Cardiorespiratory Fitness Purpose of Evaluation

1
Cardiorespiratory Fitness Purpose of Evaluation

• educate client about current fitness levels
  relative to age and sex
• Inspire individuals to take action to improve
  their health-related physical fitness
• Use data to develop an individualized exercise
  program
• identify areas of health/injury risk and possible
  referral to the appropriate health professional
• to establish goals and provide motivation
• to evaluate effectiveness of exercise program

2
Prolonged uninterrupted sitting, independent of
physical activity may be a risk factor for
chronic disease.
Fig. 1. The movement continuum, illustrating the
different focus of sedentary physiology and
exercise physiology. METs, metabolic equivalent
tasks.
3
Fig. 3. Illustration of accelerometer data
portraying an active couch potato (moderate to
vigorous intensity physical activity
meeting guidelines considered physically
active but also a high level of sedentary
behaviour) versus an active non-couch potato
(similar level of moderate to vigorous intensity
physical activity but low level of sedentary
behaviour). (From Dunstan et al. 2010a,
reproduced with permission of Touch Briefings,
European Endocrinology, Vol. 6, p. 21, 2010.)
4
Fig. 4. Portrayal of significantly different
patterns of breaks in sedentary time, based on
accelerometer data from 2 different
individuals (a prolonger and a breaker).
(From Dunstan et al. 2010a, reproduced with
permission of Touch Briefings, European
Endocrinology, Vol. 6, p. 21, 2010.)
5
Pretest and Safety Procedures

• we have already discussed screening in this area
  (HR, BP, observation)
• note the very cautious stance in the USA
  (everyone over 45 should have physician
  supervised graded exercise test)
• written emergency procedures
• written consent
• Cardiovascular responses to Acute exercise are
  described on the following slides

6

• Cardiac output - rises with work rate
• Rest 5 L/min Max 20 L/min

7

• Heart rate increases linearly with work rate and
  O2 consumption
• Max HR 220 - Age (one standard deviation is /-
  12bpm)

8

• Stroke volume rises with exercise to maximum at
  50
• Rest 60-100ml exercise 100-120 ml

9
Blood Pressure - Systolic increases linearly with
intensity (max 190 - 220 mmHg) -Diastolic may
increase slightly ( 10 mmHg) or not change
10
(a-v)O2 difference - Rest 5 ml/dl Max 15 ml/dl
11
Blood flow to working muscle increases with
exercise - from 20 to 85 of Q
12
(No Transcript)
13
Oxygen Consumption

• Maximal oxygen consumption is most widely
  recognized measure of cardiopulmonary fitness
• VO2 Max - highest rate of O2 use that can be
  achieved at maximal exertion
• Fick Equation - VO2 HR X SV X (a-v) O2
• Table 3.3 ACSM
• Absolute VO2- L/min or ml/kg/min (relative to
  body weight)
• Relative VO2- given as of VO2 max

14
Oxygen Consumption

• Direct measurement of maximal oxygen uptake is
  the most accurate - Douglas Bag
• Can also be estimated from peak work rate
• Treadmill speed and grade, cycle work rate

15
O2 consumption Sub max estimates

• sub-maximal tests have four assumptions
• Linear relationship between HR and O2 uptake
• Valid between 110 and 150 bpm
• Linear relationship between O2 uptake and
  workload
• That the max HR at a given age is uniform
• That the mechanical efficiency (O2 uptake at a
  given workload) is the same for everyone
• Not entirely accurate - can result in 10-15
  error in estimating VO2 max
• Tend to overestimate in highly trained,
  underestimate in untrained

16
(No Transcript)
17
Sub-maximal Tests

• We have done (or will do) the following sub-max
  tests
• YMCA sub-maximal bicycle test
• Sub-maximal step test (mCAFT)
• Rockport Fitness Walking Test
• Cooper test
• 1.5 mile test
• Caution client to stop if feeling dizzy,
  nauseous, very short of breath

18
Metabolic Equivalent (MET)

• Absolute resting O2 consumption
• 250 ml / min divided by body weight
• An MET is the average amount of oxygen consumed
  while at rest. It is used a lot in ACSM exercise
  prescription guidelines.
• MET 3.5 ml / kg min
• Capacity to increase work rate above rest is
  indicated by number of METs in max test
• Sedentary can increase to 10, an athlete up to 23
  MET

19
Cardiorespiratory Capacities

• METs VO2max (ml/kg/min)
• Athlete 16-20 56-70
• Active 10-15 35-53
• Sedentary 8-10 28-35
• Cardiac Patient
• - Class II 5-7 18-25
• - Class III 3-5 11-18
• - Class IV lt3 lt11

20
Stress Tests

• Bruce protocol is a maximal stress test
• 3 min stages on treadmill
• Increase speed and percent grade (3.5 MET /
  stage)
• Used as a diagnostic test for coronary heart
  disease and estimating VO2 max
• must be cautious as Coronary Heart Disease is the
  1 killer in Canada
• if client has positive PAR-Q or is over 45 in
  the states need physician to be present
• ECG (electrocardiograph) is used during stress
  test, as 30 with confirmed CAD have normal
  resting ECG
• but 80 of these abnormalities will show during
  the stress of exercise

21
(No Transcript)
22
(No Transcript)
23
Why Use Stress Tests?

• To establish, from ECG, a diagnosis of heart
  disease and to screen for "silent" coronary
  disease in seemingly healthy individuals.
• To reproduce and assess exercise-related chest
  symptoms.
• To screen candidates for preventive and cardiac
  rehabilitative exercise programs.
• To detect abnormal blood pressure response
• To define functional aerobic capacity and
  evaluate its degree of deviation from normal
  standards.

24
Exercise-Induced Indicators of CHD

• Angina Pectoris present 30 of time.
• Electrocardiographic Disorders
• S-T segment depression
• Cardiac Rhythm Abnormalities
• premature ventricular contractions
• ventricular fibrillation
• Other Indices of CHD
• blood pressure (hypertensive and hypotensive)
• heart rate (tachycardia or bradycardia)

25
Blood Pressure Response

• normal for systolic to rise to 190-220 mmHg
• normal for diastolic to increase by 10 mmHg (can
  actually drop or stay the same)
• systolic should not exceed 260 mmHg
• diastolic increase gt20 mmHg hypertensive
• exertional hypotensive response
• failure of Systolic pressure to rise by at least
  20-30 mmHg, Or SBP drops (20 mmHg)
• Correlated with myocardial ischemia, left
  ventricular dysfunction and risk of cardiac events

26
Heart Rate Response

• average resting HR 60-80 bpm but males usually
  7-8 beats/min lower than females
• tachycardia early in exercise is indicator of
  potential problems
• bradycardia during exercise could be sinus node
  malfunction or other heart disease problems - or
  extreme fitness
• Remember max HR declines with age

27
Rate Pressure Product

• Commonly used estimate of myocardial workload and
  resulting oxygen consumption.
• RPP SBP x HR
• Where RPP rate pressure product
• SBP systolic blood pressure
• HR heart rate
• expect RPP to rise to gt 25,000 (minimum
  adequate)
• - age, clinical status, and medications(b
  blockers) can influence results

28
Guidelines for Stopping a Stress Test

• Repeated presence of premature ventricular
  contractions (PVCs).
• Progressive angina pain regardless of the
  presence or absence of ECG abnormalities
  consistent with angina.
• An extremely rapid increase in heart rate may
  reflect a severely compromised cardiovascular
  response.
• Electrocardiograph changes that include
• S-T segment depression of 2 mm or more,
• AV block, PVC
• Failure of heart rate or blood pressure to
  increase with progressive exercise
• or a progressive drop in systolic blood pressure
  (20mmHg) with increasing work load.

29
(No Transcript)
30
(No Transcript)
31
Guidelines for Stopping a Stress Test

• An increase in diastolic pressure of 20 mm Hg or
  more, a rise above 115 mm Hg.
• Rise in systolic pressure gt 250 mmHg
• Headache, blurred vision, pale, clammy skin, or
  extreme fatigue.
• Subject requests to stop
• Marked dyspnea (breathlessness) or cyanosis.
• Dizziness or near fainting, light-headedness or
  confusion
• Nausea
• Failure of equipment

32
Interpretation of Bruce

• Prediction equations for VO2 max available based
  on activity and health status and gender (see lab
  book)
• Outcomes
• True positive - correctly predicts problem
• False Negative - results are normal - patient has
  disease
• True Negative - results normal - no disease
• False Positive - abnormal test - no disease
• With any positive results secondary tests are
  performed to confirm diagnosis

33
CPAFLA - mCAFT

• mCAFT- modified Canadian Aerobic Fitness Test
• Ability and efficiency of lungs, heart,
  bloodstream, and exercising muscles in getting
  oxygen to the muscles and putting it to work.
• Benefits of larger aerobic capacity
• daily activities
• reserve for recreation and emergencies
• decline 10 per decade after age 20
• regular vigorous activity to deter this decline

34
mCAFT Structure

• Step for 3 min intervals
• predetermined height and frequency (work rate)
• Note - final stages use one large step up from
  back of steps
• Men stages 7 and 8, women stage 8
• Take HR at end of each stage
• assess if client will continue based on ceiling
  HR (fig 7-10)
• utilize heart rate monitor, or radial pulse
• Take BP and HR after recovery
• to determine if client is back to resting levels
  before release
• Cuff can be attached before trial, or quickly
  after

35
Before Starting mCAFT

• Ensure Par-Q and consent completed
• Determine starting stage Figs 7-8,9
• have clients practice (p. 7-26)
• note ceiling HR for that client (fig 7-10)
• Upon completion client walks around for 2 minutes
• Sit down and get recovery BP and HR (set times
  listed in CPAFLA)

36
(No Transcript)
37
(No Transcript)
38
mCAFT

• Aerobic Fitness Score 10 X 17.2 ( 1.29 X O2
  cost) - (0.09 X wt (kg)) - (0.18 X age (yrs))
• O2 cost is determined using Fig 7-11
• The final heart rate is not considered, only the
  stage attained in assessing benefit zone
• Heart rate can be used to determine improvement
  upon reappraisal if client does not move zones
• Determine health benefit zone using fig 7-12

39
(No Transcript)
40
(No Transcript)
41
(No Transcript)