Pulmonary Rehab: Exercise Testing & Prescription

Pulmonary Rehab: Exercise Testing & Prescription

Advanced · 12 chapters · 144 MCQs · 144 flashcards · Illustrated

Pulmonary Rehab: Exercise Testing & Prescription - complete clinical course for physiotherapy students and clinicians.

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What you'll learn

  1. Chapter 1: Respiratory Foundations: Anatomy, Ventilation and Gas Exchange Relevant to Exercise

    The respiratory system moves air between the atmosphere and the alveoli, where gas exchange occurs across a membrane of roughly 0.5 µm thickness.

  2. Chapter 2: Pathomechanics of Chronic Lung Disease: COPD, Interstitial Lung Disease, Bronchiectasis and Pulmonary Vascular Disease

  3. Chapter 3: Subjective Assessment in Pulmonary Rehabilitation: History, Symptom Burden and Functional Goals

    Subjective assessment is the foundation of pulmonary rehabilitation (PR). It establishes what the patient experiences, what limits them, and what they want to achieve.

  4. Chapter 4: Clinical Exercise Tests: Six-Minute Walk, Incremental and Endurance Testing, and Cardiopulmonary Exercise Testing

    Exercise capacity depends on a chain of systems: ventilation (chest wall, respiratory muscles, airways, alveoli), gas exchange across the alveolar-capillary membrane, cardiac output, peripheral oxygen extraction by skeletal muscle, and…

  5. Chapter 5: Imaging, Investigations and Red Flags: Interpreting Findings to Guide Safe Exercise Testing

    Exercise places demands on the entire oxygen cascade: ventilation, alveolar gas exchange, diffusion across the alveolar-capillary membrane, pulmonary and systemic circulation, and oxygen extraction by skeletal muscle.

  6. Chapter 6: Staged Management: Exercise Training Principles, Intensity Prescription and Breathing Strategies

  7. Chapter 7: Progressions and Criteria: Load Advancement, Monitoring Thresholds and Stop Rules

    Exercise capacity in chronic respiratory disease is set by the interaction of ventilatory, cardiovascular, and peripheral muscle systems.

  8. Chapter 8: Special Considerations: Oxygen Therapy, Comorbidities, Frailty, Exacerbations and Pulmonary Hypertension

  9. Chapter 9: Outcomes and Return Criteria: Measuring Change, Minimal Clinically Important Differences and Discharge Planning

    Outcomes in pulmonary rehabilitation (PR) reflect changes in a chain of linked systems: ventilatory mechanics, gas exchange, cardiovascular response, peripheral muscle function, and the psychological and behavioural factors that shape…

  10. Chapter 10: Clinical Pearls: Communication, Motivation, Self-Management and Common Pitfalls

    Exercise limitation in chronic obstructive pulmonary disease (COPD) and other chronic respiratory diseases is driven by more than lung mechanics.

  11. Chapter 11: Case-Based Reasoning: Integrated Clinical Scenarios from Assessment to Discharge

  12. Chapter 12: Summary, Key Takeaways and References

    Exercise limitation in chronic lung disease arises from interacting limitations in the ventilatory, cardiovascular, peripheral muscle, and neural systems.

Free chapter

Chapter 1: Respiratory Foundations: Anatomy, Ventilation and Gas Exchange Relevant to Exercise

Learning Outcomes

By the end of this chapter, you should be able to:

  • Describe the mechanical and neural determinants of ventilation at rest and during exercise.
  • Explain how ventilation-perfusion matching and diffusion govern arterial oxygenation.
  • Identify the principal mechanisms that limit exercise in chronic respiratory disease.
  • Select and interpret spirometry, gas exchange, and exercise tests used in pulmonary rehabilitation.
  • Apply screening criteria and a staged exercise prescription with defined dosage parameters.

Respiratory Anatomy and Mechanics

The respiratory system moves air between the atmosphere and the alveoli, where gas exchange occurs across a membrane of roughly 0.5 µm thickness. Its pump consists of the diaphragm (the primary inspiratory muscle, innervated by C3-C5 via the phrenic nerve), the external intercostals, and the accessory muscles of inspiration: scalenes, sternocleidomastoid, and serratus anterior. Expiration is largely passive at rest but becomes active during exercise, when the abdominal muscles and internal intercostals contribute.

Lung recoil and chest wall compliance determine the work of breathing. In emphysema, loss of elastic recoil increases static compliance and produces dynamic hyperinflation: expiratory flow limitation prevents complete exhalation, so end-expiratory lung volume (EELV) rises during exercise and shifts the tidal breath toward the flatter, less efficient part of the pressure-volume curve. The inspiratory muscles then operate at a mechanical disadvantage. In restrictive disease, reduced compliance raises the elastic work of breathing, while in neuromuscular disease the pump itself is weakened.

Ventilation and Gas Exchange at Rest and During Exercise

Minute ventilation (V̇E) equals tidal volume multiplied by respiratory rate. Dead space (V̇D/VT, normally 0.25-0.35 at rest) is wasted ventilation that does not participate in gas exchange. During incremental exercise, V̇E rises approximately linearly with carbon dioxide production (V̇CO2) until the ventilatory threshold, after which V̇E rises disproportionately.

Oxygen uptake (V̇O2) is delivered through the cardiovascular system, but the lungs must supply oxygen and remove carbon dioxide. Normal arterial values at rest are PaO2 80-100 mmHg and PaCO2 35-45 mmHg. Ventilation-perfusion (V̇/Q) mismatch, the most common cause of hypoxaemia in lung disease, reduces PaO2 by shunting or by dead-space ventilation. During exercise, the pulmonary capillary transit time shortens (from about 0.75 s to under 0.3 s in healthy individuals), so impaired diffusion or V̇/Q mismatch can cause exercise-induced desaturation even when resting saturation is acceptable.

Pathophysiology of Exercise Limitation in Chronic Lung Disease

Exercise intolerance in chronic obstructive pulmonary disease (COPD), interstitial lung disease, and related conditions arises from several interacting mechanisms:

  1. Ventilatory limitation: Expiratory flow limitation and dynamic hyperinflation reduce the ventilatory reserve. Breathing reserve (BR = [maximum voluntary ventilation − peak V̇E] / MVV × 100) falls below 15% in many patients, indicating that the ventilatory system is near its ceiling.
  2. Gas exchange abnormality: Exercise-induced hypoxaemia occurs from V̇/Q mismatch and diffusion limitation, particularly in emphysema and interstitial disease.
  3. Peripheral muscle dysfunction: Deconditioning, systemic inflammation, oxidative stress, and corticosteroid exposure reduce oxidative capacity and muscle mass, so the same absolute workload demands a higher proportion of maximal effort.
  4. Cardiovascular involvement: Pulmonary hypertension and right ventricular dysfunction may limit cardiac output, reducing oxygen delivery.
  5. Symptom-driven behaviour: Dyspnoea and anxiety drive avoidance, which further reduces conditioning and creates a self-perpetuating cycle.

Clinical Presentation

Patients typically report exertional dyspnoea, reduced walking distance, fatigue, and activity avoidance. Common observations include pursed-lip breathing, use of accessory muscles, forward-leaning posture, prolonged expiration, and reduced chest expansion. Clinicians should also record weight, nutritional status (BMI below 21 kg/m² in COPD is associated with poorer prognosis), and comorbidities such as ischaemic heart disease, diabetes, and anaemia, all of which influence exercise tolerance and risk.

Common observations in chronic lung disease include pursed-lip breathing, accessory muscle use, a forward-leaning posture and prolonged expiration.

Common observations in chronic lung disease include pursed-lip breathing, accessory muscle use, a forward-leaning posture and prolonged expiration.

Assessment: Lung Function and Gas Exchange

Spirometry (ATS/ERS standards) provides FEV1, FVC, and FEV1/FVC ratio. Airflow obstruction is confirmed by a post-bronchodilator FEV1/FVC below 0.70 or below the lower limit of normal. Severity is graded by FEV1 % predicted: GOLD 1 ≥80%, GOLD 2 50-79%, GOLD 3 30-49%, GOLD 4 <30%.

Lung volumes and diffusion: Body plethysmography measures total lung capacity and residual volume. Transfer factor for carbon monoxide (DLCO) below 60% predicted suggests significant diffusion impairment or vascular disease.

Respiratory muscle strength: Maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) are measured with a manometer. Values of MIP more negative than −60 cmH2O (women) and −80 cmH2O (men) are typically considered adequate; values below about 30% predicted indicate significant weakness.

Arterial blood gases: Resting PaO2 below 60 mmHg or PaCO2 above 50 mmHg indicates the need for oxygen assessment and specialist review.

Assessment: Exercise Capacity and Symptoms

Six-minute walk test (6MWT): Performed along a 30 m corridor following ATS guidelines, with SpO2, heart rate, and Borg dyspnoea ratings recorded before and after. Reference equations (Enright and Sherrill, 1998) estimate predicted distance from age, sex, height, and weight. A change of 30-50 m is generally regarded as clinically meaningful in COPD.

Incremental shuttle walk test (ISWT) and endurance shuttle walk test (ESWT): The ISWT uses an audio-paced protocol with increments each minute; the ESWT, performed at 85% of ISWT peak speed, measures endurance and is sensitive to change after rehabilitation.

Cardiopulmonary exercise testing (CPET): Provides peak V̇O2, anaerobic threshold, V̇E/V̇CO2 slope, breathing reserve, and exercise SpO2. Peak V̇O2 below 50% predicted indicates severe impairment. A V̇E/V̇CO2 slope above 35 suggests ventilatory inefficiency.

Symptom and quality-of-life measures: The Modified Medical Research Council (mMRC) dyspnoea scale (grade 0-4), the COPD Assessment Test (CAT; minimal important difference approximately 2 points), and the St George's Respiratory Questionnaire (SGRQ) are standard. Sit-to-stand tests (for example, the 1-minute sit-to-stand) provide a practical measure of lower-limb endurance in the clinic.

Physiotherapy Management: Pre-Training Screening and Safety

Before exercise, screen for contraindications and red flags:

  • Absolute contraindications: Unstable angina, uncontrolled arrhythmia, severe symptomatic aortic stenosis, resting SBP above 200 mmHg or DBP above 110 mmHg, acute systemic illness, untreated pneumothorax, and recent haemoptysis without medical review.
  • Red flags to stop exercise: SpO2 below 88% despite supplemental oxygen, new chest pain, presyncope or syncope, ST-segment depression of more than 1 mm, sustained heart rate above 85% of age-predicted maximum (220 − age), severe dyspnoea (Borg above 7-8 on the 0-10 scale), or new neurological signs.
  • Oxygen: Patients with exercise desaturation should train with titrated oxygen to maintain SpO2 at or above 90%, using a documented prescription.

Monitor SpO2 and heart rate continuously during initial sessions, and use the Borg CR-10 scale for dyspnoea and leg effort.

Physiotherapy Management: Staged Exercise Prescription

A graded programme should progress from low-intensity conditioning to high-intensity training over an initial period of 6-12 weeks, with a maintenance component thereafter.

Stage 1 (weeks 1–2): 2–3 supervised sessions a week of cycle ergometry or treadmill walking, 10–15 minutes at Borg dyspnoea 2–3.

Stage 1 (weeks 1–2): 2–3 supervised sessions a week of cycle ergometry or treadmill walking, 10–15 minutes at Borg dyspnoea 2–3.

Stage 1 (weeks 1-2): Familiarisation and tolerance

  • Frequency: 2-3 sessions per week, supervised.
  • Mode: Cycle ergometry or treadmill walking, with upper-limb and lower-limb circuits.
  • Intensity: Borg dyspnoea 2-3 (on a 0-10 scale), or 60% of the 6MWT peak heart rate response.
  • Duration: 10-15 minutes continuous, progressing in five-minute blocks.
  • Breathing: Pursed-lip breathing and controlled diaphragmatic breathing practised during activity.

Stage 2 (weeks 3-6): Endurance building

  • Frequency: 3 sessions per week.
  • Intensity: 60-70% of peak work rate (from incremental test) or 70-80% of peak heart rate, Borg 3-4.
  • Duration: 20-30 minutes continuous, or interval bouts (for example, 2 minutes at 80% followed by 1 minute at 40%).
  • Progression: Add 5-10 W on the cycle, or increase speed and gradient on the treadmill, when the patient completes the session without exceeding Borg 4 for the full duration.

Stage 3 (weeks 6-12): High-intensity and functional training

  • Intensity: Up to 80% of peak work rate, or Borg 4-6, with high-intensity interval training used cautiously in patients with stable cardiovascular status.
  • Duration: 30-45 minutes including warm-up and cool-down.
  • Include strength training: 2-3 sets of 8-12 repetitions at 60-80% of one-repetition maximum for quadriceps and upper limb, or using a 10-15 repetition maximum with Borg 5-6 (dyspnoea-limited loads are acceptable).
  • Include balance and functional tasks: sit-to-stand, stair climbing, and carrying tasks.

Maintenance (after week 12): At least 2 sessions per week for life, or a structured home programme with regular telephone or telehealth review, to preserve gains.

Reassess the 6MWT, ISWT or ESWT, and symptom measures at completion and at 6-12 months.

Evidence and Clinical Pearls

Pulmonary rehabilitation is one of the most robustly supported interventions in chronic respiratory disease. It reduces dyspnoea and fatigue, improves exercise capacity and health status, and reduces hospital readmission after exacerbation (Puhan et al., 2016). The ATS/ERS statement (Spruit et al., 2013) recommends a minimum of 6 weeks of supervised training, with endurance and strength components.

Clinical pearls:

  • Test before you prescribe. Use the 6MWT or ISWT to set training intensity; do not rely on predicted values alone.
  • Dyspnoea is not harm. Breathlessness at Borg 3-5 is expected during training; sustained chest pain, desaturation, or dizziness is not.
  • Assess muscle, not just lungs. Quadriceps weakness is often a stronger predictor of disability than FEV1.
  • Prevent the drop-off. Adherence falls after supervised completion; plan the maintenance phase from the first session.
  • Use the MCID. Interpret change scores against the minimal clinically important difference, not statistical significance alone.

Summary

Effective exercise prescription in pulmonary rehabilitation depends on understanding how the respiratory pump, gas exchange, and peripheral muscles interact to limit exercise. Assessment should combine spirometry, diffusion, respiratory muscle strength, and field or laboratory exercise tests with symptom measures. Screening must identify contraindications and red flags before training begins. A staged programme, progressing from familiarisation through endurance and strength training to maintenance, with intensity guided by Borg scores, heart rate, and oxygen saturation, provides a safe and evidence-based framework for the remainder of this course.

References

  1. Enright PL, Sherrill DL. (1998). Reference equations for the six-minute walk in healthy adults. American Journal of Respiratory and Critical Care Medicine, 158(5), 1384-1387.
  2. Holland AE, Spruit MA, Troosters T, et al. (2014). An official European Respiratory Society/American Thoracic Society technical standard: field walking tests in chronic respiratory disease. European Respiratory Journal, 44(6), 1428-1446.
  3. Miller MR, Hankinson J, Brusasco V, et al. (2005). Standardisation of spirometry. European Respiratory Journal, 26(2), 319-338.
  4. Puhan MA, Gimeno-Santos E, Cates CJ, Troosters T. (2016). Pulmonary rehabilitation following exacerbations of chronic obstructive pulmonary disease. Cochrane Database of Systematic Reviews, (12), CD005305.
  5. Spruit MA, Singh SJ, Garvey C, et al. (2013). An official American Thoracic Society/European Respiratory Society statement: key concepts and advances in pulmonary rehabilitation. American Journal of Respiratory and Critical Care Medicine, 188(8), e13-e64.
  6. Weisman IM, Zeballos RJ. (2003). ATS/ACCP statement on cardiopulmonary exercise testing. American Journal of Respiratory and Critical Care Medicine, 167(2), 211-277.
  7. Global Initiative for Chronic Obstructive Lung Disease (GOLD). (2024). Global Strategy for the Diagnosis, Management, and Prevention of COPD. Available at: goldcopd.org.

The other 11 chapters, all 144 MCQs and the flashcards are in the PhysioAI app.

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Practice questions

5 sample MCQs from this course. Tap a question to see the answer.

  1. A 71-year-old man with severe COPD (GOLD 3) reports breathlessness after walking 50 metres on the level. At rest he uses his neck and shoulder muscles to breathe, and his physiotherapist notes a prolonged expiratory phase.

    1. Which muscle is the principal muscle of inspiration during both quiet breathing and exercise?

    • A. Diaphragm
    • B. Rectus abdominis
    • C. Latissimus dorsi
    • D. Pectoralis minor
    Show answer

    Answer: A. The diaphragm is the primary inspiratory muscle, contracting to descend and increase thoracic volume during both quiet and exercise breathing. Accessory muscles such as the sternocleidomastoid and scalenes are recruited when demand rises or mechanics are impaired, as in COPD, but they are not the principal muscle.

  2. A 68-year-old man with COPD (GOLD stage 3) and a 50 pack-year smoking history attends his first rehabilitation assessment. He reports breathlessness when walking 100 metres on the flat and must stop to rest. He has no recent exacerbations and his referring physician wants a brief, standardised measure of breathlessness.

    2. Which validated instrument is most appropriate to quantify this patient's breathlessness-related functional limitation during the subjective assessment?

    • A. Modified Medical Research Council (mMRC) dyspnoea scale
    • B. Berg Balance Scale
    • C. Timed Up and Go test
    • D. Six-minute walk test distance
    Show answer

    Answer: A. The mMRC is a brief, validated, single-question grade of breathlessness-related activity limitation and is standard in the subjective history. The Berg, Timed Up and Go and six-minute walk test are objective or balance measures rather than subjective symptom instruments.

  3. A 71-year-old man with COPD (FEV1 42% predicted) is referred for a six-minute walk test before pulmonary rehabilitation. On his first attempt he walked 310 m, used no walking aid, and stopped twice to rest. He is planning a second test to establish a reliable baseline.

    3. Which standardised action should be taken before the second walk so that the two distances can be meaningfully compared?

    • A. Repeat the walk after a rest period, using identical standardised instructions and consistent encouragement.
    • B. Ask him to walk as fast as possible from the start to maximise the distance covered.
    • C. Provide continuous supplemental oxygen at 4 L/min throughout the walk regardless of saturation.
    • D. Shorten the course to 20 m to reduce fatigue and allow more repetitions.
    Show answer

    Answer: A. Six-minute walk tests are only comparable when the protocol is standardised, including scripted instructions, identical encouragement, and a consistent course. Repeat testing after adequate rest also helps reduce learning effects and establishes a reliable baseline. Changing the pace strategy, oxygen use, or course length would invalidate comparison with the first walk.

  4. A 68-year-old man with severe COPD (FEV1 35% predicted) is being screened before pulmonary rehabilitation. He reports breathlessness walking to his letterbox and has lost 6 kg over the past three months. Today he also mentions coughing up blood-streaked sputum for two weeks, and his chest X-ray shows a new 3 cm right upper lobe opacity.

    4. Which screening finding should prompt medical review before exercise testing proceeds?

    • A. Unexplained weight loss, haemoptysis, and a new lung opacity on chest X-ray
    • B. Stable baseline breathlessness rated on the mMRC scale
    • C. Mild ankle oedema that has been present for years and is stable
    • D. Resting SpO2 of 91% on room air at rest
    Show answer

    Answer: A. Haemoptysis with weight loss and a new lung opacity raises concern for malignancy or another serious pathology that must be excluded before exercise. Stable chronic symptoms and a resting SpO2 of 91% are expected in severe COPD and do not by themselves prevent testing.

  5. A 68-year-old man with moderate COPD (FEV1 42% predicted) is cycling during an outpatient session. Within 3 minutes of increasing the work rate he reports sudden dizziness and new pressure-like chest discomfort, and his SpO2 falls to 84% on the oximeter.

    5. Which finding requires immediate termination of the exercise session?

    • A. SpO2 below 85% with new dizziness and chest discomfort
    • B. Borg CR10 dyspnoea rating of 4 that settles within 1 minute of rest
    • C. Heart rate 15 beats/min above resting value during warm-up
    • D. Mild leg fatigue that resolves after a short pause
    Show answer

    Answer: A. Desaturation combined with new symptoms such as dizziness and chest discomfort meets stop criteria and requires immediate cessation with monitoring. Expected training responses such as a moderate dyspnoea rating or brief leg fatigue that resolves quickly do not warrant termination.

Flashcards

  • What is the approximate resting tidal volume in an adult, and how does it change during moderate-to-heavy exercise?

    Resting tidal volume is about 500 mL (roughly 6-8 mL/kg). During exercise, tidal volume rises mainly by deeper breaths, often reaching around 50-60% of vital capacity, while frequency increases as well.

  • What are the five grades of the modified Medical Research Council (mMRC) dyspnoea scale, and which grade is commonly used to flag clinically significant breathlessness?

    Grade 0 is breathlessness only with strenuous exercise, grade 1 is breathlessness when hurrying on level ground or walking up a slight hill, and grade 2 is walking slower than peers or stopping for breath on level ground. Grade 3 is stopping after about 100 m or a few minutes on level ground, and grade 4 is being too breathless to leave the house or while dressing. Grade 2 or higher is often used to indicate significant limitation.

  • How is the six-minute walk test (6MWT) performed, and what is the typical distance measured?

    The 6MWT is performed in a flat, straight corridor, usually 30 metres long, where the patient walks at their own pace for six minutes, with standardised encouragement at set intervals. The total distance walked is recorded, along with SpO2, heart rate, and Borg dyspnoea and fatigue ratings before and after. A change of about 30 metres is generally considered the minimal clinically important difference.

  • Which nerve innervates the diaphragm, and which accessory muscles are recruited when breathing becomes laboured?

    The diaphragm is innervated by the phrenic nerve, arising from cervical roots C3 to C5. When breathing becomes laboured, accessory inspiratory muscles are recruited, including the sternocleidomastoid, scalenes, pectoralis major, and trapezius, and during forced expiration the abdominal muscles are also activated.

  • What Borg CR10 breathlessness range is typically used as the training target in pulmonary rehabilitation?

    Most programmes aim for moderate breathlessness, roughly 3 to 4 on the Borg CR10 scale, during exercise training. This keeps the stimulus challenging but tolerable, so the patient can talk and sustain the session. Ratings persistently above this range suggest the load is too high.

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