Understanding Osteoporosis

• Osteoporosis

Musculo-Skeletal System Composition

• This system comprises the skeleton, muscles, cartilage, tendons, and connective tissues.

Musculo-Skeletal System Functions

• Allows ambulation, performing tasks, and vital organ protection.

Bone Count

• The human skeleton contains 206 bones.

Bone Properties

• Bones are strong, light, and account for 10 to 12 kgs of body weight, imposing less metabolic burden.

Bone Dynamics

• Bone deposition and resorption are continuous processes.

Bone reservoirs

• Bones serve as calcium and phosphate reservoirs.

Calcium's Roles

• It is critical for muscular contraction, cellular signaling, and blood clotting.

Bone Equilibrium

• A constant equilibrium is maintained between bone resorption, the breaking down and digesting of bone, and bone deposition, the formation of new bone.

Bone Dynamics through life

• During childhood, bone deposition exceeds resorption.
• After approximately 30 years of age, bone resorption exceeds deposition.

Sex hormones

• They significantly contribute to bone formation.
• Estrogen plays a key role in females, while testosterone does in males.

Bone density

• Bone density accounts for 70% of bone strength and decreases with age after 30 years.

Bone density decrease

• A decrease in estrogen, particularly during menopause, and testosterone concentrations contribute to bone density loss.

Osteoporosis

• It is a disease characterized by thinning and weakening of bones to the point where they become fragile and easily fractured.
• It is regarded as a silent thief because it presents no symptoms.

Problems from Osteoporosis

• Osteoporosis leads to an increased risk of fractures, including stress fractures, compression fractures of the spine, and fractures resulting from falls or sneezes.

Lifetime Osteoporotic Risk

• 1 in 2 women over 50 face the risk of an osteoporotic fracture.
• 1 in 4 men over 50 face the risk of an osteoporotic fracture.

Osteoporosis prevalence

• 10 million US adults have osteoporosis.
• 55% of all older adults are affected.
• 8 million (80%) of osteoporosis patients are women.
• 2 million (20%) of osteoporosis patients are men.

Physical Activity Benefits

• Physical activity positively impacts bone health.

Mechanical Loading

• Mechanical loading involves bone strain.

Bone growth

• Unique strain that exceeds usual loading conditions along with variable strain, which involves the rate of applying different loads are required for bone growth.

Site-Specificity of Exercise

• Similar to muscle development, exercise benefits are localized to the sites experiencing the strain.
• Exercising only the upper body can result in skinny legs
• Over time, the benefits reach a plateau effect.

High-impact force strain

• High impact gravitational exercises include running and jumping.

Runners vs. Cyclists

• There are differences between high impact weight bearing and low impact non-weight bearing activity.
• Runners and cyclists highlight the impact of different activities on bone density.

High impact

• This involves force production achieved via contact between the body and a surface.
• Running imposes approximately 3 to 6 times the body weight, while jumping imposes around six times the body weight.
• The skeleton transfers the impact force up to the hip.

Loading effect

• Space flight affects astronauts due to the lack of high-impact strain.

Joint Reaction Strain Factors

• Joint reaction strain is a result of muscle contraction where muscle generates the force.
• The generated force equals the weight lifted and causes bone to bend, with force exerted where the muscle attaches.

Obesity rates

• Between 1960 and 2000, obesity rates in US adults climbed from 13% to 30%.

Child obesity rates

• Percentages of overweight children ages 2–19 who are obese are grouped between ages 2-5, 6-11, and 12-19
• Rates have been consistently increasing from 1971-1974 to 2011-2012.

Obesity-Related Medical Hazards

• Pulmonary disease, nonalcoholic fatty liver disease, gall bladder disease, gynecologic abnormalities, osteoarthritis, and gout can be caused by obesity
• Obesity can cause idiopathic intracranial hypertension, stroke, cataracts, coronary heart disease, severe pancreatitis and phlebitis
• Obesity increases risk of diabetes, dyslipidemia, hypertension, and cancer

Energy Balance

• It is achieved with energy intake from food matches energy expended.
• A positive energy balance is when energy intake exceeds energy expended, leading to weight gain.
• A negative energy balance is when energy intake is less than energy expended, leading to weight loss.

Energy from food

• Fat provides 9 calories per gram
• Carbohydrates and protein provide 4 calories per gram.
• Alcohol provides 7 calories per gram.

Basal or Resting Metabolism

• This is the minimum energy to keep a resting, awake body alive, constituting approximately 60-70% of total energy expenditure.
• It includes energy for heartbeat, respiration, and body temperature.

Thermic Effect of Food (TEF)

• This is the energy to digest, absorb, and metabolize food nutrients.
• It is also known as "Sales tax” of total energy consumed.
• It accounts for approximately 5-10% of energy expenditure.

Energy Expenditure

• Physical activity varies widely among individuals.
• More activity leads to more energy burned.

NEAT expenditure

• It stands for Non-exercise activity thermogenesis

Exercise Duration

• Duration of weekly exercise is related to weight loss in overweight and obese women.
• An 18-month weight loss program studied 148 overweight and obese women.
• Intake of energy and fat was restricted in addition to exercise.

Fat burning

• The body prefers to use carbohydrates as its primary energy source.
• Physical activity training encourages dietary fat burning
• A trained individual will burn more fats than an untrained person for the same activity.

Weight Loss

• Average weight loss can vary among individuals
• The average weight loss was 3.5 KG after 12 weeks of training.

Compensation

• Individuals tend to compensate for time spent exercising by being sedentary the rest of the day.

Cardio Fitness

• Deconditioned individuals have a higher risk of premature death than conditioned individuals (fat but fit concept).

Health and fitness

• Increasing fitness reduces all-cause mortality while "healthy obesity" shows that physically-fit obese patients have lower mortality rates than unfit normal-weight adults.
• Being thin does not guarantee being healthy and being fat does not have to be unhealthy.

Resistance Training

• Resistance exercise may not lead to weight loss or weight gain from studies.
• It does preserve and increase fat-free mass and resting metabolic rate, contributing to increasing energy expenditure.

Weight loss maintenance

• Exercise is critical to maintaining weight loss and helps to maintain muscle mass and metabolic rate.