Chapter 3 - Principles of Exercise Training to Improve Physical Fitness ________________________________________________________________________________________________
Training Considerations _________________________________________________________________________
- The Overload Principle and Progressive Resistance There are two principles that you will need to adhere to when developing strength or any other fitness component. The first principle is called the overload principle. When the body is exercised at a level which is above normal, (that is, “overloaded”) the body will eventually adapt to that level and function more efficiently. Thus, in order to improve performance, the muscles must be overloaded or stressed beyond what they are normally accustomed to. An individual can produce an overload by adjusting the frequency, intensity, or duration of the exercise until the muscle is sufficiently trained. As mentioned, this principle applies not only to the development of strength, but also to the development of muscular endurance and cardiovascular fitness. The second principle is called progressive resistance. This principle simply states that as you increase in ability you must increase your resistance if you want to continue to get a training effect. Actually, progressive resistance is a good example of the proper way to apply the overload principle if you want to continue to develop. In order to become more and more physically fit, you must systematically increase the resistance of the exercises. Each higher level of fitness requires a greater workload.
- Reversibility Although your muscles won’t turn to fat, your level of fitness will drop off rather quickly after you quit training. It does not matter if you have been training for a year or for a lifetime, a significant loss is inevitable within five or six weeks after you stop. We know that’s a real kick in the butt, but it’s a fact of life. This regression in fitness is referred to by physiologists as reversibility. Why reversibility occurs so quickly is not yet understood. However, muscles that are not continually conditioned quickly lose their ability to utilize oxygen efficiently. Consequently, aerobic activities that require the muscles to use large amounts of oxygen, such as swimming, jogging, cycling and wrestling are prone to rapid reversibility. On the other hand, anaerobic activities which have low oxygen requirements, such as powerlifting and sprinting, resist reversibility for a longer period of time. Thus strength or power reversibility is a result of muscle atrophy rather than the muscle’s decreased oxygen efficiency. Since it takes considerably more time and effort to get in shape than it does to experience reversibility, it is a good practice to stay in shape all year if possible. Many athletes who compete in seasonal sports make the mistake of staying in shape only during the time their sport is in season. By doing this, they must engage in extensive training when their sport comes back in season in order to regain the fitness they lost from reversibility. We do have some good news for you though, concerning reversibility. There is considerable research which indicates that it takes less time and energy to reverse reversibility than it does to develop fitness from the beginning. In other words, because of muscle memory, you can get your fitness back faster after you’ve stopped training than it took you to develop it in the first place.