Physiologic Changes Associated w by pengtt

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									  Personal Health Factors:
The Etiology of Chronic Disease
            Health
             care
             10%


 Heredity
  20%
                      Lifestyle
                        50%



     Environ
      ment
      20%
    EXERCISE
  TESTING and
PRESCRIPTION for
   CHILDREN
   What has prompted interest in PA and
   exercise in the pediatric population?

• Recognition of the role of regular exercise in
  the present and future health of youth,
  especially childhood obesity
  – NHANES (1999-2002) indicates 16% of children &
    adolescents are overweight (more than tripled since
    1980)
• Growing rates of participation in elite-level
  sports competition
• Awareness of the role of exercise testing &
  intervention in C&A with chronic diseases
 Somatic Growth and Biological
 Maturation
• Physiologically, children are not miniature
  adults.
• Substantial variability in growth status and
  maturity level for any given chronological age
• Physical activity and exercise (esp. weight
  bearing) are necessary for attainment of
  maximal genetic bone density
• Activity level has a negative/adverse impact on
  growth only if:
  1. activity level falls below a biological threshold, or
  2. training is excessive (reduce growth potential)
Physiological Differences
Respiratory System
• Higher breathing frequency
• Lower tidal volume
• Lower ventilation
Cardiovascular System
• Lower stroke volume
• Higher heart rate
• Lower cardiac output
• Lower lactate concentration
• Lower absolute VO2 values; Higher or equal
   relative VO2 values
Physiological Differences
Temperature Regulation
• Larger surface area-to-mass ratio
    –     allows for greater heat exchange by convection
          and radiation
    –     Greater heat loss when environment is lower than
          body temperature
•       Poor sweating capacity
    –     Activation of sweat glands occurs at higher temps
    –     Less sweat is produced
•       Shorter tolerance time for exercise in
        temperature extremes
Physiological Differences
Neuromuscular-Skeletal System
• Exhibit less strength, power & muscular
   endurance
    –     Nerve myelination is lower
    –     Motor unit activation is lower
    –     Testosterone levels are lower
•       Fiber type distribution and number is fixed
        at or soon after birth
    –     Only 15% are “undifferentiated” at both
•       Strength measurements
    –     Pre-pubertal vs peri- and post-pubertal
Physiological Differences
Metabolic System
• Lack of metabolic specialization
• Slower times for long distances
• Lower ability to generate & maintain
   mechanical power
• Lower amounts of stored PC and glycogen
• Less economical at any given speed
    –     Use more O2 at any given speed
•       Less able to facilitate anaerobic pathways
    –     Age has greater impact on anaerobic metabolism
          than aerobic metabolism
Benefits of Exercise
•   Establish active lifestyle
•   Weight management
•   Protective effect against disease
•   Fitness
•   Stress management
•   Increase peak bone mass
Consideration in Selecting Physical Activities
•   Age
•   Attention span
•   Motor development
•   Muscular development
•   Physical stature
•   Fitness level
Fitness Testing
Field Tests for Children
• FITNESSGRAM and the President’s
    Challenge Test

H/F Component             Field Test
Cardiorespiratory Fitness 1 mile walk/run
Muscular Fitness          Curl-up test
                          Pull-up/push-up test
Flexibility               Sit and reach test
Body Composition          BMI or skin folds
Fitness Testing
Graded Exercise Tests
• Ergometers (electronically braked) vs. TMs
• Variety of protocols are appropriate
  – Bruce, Balke, McMaster, James Protocols
• Goals, objectives, measurements to be obtained
  – Heart rate, Blood pressure, endurance time
• Physician present for serious rhythm disorders,
   aortic stenosis, CAD, heart disease
• Criteria for stopping a test are similar to those
   for adults
Exercise Prescription:
Large Muscular Activity
• 60 minutes of accumulated activity/day
• Participate in several bouts of PA lasting 15
  min or more each day
• Participate in a variety of age-appropriate PA’s
  designed to achieve optimal health, wellness,
  fitness and performance benefits.
• Adolescent girls may require additional support
  to be physically active
• Extended periods of inactivity are
  discouraged, esp. during the daytime hrs.
To accomplish these goals:
• Prefer short-term intermittent activities with
  a high recreational component and variety
  – Best suited for repeated activities of varying
    intensities lasting a few seconds
• Allow to be naturally active (enjoyable)/
  encourage play outside – The Exercise “Menu”
• Allow to control the intensity and duration of
  the activity
• Involve with organized activities where
  emphasis is placed on gaining basic motor and
  sport skill competency
• Provide active role models
Exercise Prescription:
Strength Training
• Consider potential benefits of training
  and potential risks (weigh them)
• Benefits may include:
  –   Strength gains
  –   Injury protection
  –   Improved sports performance
  –   Long-term salutary influence on infirmities
• Risks include:
  – Low back and growth plate injury
  – acute & chronic musculoskeletal injuries
Strength Training Programs
• Adequate warm-up followed by close,
  continuous, trained supervision
• Emphasis on proper form, not the amount of
  resistance
• Higher repetitions per set
  – no less than 8 reps/set; ideally 8-15 reps/exercise
• Adequate recovery between sessions
   – frequency of no more than 2 to 3 days/week
• Inclusion of flexibility exercises, esp. during
  growth spurts
• Strength gains pre-pubescent - strictly neural
Precautions
• Higher energy expenditure at any
  given submaximal intensity
  – Excessive body heat and higher VO2/unit of body mass
• Greater susceptibility to heat stress
  – Replace fluids every 15-30 minutes at a rate of 100-
    150 ml
• Takes longer for children to acclimatize (poor
  sweating capacity)
• Expression of motor skills in sport & recreational
  activities
• Monitor menstrual status in females
Precautions
• Vulnerable to injury (esp. during growth spurts)
  – Monitor growth rate to identify periods of
    accelerated growth
• Risk factors for overuse injury include:
   – significant changes in FITT (<10% in training)
   – inflexibility
   – imbalance of strength and flexibility
   – incorrect biomechanics and footwear
• 50% of overuse injuries are preventable
    EXERCISE
  TESTING and
PRESCRIPTION for
 ELDERLY PEOPLE
 Ed Rondthaler
      vs.
the naked mole
      rat
     THEORIES OF AGING
The processes underlying aging (senescence)
 are largely unknown

Biological Processes
• Cellular Theories
  – Alteration in cellular genetic coding that results in
    abnormalities in synthesis of the cell’s various
    constituents
  – Programmed cell death (apoptosis)
• Physiological Theories
  – Autoimmunity
  – Impaired neuroendocrine control mechanisms
     THEORIES OF AGING
Wear and Tear
• Looks at the impact of damage from tobacco,
  pollution, too much food, not enough exercise,
  etc.
• Telomeres – chunks
  of DNA on the ends
  of chromosomes that
  shorten every time
  the cell divides.
• Stress shortens
  telomeres, which
  hastens aging
     THEORIES OF AGING
Wear and Tear, cont.
• Oxidative stress – oxidants damage DNA,
  proteins, and lipids
  – As we get older, we become less efficient at turning
    O2 into energy, creating free radicals that damage
    our cells.




• Glycation – glucose sugar binds to proteins,
  resulting in the formation of AGEs 
  deterioration in tissue protein function
              Ed                  Naked mole rat
101 yrs old                Live ten times longer than
                           any other mammal their size
                           (up to 30 yrs)
Copes well with stress     Extremely high levels of
                           damaged DNA from
                           oxidation

Never smoked, healthy      Very short telomeres and no
weight, avoids drinking,   telomerase
physically active daily
Favorable genetics         Contradicts the disposable
                           soma theory
    THE IMPACT OF AGING
Data Collection
• Cross-sectional studies
• Longitudinal studies
Deterioration of systems leads to:
• Decreased exercise performance/
  recreational activities/ sport
• Performance of normal daily activities
Is there a way to preserve functional
  capacity & maximize independence?
THE IMPACT OF AGING:
Overview of Pathophysiology
The Heart
• Increased left ventricular hypertrophy
  (preserves resting SV)
• Decreased blood vessel elasticity  increased
  resting & exercising SBP & mean BP
• Decreased resting and exercising Q
• Decreased exercising SV
• Increased peripheral resistance in
  vasculature
• Aortic stiffness
THE IMPACT OF AGING:
Overview of Pathophysiology
Heart Rate
• No change in resting HR
• Decreased SNS stimulation of SA node
• Decreased maximal exercise heart rate
Decreased Max VO2
• Decreased blood redistribution
• Reduction in muscle mass, capillary density,
  oxidative capacity
Pulmonary System
• Decreased elasticity/stiffening of the chest wall
• Increased RV / Decreased VC
THE IMPACT OF AGING:
Overview of Pathophysiology
 Skeletal muscle and strength
 • Decline in muscle strength
 • Change in fiber type distribution
 • Increasing unsteadiness
 Bone
 • Decreased calcium content
 • What accelerates bone loss?
 • Development of osteoarthritis
THE IMPACT OF AGING:
Overview of Pathophysiology
 Joints and flexibility
 • Degeneration of collagen fibers
 • Connective tissue becomes less
   extensible
 • Decreased range of motion
 Body composition and metabolism
 • Decrease in lean body mass
 • Progressive increase in body fat
THE IMPACT OF AGING:
Overview of Pathophysiology

 Renal function and Nervous System
 • Predisposed to rapid dehydration
 • Decreased reaction time and
   nerve conduction time
 • Decreased sensory deficits
Physiologic Changes Associated
with Aging

System     Function      Change
            Rest HR      No change
            Max HR       Lower
Cardio-    Rest C.O.     Lower
vascular   Max C.O.      Lower
           Rest SV       No change
           Max SV        Lower
Physiologic Changes Associated
with Aging

System     Function      Change
           Rest BP       Higher
  CV      Exercise BP    Higher
           Max VO2       Lower
Physiologic Changes Associated
with Aging
System        Function            Change
Respiratory        RV             Higher
             Vital Capacity       Lower
             Total Lung
                   capacity       No change
            Respiratory
                  frequency       Higher
           Work of breathing      Higher
          Ventilation:Perfusion   Mismatch
Physiologic Changes Associated
with Aging

System         Function     Change
Musculo-       strength      Lower
skeletal        mass         Lower
              flexibility    Lower
               balance       Lower
             bone density    Lower
Physiologic Changes Associated
with Aging

System          Function      Change
Renal        Kidney fxn        Lower
           Acid-base cntl      Lower
          glucose tolerance    Lower
           drug clearance      Lower
            cellular water     Lower
Physiologic Changes Associated
with Aging

System         Function      Change
Metabolic         BMR         Lower
            Lean body mass    Lower
               Body fat       Higher
Medical Disorders
Cardiovascular:
  HTN, Hypotension, CAD, Valvular Heart
    Disease, Dysrhythmias, Peripheral
    Arterial Disease
Pulmonary:
  Asthma, COPD, Pneumonia
Musculoskeletal:
  Arthritis, Degenerative Disk Disease,
    Osteoporosis, Degenerative Joint
    Disease
Medical Disorders
Metabolic/Endocrine:
  Diabetes, Hypercholesterolemia
Gastrointestinal:
  Dental, Malnutrition, Incontinence,
   Diarrhea
Hematologic/Immunologic:
 Anemia, Leukemia, Cancer
Neurologic:
 Alzheimer’s Disease, Parkinson’s Disease
    Major Benefits of Exercise
•   Improves cardiovascular function
•   Enhances work capacity and performance
•   Reduces CAD risk factors
•   Decreases morbidity and premature mortality
•   Aids in weight management
•   Builds muscle and strong bones
•   Decreases stress, anxiety and depression
•   Enhances self esteem and sense of well being
•   Enhances quality of life
•   Reduces risks of falls and complications in
    elderly
Benefits of Training-Specificity
Endurance Training
Peripheral adaptations (increased capillarization,
  increased oxidative capacity)
Central adaptations (increased LV compliance and
  mass,increased contractility, increased SV)
Changes in body composition

Resistance Training
Increases in strength (most likely related to
  neural mechanisms than to hypertrophy)
Specific programs for ADL’s
Factors to consider when
selecting an exercise protocol
Characteristic        Test Modification
Low VO2max          Start at low intensity
Time to attain
  a steady state        Long warm-up
Increased fatigue   Reduce total test time
Monitor BP, HR         Cycle ergometer
Poor balance           Cycle ergometer
Poor ambulation       Increase TM grade
Factors to consider when
selecting an exercise program
Mode
Does not impose significant orthopedic
 stress
The activity should be accessible,
 convenient and enjoyable
Intensity
Sufficient to stress (overload) the CVE,
 pulmonary and musculoskeletal systems
 without overtaxing them
Factors to consider when
selecting an exercise program
Intensity
Use a measured maximal heart rate
 (HRmax) vs. age-predicted; 55%
40-70% of HR reserve
Duration
Several 10 min bouts throughout the day if
  difficulty sustaining
Increase duration rather than intensity
Management & Medications in
the Elderly
Dizziness
Confusion/depression (diuretics, anti-HTN)
Fatigue and weakness (beta blockers, diuretics)
Postural hypotension (vasodilators, nitrates, anti-
  HTN, diuretics)
Involuntary muscle movements
Urinary Incontinence (anticholinergics, diuretics)
Increases in heart rate (bronchodilators)

								
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