Strength Assessment

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Cardiorespiratory training when the
cardiorespiratory system is stuffed Endurance
training in COAD, CAD, CHF PVD
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endurance ? reduced fatigue
training (at same intensity)
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after training when exercising at the same
submaximal intensity
One popular (incorrect ) hypothesis of fatigue

• VO2max

• SVmax ? COmax

? fatigue
? muscle H, Pi, IMP
O2 demand O2 supply
? muscle blood flow
muscle
? O2 supply
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• Lets examine this type of hypothesis by looking
  at examples of endurance training in subjects
  with pathologies that limit O2 supply

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• Ades PA et al. Circulation 94323-330, 1996
• Training group 60 men women (avg. age 68
  yrs) with coronary artery disease
• On average training began training 8 weeks after
  either myocardial infarction or coronary bypass
  surgery
• Control group 10 age-matched subjects with CAD

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• Training
• 12 week program (. 1 year for n 22)
• 1 hr/session
• 3 sessions per week
• 25 min treadmill ex.
• 15 min bicycle ex.
• 10 min rowing ex.
• initially at 75-85 of peak HR in symptom
  limited incremental test ? at wk 2 to 85-90 of
  peak HR

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• Assessments
• Radionuclide ventriculography
• Inject radioactively labeled red blood cells
  (99Tc) directly into the left ventricle
• Take pictures of the left ventricle with a gamma
  camera
• SV end diastolic volume end systolic volume
• CO SV x HR

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no sig. diff.
no sig. diff.
sig. increase at 3 mo and 12 mo
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• Summary point
• When subjects with pathology perform endurance
  training
• training may not reverse/minimise the primary
  pathology
• training in virtually ALL pathologies can
  increase the oxidative potential of the trained
  muscles

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Muscle oxidative capacity Patients with many
pathologies retain responsiveness to training
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Conclusion In health or pathology train the
muscle and the muscle will respond.
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• Consequences of increased muscle oxidative
  capacity
• At the same power output
• muscle VO2 is the same
• mitochondrial rates of ATP synthesis and ADP
  consumption are the same
• but since ? enzymes can get same rate with
  ?substrate
• therefore ? ADP
• therefore ? breakdown of CrP , ?Pi and ?AMP
• ?Pi may directly cause ?fatigue
• ?Pi, ?ADP and ?AMP may cause ?glycogen
  breakdown, ? glycolytic rate and ? H

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• Sala et al. Am J Respir Crit Care Med.
  1591726-1734, 1999
• N 14 male subjects (average age 64 years)
  with COPD (FEV1 40 of predicted)
• N 8 healthy male subjects (average age 61
  years) (FEV1 95 of predicted)

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• Assessments
• rate of leg 02 delivery during incremental
  exercise (via catheters in radial artery and
  femoral vein)
• intracellular muscle Pi, PCr pH (via
  magnetic resonance spectroscopy)

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• Training
• stationary cycle egrometer exercise for 8 weeks
• 5 days / week
• 60 min per session
• 40 min at 70-90 of the peak power determined
  from an incremental symptom-limited exercise test

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COPD
PRE POST
Pi PCr
Healthy
PRE POST
Power output (W)
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COPD
PRE POST
Muscle intracellular pH
Healthy
PRE POST
Power output (W)
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• Results
• VO2peak for 2 leg cycling
• healthy 13
• COPD 10
• max leg blood flow
• healthy 24
• COPD ns
• max leg O2 consumption
• healthy 20
• COPD ns

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COPD
PRE POST
One-leg O2 delivery (L/min)
Healthy
PRE POST
Power output (W)
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• How to optimally increase COmax?

• How to optimally increase muscle oxidative
  capacity?

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• How to optimally increase COmax?
• Likely need repeated sustained load on
  heart of high CO (large muscle mass ex.)

• How to optimally increase muscle oxidative
  capacity?
• Likely need repeated sustained load of high
  muscle metabolic rate

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• How to optimally increase COmax?
• Likely need repeated sustained load on
  heart of high CO (large muscle mass ex.)
• with pathologies of COPD, CAD, CHF, PVD
  sustained high absolute power outputs with large
  muscle mass are not possible

• How to optimally increase muscle oxidative
  capacity?
• Likely need repeated sustained load of high
  muscle metabolic rate
• Can train muscle groups individually

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• Tyni-Lenne R et al. J Cardiac Failure.
  5300-307, 1999
• N 24 subjects (avg age 63 years) with stable,
  moderate CHF (LVEF 30)
• Allocated to
• Leg cycle training (n8)
• Knee extensor training (n8)
• Control group (n8)

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• Training
• Both groups trained 3 x per week for 8 weeks
• Cycle training
• initial exercise intensity 50 of peak cycle
  power? to 60 at wk 1? to 70 at wk 5
• Duration 20 min

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• Knee extensor training
• Mode 1 leg training, i.e. left right legs
  training separately
• initial exercise intensity 50 of peak knee
  extensor power? to 60 at wk 1? to 70 at wk 5
• Duration so that total O2 consumption approx
  to 20 cycle O2 consumption . approx 16-18 min
  per leg

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• Conclusions
• Multiple strategies to increase muscle oxidative
• capacity, including
• large muscle mass continuous ex. (traditional
  approach may be suboptimal in pathololgies
  where O2 delivery is impaired)
• sequential small muscle mass ex.
• high power interval long recovery ex.