Prescribing Exercise from Test Results

Our library documents the tests thoroughly — 6MWT, ISWT, ESWT, CPET, sit-to-stand, gait speed and cardiac stress testing. What none of them said, until this page, is what to do with the number. A test that does not change the prescription is a measurement, not an assessment.

The principle

Field and laboratory tests establish a ceiling. Training is prescribed as a defined proportion of that ceiling, monitored by symptom scales, and progressed on rules agreed in advance. The proportions below come from the trials that established pulmonary and cardiac rehabilitation; they are starting points to be adjusted against the patient in front of you, not formulas to be applied blind.^1,2

From the six-minute walk test

Convert distance to average speed, then train below it.

Note the 6 m rise per 30 m corridor length difference between test corridors: if the test corridor differs from the one used previously, the comparison is not clean.

From the incremental shuttle walk test

The ISWT is externally paced and maximal, which makes it a better basis for intensity than the 6MWT.

• Estimate peak oxygen uptake: VO₂peak (mL/kg/min) ≈ 4.19 + (0.025 × ISWD in metres).⁴
• Train at 85% of predicted VO₂peak, which is the intensity at which the ESWT is set and the level used in the pulmonary rehabilitation trials.⁵
• In practice the ESWT speed is the prescription: walk the patient at that speed and progress duration.

⚠ Do not apply the 6MWT percentages to an ISWT distance. The tests measure different things — one submaximal and self-paced, one maximal and externally paced — and the distances are not comparable.

From the endurance shuttle walk test

The ESWT is a constant-speed endurance test at 85% of ISWT-predicted peak. Its output is a time, which becomes the training target directly: prescribe walking at ESWT speed and progress toward, then beyond, the endurance time achieved. It is also the most responsive of the field tests to rehabilitation, with a minimal important difference of around 180 seconds or 65–85% change, so it is well suited to demonstrating benefit.⁶

From cardiopulmonary exercise testing

CPET gives the most precise prescription available because it identifies the actual physiological transition points rather than estimating them.

CPET also identifies why the patient stopped — ventilatory limitation, cardiac limitation, deconditioning, or a mismatch suggesting effort or anxiety — and that determines the shape of the programme as much as the intensity does.⁷

From sit-to-stand and gait speed

These do not yield an aerobic intensity, but they answer a prior question: is the limitation strength or endurance?

• 1-minute sit-to-stand — set training volume at 60–80% of the count achieved, in sets with rest, progressing repetitions before sets. The test is the exercise, which makes it ideal for home programmes.
• Five-repetition sit-to-stand >12 seconds, or gait speed <0.8 m/s — prioritise lower-limb strength, power and balance first. Adding aerobic volume to a patient who cannot rise from a chair addresses the wrong deficit.

Resistance training

Aerobic prescription is only half a programme. Peripheral muscle dysfunction is a major contributor to exercise limitation in chronic respiratory and cardiac disease and responds to resistance training independently of aerobic work.⁸

• Estimate a one-repetition maximum from a submaximal test, or work directly to a repetition-maximum target.
• Strength: 60–80% 1RM, 8–12 repetitions, 2–3 sets, 2–3 sessions weekly.
• Endurance/hypertrophy in the very deconditioned: 40–60% 1RM, 12–15 repetitions.
• ⚠ Avoid Valsalva; teach exhalation on effort. This is a hard rule in aortic aneurysm and in uncontrolled hypertension.

Symptom scales — the running check

Whatever the calculated intensity, the modified Borg scale governs the session. Target 3–4 out of 10 for breathlessness or leg fatigue during moderate training, and 4–6 for interval work periods. A patient consistently reporting 1–2 is under-dosed; one reporting 7 or more will not sustain the programme and is at risk of an adverse event.

When the numbers cannot be used

• Beta-blockade and chronotropic incompetence — heart-rate targets are invalid. Prescribe by Borg, by workload, or by walking speed. This applies to most cardiac rehabilitation patients.
• Atrial fibrillation — rate is variable and unreliable as a target; use Borg and workload. See atrial fibrillation.
• Pacemakers and ICDs — stay a clear margin, conventionally at least 20 bpm, below the programmed therapy zone. See pacemakers and ICDs.
• Exertional desaturation — if SpO₂ fell ≥4% or below 88% during the test, it will fall during training. Prescribe intervals, reduce intensity, or arrange ambulatory oxygen assessment; do not simply accept it.
• Ventricular arrhythmia during testing — see ventricular arrhythmias for the thresholds that stop a session.

Progression

Agree the rule before starting, so progression is not left to impression:

1. Duration first — extend to the target duration at the prescribed intensity.
2. Then intensity — increase speed or workload by roughly 5–10% once the target duration is achieved comfortably at Borg 3–4.
3. Then frequency, where adherence allows.
4. Re-test at 8–12 weeks and re-derive the prescription. A programme running on a three-month-old test result is under-dosing a patient who has improved.

A caution about precision

These equations produce numbers to two decimal places from tests with meaningful measurement error and a learning effect. Treat the output as a starting point with a sensible range, not a target to be defended. The patient's symptoms, their observed response over the first two or three sessions, and their ability to keep doing it are all better guides than the arithmetic.

References & evidence base

1. Spruit MA, Singh SJ, Garvey C, et al. An official American Thoracic Society/European Respiratory Society statement: key concepts and advances in pulmonary rehabilitation. Am J Respir Crit Care Med 2013;188(8):e13–e64.
2. Ambrosetti M, Abreu A, Corrà U, et al. Secondary prevention through comprehensive cardiovascular rehabilitation: 2020 update. Eur J Prev Cardiol 2021;28(5):460–495.
3. Zainuldin R, Mackey MG, Alison JA. Prescribing cycle exercise intensity from a six-minute walk test for people with COPD. BMC Pulm Med 2012;12:44.
4. Singh SJ, Morgan MD, Hardman AE, et al. Comparison of oxygen uptake during a conventional treadmill test and the shuttle walking test in chronic airflow limitation. Eur Respir J 1994;7(11):2016–2020.
5. Revill SM, Morgan MD, Singh SJ, et al. The endurance shuttle walk: a new field test for the assessment of endurance capacity in chronic obstructive pulmonary disease. Thorax 1999;54(3):213–222.
6. Pepin V, Laviolette L, Brouillard C, et al. Significance of changes in endurance shuttle walking performance. Thorax 2011;66(2):115–120.
7. American Thoracic Society/American College of Chest Physicians. ATS/ACCP statement on cardiopulmonary exercise testing. Am J Respir Crit Care Med 2003;167(2):211–277.
8. Maddocks M, Nolan CM, Man WD, et al. Neuromuscular electrical stimulation to improve exercise capacity in patients with severe COPD. Lancet Respir Med 2016;4(1):27–36.
9. Holland AE, Spruit MA, Troosters T, et al. An official ERS/ATS technical standard: field walking tests in chronic respiratory disease. Eur Respir J 2014;44(6):1428–1446.

References are numbered in citation order (Vancouver/BMJ style) and were current at the time of writing. Guidelines are living documents — verify against the latest version before clinical use.