Cardiovascular Fitness Flashcards
Cardiorespiratory fitness is a good measure of…
the heart’s ability to pump oxygen-rich blood to the muscles
Cardiorespiratory fitness AKA
cardiovascular or aerobic fitness
Cardiorespiratory fitness: the ability…
- of the heart to serve as good functioning “pump”
- of the lungs to “load” O2 and “blow off” CO2
- of the blood to accept and carry/transport O2 and CO2
- of the working tissue (muscles) to extract and utilize the O2 delivered
Aspects of the CR system
Heart, vessles, blood, lungs, muscles
CR fitness usually expressed in:
Absolute terms: (L/min)
Relative terms: (mL/Kg*min)
Standard Units: multiples of METs
Absolute measure of CR fitness
L/min
Relative measure of CR fitness
mL/kg*min
standard units of CR fitness
multiples of METs
CR fitness best measured…
in laboratory setting
using O2 uptake (VO2)
Resting measures
HR, EKG, BP, Ventilation, O2 consumption
some (less value in knowing these measures)
important because “if there’s a problem at rest, the person has a REAL problem”
measures during submaximal and maximal GXT
HR, EKG, BP, ventilation,O2 consumption
PROVIDES DYNAMIC MEASURE OF CR FITNESS
best measure of CR fitness
GXT
graded exercise test
What is the best measure of CR fitness?
Sabmaximal or Maximal GXT
Why Test CR fitness? (4 reasons)
- Determines physiological responses at rest and during submaximal or maximal work
- provides a basis for exercise programming
- screening for CHD and pulmonary disease
- determining a person’s ability to perform a specific work task
Factors to determine which test is appropriate to use
(4 factors)
Client’s age
Client’s fitness level
Client’s known health problems
Client’s risk of CHD
Testing Sequence of Testing and Activity prescription
Informed Consent –> Health History –> Screening –> Resting CRF, body comp, and psychological tests –> submaximal CRF tests –> test for low back function –> beginning of light activity program –> tests for muscular strength and endurance –> maximal CRF tests –> activity program revision (include games and sports here) –> periodic retest (and activity revision)
- Informed Consent
participants should be informed volunteers
- Health history
helps determine appropriate testing protocols and activity recommendations
- Screening
helps determine risk-benefit ratio and contraindications to testing and training
- Resting CRF, body comp and psychological tests
helps determine if abnormalities requiring further medical attention exist
- submaximal CRF tests
helps determine if it is OK to begin light activity
used to estimate maximal functional capacity
- test for low back function
flexibility (particularly low back function) is tested
- maximal CRF test
if no problems occur up to this point
max GXT provides info to select fitness activities
- activity program revision
include games and sports here
“variety is the spice of life”
keeps client interested and reduces repetition injuries
- periodic retest
after client achieves a minimum, fitness level program needs to be revised
increase challenge to improve results/performance
Maximal VO2 obtained?
O2 consumption plateaus with increasing workload
<= 150 mL/min increase with increasing workload
not relative to body weight
most people do not achieve this criteria
Peak VO2 Criteria
Predicted maximal HR achieved/exceeded (failure of HR to increase in exercise intensity)
Venous lactate [ ] exceeds 8 mM/L
RER greated than 1.15
RPE greater than 17 on Borg 20 pt scale
If max or peak VO2 not obtained?
measure of functional aerobic capacity
For CHD screening and classification, bring client to 85% of age-predicted max HR
RER equation
volume CO2 produced / volume O2 consumed
RER (fat vs carb burning)
mostly fat burned, RER ~ 0.7
mostly carbs burned, RER ~ 1.0
RER 1.15 is VERY ANAEROBIC
VO2 max reflects…
capacity of heart and lungs to transport O2 to working muscles
utilization of O2 by the muscles during exercise
VO2 max used to…
classify the cardiorespiratory fitness level of client
evaluate progress of client
set realistic goals for client (when periodic retest is performed)
VO2 expressed in absolute terms
used to…
L/min or mL/min
provides a measure of energy cost FOR NON WEIGHT BEARING ACTIVITIES
(ex. leg or arm ergometry)
directly related to body size
issue: cannot compare people who are different weights
Relative expression of VO2
ml/kg/min or ml/kg FFm/min or ml/kg MFL/min
used to estimate the energy cost of WEIGHT BEARING ACTIVITIES (ex. walking, running, aerobic dance, stair climbing, bench stepping)
used to compare people of different sizes
used to estimate CR endurance that is independent of body weight changes
Scaling Vo2 to an exponential function
because the relationship between VO2max and body mass is strong (r=0.86) but not perfect, some investigators use scaling to avoid under or over classification of a client’s fitness level
oftentimes used for children to control for maturation differences
body mass exponents used for scaling VO2 to an exponential function
Body mass exponent of 0.67 for individuals of similar height, weight, and training status (mL/kg^0.67/min)
body mass exponent of 0.75 to compare heterogeneous groups (young vs old, trained vs sedentary) (mL/kg^0.75/min)
Gross VO2
represents the total rate of oxygen consumed
reflects the caloric cost of BOTH rest and exercise
Gross VO2 = Resting VO2 + Exercise VO2
can be expressed in absolute or relative terms
Net VO2
can be expressed in absolute or relative terms
represents the rate of O2 consumption in excess of resting VO2
USED TO DESCRIBE THE CALORIC COST OF EXERCISE
Net Vo2 = Gross Vo2 - Resting VO2
What describes the caloric cost of exercise?
net Vo2
ACSM recommends a MAXIMAL GXT before beginning VIGOROUS (>60% VO2max) exercise program for: (4 populations)
WILL NEED TRAINED MEDICAL PROFESSIONAL PRESENT FOR MAX GXT
Older men (>=45) and older women (>=55)
Individuals of any age with moderate risk (2 or more CHD risk factors)
high risk individuals with one or more signs/symptoms of cardiovascular and pulmonary disease
high-risk individuals with known cardiovascular, pulmonary, or metabolic disease
ACSM recommends a SUBMAXIMAL GXT before beginning a MODERATE (40-60% VO2max) exercise program
low risk and moderate risk individuals
Factors for selection of maximal or submaximal GXT
your client’s age and risk stratification (low, moderate, or high risk)
your reasons for administering the test (fitness testing vs clinical testing)
availability of equipment and qualified personnel
Maximal or Submaximal VO2 testing - requirements
multi-stage, graded test (increase in intensity)
most require 3 minute stages
why 3 minute stages are important for GXT
stage length is esp important for measuring lactate levels in the blood. Lactate must travel from legs, where most of the work is being performed, to the arms where blood is being drawn)
Procedure for administering a GXT
- Measure the client’s resting BP and HR IN EXERCISE POSTURE
- begin GXT with 2-3 min warmup
- monitor client’s HR, BP, and RPE at regular intervals
- discontinue GXT if test termination requirements are met
- Active, low work rate recovery or passive cooldown
MONITOR CLIENT’S APPEARANCE AND SYMPTOMS AT ALL TIMES
When measuring client’s resting BP and HR in the exercise posture, measures may…
increase. “thoroughbred response”
let client know that this is perfectly normal
Warm up for GXT allows for…
familiarize client with the equipment
prepare client for 1st stage of GXT
Test termination requirements for GXT
client requests to stop (remember they are always considered a volunteer)
indications for stopping test are present
Recovery post GXT
active low rate (not exceeding 1st stage intensity) recovery
continue measuring HR, BP, and RP every 1-2 mins for a minimum of 5 minutes
if client has had signs of discomfort or emergency, use a passive cool down, still measuring vital signs for at least 5 minutes
General Indications for stopping a GXT
- Onset of Angina or angina-like symptoms
- Drop >= 10mmHg in SBP from baseline BP despite increase in intensity
- Excessive rise in BP, SBP >= 250 or DBP>115
- shortness of breath, wheezing, leg cramps, or claudication
- signs of poor perfusion (ataxia, dizziness, pallor, syanosis, cold or clammy skin, nausea)
- failure of HR to rise with increased exercise intensity
- noticeable change in heart rhythm
- subject desires to stop
- physical or verbal manifestations of severe fatigue
- failure of testing equipment (ex. ECG lead falls off)
What is considered to be an excessive rise in BP/hypertensive response?
SBP >= 250mmHg
DBP > 115mmHg
Absolute indications for stopping GXT
- moderate to sever angina
- drop >= 10mmHg in systolic BP from baseline BP despite an increase in workload, when accompanied by other evidence of ischemia
- increasing nervous system symptoms (ataxia, dizziness, or near syncope, etc)
- signs of poor perfusion
- ST elevation in leads without diagnostic Q waves (other than V1 or AVR)
- sustained ventricular tachycardia
- subject desires to stop
- failure of testing equipment
Relative indications for Stopping GXT
- drop >= 10mmHg in SBP from baseline BP despite an increase in workload, in the absence of other evidence of ischemia, or failure of SBP to increase with increasing workload
- hypertensive response (SBP >250 DBP >115)
- increasing chest pain
- fatigue, shortness of breath, wheezing, leg cramps, or claudication
- arrythmias other than sustained ventricular tachycardia, including multifocal preventricular contractions (PVCs), supraventricular conduction delay that cannot be distinguished from ventricular tachycardia
- development of BBB or intraventricular conduction delay that cannot be distinguished from ventricular tachycardia
- ST or QRS changes such as excessive ST segment depression or marked axis shift
PVC
multifocal preventricular contractions
arrythmias other than sustained ventricular tachycardia
PVCs (multifocal preventricular contractions), supraventricular conduction delay that cannot be distinguished from ventricular tachycardia
What is so important to do when conducting a GXT?
MONITOR CLIENT’S APPEARANCE AND SYMPTOMS AT ALL TIMES
General principles of exercise testing
- Calibrate equipment
- 2-3 min warmup
- initial intensity considerably lower than anticipated maximal capacity
- intensity gradually increased
- closely observe for contraindications for testing and indications of stopping
- monitor HR at least 2 times per stage, no stabilization then extend stage by 1 minute
- measure BP and and RPE once per stage (latter portion of stage)
- submaximal GXT termination: 70% HRR or 85% HR max (unless protocol indicates otherwise
- cool-down minimum of at least 5 minutes (monitor HR and BP each min)
- testing area should be quiet and PRIVATE
- thermoneutral room
warm up duration for GXT
2-3 minutes
intensity increased by …. each stage during GXT
0.5 METs - 2 METs at a time
intensity increases for GXT for older individuals
should be smaller
0.5 - 1 METs
how many times should you monitor HR during each stage of GXT?
2
if there is no stabilization (+- 5 or 6 bpm), extend stage by 1 minute
when should you measure BP and RPE during GXT
once per stage, during latter portion of stage
submaximal GXT termination
70% HRR
85% HR max
(unless protocol specifies otherwise)
cool down for GXT should be… and HR and BP monitored every
minimum of 5 minutes
HR and BP monitored each minute
active recovery vs passive recovery
active recovery: workload should be no more than that used for 1st stage GXT
passive recovery: used in emergency when client cannot actively cool-down
exercise tolerance should be estimated in… or assess …. if measured directly during GXT
estimated in METs
assessed in O2 uptake if measured directly
thermoneutral
room temp 70-72 deg F
humidity < 60%
considerations for protocol selection
age, sex, health and fitness status of the client
ergometry type or field test
reason for testing
type of training you areprescribing, monitoring and evaluating
types of ergometry used in GXT protocols
treadmill, bike, arm crank
examples of field tests used in GXT protocols
step test, mile walk/run
types of protocols (3)
continuous protocol
continuous ramping protocol
discontinuous protocol
continuous protocol
no rest between work increments 2-3 min stages 2-3 MET increases workload may be increased linearly or nonlinearly 8-12 min duration
which is the “classic” protocol
continuous protocol
continuous ramping protocol
10-20 sec stages
MET increments much higher
10 minutes in duration
discontinuous protocol
client rests 5-10 minutes between workloads
5-6 min stages
typically takes 5x longer to administer than continuous protocol
reasons for GXT testing
clinical evaluation or fitness evaluation
bike protocols
typically VO2max 6-11% lower than treadmill protocol
people quit sooner due to local discomfort and fatigue
exception is trained cyclists
bike protocols typically …. lower than treadmill protocols
~10% lower VO2max
treadmill protocols issues to consider
balance
orthopedic issues
BP more difficult to measure
calf and lower back pain
Testing with bicycle ergometers
calibrate the bicycle
release tension on belt between tests
establish pedal frequency prior to setting workload
check load setting frequently during test (belt warming)
set metronome
adjust seat height so knee slightly flexed at max extension
ensure proper client position
setting metronome for bicycle ergometry GXT
1 revolution = 2 beats
metronome 120 = 60 rpm
adjust seat height so knee is slightly flexed at max extension, approx …deg
(bicycle ergometry)
5deg
proper client position for bicycle GXT
upright
seated
hands properly positioned on handlebars
modifications for standard GXT
for older adults
extend warm-up to more than 3 minutes
set initial intensity to 2-3 METs
work increments should be 0.5-1 METs
adjust (Reduce) the treadmill speed to the walking ability of client when needed
extend duration of each stage (at least 3 min) allowing steady state achievement
select treadmill protocols that increase speed, instead of grade
select protocol likely to produce total test time of 8-12mins
bike protocols with clients with poor balance, poor neuromuscular coordination or impaired vision
protocol best for older adults
bicycle ergometry
protocol time range for older adults GXT
8-12 minutes
for older adults, GXT protocol should increase… instead of ….
increase speed, not grade
older adults GXT should extend warm up, stages
warm up - more than 3 minutes
stage length - at least 3 minutes so steady state is reached
GXT for children
bike not typically recomended
why bike protocol not recommended for children
volitional effort to maintain cycling cadence cycle size (seat height, handlebar height and position)
height requirement for most cycle ergometers
125 cm (50 inches)
