Chapter 13: Exercise for Health and Fitness

endorphins

Brain chemicals that seem to be involved in modulating pain and producing euphoria.

lipoproteins

Substances in blood, classified according to size, density, and chemical composition, that transport fats.

The type of activity varies with each fitness component and with a person's fitness goals.

(1) To develop cardiorespiratory endurance, a person needs to engage in continuous activities involving large-muscle groups. (2) Resistive exercises develop muscular strength and endurance. (3) Stretching exercises build flexibility. (4) Frequency, intensity, and time of exercise will be different for each type of activity.

A complete fitness program includes:

1. Cardiorespiratory endurance exercise—at least 20 minutes of aerobic exercise at target heart rate three to five times a week. 2. Muscular strength and endurance exercise—works the major muscle groups (1 or more sets of 8 to 10 exercises) two or three times a week. 3. Flexibility exercise—stretching exercises three to five times a week. 4. Skill training—incorporating exercise into an enjoyable sport or physical activity.

cardiovascular disease (CVD)

A collective term for diseases of the heart and blood vessels.

electrocardiogram (ECG or EKG)

A recording of the changes in electrical activity of the heart.

neurotransmitters

Brain chemicals that transmit nerve impulses.

resistance exercise

Exercise that forces muscles to contract against increased resistance; also called strength training.

synovial fluid

Fluid found within many joints that provides lubrication and nutrition to the cells of the joint surface.

cross-training

Participating in two or more activities to develop a particular component of fitness.

cardiorespiratory endurance (aerobic) exercise

Rhythmical, large-muscle exercise for a prolonged period of time; partially dependent on the ability of the cardiovascular system to deliver oxygen to tissues.

anabolic steroids

Synthetic male hormones used to increase muscle size and strength.

muscular endurance

The ability of a muscle or group of muscles to remain contracted or to contract repeatedly for a long period of time.

cardiorespiratory endurance

The ability of the body to perform prolonged, large-muscle, dynamic exercise at moderate to high levels of intensity.

Selecting the proper activities is essential for a successful fitness program.

a. A person who has been inactive should begin with moderate physical activity, such as walking. As fitness level increases, more activity can be added to the program. b. Activities should fit a person's interests, personality, and lifestyle. A competitive person may want to take up racquetball, basketball, or tennis; a person who prefers to exercise alone might consider running or cross-country skiing. Classes in activities such as aerobic or jazz dancing are enjoyable and healthy. c. Accessibility, expense, and time are important factors. An activity that is inconvenient to do or requires time to master might lead a novice to lose interest.

Intensity of training is the crucial factor in attaining a significant training effect, that is, increasing the body's cardiorespiratory capacity.

a. A primary purpose of endurance exercise is increasing maximal oxygen consumption (VO2max)—the maximum ability of the cells to use oxygen. b. It is intensity of training that determines improvement in VO2max. (1) Beneficial effects occur at rates lower than the maximum rate with much less chance of injury. (2) The ideal is a range between that achieved with moderate-intensity exercise and that achieved with high-intensity exercise. (3) Target heart rate range is the range of rates at which you should exercise to obtain cardiorespiratory benefits.

Physical fitness reduces stress reactions, providing protection against physical effects of stress, such as cardiorespiratory illness.

a. Psychological stress increases secretion of epinephrine and norepinephrine, which may speed development of atherosclerosis. b.Endurance exercise reduces the secretion of hormones and can provide an outlet for feelings of hostility and anxiety. It can also relieve sleep disturbances

Warming up improves performance and reduces chance of injury.

(1) The muscles work better when their temperature is elevated slightly above resting level. Warming up helps redirect the blood to active muscles, lets the heart adapt to increased demands, and spreads synovial fluid throughout the joints to protect them. (2) Warm up with low-intensity movements similar to those in the activity—for example, a slow jog before moving into faster running. Stretching done after warm-up and before the activity might be beneficial.

One can gain training in specific skills only by practicing those skills. Acquiring competence in an activity leads to a sense of mastery and satisfaction.

1. Lessons from a qualified teacher allow a person to learn the basic movements from someone who has mastered the skill. 2. Additional instruction also can help people refine skills they may have been performing for years.

Flexibility or stretching exercises are needed to maintain the normal range of motion for the body's major joints. A good stretching program should include exercises for all the major muscle groups and joints of the body.

1. Stretching should be performed statically; "bouncing" is dangerous and counterproductive. 2. Active stretching means stretching a muscle by contracting opposing muscles. Each stretch should be held 10 to 30 seconds. 3. Passive stretching uses an outside force or resistance. It is more intense and uses a greater range of motion, and the risk of injury is higher. 4. A complete flexibility workout with at least 4 repetitions of each exercise takes 20 to 30 minutes. 5. Stretching exercises should be performed at least 2 to 3 days per week. If they are performed after exercise, as part of a cool-down, more flexibility may develop, because the muscles are warm and will stretch further.

Exercise improves social, psychological, and emotional wellness.

2. Exercise reduces fatigue, anxiety, and depression. 3. Physical activity contributes to feelings of self-control, increases self-confidence, and improves self-esteem. Sticking with an exercise regimen increases people's belief in their ability to be active, thereby boosting self-efficacy. 4. Exercise increases the formation and survival of new nerve cells and the connection between nerves, which in turn improve memory and learning. 5. Exercise itself is enjoyable and offers chances to interact with other people.

physical fitness

A set of physical attributes that allows the body to respond or adapt to the demands and stress of physical effort.

What is physical fitness?

A. Physical fitness is a set of physical attributes that allows the body to respond or adapt to the demands and stress of physical effort. B. The five components of fitness most important for health are cardiorespiratory endurance, muscular strength, muscular endurance, flexibility, and body composition. C. Cardiorespiratory endurance is the ability to perform prolonged, large-muscle, dynamic exercise at moderate to high levels of intensity. D. Muscular strength is the amount of force a muscle can produce with a single maximum effort. E. Muscular endurance is the ability to resist fatigue and sustain a given level of muscle tension, that is, to hold a muscle contraction for a period of time or to contract the muscle repeatedly. F. Flexibility is the ability to move joints through their full range of motion. G. Body composition refers to the proportion of fat and fat-free mass (muscle, bone, and water) in the body.

The benefits of exercise

A. Regular exercise increases energy levels, improves emotional and psychological well-being, boosts the immune system, and helps prevent many dangerous diseases. B. Regular endurance exercise improves cardiorespiratory functioning and reduces the risk of cardiovascular disease. C. Metabolism, the process by which food is converted to energy and tissue is built, becomes more efficient through regular exercise. Physical training protects cells from damage by the free radicals produced during normal metabolism, and from inflammation caused by high blood pressure, nicotine, and overeating. It activates antioxidant enzymes that prevent free-radical damage and keep the body's cells healthy. D. Exercise improves body composition by increasing calorie expenditure, slightly raising the metabolic rate, and altering the body composition in favor of fat-free mass. Greater muscle mass also increases metabolic rate. Physical activity reduces the risk of death regardless of its effect on body composition. E. Regular exercise reduces the risk of many diseases and can help people with those diseases improve their health. Worldwide, it is estimated that physical inactivity causes 1.9 million deaths per year.

Designing your exercise program

A. The best exercise program promotes health and is fun. C. Physical activity can improve health. 1. The Surgeon General's report and joint guidelines from the CDC and the American College of Sports Medicine (ACSM) recommends that all Americans be moderately active on most or all days of the week and perform resistance training. 2. A goal of expending 150 calories per day or 1000 calories per week is recommended. F. Planning is important in beginning a formal exercise program. 1. Men over age 40 and women over age 50 should get a medical examination. Certain medical conditions may require a modified exercise program. 2. Particular types and amounts of exercise are most effective in developing the various components of fitness. To develop an effective exercise program, a person should first understand the basic principles of physical training. a. To develop a particular fitness component, a person must perform exercises that are specifically designed for that component. This is the principle of specificity. b. For example, weight training develops muscular strength but does little in developing flexibility. c. A well-rounded exercise program includes exercises geared to each component of fitness, to different parts of the body, and to specific activities or sports. 3. When the amount of exercise is progressively increased, a process called progressive overload, the body adapts by improving its functioning, and fitness improves. The amount of exercise needed to improve fitness depends on each person's current fitness level and fitness goals.

muscular strength

The amount of force a muscle can produce with a single maximum effort.

overload

The amount of stress placed on the body; a gradual increase in the amount of overload causes adaptations that improve fitness.

isotonic exercise

The application of force with movement.

isometric exercise

The application of force without movement; also called static exercise.

maximal oxygen consumption (MOC)

The body's maximum ability to transport and use oxygen.

target heart rate

The heart rate at which exercise yields cardiorespiratory benefits.

body composition

The proportion of fat and fat-free mass (muscle, bone, and water) in the body.

flexibility

The range of motion in a joint or group of joints; flexibility is related to muscle length.

Exercise affects the risk factors for cardiovascular disease and interferes with the disease process itself. Moderate levels of physical activity produce benefits, which increase as activity level increases.

a. Endurance exercise and strength training lead to a better balance of blood lipid (fat) levels by increasing high-density lipoproteins and reducing low-density lipoproteins and triglycerides. High levels of HDL and low levels of LDL are associated with lower risk of cardiovascular disease. b. High blood pressure, which contributes to coronary heart disease, stroke, kidney failure, and blindness, is reduced by even moderate levels of exercise. c. Exercise directly interferes with the disease process that causes coronary artery blockage and minimizes other risk factors for coronary heart disease. d. Regular exercise reduces the risk of stroke, which often occurs through the same disease process that leads to heart attacks.

The amount of overload needed to maintain or improve a person's level of fitness is determined in four dimensions, which are represented by the acronym FITT: Frequency, Intensity, Time, and Type.

a. Frequency, the number of days per week a person exercises, varies with fitness component and personal goals. In general, cardiorespiratory endurance exercise has a recommended frequency of 3 to 5 days per week; strength training, 2 to 3 days per week; stretching, 2 or more days per week. b. Increasing intensity of exercise boosts its health benefits as well. Developing cardiorespiratory endurance requires raising the heart rate above normal. To develop muscular strength, one must lift heavier weights than normal. Developing flexibility requires stretching muscles beyond their normal lengths. Intensity should be increased gradually to avoid injury. c. Time or duration of exercise is important in developing fitness; a duration of 20 to 60 minutes is usually recommended, depending on the component being developed and the intensity level.