Exercise Health Article

Definition

Exercise is physical activity that is planned, structured, and repetitive for the purpose of conditioning any part of the body or to improve performance in a specific task. Exercise is utilized to improve health, maintain fitness, and is important as a means of physical rehabilitation.

Purpose

Exercise is used in preventing or treating coronary heart disease, osteoporosis, weakness, diabetes, obesity, and depression. Range of motion is one aspect of exercise important for increasing or maintaining joint function. Strengthening exercises provide appropriate resistance to the muscles and increase endurance and strength. Cardiac rehabilitation exercises are developed and individualized to improve the cardiovascular system for prevention of and rehabilitation from cardiac disorders and diseases. A well-structured exercise program can improve general health by increasing strength, endurance, balance, and confidence. Furthermore, an exercise program may delay or minimize the effects of disease and aging. The benefits of exercise not only extend into the areas of physical health, but also enhance emotional well-being.

Precautions

Before beginning any exercise program, evaluation by a physician is recommended to rule out any potential health risks. Once health and fitness are determined and any or all physical restrictions identified, the exercise program should be under the supervision of a health care professional, especially when used as a form of rehabilitation. If symptoms of dizziness, nausea, excessive shortness of breath, or chest pain are present during any exercise program, the individual should stop the activity and inform the physician before resuming activity. Exercise equipment must be checked often for wear and durability.

Description

There are two types of rehabilitation to restore or improve function: cardiac and physical rehabilitation.

Cardiac rehabilitation

Exercise is very helpful in prevention of and rehabilitation from cardiac disorders and disease. With an individually designed exercise program set at a safe level, heart failure patients can improve their fitness levels substantially. Endurance or aerobic routines, such as running, brisk walking, cycling, or swimming, increase the strength and efficiency of the muscles of the heart. The increase in endurance should also translate into a generally more active lifestyle.

Physical rehabilitation

Physical rehabilitation deals with improving function in specific individuals who have functional impairments secondary to disease, injury, or disuse. This is accomplished by therapeutic exercise that focuses on strengthening, coordination, balance, and endurance training. Both types of rehabilitation can incorporate range of motion exercises and strengthening exercises.

RANGE OF MOTION EXERCISE. Range of motion exercise refers to activity aimed at improving movement of a specific joint. This motion is influenced by several structures: configuration of bone surfaces within the joint; joint capsule; ligaments; and muscles and tendons acting on the joint. There are three types of range of motion exercises: passive, active, and active assistive. Passive range of motion is movement applied to the joint solely by another person or persons or by a passive motion machine. When passive range of motion is applied, the joint of the individual receiving exercise is completely relaxed while the outside force takes the body part, such as a leg or arm, throughout the available range. Injury, surgery, or immobilization of a joint may affect the normal joint range of motion. Active range of motion is movement of the joint provided entirely by the individual performing the exercise. In this case, there is no outside force aiding in the movement. Active assistive range of motion is described as the joint receiving partial assistance from an outside force. This range of motion may result from the majority of motion applied by the exerciser or by the person or persons assisting the individual. It may also be a half-and-half effort on the joint from each source.

STRENGTHENING EXERCISE. Strengthening exercise increases muscle strength and mass, bone strength, and the body's metabolism. It can help attain and maintain proper weight and improve body image and self-esteem. A certain level of muscle strength is needed to do daily activities, such as walking, running, and climbing stairs. Strengthening exercises increase muscle strength by putting more strain on a muscle than it is normally accustomed to receiving. This increased load stimulates the production of proteins inside each muscle cell that allow the muscle as a whole to contract with greater force. There is evidence indicating that strength training may be better than aerobic exercise alone for improving self-esteem and body image. Weight training allows immediate feedback through observation of progress in muscle growth and improved muscle tone.

Strengthening exercises can be further categorized in terms of the mode of resistive training, such as isometric, isotonic, or isokinetic.

ISOMETRIC EXERCISE. During isometric exercises muscles contract; however, there is no motion in the affected joints. The muscle fibers maintain a constant length throughout the entire contraction. The exercises are usually performed against an immovable surface or object, such as pressing the hand against the wall. The muscles of the arm are contracting but the wall is not moving as a result of the physical effort. Isometric training is effective for developing total strength of a particular muscle or group of muscles. It is often used for rehabilitation, since the exact area of muscle weakness can be isolated and strengthening can be administered at the proper joint angle. This kind of training can provide a relatively quick and convenient method for overloading and strengthening muscles without any special equipment and with little chance of injury.

ISOTONIC EXERCISE. Isotonic exercise differs from isometric exercise in that there is movement of the joint during the muscle contraction. It is exercise with a fixed resistance and variable speed. A classic example of an isotonic exercise is weight training with dumbbells and barbells. As the weight is lifted throughout the range of motion, the muscle shortens and lengthens. Calisthenics are also an example of isotonic exercise. These would include chin-ups, push-ups, and sit-ups, all of which use body weight as the resistance force.

ISOKINETIC EXERCISE. Isokinetic exercise utilizes machines that control the speed of movement within the range of motion. Isokinetic exercise attempts to combine the best features of both isometrics and weight training. It is resistive exercise utilizing a fixed speed and variable resistance. It provides muscular overload at a constant preset speed while the muscle mobilizes its force through the full range of motion. For example, an isokinetic stationary bicycle set at 90 revolutions per minute means that no matter how hard and fast the exerciser works, the isokinetic properties of the bicycle will allow the exerciser to pedal only as fast as 90 revolutions per minute. Machines known by such brand names as Cybex and Biodex provide isokinetic resistance; they are generally used by physical therapists and are not readily available to the general population.