuals in the 30 to 50 range require about 130 beats/minute, those over 50 require 120 beats/minute or even less. Remember that these are approximate minimum values; in general, exercising at higher levels will produce a stronger training effect, but one should only gradually work up to higher levels. We will talk more about this later. The “best” aerobic exercises are probably those that readily elevate and maintain the heart rate at the level necessary for a training effect. However, the best exercise will also be one that you enjoy and are likely to engage in several times a week.
- Anaerobic Exercise Anaerobics? You see that “A” in front of aerobics? That means without. Consequently, anaerobics are exercises or activities that can be performed without oxygen. Such exercises as sprinting short distances or lifting near maximum weight would be examples of anaerobic exercises. These are exercises you can do without breaking into a severe sweat…which is good because sweating can cause jock itch or worse yet, bad body odor. Jane knows…so does Bo!