Functional Exercise Capacity: Field Walking Tests

1. Six-Minute Walk Test (6MWT)

Overview

Indications

Contraindications

• Unstable angina or myocardial infarction within the previous 30 days
• Syncope
• Acute respiratory failure
• Any noncardiopulmonary condition that may be impaired or exacerbated by exercise (e.g., acute musculoskeletal injury, severe peripheral arterial disease)
• Symptomatic severe aortic stenosis
• Acute pulmonary embolus or pulmonary infarction

• Resting heart rate greater than 120 bpm
• Systolic blood pressure greater than 180 mmHg
• Diastolic blood pressure greater than 100 mmHg
• High-degree atrioventricular block
• Hypertrophic cardiomyopathy
• Left main coronary stenosis or its equivalent
• Significant pulmonary hypertension

Precautions

• Continuous SpO2 monitoring is recommended because end-test SpO2 does not always capture the nadir desaturation during walking
• Oxygen must not be titrated during the walk; it should be delivered at the prescribed or protocol-defined rate throughout
• The patient should not carry or push their own oxygen source
• The patient should be at rest for at least 10 minutes before the test begins
• Baseline blood pressure, heart rate, oxygen saturation, and dyspnea (Borg scale) must be documented before starting
• Standardized verbal encouragement phrases must be used exclusively at one-minute intervals; over-encouragement artificially inflates walk distance
• Assistive devices (walkers, canes) may be used but must be noted and kept consistent across repeat tests
• A modest training/learning effect occurs; when two tests are performed within one week, the second typically yields a greater distance - for this reason, two tests may be performed on the same day or within a week when establishing a baseline, with the best result recorded

• Chest pain
• Severe dyspnea
• Leg cramps or staggering
• Diaphoresis
• Pallor or cyanosis
• Profound oxyhemoglobin desaturation (typically SpO2 below 80-85%)
• Patient request to stop

Procedure

1. The test is conducted indoors on a flat, hard surface with a 30-metre corridor (cones mark turnaround points). The walking course is marked every 3 metres.
2. The patient rests in a chair for at least 10 minutes before the test. Baseline vital signs (BP, HR, SpO2), dyspnea, and fatigue (Borg scale 0-10) are recorded.
3. The patient stands and receives scripted instructions: walk as far as possible in six minutes, back and forth along the 30-metre course; they may slow down or rest but should resume walking as soon as able; the timer does not stop if they rest.
4. Standardized encouragement is given at each one-minute mark using scripted phrases only (e.g., "You are doing well, keep it up").
5. The number of laps, any rest stops taken, and the total distance walked (6MWD) are recorded. Post-walk Borg dyspnea and fatigue scores are also recorded, along with HR and SpO2.
6. The patient rests for at least 10 minutes post-test. If a second test is needed, a minimum 30-minute recovery period is required.

Clinical Use

2. Two-Minute Walk Test (2MWT)

Overview

Indications

• Severely deconditioned patients or those in acute/subacute rehabilitation who cannot complete the 6MWT
• Frail elderly individuals, particularly those in long-term care
• Patients with severe COPD, advanced heart failure, or post-cardiac surgery where brief assessments are more feasible
• Obesity with limited mobility
• Musculoskeletal conditions limiting prolonged ambulation
• Neurological conditions including multiple sclerosis, Parkinson disease, stroke recovery, and traumatic brain injury (TBI)
• Spinal cord injury (validated with high test-retest reliability, ICC = 0.98)
• Amputees and those with limb loss or impairment
• Pediatric populations (normative data available for ages 5-85 from NIH Toolbox study, n = 4800)
• When the 6MWT is impractical due to space or time limitations
• Research settings requiring a brief, well-tolerated measure of walking endurance

Contraindications

Precautions

• Rest breaks are permitted during the test; the total distance including any rest periods is recorded
• Assistive devices are allowed but must be documented and kept consistent across tests
• In Parkinson disease, up to two practice sessions may be required before a stable result is obtained due to a significant learning effect (walking distance increases over the first three trials)
• The patient must be able to ambulate without physical assistance from the tester
• Baseline and post-test vital signs should be recorded
• SpO2 monitoring is recommended for patients with known respiratory disease

Procedure

1. A measured corridor or course (commonly 50 feet / ~15 metres, or up to 30 metres) is marked with cones at turnaround points.
2. The patient rests before the test (at least 5-10 minutes). Baseline HR, BP, and SpO2 are recorded.
3. Scripted instructions are provided: walk as far as possible in two minutes; they may slow down or rest; the assessor walks slightly behind to avoid pacing the patient.
4. At the two-minute mark, the assessor marks the patient's position and calculates total distance walked (in metres), rounded to the nearest metre.
5. Number and duration of rest periods are also recorded.
6. Post-test HR, SpO2, and Borg dyspnea score are documented.

Clinical Use

3. Twelve-Minute Walk Test (12MWT)

Overview

Indications

• Assessment of exercise capacity in COPD and chronic obstructive airways disease (the original clinical population)
• Evaluation of functional status in patients with chronic respiratory disease when a longer, more challenging test is appropriate and tolerated
• Monitoring response to pulmonary rehabilitation in patients with moderate disability
• Fitness assessment in healthy and near-healthy populations when testing maximal aerobic capacity (Cooper protocol variant)
• Community-dwelling older adults with good baseline mobility
• Research settings where historical comparisons with early COPD literature are needed

Contraindications

Precautions

• Because the 12MWT is longer and traditionally more demanding, patients may push into a higher exercise intensity than during the 6MWT
• A rest before testing (10-15 minutes) and close monitoring of HR, SpO2, and symptoms throughout are important
• Standardized encouragement should be given at regular intervals
• Patients must be informed they may slow down or rest if needed (clinical variant), but the test remains time-limited
• A significant learning/pacing effect is expected, particularly in patients unfamiliar with paced walking tests

Procedure

1. A flat, measured corridor of at least 30 metres is prepared with turnaround cones.
2. The patient rests for 10-15 minutes. Baseline HR, BP, SpO2, and Borg scores are obtained.
3. Instructions are given: walk as far as possible in 12 minutes; the patient may slow or rest but should resume walking; the examiner walks behind and does not pace the patient.
4. Time checks at 3, 6, 9, and 12 minutes are given with scripted encouragement.
5. At 12 minutes, the examiner marks the patient's position and records total distance walked in metres.
6. Post-test HR, SpO2, Borg dyspnea, and fatigue scores are recorded. The patient rests until vital signs return to baseline.

Clinical Use

4. Incremental Shuttle Walk Test (ISWT)

Overview

Indications

• Assessment of maximal or near-maximal functional exercise capacity in patients with chronic respiratory disease (COPD, IPF, bronchiectasis, pulmonary hypertension)
• Pre- and post-pulmonary rehabilitation assessment - the ISWT is sensitive to rehabilitation-induced improvements and is widely used as an outcome measure in pulmonary rehabilitation programs
• Prescription of exercise training intensity: because the ISWT reaches near-maximal VO2, heart rate and speed attained at the end of the ISWT can be used to set target intensities for training (e.g., endurance training at 85% of peak ISWT speed for the ESWT)
• Evaluation of treatment response to bronchodilators, surgical interventions, and pharmacological therapies
• Combined use with the ESWT on the same 10-metre course to provide a comprehensive picture of both maximal and endurance exercise capacity
• Preoperative functional assessment in patients being evaluated for lung resection or transplantation
• Cardiac rehabilitation and heart failure management
• Research settings requiring a standardized, reproducible, externally-controlled maximal exercise test

Contraindications

• Myocardial infarction within the previous month (or within the last 10 days for cardiac rehabilitation patients)
• Uncontrolled arrhythmias or syncope
• Severe aortic stenosis
• SpO2 at or below 85% at rest

• Resting heart rate above 120 bpm
• Systolic BP at or above 180 mmHg
• Diastolic BP at or above 100 mmHg
• Stenotic coronary or valvular heart disease
• Significant pulmonary hypertension with syncope
• Symptomatic hypotension
• Unstable diabetes
• Unstable or acute heart failure

Precautions

• Because the ISWT elicits a peak VO2 similar to formal CPET, it carries the same risk level as maximal exercise testing - this must be factored into patient selection and monitoring
• The ISWT must be performed twice on separate occasions (at least one day apart, typically the same week) to account for a learning effect - the first test consistently underestimates capacity. The second test result is used as the true baseline. If both tests are within 10% of each other, no third test is needed
• The patient should not eat a heavy meal within two hours of the test and should limit caffeine
• Comfortable clothing and appropriate footwear are required
• Equipment required: two cones placed 9 metres apart (with 0.5-metre inset at each end to avoid abrupt turns) within a 10-metre course; validated Borg scale; audio recording with pre-recorded bleep signals; pulse oximeter; sphygmomanometer; access to emergency oxygen and a telephone
• Baseline HR, BP, and SpO2 should be measured and documented before the test
• The patient should remain in a clinical area for at least 15 minutes after an uncomplicated test

• The patient fails to reach the turnaround cone before the bleep on two consecutive shuttles
• The patient's SpO2 drops to a critically low level (typically below 80%)
• The patient requests to stop
• Clinical signs of distress: chest pain, severe dyspnea, leg cramps, pallor, diaphoresis, cyanosis

Procedure

1. A 10-metre course is set up with two cones placed 9 metres apart (0.5-metre inset from each end) to form each shuttle. The course is on a flat, quiet corridor or dedicated exercise testing area with comfortable ambient temperature.
2. Baseline measurements (HR, BP, SpO2, Borg dyspnea) are taken after the patient has rested.
3. The audio recording is started. Scripted instructions are read or played to the patient before the test begins.
4. The patient begins walking at level 1 (0.50 m/s), completing 10-metre shuttles back and forth, reaching the turnaround cone at each single bleep signal.
5. At the end of each minute, a triple bleep signals an increase in walking speed. The patient must correspondingly walk faster. Speed levels progress as follows: Level 1 = 1.80 km/h, Level 2 = 2.41 km/h, Level 3 = 3.03 km/h, increasing by approximately 0.61 km/h per level up to Level 12 = 7.31 km/h.
6. The examiner records the number of completed shuttles. The test ends when the patient can no longer maintain the required pace (fails to reach the cone before the bleep on two consecutive occasions) or when stopping criteria are met.
7. Total distance walked is calculated: number of completed shuttles x 10 metres, plus any partial shuttle.
8. Post-test HR, SpO2, and Borg scores are immediately recorded. The patient rests in a supervised clinical area for at least 15 minutes.

Clinical Use

5. Endurance Shuttle Walk Test (ESWT)

Overview

Indications

• Assessment of endurance exercise capacity in patients with chronic heart and lung disease (primarily COPD but also heart failure, IPF, and bronchiectasis)
• Evaluation of treatment response to pulmonary rehabilitation - the ESWT is particularly sensitive to detecting rehabilitation-induced changes in endurance capacity and is arguably more sensitive than the 6MWT or ISWT for this purpose
• Assessment of bronchodilator therapy effects - the ESWT has been validated as sensitive to improvements following bronchodilator use in COPD
• Paired use with the ISWT: performed on the same day or visit to comprehensively assess both maximal and endurance functional capacity using the same equipment and course
• Research settings requiring a sensitive, reproducible outcome measure of therapeutic interventions
• Monitoring disease progression in chronic respiratory disease over time

Contraindications

• Unstable angina
• Myocardial infarction within the previous month (or within 10 days for cardiac rehabilitation)
• Uncontrolled arrhythmias or syncope
• Severe aortic stenosis
• SpO2 at or below 85% at rest

• Resting heart rate above 120 bpm
• Systolic BP at or above 180 mmHg
• Diastolic BP at or above 100 mmHg
• Stenotic coronary or valvular heart disease
• Significant pulmonary hypertension with syncope
• Symptomatic hypotension
• Unstable diabetes
• Unstable or acute heart failure

Precautions

• The ESWT requires a prior ISWT result to determine the appropriate walking speed (set at 85% of peak ISWT speed). It cannot be administered without this reference value.
• If the ESWT is performed on the same day as the ISWT, the patient must rest for at least 30 minutes between tests, and HR and SpO2 must have returned to baseline before starting the ESWT.
• If the ESWT is performed without a same-day ISWT (i.e., as a standalone follow-up), only one ESWT is required.
• Medication type, dose, and time of last administration before the test should be documented, as bronchodilators significantly affect ESWT performance in COPD.
• Oxygen supplementation: if required, it must be delivered in the same way (same flow rate, same device) across all serial test sessions. If flow must be increased at subsequent visits due to disease progression, this should be noted on the worksheet for interpretation.
• The course, equipment, and verbal encouragement must be standardized identically across all repeat tests to ensure comparability.
• Only standardized scripted encouragement phrases are used during the test.
• The patient should rest for at least 15 minutes before the ESWT begins (or 30 minutes if performed after the ISWT on the same day).
• Baseline HR, BP, SpO2 are documented before starting.

Procedure

1. The same 10-metre course used for the ISWT is used (two cones 9 metres apart with 0.5-metre insets).
2. The ESWT level is calculated from the patient's prior ISWT result. Using the speed attained at the final completed ISWT level, 85% of that speed is calculated, and the corresponding ESWT level (1-16) is selected from the standardized table.
3. The audio CD or recording for the ESWT level is loaded. The patient is positioned at the start.
4. Scripted warm-up instructions are played: "The walking speed for the first 2 minutes is fairly slow, so don't go too fast." The test begins with a triple bleep after a 4-second countdown.
5. The patient walks at the warm-up speed for approximately 2 minutes. At the next triple bleep, the patient increases to the test speed (85% of peak ISWT speed), which is maintained for the remainder of the test.
6. The test is time-unlimited - the patient continues until they can no longer maintain the set speed (misses the turnaround cone twice consecutively) or a stopping criterion is met.
7. Time walked in seconds (the primary outcome) is recorded. The total distance can also be calculated.
8. Post-test HR, SpO2, and Borg dyspnea and fatigue scores are immediately documented. The patient rests in a supervised area until vitals return to baseline.

Clinical Use

Key Distinguishing Comparisons