Principles of Clinical Exercise Testing & Prescription

PHTH 652: Integrated Clinical Exercise Rehabilitation

Date: Friday September 5th, 2014

Jadranka Spahija, PhD, pht,Associate Professor

School of Physical & Occupational Therapy

PHTH 652: Integrated Clinical Exercise RehabilitationPHTH 652: Integrated Clinical Exercise Rehabilitation

• Introduction– Course outline: course structure, objectives, materials, evaluation – Course schedule (preliminary)

• Overview and Terminology– Physical activity, exercise, fitness– Health benefits and ACSM recommendations

• Assessment– Health screening and risk assessment (class exercise)– General assessment– Exercise testing :

• Purpose, contraindications, procedures, normal/ abnormal responses• Interpretation (class exercise)

• Exercise prescription (FITT)– Methods for calculating exercise intensity: HRR, VO2R, METS

General principles of exercise prescription (Dr. Preuss)

Definitions related to Physical ActivityDefinitions related to Physical Activity

Physical activity:• Any form of body movement generated by skeletal muscle contraction

that results in a significant metabolic demand and energy expenditure.Exercise:• Planned and purposeful physical activity with repetitive bodily movement

done for health and fitness pursuits.Physical fitness:• A set of attributes or characteristics that individuals have or achieve that

relates to their ability to perform physical activity

• Cardiorespiratory endurance: The ability of the circulatory and respiratory system to supply oxygen during sustained physical activity.

• Body composition: The relative amounts of muscle, fat, bone, and other vital parts of the body.

• Muscular strength: The ability of muscle to exert force. • Muscular endurance: The ability of muscle to continue to perform without

fatigue. • Flexibility: The range of motion available at a joint. • Neuromotor fitness: Motor skills such as balance, agility, coordination and

gait

HEALTH-RELATED PHYSICAL FITNESS COMPONENTS

Physical Activity and Fitness TerminologyPhysical Activity and Fitness Terminology

Dose-response relationship between physical activity and health

Dose-response relationship between physical activity and health

• Important health benefits obtained by performing a moderate amount of physical activity on most, if not all, days of the week.

• Additional health benefits from greater amounts of physical activity. • Individuals who maintain a regular program of physical activity that is longer in

duration and/or is more vigorous in intensity are likely to derive greater benefit.

Type and amount of activity

What are the health benefits?What are the health benefits?

Reduction of all cause mortality Reduction of cardiovascular events Improved diabetic control Improved hypertension control Improved lipid profile Weight reduction Improved musculoskeletal health Improved psychological well-being Improved health-related quality of life Reduced health care utilization

Increased physical activity delays premature mortality and reducing the risks of many chronic diseases and health conditions.

Bottom line: physical activity should be encouraged!!

ACSM-AHA Primary Physical Activity - Recommendations -

ACSM-AHA Primary Physical Activity - Recommendations -

Healthy adults, 18–65 yrs of age (Initial target):

• Moderate intensity aerobic physical activity for 30 minutes, 5 d/wk

or • Vigorous intensity aerobic activity for a

minimum of 20 min 3 d/wk• Combinations of moderate and vigorous

intensity exercise can be performed to meet this recommendation.

• Moderate intensity, aerobic activity can be accumulated to total the 30 min minimum by performing bouts each lasting ≥10 min.

• Every adult should perform activities that maintain or increase muscular strength and endurance for a minimum of 2 d/wk.

• Additional health benefits result from greater amounts of physical activity. (dose-response relationship) i.e. 300 min/wk or more of moderate intensity, aerobic activity; 150 min/ wk or more of vigorous intensity, aerobic activity; or an equivalent combination of moderate and vigorous intensity, aerobic activity.

• To minimize musculoskeletal injuries, physical activity bouts can be broken up during the week (e.g., 30 min of moderate intensity, aerobic activity on 5 d/wk.)

ACSM-AHA Primary Physical Activity- Recommendations -

ACSM-AHA Primary Physical Activity- Recommendations -

• All individuals wishing to initiate a physical activity program should be screened at minimum by a self-reported medical history or health risk appraisal questionnaire.

• Emphasizes identifying individuals with known disease because at greatest risk for an exercise-related cardiac event.

ACSM Pre-participation Health Screening - Recommendations -

ACSM Pre-participation Health Screening - Recommendations -

Physical Activity Readiness Questionnaire (PAR-Q) Physical Activity Readiness Questionnaire (PAR-Q)

• self-reported medical history or health risk appraisal

AHA/ACSM Health/Fitness Facility - Pre-participation Screening Questionnaire -

AHA/ACSM Health/Fitness Facility - Pre-participation Screening Questionnaire -

CV, cardiovascular; CVD, cardiovascular disease. Ex Rx, exercise prescription; HR, heart rate; METs, metabolic equivalents; VO2R, oxygen uptake reserve.

Severe headache

Key point: Low intensity exercise is feasible formost patients regardless of risk level

Case for Risk AssessmentCase for Risk Assessment

• Man, 55 years old, smokes at work (10-20 cigs). • Height = 70 in (177.8 cm), weight = 217 lbs (98.4 kg). • RHR=80 bpm, RBP=140/80. • Total serum cholesterol 178 mg/dL (4.61 mmol/L), LDH=106 mg/dL

(2.75 mmol/L), HDL=52mg/dL (1.35 mmol/L). • FBG=140 mg/dL (7.8 mmol/L). • Walks 1 mile twice a week. • Father had Type 2 diabetes and died at 68 years of cancer, mother alive

and well. • No CVD, no medications, reports no symptoms.

High, moderate or low risk??

Patient AssessmentPatient Assessment

General Interview• Demographics: Age, sex, height, weight• History of Present Illness

– Reasons for referral, nature of admission– Chief complaint, medical diagnosis, cause and mechanism of injury– Length of illness, surgical procedures– Types of symptoms: onset, quality, quantity (intensity), frequency, duration,

exacerbating/alleviating factors, chronicity of symptoms, major interventions, current disease status)

– Other manifestations of the illness (mobility restrictions, system dysfunction…)– Comorbid conditions

• Medications– Dosage, route, frequency, meds including over the counter and herbal

supplements, drug intolerances• Known allergies, irritants

Patient AssessmentPatient AssessmentGeneral Interview• Past Medical & Surgical History

All bodily systems: o CHD = severity of CAD, date of previous MI, types of bypasses, target

vessels, pain on exertion (i.e. angina or intermittent claudication? o Lung disease = asthma versus COPD, acute versus chronic

• Family History– relevant heritable disorders in first-degree family members (cancer,

diabetes, hypercholesterolemia, sudden death, premature CAD)• Social History:

– marital status, employment, transportation, housing, routine/leisure activities, assistance at home

– habits (smoking, drugs alcohol, diet etc.)– occupational, environmental & recreational exposures– social supports

Patient AssessmentPatient AssessmentGeneral Interview• Health Care Utilization

– Number of hospital admissions, average hospital LOS over the previous 12 months

– Number of visits to the ER– Number of visits to the GP or specialist

• Functional History– Stairs – Ambulation, assistive devices/gait aids– Activities that are particularly tiring or difficult to do?– Regular exercise: frequency, intensity, type, and duration?– Exercise capacity – What limits exercise?

• Client’s goals

Patient AssessmentPatient Assessment

Physical Examination• Observation

– General appearance, body build, posture, position, spinal deformities, shape of chest

– Facial expression, eye movements– Interaction with family or environment, level of alertness, anxiety,

stress or distress, cognitive function – Skin integrity, coloration i.e. cyanosis, bruising , surgical incisions,

vascular insufficiency, pressure sores, etc.– Finger clubbing, ankle edema, JVD– Respiratory rate, chest expansion– Amount & quality of active movement, movement patterns,

involuntary movements, i.e. tremors, willingness to move or guarding, ADLs, etc.

– Presence of lines, leads, devices, splints, bandages etc.

Patient AssessmentPatient AssessmentPhysical Examination• Pulmonary/cardiovascular

– Vital signs: BP, HR (pulses), RR, temp– Height, Weight, BMI– Breathing pattern, chest expansion, auscultation, percussion, diaphragm excursion– SaO2 rest and exercise

• MSK– ROM– Strength– Functional mobility: bed, transfers, ambulation, stairs– ADLs, IADL’s, transfers, ortho limitations (i.e chair to standing, floor to standing) – Gait– Balance– Exercise tolerance: 6MWT, SWT

• Neuro– Reflexes– Sensation– Muscle tone– Coordination

Patient AssessmentPatient Assessment

Previous tests• Blood work: ABGs, Complete blood count (CBC), clotting factors,

cholesterol, electrolytes, glucose, liver function tests, renal function tests• PFTs• X-ray, MRI, CT, PET, EEG, bone scans, etc.• ECG, Holter monitoring, coronary angiography, radio nucleotide or

echocardiography studies• Assessments of anxiety & depression• Nutritional assessments• Exercise tests

Exercise Testing- Purpose -

Exercise Testing- Purpose -

Used to assess a patient’s ability to tolerate increasing intensities of exercise. Diagnosis Disease severity/prognosis Effects of medical/surgical interventions Physical activity counseling & exercise prescription

Exercise Testing- Participant Instructions -

Exercise Testing- Participant Instructions -

• No food, alcohol, or caffeine or tobacco products within 3 h of testing• No significant exertion or exercise on day of assessment.• Clothing should permit freedom of movement + walking or running shoes. • For functional or exercise prescription purposes, patients should continue

their medication regimen on their usual schedule exercise responses consistent with responses expected during exercise training.

Exercise Testing- Contraindications -

Exercise Testing- Contraindications -

ABSOLUTE• Recent ischemia, MI within 2 d, or other acute cardiac event • Unstable angina • Uncontrolled cardiac dysrhythmias causing symptoms or hemodynamic

compromise • Symptomatic severe aortic stenosis • Uncontrolled symptomatic heart failure • Acute pulmonary embolus or pulmonary infarction • Acute myocarditis or pericarditis • Suspected or known dissecting aneurysm • Acute systemic infection, accompanied by fever, body aches, or swollen

lymph glands

Exercise Testing - Contraindications -

Exercise Testing - Contraindications -

RELATIVE• (L) main coronary artery stenosis • Moderate stenotic valvular heart disease • Electrolyte abnormalities (hypokalemia or hypomagnesemia)• Severe hypertension (resting SBP >200 mm Hg and/or DBP >110 mm Hg) • Tachydysrhythmia or bradydysrhythmia• Hypertrophic cardiomyopathy• Neuromotor, musculoskeletal, or rheumatoid disorders exacerbated by

exercise • High-degree atrioventricular block ( 2nd & 3rd degree)• Ventricular aneurysm • Uncontrolled metabolic disease (e.g., diabetes, thyrotoxicosis, or

myxedema) • Chronic infectious disease (e.g., HIV, mononucleosis, hepatitis) • Mental or physical impairment leading to inability to exercise adequately

Exercise Testing- Modes -

Exercise Testing- Modes -

Field tests : 6MWT, SWT

Graded exercise tests: cycle ergometer, treadmill tests

Functional tests: step, sit to stand, timed up and go

Exercise Testing- Cardiorespiratory Measures -

Exercise Testing- Cardiorespiratory Measures -

Hemodynamics:• HR, SBP/DBP responses.

ECG waveforms: • ST segment displacement and supraventricular/ventricular

dysrhythmias Subjective ratings

RPE (Borg 6-22 or 0-10; VAS) Limiting clinical signs or symptoms

Patient appearance, Pain: angina, legs etc

Gas exchange and ventilatory response ( e.g. VO2 max and VE) SpO2

NOTE: ST-segment changes that occur only during the post-exercise period currently recognized as an important diagnostic part of the test.

Heart Rate Response during ExerciseHeart Rate Response during Exercise

• Normal HR response:– Linear increase (10 ± 2 beats ∙ MET−1 ) with progressive exercise

(physically inactive individuals)– HRmax = 220-age– HR recovery:

• ≥12 beats /min at 1 min (walking in recovery)• ≥22 beats / min at 2 min (supine position in recovery)

Chronotropic incompetence :– Failure of HR to despite workload– Unable to reach ≥85% of the age-predicted HRmax (when not on any β-

blockers)– Slowed HR recovery associated with poor prognosis

Blood Pressure Response during ExerciseBlood Pressure Response during Exercise

• Normal BP response: – Progressive increase in SBP = 10 ± 2 mm Hg ∙ MET−1 ; a possible

plateau at peak exercise – no change or slight decrease in DBP

• Abnormal BP response:– Hypertensive response: SBP >250 mm Hg or DBP >115 mm Hg – SBP that fails to rise or falls [>10 mm Hg]) is abnormal response

may signify MI and/or LV dysfunction– A widening of the pulse pressure– SBP <140 mm Hg at max exercise suggests poor prognosis

• Normal VE response:– ventilatory demand ( VE )

• metabolic rate• PaCO2 • VD/VT

• VEmax/MVV ratio normally ≤0.80. • VEmax/MVV > 0.80 = possible pulmonary limitation to exercise

– ↓ventilatory capacity (↓ MVV)• in both obstructive and restrictive lung diseases

(MVV estimated from FEV1 x 40)

Combination of reduced MVV and increased VE

Ventilatory Response during ExerciseVentilatory Response during Exercise

Ventilatory Efficiency

– Normal VE/VCO2 slope value <30. – slope = strongly prognostic in

patients with heart failure and patients with pulmonary hypertension.

– Values of ≥ 45 = particularly poor prognosis in patients with heart failure.

– Elevated values clearly indicative of worsening ventilation perfusion abnormalities in heart failure and pulmonary hypertension accurate depiction of disease severity

Indications for Terminating GXTIndications for Terminating GXT ↓ SBP >10 mm Hg from baselines despite ↑ work rate or if SBP decreases

below value obtained in same position prior to testing Hypertensive response: SBP > 250mm Hg and/or DBP > 115 mmHg

Onset of angina or angina like symptoms Failure of HR to despite workload Signs of hypoperfusion:

light-headedness, confusion, ataxia, dizziness, pallor, cyanosis, nausea, or cold and clammy skin.

ST elevation (+1.0 mm); ST depression > 2mm horizontal Multifocal PVCs, PVC triplets, SVT, heart block or bradyarrythmias or A-fib

with uncontrolled ventricular rate (>120bpm) Heart block ( 2nd Type II or 3rd degree), Vtach, Vfib Fatigue, SOB, wheezing, leg cramps, or claudication Technical difficulties monitoring the ECG or SBP Subject requests to stop

GXT InterpretationGXT InterpretationPredicted Maximum Exercise ValuesHRmax

• HRmax = 220-age

VO2max• Males: VO2max (L/min) = [3.45* ht (m)] – [0.028 * age (yrs)] + [0.022 * wt (kg)] - 3.76• Females: VO2max (L/min) = [2.49* ht (m)] – [0.018 * age (yrs)] + [0.010 * wt (kg)] – 2.26

Workload• Males: ([2169 * ht (m)] – [9.63 * age (yrs)] + [4.00 * wt (kg)] – 2413) ÷ 6.12 • Females: ([950*ht (m)] – [9.21* age (yrs)] + [6.1* wt (kg)] – 765) ÷ 6.12

Oxygen Pulse• O2 pulse = VO2max predicted/HR predicted

CPET Interpretation: Normal reference values CPET Interpretation: Normal reference values

Variables Criteria of Normality

Maximum or Peak VO2 & Cycle Work Rate >85% predicted

Anaerobic (AT) or Ventilatory (Tvent) Threshold >40% predicted VO2max

Respiratory exchange ration (RER) > 1.10

Maximum or Peak Heart Rate >85% age predicted

Maximum or Peak Heart Rate Reserve <20 beats/min

Maximum or Peak Blood Pressure <220/90

Maximum or Peak O2 pulse (VO2 ÷ HR) >80% predicted

Maximum or Peak Ventilatory Reserve >11 L/min or <80%MVV

Maximum or Peak Breathing Frequency <60 breaths/min

Maximum or Peak Tidal Volume <80% IC or <70% of VC

VE/VCO2 ratio at AT or Tvent and at Maximum or Peak <32-34 and <36-40

VE/VCO2 slope <30

Maximum or Peak VD/VT <0.28 for age < 40 yrs; <0.30 for age > 40 yrs

Maximum or Peak SaO2 (arterial blood O2 saturation) Change in SaO2 of <5% from baseline

Maximum or Peak Dyspnea & Leg Discomfort ratings 5-8 at a peak VO2 or WR >85% predicted

Modified from Dennis Jensen EDKP 485: Exercise Pathophysiology course notes 2012

Case studyCase study

• 50 year old male long time smoker, referred for exertional dyspnea. ‐ ‐• Symptomatic after walking one block. • Height 168 cm; weight 66 kg; BMI 23.4

Table 1. Demographic information and resting PFT data Measurement Predicted Measured % PredVC, L 4.06 4.10 101IC, L 2.71 3.30 122TLC, L 5.92 7.07 119FEV1, L 3.22 2.57 80FVC, L 4.08 4.08 100FEV1/FVC (%) 79 63 80MVV, L/min 141 91 65DLCO (mL/mmHg/min) 25.4 14.7 58%

Case studyCase study• GXT on cycle ergometer: 3 min

resting breathing, 3 minutes without added load and WR then increased by 15 watts per min to tolerance.

• Patient stopped exercise because of SOB (Dyspnea 7 Borg, leg fatigue 7 Borg)

• No chest pain, occasional multifocal PVCs during exercise and recovery.

Selected cardiopulmonary exercise test data

Measurement Predicted Measured % PredPeak WR (watts) 166 113 68Peak VO2 (L/min) 2.09 1.39 67Peak HR (beats/min) 170 126 74Peak O2 pulse (mL /beat) 12.2 11.0 90Peak VE (L/min) MVV = 91 89 98Exercise breathing reserve (L/min) >15 2VE/VCO2 ratio at AT 27.2 53.3 195SaO2 (%) [Rest , Peak Exercise ] ‐ 93, 88 -

Time (min)

Work Rate (Watts)

BP (mmHg)

HR (beats/min)

Fb(bpm)

VE(L/min)

VO2 (L/min)

VCO2 (L/min)

O2 pulse (mL/beat)

RER PETCO2 (mmHg)

VE/VCO2 (%)

0 (Rest) 120/80 77 18 17.8 0.33 0.27 4.3 0.82 22 606 0 140/90 88 22 31.9 0.67 0.57 7.6 0.85 23 537 15 88 22 33.2 0.67 0.60 7.6 0.90 24 528 30 140/90 91 25 40.9 0.69 0.68 7.6 0.99 22 579 45 93 25 44.9 0.86 0.80 9.2 0.93 24 53

10 60 150/92 105 28 55.3 0.99 1.01 9.4 1.02 24 5211 75 111 31 66.8 1.12 1.21 10.1 1.08 24 5312 90 160/100 117 37 75.2 1.22 1.35 10.4 1.11 24 5313 105 124 41 87.9 1.34 1.54 10.8 1.15 24 55

13.5 (Peak) 113 160/100 126 41 89.3 1.39 1.60 11.0 1.15 23 54

Exercise PrescriptionExercise PrescriptionFITT-VP principle

Frequency (how often)

Intensity (how hard)

Time (duration or how long)

Type (mode or what kind)

Total Volume (amount)

Progression (advancement)

Exercise prescription- Heart Rate Reserve Method (Karvonen) -

Exercise prescription- Heart Rate Reserve Method (Karvonen) -

Predicted HRmax = 220-age

Direct method of HR max determination from GXT is preferred method for persons with:• low fitness levels• cardiovascular and/or pulmonary disease• taking medications (e.g. Beta-blockers) that affect the HR response to

exercise.

Aerobic Exercise Prescription - Heart Rate Reserve Method (Karvonen) -

Aerobic Exercise Prescription - Heart Rate Reserve Method (Karvonen) -

• Heart rate reserve (HRR) = HRmax – HRrest– HRrest = 60 bpm ; HRmax = 180 bpm– HRR = 180 - 60 = 120 bpm

• Target HR (THR) = [HRR × % intensity desired] + HRrest • Desired exercise intensity range: 50-60% HRR• 50% HRR = (120x0.50) = 60 bpm• 60% HRR= (120x0.60) = 72 bpm

• THR range (THRR)– Lower THR = 60+60 + 120 bpm– Upper THR = 72+70=132 bpm– THRR = 120-132 bpm

Aerobic Exercise Prescription - VO2 Reserve Method -

Aerobic Exercise Prescription - VO2 Reserve Method -

• VO2reserve (VO2R) = VO2max-VO2rest– VO2 max = 30 ml/kg/min– VO2rest = 3.5 ml/kg/min– VO2R = 30-3.5=26.5 ml/kg/min

• Target VO2 = (VO2R x %intensity)+VO2rest• Desired exercise intensity range: 50-60%• 50% VO2R: = (26.5*0.5) = 13.3 ml/kg/min

• 60% VO2R = (26.5*0.6) = 15.9 ml/kg/min

• Target VO2R range – Lower target range = 13.3+3.5 = 16.8 ml/kg/min– Upper target range = 15.9+3.5 = 19.4 ml/kg/min– Target VO2 range = 16.8-19.4 ml/kg/min

Aerobic Exercise PrescriptionMET calculation

Aerobic Exercise PrescriptionMET calculation

• Target VO2 range = 16.8-19.4 ml/kg/min• 1 MET = 3.5 ml/kg/min

• Lower MET target= 16.8/3.5 = 4.8 METS• Upper MET target= 19.4/3.5=5.5 METS

• Identify physical activities requiring EE within from the table the Target range