If you have children or are thinking about having children, how would you encourage them to maintain a balance between the time they spend engaging in sedentary activities such as watching TV and in activities that develop physical fitness?
Chapter 11
Physical Fitness
Physical Fitness
• Important health benefits are derived from physical
activity.
• Lack of regular physical activity contributes to
premature death.
• Developing strength, endurance, and flexibility allow
us to perform daily living activities.
Physical Fitness
• 150 minutes of physical activity is recommended for
adults each week.
• In 2012, less than 25% of American adults met
exercise recommendations.
The Body in Motion
• Physical movement involves the functioning of the
muscular and skeletal system.
• Skeletal muscles provide shape, support, and
movement.
• Skeletal muscle contains hundreds of muscle cells
called muscle fibers.
• When muscle fibers contract, they shorten, causing
movement.
The Body in Motion
• Tendons—connect muscles to bones
• Joints—where bones come together
• Ligaments—hold bones together at the joints
The Circulatory and Respiratory
Systems
• Heart and lung functions are interrelated.
• The heart pumps blood to the lungs.
• Oxygenated blood returns to the heart where it is
pumped to rest of body.
• Oxygen leaves blood and enters cells.
• Waste products such as carbon dioxide leave cells and
enter blood.
• Blood carries waste products to kidneys and back to the
heart.
Defining Physical Activity
and Exercise
• Physical activity—movement that occurs when
muscles contract
• Exercise—physical activity that is usually planned and
performed to improve or maintain physical condition
Physical Activity and Health
• Reduces risk of chronic diseases, including heart
disease, certain cancers, type 2 diabetes,
hypertension, and osteoporosis
• Improves immune system
• Improves and maintains muscle strength and
joint function
• Improves balance
• Reduces risk of premature death
Physical Activity and Health
• Reduces symptoms of anxiety and depression
• Fosters improvement in mood and sense of well-being
• Can improve quality of sleep
• Stimulates release of endorphins
The Health-Related Components of
Physical Fitness
• Cardiorespiratory fitness
• Muscular strength
• Muscular endurance
• Flexibility
• Body composition
Cardiorespiratory Fitness
• The ability of cardiovascular and pulmonary systems to
supply oxygen to working muscles
• Intense physical activity requires more oxygen to
support the work of skeletal muscles.
• Cardiorespiratory fitness can be developed through
aerobic activities, including running, swimming, rope
skipping, or any movement that involve major muscle
groups.
Muscular Strength
• Muscular strength—ability of muscles to apply
maximum force against an object that is resisting that
force
• Muscular endurance—ability to contract muscles
repeatedly without becoming fatigued easily
• Training effect—an increase in size and strength of the
muscle
Muscular Strength
• To increase muscular strength, muscles need to be
overloaded.
• Hypertrophy—condition in which muscles become
larger and stronger
• Atrophy—when muscles lose size and strength, usually
from inactivity
Exercising for Muscular Strength
• Repetition—completion of a single exercise that
overloads a particular muscle group
• Exercise set—involves performing the same exercise
movement a number of times
• Isotonic exercise—muscular force against a movable
but constant source of resistance
• Isometric exercise—muscular force against a fixed,
immovable object of resistance
Muscular Endurance
• Muscular endurance—the ability of a muscle to
contract repeatedly without becoming fatigued easily
• Training for muscular endurance involves lifting
lighter weights repeatedly.
Flexibility
• The ability to position a movable joint anywhere within
its normal range of motion
• Static stretching—slowly and fully extending muscles
and joints within natural range of motion (hold for 15
seconds)
• Ballistic stretching—stretching with bouncing; not
recommended for most people
• Dynamic stretching—moving through a challenging
but comfortable range of motion with controlled,
deliberate motion
Diet and Performance
• Drink adequate amounts of water and choose a wellbalanced diet composed of a variety of foods.
• Eating more protein than needed does not result in
bigger muscles.
• High-protein diets may cause dehydration and
accelerate the loss of calcium from bones.
• Carbohydrate loading can help certain athletes.
Exercising for Health:
The Exercise Session
• Warm up: low intensity activity for 5 minutes
• Stretch: 5 minutes
• Aerobic activity: 30 minutes
• Cool down: less intense activity for 5 minutes
• Stretch: 5 minutes
Exercise Danger Signs
• Irregular heartbeat
• Pain or pressure in the chest, throat, or arms
• Shortness of breath
• Dizziness
• Sudden loss of coordination
• Cold sweating
• Fainting
Preventing and Managing Common
Exercise Injuries
• Strain—generally refers to damage that a muscle or
tendon sustains when overextended rapidly
• Sprain—usually refers to a damaged ligament
• Sprains tend to be more severe than strains.
Preventing and Managing Common
Exercise Injuries
• RICE—effective for treating strains and sprains
– Rest
– Ice
– Compression
– Elevation
• Consult a physician if injured area does not improve in
2 days, or if pain worsens.
Warm Weather Injuries
• Dehydration (lack of body water)
• Hyperthermia (higher than normal body temperature)
can lead to:
– Heat cramps
– Heat exhaustion
– Heatstroke
Preventing Warm Weather Injuries
• Avoid physical exertion outdoors during hottest time of
the day.
• Drink enough fluids to replace that which is lost through
sweat.
• Wear light-colored, loose-fitting clothing when exercising
in warm conditions.
• Consider reducing the intensity and duration of activity
when weather is hot and humid.
• Avoid alcoholic beverages.
Cold Weather Injuries
• Frostbite
– Ice crystals form in the deeper tissues of skin when
exposed to extreme cold
– Causes damage to tissues
• Hypothermia
– Body core temperature drops below 95°F
– Shivering
– Tiredness
– Poor judgment
– Disorientation
– Loss of consciousness
Preventing Cold Weather Injuries
• Layers of warm dry clothing
• A hat that can be pulled down over ears
• Scarf
• Gloves or mittens
• Thick socks
Developing a Personal Fitness
Program
• Determine your needs, interests, and limitations.
• Set general fitness goals.
• Choose activities that you enjoy.
• Incorporates fitness session into your routine.
Active for a Lifetime
• Individuals are more likely to engage in regular
physical activity if they enjoy being active, recognize
the health benefits of physical activity, and can find the
time to exercise.
• To maintain motivation, people should choose physical
activities that they can perform throughout their
lifetimes.
Across the Life Span
• Physical activities adopted in childhood are more likely
to be practiced for a lifetime.
• Healthy, physically fit women can generally continue
engaging in mild-to-moderate intensity exercise during
pregnancy.
• Pregnant women should discuss exercise plans with
their physicians.
Across the Life Span
• Most Americans become less active as they age.
• Light regular physical activity can help:
• Reduce risk of heart disease, colon cancer,
diabetes, obesity, and hypertension
• Maintain or improve joint flexibility and muscle
strength and endurance
• Improve mood
• Increase ability to live independently