We all know there is a correct dosage of medicine for treating an illness just as there is the right amount of exercise for developing physical fitness. The minimum amount of exercise for developing physical fitness is called the threshold of training. The fitness target zone is the optimal amount of physical activity. There is new evidence that the threshold for performance improvement differs from the threshold for achieving some health benefits of physical activity. It is also true that the amount of exercise necessary for maintaining fitness may differ from the amount needed to develop it.
The basis for improving physical fitness is to apply the “overload principle”. In order for a muscle (including the heart muscle) to get stronger, it must be “overloaded”, or worked against a load greater than normal. To increase flexibility, a muscle must be stretched longer than normal. To increase muscular endurance, muscles must be exposed to sustained exercise for a longer than normal period. If overload is less than normal for a specific component of fitness, the result will be a decrease in that particular component of fitness. A normal amount of exercise will maintain the current fitness level.
Based on this principle, there is no substitute for overload in developing physical fitness. Many people do not overload enough to develop good fitness. Often the programs found in health clubs and in exercises described in popular books and magazines do not provide for adequate overload. Some people try exercise machines or quack devices that violate the overload principle and are therefore ineffective.
An important law of exercise that should be observed if optimal fitness is to be obtained is the “principle of specificity”. This principle states that to develop a certain characteristic of fitness, you must overload specifically for that particular fitness component. As an example, strength-building exercises may do little for developing cardiovascular fitness and flexibility exercises may do little for altering body composition.
Overload is specific to each component of fitness and is also specific to each body part. If you exercise the legs, you build fitness of the legs. If you exercise the arms, you build fitness of the arms. For this reason, it is not unusual to see some people with disproportionate fitness development. Some gymnasts, for example, have good upper body development but poor leg development, whereas, some soccer players have well-developed legs but lack upper body development.
Specificity is important in designing your warm-up, workout and cool-down programs for specific activities. Training is most effective when it closely resembles the activity for which you are preparing. For example, if your goal is to improve your skill in tennis, it not enough to overload your cardiovascular endurance. You should perform training requiring you to overload your upper body’s ability to swing a racket and hit the ball with increased force.
The “progression concept” indicates that overload should not be increased too slowly or too rapidly if fitness is to result. The concepts of threshold of training and fitness target zones are based on the “progression principle”. Beginners can exercise progressively by starting near threshold levels and gradually increasing in frequency, intensity, and time (duration) within the target zone. Exercise above the target zone is counterproductive and can be dangerous. If you are a weekend athlete who exercises vigorously only on weekends you do not exercise often enough, and so violate the principle of progression. It should be noted that it is possible to do too little or too much exercise to develop optimal fitness.
For each component of fitness there is a threshold of training and a fitness target zone. The threshold of training is the minimum amount of exercise necessary to produce gains in fitness. What you normally do, or just a little more than normal exercise, is not enough to cause improvements in fitness. The fitness target zone begins at the threshold of training and stops at the point where the benefits of exercise become counterproductive.
Some people incorrectly associate the concepts of threshold of training and fitness target zones with only cardiovascular fitness. As the principle of specificity suggests, each component of fitness has its own threshold and target zone.
For exercise to be effective, it must be done with enough Frequency, Intensity and for a long enough Time. The first letter from these three words spells FIT and can be considered as the formula for fitness.
F: Frequency (how often) means exercise must be performed regularly to be effective. The number of days a person exercises per week is used to determine frequency. Exercise frequency depends on the specific component to be developed. Most fitness components require at least three (3) days and up to six (6) days of activity per week.
I: Intensity (how hard) means exercise must be hard enough to require more exertion than normal to produce gains in health-related fitness. The method for determining appropriate intensity varies with each aspect of fitness. For example, flexibility requires stretching muscles beyond normal length, cardiovascular fitness requires elevating the heart rate above normal, and strength requires increasing the resistance more than normal.
T: Time (how long) means exercise must be done for a significant length of time to be effective. Generally, an exercise period must be at least fifteen minutes in length to be effective, while longer times are recommended for optimal fitness gains. As the length of time increases, intensities of exercises may be decreased. Time of exercise involvement is also referred to as exercise duration.
Sometimes a second “T” is added to the FIT Formula (FITT) to indicate the Type of physical activity you perform is important. As the specificity principle indicates, different types of activity build different components of fitness.
Lifestyle activities are a part of everyday living and can contribute significantly to good health, fitness and wellness. Lifestyle activities include walking to or from work, climbing stairs rather than taking the elevator, working in the yard, or doing any other type of exercises as part of normal daily activities.
Aerobic activities include those that are of such intensity that they can be performed for relatively long periods of time without stopping. Brisk fitness walking, jogging, biking and aerobic dance are a few of the common aerobic activities. Aerobic activity is especially good for building cardiovascular fitness and helping to control body fatness.
Flexibility (stretching) exercises are a type of exercise that are planned specifically to build flexibility. This type of exercise is necessary because most other activities do not contribute to flexibility. This type of exercise should be performed at least three days per week and for best results more often.
Strength training is important to developing muscle strength and muscle endurance. This type of exercise should be performed two to three days per week.
Active sports are a type of activity that improve cardiovascular fitness and can help control boy fatness if done for relatively long periods of time without stopping. They also contribute to the development of other parts of fitness. Examples include basketball, tennis, golf and bowling. Active sports done more than a few days a week can have many of the benefits of aerobic activities.
Rest or inactivity can also be important to good health. Some time off just to relax is important to us all and of course proper amounts of rest and sleep help us recuperate.
As you become more fit by doing correct exercises, your threshold of training and fitness target zones may change. Likewise, if you stop exercising for a period of time, they will also change. Your threshold of training and fitness target zones are based on your current physical fitness levels and your current exercise patterns. Recent studies have shown that the exercise necessary to maintain fitness need not be as often as exercise designed to build fitness.
It takes time for exercise to benefit health-related physical fitness. Sometimes people just beginning an exercise program expect to see immediate results. They expect to see large losses in body fat in short periods of time, or great increases in muscle strength in just a few days. Evidence shows, however, that improvements in health-related physical fitness and the associated health benefits take several weeks to become apparent. Some people will report psychological benefits, such as “feeling better” and a “sense of personal accomplishment” almost immediately after beginning regular exercise. This is a great moment and should be used to build confidence in the fitness process. A word of caution: the physical result will take considerably longer to be realized. Proper preparation for exercise includes learning not to expect too much too soon, and not to do too much too soon. Attempts to overdo it and to try to get fit fast will probably be counterproductive, resulting in soreness and even injury. The key is to start slowly, stay with it and enjoy the exercise. Benefits will come to those who persist!