Cardiopulmonary exercise testing (CPET) is an exercise test for diagnostic and prognostic assessment by assessing submaximal and peak exercise responses involving the pulmonary, cardiovascular, hematopoietic, neuropsychological, and skeletal musculature  CPET aims to Assess motor performance functional capacity and impairment by assessing undiagnosed exercise intolerance and exercise-related symptoms. The patient is exercising on a treadmill or bicycle ergometer for a duration and level of exercise (walking and jogging). this Exercise testing can be used in patients undergoing lung and heart surgery to manage COPD unexplained dyspnea heart and respiratory disease, and as a training tool for athletes. During CPET, different patients have different exercise protocols and exercise levels to follow.
Cardiopulmonary exercise testing (CPET) is the study of the cardiovascular and ventilatory system’s response to known exercise stress. This is because gas exchange in the airways is a consequence of cardiac output and pulmonary blood flow, as well as peripheral O2 extraction associated with ventilation. Thus, a heart with circulation combines the gas exchange (O2 and CO2) of muscular respiration with that of the lungs. Pulmonary gas exchange describes the adequacy of O2 cardiovascular delivery at a known exercise effort. 
CPET is primarily concerned with the analysis of respiratory gases, incl.
- Respiratory oxygen uptake (Vo2),
- Carbon dioxide production (Vco2),
- Ventilatory measures during symptom-limited exercise testing.
- Diagnosis and prognostic assessment of cardiovascular and pulmonary diseases.
- Assess disease severity and functional impact.
- Assess suitability of treatment (ie, surgical transplant with supplemental oxygen therapy)
- EVALUATION OF THE EFFECTS OF THERAPY INTERVENTIONS
- The Outcome variable for clinical trials
- Measurable goals to improve fitness
- Measuring Exercise Rehabilitation Training Intensity
- Develop knowledge and understanding of disease.
Cardiopulmonary exercise testing (CPET) can be assessed by laboratory methods
- Bicycle ergometer
Common measurements like
- Blood pressure
- Heart rate
- ECG changes
- Subjective ratings
- Signs and symptoms
- Ventilation Exhaled Gas Analysis Response
- Arterial blood gas analysis
Several clinical measures are used in CPET, depending on the type of exercise and the diagnosis
Different patients use many different CPET protocols
Common protocols are
- The Bruce treadmill test is one of the most commonly used tests in CPET
- Bruce or Ellestad are better for screening younger and/or physically active individuals (greater progressive workload)
- Naughton or Balke-Ware are better for the elderly or those who are out of shape and those with chronic medical conditions. (smaller incremental effort)
- Evaluation of Exercise Intolerance
- Unexplained Dyspnea
- Evaluation of patients with cardiovascular disease 
- Evaluation of patients with respiratory disease 216
- Chronic Obstructive Pulmonary Disease (COPD)
- Interstitial Lung Disease (ILD)
- Chronic Pulmonary Vascular Disease (PVD)
- Cystic Fibrosis
- Exercise-Induced bronchospasm (EIB)
- Preoperative Evaluation
- Preoperative evaluation for lung cancer resection
- Lung Volume Reduction Surgery (LVRS)
- Evaluation for lung or heart-lung transplant
- Preoperative Evaluation for Other Surgery
- Pulmonary Rehabilitation Exercise Prescription 
- Evaluation of Impairment/Disability
Absolute relative Acute myocardial infarction (3-5 days) Left main coronary artery stenosis or similar Unstable angina Moderate stenotic valvular heart disease Uncontrolled arrhythmia causing severe symptoms Untreated arterial hypertension Convalescent blood flow Kinetic compromise (> 200 mmHg systolic blood pressure > 120 mm Hg diastolic) syncope tachyarrhythmia or bradycardia active endocarditis high degree atrioventricular block acute myocarditis or pericarditis hypertrophic cardiomyopathy symptomatic severe aortic stenosis significant pulmonary hypertension uncontrolled advanced or complicated heart failure Pregnancy Acute pulmonary embolism or pulmonary infarction Electrolyte abnormalities Thrombosis of lower extremities Orthopedic injury affecting athletic performance Suspected dissection Aneurysm Uncontrolled asthma Pulmonary edema Decreased room air saturation at rest 85%[null *]Respiratory system Failure Acute noncardiopulmonary disease that may affect performance or be exacerbated by exercise (ie, infectious renal failure thyrotoxicosis) Mental disturbance leading to inability to cooperate
ATS/ACCP Statement on Cardiopulmonary Exercise Testing
ACSM’s Guidelines for Exercise Testing and Prescribing
- American Thoracic Society; American College of Chest Physicians. ATS/ACCP Statement on cardiopulmonary exercise testing. Am J Respir Crit Care Med. 2003 Jan 15;167(2):211-77. doi: 10.1164/rccm.167.2.211. Erratum in: Am J Respir Crit Care Med. 2003 May 15;1451-2. PMID: 12524257.
- Karlman Wasserman. Principles of Exercise Testing and Interpretation Including Pathophysiology and Clinical Application. 5th edition. Wolters Kluwer Bussiness. 2012
- Cardiopulmonary Exercise testing CPET. Natural Medicine & Detox. Available from: https://youtu.be/UBupw-HNXI4