Physical Activity and Aging Quiz

Exercise and Physical Activity for Older Adults

• Exercise and physical activity are important for older adults.
• Older adults are very different from younger adults.
• Aging causes a loss of function.
• Natural causes (eugeric) contribute to aging.
• Disease (pathogeric) is another cause, including factors like the loss of skeletal muscles.
• Disuse or sedentary lifestyles also impact aging.

Aging Causes

• Aging fundamentally is a loss of function.
• Natural causes, including the loss of muscle tissue, play a role.
• Disease, or pathogeric conditions, contributes to aging.
• Disuse, meaning a lack of physical activity, has an impact.

Aging Demographics in the US

• In 2000, 35 million people aged 65 or older lived in the US, representing 13% of the population.
• In 2011, the "baby boomer" generation started turning 65.
• By 2025, 25% of the population will be over 65; a large portion.
• People over 85 years old will be an increasingly large portion of the population.

Physical Therapy and Aging

• Primary disease prevention measures are important for all ages.
• Prolonging life and increasing healthy years are goals in physical therapy for the aged population.
• Better living standards and healthcare systems are key improvements.
• 34% of all healthcare expenditures are for those over 65.
• Improving physical performance is a key goal.

Normal Human Aging

• Structural and functional decline occurs with aging.
• Physical activity is reduced as a consequence.
• Chronic disease risks increase.

Skeletal Muscle Changes with Aging

• A decrease in the ability to produce force is a common change.
• Sarcopenia sets in at an early age as the body ages.
• Force production decreases with age no matter the speed of movement.

Why does force decrease?

• Decreased cross-sectional area (CSA) of muscles is proportional to force.
• Older adults have reduced CSA in their muscles.

Why does CSA decrease?

• Disuse, particularly in type II muscle fibers, is a cause.
• Physical activity level also impacts the loss of cross-sectional area in the muscles.

1a. Fiber size decrease

• Muscle fiber size decreases with age, peaking at age 20 and then decreasing with aging throughout the life.
• Resistance training can help maintain fiber size.

2. Selective loss of type II motor neurons

• Type II muscle fibers are generally larger and used for quick movement.
• Selectively losing type II motor neurons reduces muscle fiber size, decreasing force capability.
• These fibers can't be as easily replaced as other fibers, or maintained through exercise.
• Older adults have generally a reduced amount of type II motor neurons compared to a younger counterpart.

Older have higher % of type I fibers

• In older adults, there is a higher percentage of type I fibers (slow-twitch muscles), compared to type II fibers (fast-twitch).

CSA and Force

• Force decreases by approximately 40% between the ages of 65 and 80,
• Only about 12% of this decline can be associated with cross-sectional area alone.
• Type II to Type I muscle type transitions have roles in diminishing force generation.
• Differences in muscle composition play roles too.

Muscle composition changes

• Older adults lose muscle mass and gain fat and connective tissue, as their body composition shifts.
• Muscle mass remains comparable.

Muscle size, # of muscle cells

• A loss of fast-twitch muscle fibers occurs with age.
• Older adults experience a decrease in cell amounts, especially in their fast-twitch muscle fibers.

Biochemical and Metabolic Changes

• Enzymes slow down with aging, including decreasing metabolic rate and ATPase activity.
• Muscle protein synthesis decreases.

Overall

• Force decreases, due to a reduction in muscle size (CSA), as well as muscle contractility.
• Reduced efficiency in muscle function can be observed.

Response to Damage

• Exercise can cause damage to muscle tissues.
• Older adults are more susceptible to damage from exercise than younger adults.
• Delayed recovery and atrophy are common responses.
• Satellite cells are needed for muscle regeneration.
• Reduced adaptation to exercise, is a noticeable factor in ageing.

Older adults

• Older adults experience greater susceptibility to muscle damage from exercise than their younger counterparts.
• Increased atrophy and slower recovery are observed, along with reduced satellite cell proliferation.
• Increased delayed muscle recovery can impact adaptation to exercise.

Changes in Cardiovascular System with Aging

• Vessel stiffness increases, and blood vessel diameter decreases as elastin decreases and collagen increases.
• Increased sympathetic tone (vasoconstriction) is a common feature.

Vessel stiffness

• Increased blood pressure (up to 40mmHg) in older adults is a common feature with vessel stiffening.
• Blood vessels become less receptive, making them stiffer.
• Left ventricle hypertrophy is a typical consequence.

Heart Valves

• Stiffness and stenosis occur, hindering blood flow to the body and lungs.

Baroreceptors

• Response time to changes in blood pressure slows with age.
• Orthostatic hypotension is more likely to occur.
• Fast positioning changes can present issues for the aged.
• Beta- and calcium-channel blockers may worsen this effect.

Pacemaker cells

• The number of pacemaker cells decreases, slowing heart rate and reducing conduction regularity.
• Irregular heartbeats (arrhythmias) and fibrillation are more common.
• Slower heart rate and reduced frequency/regularity are typical symptoms of aging pacemaker cells.

Cardiac Output (Q)

• Cardiac output (Q) decreases with age, but remains similar during rest.
• Qmax, or the maximum cardiac output, shows only a gradual decrease in older adults at rest.
• An increased intensity of exercise is needed to have a noticeable impact on older adults.

Pulmonary System w/ Age

• Thoracic kyphosis, stiffness in costo-vertebral joints, decreases ribcage expansion, making it harder to breathe.
• Respiratory muscle strength, lung expansion, and the overall surface area of lung tissue decreases, increasing breathing difficulty.
• The number of alveoli decreases, decreasing the amount of gas exchange.
• Airway diameter and stiffness increases making it harder to breathe.
• Lung volumes and capacity change with age, including a loss of capacity.

Ventilation/perfusion mismatch

• Mismatch between ventilation and perfusion in the lungs worsens with age due to stiffening of the vasculature and lungs.
• Waste air/blood flow occurs as a result of the stiffening in the lungs and heart.

Overall

• Older adults show a decrease in Vo2max at a rate of ~1%/yr after age 30.
• Training can offer limited improvements for those over 30.
• Age impacts the rate of decline in strength.

Decade differences?

• Age-related decline in Vo2max progresses differently for men and women between different age cohorts.
• Age-related rate of decline in Vo2max is more rapid in older individuals than younger.

Reasons

• Cardiac output decreases with aging (~30% at 80 years old), alongside the heart rate, as muscle mass decreases.

Weight and Body Fat %

• Body weight increases until the 50s then remains largely stable until the 70s and then declines thereafter; this transition depends on factors like gender or genetics.
• Body fat percentage typically increases steadily throughout life, peaking in the 50s before declining.
• Fat accretion is typically around the abdominal region.

Height

• Height declines notably in 40s and 50s.
• Vertebral disc compression occurs with age.
• Thoracic curve also increases with age.

Bone Mineral Density T-score

• Bone mineral density (BMD) declines with age.
• Measures like DEXA, T-scores reflect this decline.
• Fracture risk significantly increases with age as bone mineral content is reduced, causing weakening and increased fragility.

Fracture risk

• Older individuals have a higher risk of fracture.
• Hip fracture risk is particularly high in post-menopausal women.
• Age is a key influencing factor on fracture risk.

Decline in Cognitive Ability

• Cognitive abilities generally decline with age.
• Specific cognitive domains impacted include inductive reasoning, spatial orientation, perceptual speed, numeric ability, verbal ability, and verbal memory.
• Age influences these declines, and their individual rate.

Nerve Loss?

• Nerve tissue loss occurs between age 30 and 90 years in a measurable amount.
• Older adults have a smaller amount of nerve tissue.

Neuroanatomy

• Neurons lose dendritic branches and spines, reducing connections and communication capabilities.

Peripheral NS

• Movement and sensory function declines due to decreased motor neuron function.
• Significant motor neuron loss occurs between age 60 and 100 years old.
• Smaller motor neurons and decreased transmission speeds contribute to the decline in skill.

Declining Physical Activity

• Physical activity decreases with age.
• The amount of time spent being active may stay similar for younger vs. older adults but the intensity of such activities is reduced.

Increased Chronic Disease Risk

• The risk of chronic diseases, like CVD, diabetes, obesity, and certain cancers, increases as people age.
• Physical activity helps reduces risk of chronic diseases.

Do older adults respond to exercise?

• Regular physical activity can help older adults increase average life expectancy.

Factors Influencing Functional Decline in Aging

• People age differently, and their response to exercise programs differs widely.
• Combination of genetic and lifestyle factors cause this variability.

Acute Aerobic and Resistance Response

• Blood pressure control and fuel use can be similar to young adults, but other acute responses like heat dissipation may alter based on activity intensity.
• Older adults can experience reduced exercise tolerance during intense or large-muscle exercise and heat/cold stress.
• Lower aerobic fitness levels can also contribute to reduced tolerance to these activities.

Physical Activity and Successful Aging

• Exercise, and positive mental attitudes alongside a favorable social network, are valuable factors to increasing life wellness in older adults.
• Health benefits come from physical activity that's done regularly.

Physical Activity Prevents Chronic Disease

• Physical activity is a key factor in preventing chronic illnesses like CVD, strokes, hypertension, diabetes, osteoporosis, obesity, cancers, and cognitive impairment.

Physical Activity as Therapeutic Intervention

• Physical activity can treat and help prevent a range of chronic diseases, such as heart conditions (CHD), hypertension (HTN), peripheral vascular disease (PVD), diabetes (DM II), obesity, high cholesterol, osteoporosis, osteoarthritis, and claudication.

Health Benefits of Long-term Physical Activity

• Physical activity has numerous benefits throughout life.
• Chronic disease risk is significantly reduced through physical activity, leading to health benefits like reducing risk of early death, chronic heart disease, strokes, high blood pressure, adverse lipid profiles, type 2 diabetes, cancer, and weight gain.

Aerobic Athletes

• Aerobic athletes show various physiological improvements resulting from exercise.
• Body composition, oxidative capacity, respiratory transport, cardiac output (Stroke Volume - SV), and cardiovascular stress are all impacted positively with training.

Resistance-trained Athletes

• Strength, power, muscle mass, bone density, and strength/power are all enhanced with resistance-trained exercise in older adults.

BENEFITS OF EXERCISE TRAINING IN SEDENTARY

• In sedentary older adults, exercise training can increase Vo2max by 0-30% (ages 50-80).

CV Effects

• Moderate-intensity exercise can show cardiovascular improvements, but for effects to be maintained, activity must be continued over time.
• Heart rate (HR) decreased, blood pressure (BP) is reduced during exercise, and oxygen uptake (a-vO2) is improved.

Aerobic Exercise Training (AET)

• Aerobic training can counteract decreases in bone mineral density (BMD) associated with aging.
• Strength training, including weighted exercise, stairs climbing, or jogging, has noticeable impacts on bone density.

Resistance Exercise Training (RET)

• Significant strength and power gains are achieved with resistance exercises, exceeding gains from the aging process itself.
• Muscle mass gains and bone density in older adults are comparable or exceed that found in younger counterparts.
• Resistance training has benefits in terms of metabolic function as well.

Strength/Power

• Significant neural adaptations occur as older adults undergo resistance training programs.
• Hypertrophy (muscle growth) is generally less than compared to young counterparts.

Balance Training

• Tai Chi is shown to reduce injuries from falls and is effective in older adults at risk for falls.

Stretching and Flexibility Training

• Flexibility training has positive effects on improving flexibility, but there are relatively few studies on this topic.

Exercise and ADLs

• Exercise effects on physical performance in older adults is poorly understood, but resistance training impacts ADL's (activities of daily living) like walking, standing, and balance.
• Specificity of training is important; exercises mimicking ADLs can help improve physical performance in older adults.

EXERCISE AND PSYCHOLOGICAL HEALTH

• Exercise can have positive effects on mental health in older adults.
• Depression, self-esteem, cognitive decline, neuro disease, and psychological factors may be improved or reduced through exercise in older adults.

Physical Activity GUIDELINES

• Physical activity guidelines for older adults are developed and updated over time.
• Government agencies have their own guidelines.

The Exercise Training Paradigm

• Prior exercise guidelines predominantly focused on endurance exercise for performance enhancement, particularly cardiorespiratory fitness, and rigorous activity such as 20 minutes of exercise three times per week.
• Greater aerobic capacity is associated with a reduced risk of cardiovascular disease (CVD).

Background - Physical Activity and CVD Prevention

• Physical inactivity is a major risk factor for cardiovascular disease (CVD) and has been recognized by various health organizations.
• Inactivity has been recognized as the 4th significant risk factor for CVD, along with cigarette smoking, high blood pressure and high cholesterol, as suggested by the American Heart Association.

The Physical Activity - Health Paradigm

• Recent guidelines emphasize the accumulation of moderate-intensity physical activity most days of the week, with emphasis on the benefits of accumulated activity over strictly adhering to strict schedules of vigorous activity.
• This paradigm advocates for accruing small bouts of moderate-intensity activity to have benefits.

Rationale to Update 1995 and 1996 Recommendations

• Updates to physical activity guidelines stemmed from new research and existing confusion from prior recommendations.
• Initial recommendations were primarily focused on preventing weight gain or weight loss, which produced conflicting advice.
• Updated recommendations are based on recent research to more accurately convey advice relevant to preventing chronic diseases.

Dietary Guidelines for Americans - 2005

• Physical activity guidelines to reduce chronic disease risk.
• For weight management, daily physical activity of 60-90 minutes of moderate intensity is recommended.
• Maintaining a balanced caloric intake is also crucial to effective weight management.
• Consultation with a healthcare provider, is essential for high levels of activity.

Dietary Guidelines for Americans - 2005 (Continued)

• Physical activity guidelines emphasize managing body weight and sustaining weight loss attained in adulthood.
• 60-90 minutes of daily moderate to vigorous intensity activity is recommended to sustain weight loss and prevent unhealthy weight gain.
• Medical consultation is crucial for older adults to adjust activity to their individual needs.

CDC and DHHS - an Issue Regarding Federal Physical Guidelines

• Updating the Physical Activity Guidelines from 1995 stemmed from a gradual increase in research on the topic.
• Updated guidelines emphasized recommendations that are more grounded in evidence from various scientific publications.

Physical Activity Recommendations for Healthy Adults ≥ 65 Years of Age

• Guidelines from 2007 for adults ≥ 65 years focus on aerobic activity (30 minutes of moderate-intensity activity 5 days per week OR 20 minutes of vigorous activity 3 days per week).
• Muscle-strengthening exercises are recommended (8-10 exercises, 10-15 reps, 2 non-consecutive days per week).
• Flexibility training is recommended at least 2 days per week.
• Balance-promoting activities should occur to prevent falls, and more activity in general is encouraged.

Physical Activity Guidelines for Americans - 2008

• Recommendations for older adults in 2008 emphasize avoiding inactivity.
• Substantial health benefits are achieved with at least 150 minutes of moderate or 75 minutes of vigorous activity per week.

Physical Activity Guidelines for Americans - 2008 (Continued)

• Moderate to vigorous intensity aerobic exercise is recommended as a goal to be achieved by accumulation throughout the week in bouts of at least 10-minutes duration.
• Resistance training is also encouraged, with 2 sessions per week, using 8-10 exercises, 1-2 sets, and 10-15 repetitions.

Persons With Disabilities

• Regular physical activity can improve fitness levels, and mental wellness in people with disabilities by enabling them to carry out daily life tasks more effectively and efficiently.
• Adapting activities to suit individual needs is essential, including using different equipment, to support individuals with disabilities.

People With Chronic Health Conditions

• Types and amounts of physical activity for older adults is dependent on individual ability and chronic conditions.
• Consult with a healthcare provider to decide on activity levels and adjust as needed.

Exercise and ADLs

• Exercise affects physical performance and has an impact on activities of daily life, however, this effect is not fully understood in older adults.
• Higher movements and their velocity as related to activities of daily living are essential aspects of exercise training programs for older adults.

EXERCISE AND PSYCHOLOGICAL HEALTH

• Exercise helps in alleviating depression and anxiety.
• Exercise enhances self-esteem and may lower cognitive decline.
• Exercise can benefit overall psychological health and wellness.

The Exercise Training Paradigm

Test your knowledge on the relationship between age, physical activity, and muscle fiber characteristics. This quiz covers trends in physical activity levels, the impact of aging on vital capacity, and the effects of training on Vo2max. Ideal for students studying exercise physiology or related fields.