High resistance training for the aged Tom Gwinn, School of Exercise and Sport Science, Faculty of He

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High resistance training for the agedTom
Gwinn, School of Exercise and Sport Science,
Faculty of Health ScienceThe University of
Sydney
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The strength of an average person declines with
age
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Individual differencesJust because someone is
old doesnt mean that they are weak.
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• summed (left right) isometric handgrip
• Kallman et al.
• (1990)

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Weakness (or strength) is not the only influence
on function.
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? max. habitual walking speed? stair climbing
capacity ? max. step height? min. chair height
Impaired mobility in elderly
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Impaired mobility in elderly
weakness
? muscle physiological CSA
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impaired balance
joint pain
poor vision
COAD
depression
PVD
Impaired mobility in elderly
protein /- energy malnutrition
stroke
Parkinsons
weakness
cognitive impairment
? muscle physiological CSA
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However despite multiple other
influencesweakness, as a isolated factor, can
shown to strongly related to disability.For
example ..
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• Rantanen T et al. JAMA 281(6)558-560, 1999
• Honolulu Heart Program
• 1965-1970 grip strength assessed in 6,089
• middle-aged men (average age 54 years)
• 1991-1993 2,259 died
• Follow up 3219 (now aged 80 y)
• assessed for functional limitations

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• From data collected 25 years earlier each
  individual was classified as being in the
• strongest 1/3 of the sample
• middle 1/3
• weakest 1/3

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frequency
middle1/3
strongest 1/3
weakest 1/3
hand grip strength

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• At the time of the first assessment the men were
  free of major incident disease or incapacity in
  mobility or ADLs.

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• Follow up assessments
• usual walking speed
• ability to rise from a chair
• self reported difficulty in mobility and ADL
  tasks

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Measured capacities
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• Authors hypothesis
• Good muscle strength in midlife may protect
  people from old age disability by providing a
  greater safety margin above the threshold of
  disability

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Concept of relationship of muscle strength to
risk of disability is similar to relationship of
bone strength to risk of fracture
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gradient of fracture risk
person 1
person 1
gradient of disability risk
person 2
person 2
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Burchner DM et al . Age Aging 25386-391, 1996

• SUBJECTS
• n 409
• age range 60 96 years
• random sample from subjects enrolled in a HMO
• exclusions
• neurological, musculoskeletal conditions or
  systemic illnesses affecting skeletal muscle
• inability to walk

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Assessments

• Voluntary strength performing the following
  movements
• knee extension
• knee flexion
• ankle plantar flexion
• ankle dorsiflexion
• summary strength score sum of absolute strength
  of 4 m groups of the R leg

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Assessments

• usual gait speed (15.2 m course)

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Results

• strength explained 22 of the variability in
  gait speed in the curvilinear model

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Recall that hypertrophy is useful for
everything (converse atrophy makes everything
more difficult)
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atrophy
hypertrophy
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2x CSA
max. isometric force
max. force
muscle velocity of shortening
muscle length
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2x CSA
Widrick, J. Am J Physiol 283 R408R416, 2002.
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Optimal dosage for strength training in
adults uses high force eccentric concentric
contractions
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• BUT
• high force contractions
• especially eccentric contractions, cause
• muscle ultrastructural damage
• delayed onset muscle soreness

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Isnt it desirable to avoid muscle damage
soreness?
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Isnt it desirable to avoid muscle damage
soreness?
Note All exercise programs should have a
introductory conditioning or adaptation
phase where initial intensity ( total volume) is
deliberately reduced below optimal target
intensity Over 1st few weeks relatively
intensity in gradually ? while monitoring trainee
for precautions
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Fiatarone MA et al. N Engl J Med 3301769-1775,
1994

• n 100 residents of long term care facility
  (rehabilitation centre for the aged)
• avg age 87 years

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Subject characteristics

• 83 required cane, walker, or wheelchair
• 66 had fallen during the previous year
• 51 met screening criteria for cognitive
  impairment
• 38 met criteria for depression

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Subject characteristics

• chronic conditions
• arthritis (50)
• pulmonary disease (44)
• osteoporotic fracture (44)
• hypertension (35)
• cancer (24)

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• Random assignment to 1 of 4 groups
• exercise
• control
• nutritional supplement
• exercise supplement

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• Training
• exercises - double leg press - knee
  extension
• dosage - 80 1RM - 3 sets of 8 lifts/sets
• duration - 3 days/week for 10 weeks, - 45
  minutes/session

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• Compliance adverse events
• compliance 97-100 for all procedures
• 2 unrelated deaths
• 2 drop-outs from training group i) generalized
  musculoskeletal pain after 1st training session,
  ii) pneumonia (week 7)
• 2 subjects reported joint pain necessitating
  alteration to training program (i- prosthetic
  hip joint, ii- osteoarthritic knee)

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Primary Outcomes
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Fiatarone-Singh MA et al. Am J Physiol
277E135-E143, 1999

• Subset of 1994 study volunteering for muscle
  biopsies
• avg age 87 years

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Pre-training Narrow myofibrils, wide
sarcoplasmic spaces, some Z band myofibril
damage Fiatarone-Singh M et al. Am J Physiol
227E135-E143, 1999
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Post-training same subject areas of extensive Z
band myofibril disorganizationFiatarone M et
al. Am J Physiol 227E135-E143, 1999
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pre
Sections of vastus lateralis stained for
IGF1 Fiatarone Singh M et al. Am J Physiol
227E135-E143, 1999
10 wk resistancetraining
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• IGF-I increased paralleled muscle damage (r2
  0.73)
• amount of damage predicted increase in
  quadriceps strength (r2 0.73)