Scientific Basis for Improving Cardiorespiratory Fitness Flashcards
1
Q
Introduction to Cardiorespiratory Fitness Testing and Prescription
A
- exercise prescription most accurate if based on known fitness level
- many methods for assessing fitness
2
Q
Base Concepts
A
- cardiorespiratory fitness (CRF): coordinated capacity of heart, blood vessels, respiratory system, and metabolic systems to take in and deliver oxygen
- VO2max: reflects the capacity of the heart, lungs,and blood to transport oxygen to exercising muscles; absolute vs. relative values
3
Q
VO2max: Absolute vs. Relative Values
A
- absolute VO2 (l/min)
- relative VO2 (ml/kg/min)
- norm values for VO2max listed in ASCM guidelines
4
Q
CRF Assessment Considerations
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- intensity: submax to maximal
- mode: aka method or type; treadmill, cycle, step, etc
- measurement: relative accuracy for population, etc
- location: laboratory vs filed
5
Q
CRF Assessment “Gold Standards”
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- intensity: max test
- mode: depends on client
- measurement: metabolic analysis system (~30K)
- location: typically in lab
6
Q
Graded Exercise Test
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- appropriate and useful prescription depends on accurate measure of VO2max
- most effectively assessed with gxt
- such tests may be maximal or submaximal
- many test modes exist for both max and submax
7
Q
Maximal GXT
A
- client performs to physiological or symptom limit
- variable or graded workload that increases gradually
- total test time of 8-12 minutes
- often monitored with EKG
- direct measure of VO2 requires analysis of expired gases: requires special equipment and personnel, costly and time consuming
- not feasible for most clinical situations
- typically reserved for research, patients with specific diseases, for athletic evaluation
- thus, submax testing is most commonly used
8
Q
CRF Assessment “Realities”
A
- often need to use submax testing secondary to:
- resource availability
- experience level
- location
- cost constraints
9
Q
Submax Testing Assumptions
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- a linear relationship exists between HR and submax workload
- steady state HR is obtained for each workload
- max workload is indicative of VO2max
- max HR for a given age is uniform
- mechanical efficiency is the same for everyone
- subject not on meds that later HR response
10
Q
Common Measurements
A
- HR: palpation (radial, carotid, auscultation), HR monitor, pulse oximeter, EKG
- BP: mercury sphygmomanometer, aneroid, arm position, cuff size (large/small)
- Rating of Perceived Exertion (RPE): Borg (Category scale or category-ratio scale), OMNI, standardized instructions
11
Q
Common Measurements-Red Flags
A
- onset of angina or angina like symptoms
- drop of SBP > 10 mm Hg from baseline with increase in workload
- SBP > 250 mm Hg or DBP > 115 mm Hg
- SOB, wheezing, leg cramps, claudication
- light-headedness, confusion, ataxia, pallor, cyanosis, nausea, or cold and clammy skin
- failure of HR to increase with workload
- noticeable change in heart rhythm
- subject requests to stop
- physical or verbal manifestations of severe fatigue
- failure of testing equipment: VO2, EKG, Pulse Ox, etc
12
Q
Common Submax Tests
A
- submax field tests commonly used to assess CRF: many modes and versions exist
- Pros: large numbers can be tested simultaneously, little or no cost, requires only basic understanding of exercise science
- cons: less accurate than laboratory assessment methods
13
Q
Rockport 1 Mile Walk Test
A
- walk as fast as possible: no running! one foot in contact with ground at all times
- record time (min and sec)
- subject measures HR via palpation
- calculate relative VO2max using formula
14
Q
12 Minute Walk/Run Test
A
- may walk or run
- distance covered in 12 minutes
- calculate relative VO2max using formula
15
Q
1.5 Mile Run
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- run 1.5 miles
- assess time to completion
- calculate relative VO2max using formula
16
Q
Step TEsts
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- queen’s college step test
- step up/down on bench for 3 minutes
- bench height 16.25 in
- step rate: men 96 steps/min; women 88 steps/min
- assess pulse immediately following: 15 sec x 4
17
Q
6 Min Walk Test (6MWT)
A
- widely used in clinical environments: inpatient facilities, nursing homes, etc
- norm values exist for many populations: preschool child 2-5 yrs, child 6-12 yrs, adult 18-64 yrs, elderly adult 65+
- performed at fastest speed possible
- documentation should include speed tested if fastest speed is not used
- assistive devices can be used but kept consistent from test to test
- individual should be able to ambulate without physical assistance
18
Q
Cycle Ergometry
A
- multiple protocols exist: YMCA< Astrand-Rhyming
- advantages: non-weight bearing mode-obese, orthopedic problems, etc; easier measurement of vitals that TM; submax test choices
- disadvantages: non-familiar work mode-especially for older individuals; treadmill testing through to give a truer physiological max for most
19
Q
Test Recovery (Cool Down)
A
- 5 min recovery: active/passive
- continue to monitor HR, BP, signs and sx, longer if symptomatic, 1-2 min intervals
- active recovery: HR and BP will not reach baseline
20
Q
Test Interpretation
A
- use in therapeutic exercise programming
- determine percentile ranking for aerobic fitness
- use a percentage of VO2max (eg 70%): metabolic calculations, exercise prescription
- compare pre-post VO2: motivation, outcomes assessment
21
Q
Technique for CV Exercise Prescription
A
- individualized exercise prescription has many components:
- specificity
- intensity
- duration
- frequency
- mode
- progression of activity
- rest/recovery/adaptation
- retrogression/plateau/reversibility
- warm-up and cool-down
- enjoyment
22
Q
Specificity
A
- what you do is what you get
- central CV adaptations: adaptations that occur in heart and contribute to an increased ability to deliver oxygen
- peripheral CV adaptations: adaptations that occur in vasculature or the muscles that contribute to an increased ability to extract oxygen (less fatigued, store more glycogen in mm)
- SAID principle: specific adaptations to impose demands
23
Q
Intensity
A
- how hard to exercise
- typically prescribed on basis of max HR, HR reserve, VO2max, RPE
- HR is widely used method to linear relationship with oxygen consumption
- HR is also easy to monitor during exercise
- max HR may be assessed directly or thru age predicted max HR
- PMHR=220-age
- training range should be between 60 and 90% of PMHR for most healthy individuals
- max HR may be assessed directly thru age predicted max HR
- training range should be between 60 and 90% of PMHR for most healthy individuals
- PMHR = 220 - 40 = 180 bpm
- THR = 180 x 70% = 126 bpm
24
Q
Karvonen Method
A
- emphasis on HRR
- another method to calculate intensity
- HRR=PMHR-RHR
- goal is 50-85% of Karvonen HR
- karvonen THR = INT(HR) + RHR
25
Q
Intensity VO2Max
A
- based on known VO2max: step test, rockport 1 mile, 1.5 mile, cycle
- 50% to 85% of VO2max is also used as the training range
- less commonly used secondary to lesser prevalence of this form of testing
26
Q
Intensity: Rating of Perceived Exertion (RPE)
A
- developed by Gunner Borg
- 80% correlation for HR and 6-20 scale
- 12-13~60% HRR
- 15~90% HRR
- average conditioning for apparently healthy: 12-15 on Borg Scale, 5-6 on modified Borg Scale
- volume response: increased pressure due to increased plasma volume, stress upon heart is what we want to elicit –> bigger L ventricle –> need bigger duration –> endurance exercise
- look at RPE scale breakdown
27
Q
Duration of Exercise
A
- answers “How long should one exercise?”
- ranges from 20-60 minutes: most often 20-30 minutes
- does not include warm up or cool down
- typically inversely related to intensity
- may increase secondary to training
28
Q
Frequency of Exercise
A
- how often
- may range from 3-6 days a week to 2x/day
- most if not all of the days of week is best
- dependent upon factors like intensity, duration, fitness level
- dependent on individual’s functional capacity (FC)
- FC < 3 METS, multiple short doily sessions
- FC 3-5 METS, 1-2 sessions/day
- FC >5 METS, 3-5 sessions/week
- 1 met = 3.5 ml oxygen/kg/min
- can’t exercise continually so you gotta break it up
29
Q
Mode of Exercise
A
- what type of activity
- aka type of exercise
- aerobic exercise should use large muscle groups
- rhythmic activities are best for cardiorespiratory fitness
- design program for the individual
- ex: walking, jogging, biking
- additional forms may include: dancing, skating, hiking
30
Q
Stationary Bike
A
- position seat to allow 5-10* knee flexion when foot is at lowest position on crank
- pros: allows decreased weight bearing exercise, no impact, relatively quiet to operate, easy to monitor/measure vitals, requires little time/effort to learn
- cons: local LE fatigue may limit performance, hard to increase HR to target secondary to LE fatigue, not all clients familiar with biking, decreased weight bearing achieved
31
Q
Recumbent Bike
A
- maintain lumbar lordosis, when LE is in most outstretched position, ankle at 90* dorsiflexion, allow 5-10* of knee flexion
- more comfortable seat than traditional bike, allows more uprights spinal posture, relatively quiet to operate, easy to monitor/measure vitals, safer than traditional bike due to wide base of support
- local LE fatigue may limit performance, supine position makes it difficult to increase HR
32
Q
Stair-Climber
A
- stepping motion is familiar to most clients, requires little habituation, provides weight bearing, no or little impact activity, occupies lesser space than other equipment
- may aggravate or cause knee problems, monitor posture on machine carefully, somewhat difficult to mount, requires good balance
33
Q
Nu-Step Recumbent Stepper
A
- position seat to allow slight knee flexion when LE in most extended position
- large seat provides comfortable sitting, stepping motion is familiar to most clients, provides low impact form of loading, safer than traditional stepper d/t wide BOS, ease of mounting, uses all 4 extremities, allowing clients to more easily achieve THR
- little or no weight bearing achieved
- difficult to monitor/measure vitals secondary to UE motion
34
Q
Treadmill
A
- walking/running familiar to most clients, requires little habituation, provides weight bearing, uses large LE muscles in traditional positions, allows HR to most easily reach THR without undue LE fatigue, easy to adjust intensity
- wt. bearing may be difficult for some patients (obese, orthopedic limitations), requires a lot of space, expensive, difficult to monitor/measure vitals, makes significant noise when in use
35
Q
Elliptical Trainer
A
- low impact, uses all 4 extremities so considered total body workout, clients can more easily achieve THR
- requires more coordination so need more time to learn, requires greater floor space than some other equipment, may be difficult to monitor/measure vitals
- may be difficult to mount/dismount
36
Q
Upper Body Ergometer
A
- adjust seat to allow slight elbow flexion at max UE extension, back maintains contact with support, spine maintains normal curvature, seat height even with axis of arm crank
- eliminates LE, provides aerobic exercise mode for those with significant impairment, easy to mount/dismount, relatively quite operation
- local fatigue limits performance, lower HR secondary to use of smaller muscles, novel movement for most clients, requiring increased habituation, difficult to monitor/measure vitals during activity
37
Q
Rate of Progression
A
- how should one modify the program?
- change program as following items change: functional capacity, injury status, fitness/wellness goals, age
- progression typically goes through 3 stages: initiation, improvement, maintenance
- general guidelines are helpful, but individual objective and subjective training responses are most important clinical markers: periodization provides a yearly plan
38
Q
Initiation Stage
A
- allows individual to slowly adapt to change in activity level
- typically lasts 3-6 weeks
- parameters are set in low range:40-60% HRR or VO2max, RPE of 11 to 12
- duration of 15-40 min per session
- at least 3 mon-consecutive days per week
39
Q
Improvement Stage
A
- able to exercise for 30-40 min for 5-6 sessions per week
- no signs of musculoskeletal overuse or excessive fatigue
- this stage generally lasts 4-5 mo
- increase intensity to 60 to 85% of HRR or VO2max
- avoid large increases in training volume: should not exceed 10% per week; volume = intensity x duration x frequency
40
Q
Maintenance Stage
A
- emphasis shifts to: maintenance of fitness level, diversifying the mode, enjoying exercise as lifetime habit
- fitness will decrease ~50% within 4-12 weeks if maintenance program not performed
- intensity is most important factor in maintaining VO2max and measures of max capacity
- activity diversification is suggested to: increase enjoyment, decrease boredom, decrease potential for overuse injuries, add competition to program, explore new interests, accomplished thru periodization and cross-training
41
Q
Rest/Recovery/Adaptation
A
- must balance stress of training with an individual’s ability to recover
- adaptation has occurred when same amount of work accomplished: in less time, less physiologic disruption, less fatigue or exertion, or when more work can be accomplished
42
Q
Retrogression/Plateau/Reversibility
A
- with failure to improve…assess for signs of overreaching or overtraining
- detraining occurs rapidly if exercise is discontinued for any reason
43
Q
Warm Up and Cool-Down
A
- beneficial effects of a warm-up: increases BF to active muscles, increases BP to myocardium, increases dissociation of oxyhemoglobin, earlier sweating, may reduce abnormal heart rhythms
- cool-down helps to: process metabolic waste products, ease transition back to resting state
44
Q
Enjoyment
A
- can we reasonably expect anyone to continue long term if it’s not enjoyable?
- exercise adherence: refers to strength of an individual’s commitment to performing physical exercise-people with strong exercise adherence continue physical activity despite opportunities and pressures to withdraw
45
Q
Adherence: Program Factors of Dropout
A
- inconvenient time or location
- excessive costs
- high intensity
- lack of variety
- solo participation
- lack of positive feedback
- inflexible goals
- poor leadership
- lack of spouse support
- inclement weather
- excessive job travel
- injury
- medical problems
- job change
- move
46
Q
Strategies for Improving Adherence
A
- minimize MS injuries by adhering to principles of exercise prescription
- encourage group participation or exercising with a partner
- emphasizing a variety of modes of activities and enjoyment in the program
- incorporate behavioral techniques and base the prescription on theories of behavior change
- use periodic testing to document progress
- give immediate feedback to reinforce behavior change
- recognize accomplishments
- invite client’s partner to become involved and support the training program
- ensure that the exercise leaders are qualified and enthusiastic
47
Q
FITTE
A
- frequency
- intensity
- time
- type
- enjoyment
