Physical Activity & Health e4 Chapter 09

Chapter 9 Achieving Optimal Bone Health

Bones: Essential for Health Bones •

Provide structural strength

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Protect vital organs

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Support essential metabolic processes

Lifestyle •

There is great deal we can do to contribute to bone health.

Bone and Its Parts

Human Skeleton

Š Philip Date/ShutterStock, Inc.

Bone Formation Osteoblasts •

Bone-forming cells

Osteocytes •

Bone cell responsible for the maintenance and turnover of the mineral content of surrounding bone

Osteoclasts •

Cell in developing bone concerned especially with the breaking down of unnecessary bone parts

Bone Remodeling Bone mineral density (BMD) •

Amount of mineralized tissue in the scanned area

Remodeling •

Ongoing dual processes of bone formation and bone resorption after cessation of growth

Nutritional Recommendations

Š Mitch Hrdlicka/Photodisc/Getty Images

Nutrition Recommendations Proper nutrition •

Critical for strong bones

Key nutrients •

Calcium

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Vitamin D

Daily Calcium and Vitamin D Requirements by Age and Sex

Calcium Supplements Guidelines •

All major forms are best taken with meals

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Best taken in small doses (500–600 mg at one time)

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Absorbability may differ due to manufacturing practices

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All calcium sources—food or supplement—reduce the absorption of iron, so calcium and iron supplements should be taken at different times

Tips for Those with Lactose Intolerance

Vitamin D Vitamin D • • •

Essential for absorption of calcium Adults require 200 IU per day May safely take in up to 1000 IU per day if needed

Sources of Vitamin D • •

Sunlight Dietary intake

Dietary Sources of Vitamin D

Bone Robbers Bone Robbers •

Sodium

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Protein

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Caffeine

Physical Activity Recommendations

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Physical Activity Recommendations

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Physical Activity Recommendations Principles •

Physical activity will only affect bone at the skeletal sites that are stressed (or loaded) by the activity.

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For bone gain to occur, the stimulus must be greater than that which the bone experiences. Static loads applied to muscle (such as standing) do not promote increased bone mass.

Physical Activity Recommendations Principles •

Complete lack of activity (immobility, paralysis, bed rest) causes bone loss.

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General physical activity most days of the week, coupled with weight-bearing, strength-building, and balance-enhancing activities two or more times a week, is effective for promoting bone health for most people.

Physical Activity Recommendations Principles •

Any activity that causes impact (e.g., jumping or skipping) may increase bone mass more than low- to moderate-intensity endurance-type activities.

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Load-bearing physical activities (e.g., jumping or skipping) need not be engaged in for long periods of time to provide benefits to skeletal health. Five to 10 minutes of physical activity that incorporates 50, 3-inch jumps per day should suffice for most adults.

Physical Activity Recommendations Principles •

Physical activities should include a variety of loading patterns to promote increased bone mass. Be creative in finding ways to add other weight-bearing activities to your daily life. (See next slide or Table 10.5.)

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Consult a physician or physical therapist if orthopedic conditions or other medical conditions make these physical activity guidelines difficult or unsafe to follow.

Weight-Bearing Exercise for Adults

Osteoporosis or Porous Bones •

Is a chronic metabolic disease characterized by excessive skeletal fragility

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Is a painful and debilitating disease that impacts a person’s quality of life

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Affects both men and women; however, 80 percent of those affected are women

Postmenopausal Risk for Fracture

Risk Factors •

Genetic factors

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Hormonal factors

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Nutritional factors

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Lifestyle factors

Progression of Dowager’s Hump

Detection of Osteoporosis

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Detection of Osteoporosis

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Types of BMD Tests