Course Instructor (P15)
General Principles Of Exercise Training
Principle of Use–the human body has the ability to adapt to use and imposed demands thereby increasing the body systems capacity and efficiency.
Principle of Disuse–dictates that your level of fitness will decline if you stop exercising.
Overload Principle— in order for your cells to increase in size (hypertrophy) the workload (stressor) must be increased beyond what the cells normally experience. This is referred to as overloading. Your body systems must be stressed beyond normal levels of activity if they are to improve. The overload is a positive stressor and is the basis of stress adaptation.
The components of overloading include exercise intensity or load, exercise duration, exercise frequency, exercise repetitions and rest. Each of these components can be increased to impose an overload. Exercise intensity or load is probably the most important component of the overload principle. For strength gains to occur, your load should represent an intensity which is at least 60% to 80% of your muscle’s maximum strength. This will usually allow the performance of seven to ten repetitions of a particular exercise before resting. Practically speaking, the amount of resistance you use in an exercise is determined by trial and error. In designing an exercise program, always underestimate an individuals lifting capabilities.
Increasing the length of the exercise period ( Exercise duration) can impose an overload. It is not uncommon for body builders to perform various exercises, in excess of eight hours per day, prior to a competition.
Exercise frequency refers to the number of days per week that an individual exercises. To improve or maintain muscular strength or endurance, the average individual would need to exercise on alternate days or approximately three to four days per week. Generally, each major muscle group should be overloaded every 36 to 48 hours. Conversely, elite athletes preparing for competition may require daily training sessions.
Exercise repetition is one complete movement of an exercise. A series of repetitions, performed consecutively, is referred to as an exercise set. Exercise repetitions will determine the type of adaptation. For example, an increased weight load with low exercise repetitions will result in muscle hypertrophy. A decreased weight load with high exercise repetitions is best for achieving muscle endurance.
Rest is the amount of time between the performance of an exercise set. The amount of rest required will depend upon the load demand. The greater the load, the greater the fatigue, and therefore, a greater rest period is necessary for recovery. The amount of rest is also dependent upon the type of adaptation which is desired. For endurance (oxidative) adaptations to occur, you will normally rest less and exercise at a lower intensity than when you are attempting to develop strength. To develop muscle endurance, rest 30 seconds between sets. High intensity strength training, such as squat activities, may necessitate rest periods of up to 5 minutes between sets. The rest period for most exercise programs is approximately one to two minutes between sets.
Principle of Progression–often referred to as progressive overload or progressive resistance exercise. As exercise adaptations occur over time, your body experiences a sensation of reduced effort for a given performance. This is due to the physiological adaptations enhancing the bodies ability to create energy and remove metabolic waste products. To achieve steady improvement, training intensity should be continually increased. However, it is important to progress slowly, as too rapid a progression may lead to overuse injuries.
Principle of Specificity–indicates that you must train a specific energy system (often referred to as metabolic specificity) or specific muscle groups (known as neuromuscular specificity) in order for them to improve.
The Principle of Warm–Up and Warm–Down— a properly designed exercise program will include a warm-up (low level activities, such as stretching and slow walking, performed prior to more strenuous exercise), a stimulus period (the performance of strenuous exercise) and a warm–down period, also known as the cool-down (performed immediately after the stimulus period). The warm–up and warm–down help to prevent muscle soreness and injury and prevent excessive strain on the heart. For example, if you stop running abruptly, blood may pool in the legs, thereby decreasing the bloods return to the heart.
The Principle of Recuperation–due to the stress placed on the body by exercise, rest and recuperation are essential. Inadequate recuperation can result in over training syndrome and overuse injuries such as epicondylitis. However, extended periods of rest may lead to deterioration in one’s fitness level.
The Principle of Reversibility— the benefits of training are transient and dependent upon continued exercise. You must continue to exercise to avoid deconditioning (use it or lose it). It is said that for every day of inactivity, it takes two days of exercise to return to one’s normal fitness level.