As health science advances towards longevity, understanding the function of the heart and lungs is key to assessing physical fitness. The cardiopulmonary exercise test, or Cardiopulmonary Exercise Test (CPET), is one of the tools used to deeply analyze physical fitness by revealing information related to the cooperation of the heart, lungs, muscles, and oxygen utilization system. 

The cardiopulmonary exercise test, or CPET differs from health measurements using scales or smartwatches because it is a more comprehensive and accurate test. It helps identify causes of easy fatigue, plan physical rehabilitation, design personalized exercise programs, and plays an important role in preoperative risk assessment in some cases.  

Moreover, medical research confirms that data from CPET is linked to the risk of chronic diseases and long-term mortality rates. Therefore, it is considered one of the preventive medical approaches that enhance quality of life and increase the chances of healthy longevity. 

What is CPET? 
A fitness test that measures the function of the heart–lungs–muscles during actual exertion by running on a treadmill or a specially designed bicycle (Cycle Ergometer). During the test, equipment is installed to monitor body functions, including 

- Measurement of maximal oxygen consumption (VO₂ max), reflecting the body’s fitness and maximal capacity.
- Measurement of the Ventilatory (Anaerobic) Threshold, which determines training zones and assesses preoperative risk.
- Measurement of carbon dioxide output efficiency (CO₂) during exertion: VE/VCO₂ slope (ventilatory efficiency).
- Electrocardiogram (ECG) to test heart rhythm and function.
- Blood pressure measurement to observe changes during exertion.
- Pulmonary function and gas exchange measurement (Spirometry and Gas Analyzer). 

The results from the test can identify where the “bottleneck” in fitness lies, helping to answer whether the “fatigue” originates from the lungs, heart, gas exchange, or inappropriate training for the body. 

The importance of CPET in increasing longevity 
The CPET test is important for longevity and healthspan as it can determine “how fit you are” and helps doctors provide targeted health improvement recommendations. If you live a long and quality life, improving heart and lung fitness through proper exercise reduces the risk of chronic diseases such as heart disease, diabetes, and stroke. 

Why longevity enthusiasts should start with CPET 
Cardiorespiratory fitness (CRF) has been elevated to a “clinical vital sign” because it correlates with mortality risk and heart disease. Increasing fitness by just 1 MET reduces all-cause mortality risk by about 15% and heart disease by about 13%, according to research reports from the American Heart Association based on meta-analyses. Therefore, CPET makes your CRF numbers and “breathing signature” clear, allowing you to set goals based on real biology, not just pulse readings from wearable devices. 

Who should consider the CPET test 
1. Those who get tired easily or have chest tightness with no cause found in basic evaluations.
2. Runners, cyclists, and triathletes who want to set training zones based on real data.
3.Those who need preoperative risk assessment, especially for heart, lung, or surgeries requiring anesthesia, to see if the body can safely undergo surgery.
4.Those recovering from illness or long rest who want to plan rehabilitation with measurable results. 
What happens in the testing room? 
This test follows clear and systematic steps to ensure safety and accurate results. Generally, it includes preparation, testing, and evaluation as follows:  

1. Medical history and initial physical examination The doctor will ask about health history, underlying diseases, current medications, as well as symptoms like fatigue, chest pain, or dizziness. Blood pressure, pulse, weight, height, and a basic physical exam will be conducted.

2. Preparation before the test Patients should wear appropriate clothing and shoes for exercise, avoid heavy meals, caffeine, and intense exercise before the test, and may need to stop certain medications as advised by the doctor.

3. Attaching monitoring equipment  

- Attach ECG leads to monitor heart function.
- Attach blood pressure monitor.
Wear a mouthpiece or mask connected to a gas analyzer to assess breathing and oxygen–carbon dioxide exchange.
In some cases, oxygen saturation may be measured using a fingertip pulse oximeter.

4. Exercise testing on a treadmill or cycle ergometer Starting with light exercise and gradually increasing intensity (according to a set protocol), heart, lung, blood pressure, and patient symptoms are closely monitored during the test.

5. Test termination The test ends when the patient reaches maximal tolerated fatigue or when the doctor decides to stop, such as in cases of chest pain, difficulty breathing, dizziness, or abnormal ECG. After stopping exercise, a cool down period follows to monitor heart and lung recovery.

6. Result analysis  The collected data are evaluated together, including maximal oxygen consumption (VO₂ max), blood pressure and pulse during exertion, respiratory system function, and gas exchange. Doctors use these results to diagnose causes of symptoms, plan treatment, or assess preoperative risk. 

From data to a personalized long-term health care plan 
After the CPET at Phyathai 2 Hospital, you will receive a report containing important information that helps you better understand your health status, including 

VO₂ peak / VO₂ max, an indicator of oxygen utilization capacity, reflecting heart and lung health.
Ventilatory Threshold (VT), the metabolic shift point, helping you determine the most appropriate training zones.
VE/VCO₂ Slope: the relationship between ventilation and carbon dioxide production, allowing doctors to accurately assess respiratory function. 

Confidence and safety during the CPET test 
You may worry that “the cardiopulmonary exercise test (CPET) requires intense exertion; is it safe?” The answer is Yes, it is safe because the test is closely monitored at every step as follows: 

Under the supervision of doctors and respiratory therapists who are specially trained to ensure the test is conducted correctly and safely.
Continuous monitoring of vital signs including ECG, blood pressure, and breathing, allowing the medical team to observe real-time changes in the body.
Immediate test termination if abnormalities occur If the patient experiences symptoms such as chest pain, difficulty breathing, dizziness, or sudden weakness, the medical team will stop the test immediately and provide prompt care and assistance. 

At Phyathai 2 Hospital, you can easily start caring for your lung health 
Phyathai 2 Hospital offers cardiopulmonary exercise testing (Cardiopulmonary Exercise Testing: CPET), a comprehensive physical fitness assessment method that collects important physiological data on the function of the heart, lungs, muscles, and oxygen utilization of the body. 

The results are analyzed by a specialized medical team to assist in planning health care or exercise programs tailored to each individual, helping patients better understand their physical condition. 

Good health starts with understanding your body. Phyathai 2 Hospital is ready to support your continuous health care through CPET, a medical tool that provides in-depth information leading to health care plans aligned with your needs. 

Consult the medical team to assess suitability and schedule a CPET at the Respiratory and Allergy Immunology Center, Phyathai 2 Hospital to transform laboratory insights into a health care approach that best fits you.