CPET – Cardiopulmonary Exercise Test

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The Role of CPET in Disability Evaluation for Fatiguing Conditions

Do you feel like your quality of life has been declining due to unexplained fatigue? Is fatigue impairing your ability to function normally or work? If so, you’re not alone. 

Fatigue is a common symptom in many illnesses. Understanding the cause can rule out various conditions and point to treatment options. Fatigue can be a more profound and persistent state of physical and mental exhaustion that goes beyond normal tiredness. This type of fatigue often is accompanied by other symptoms and not relieved by rest.

Workwell Foundation specializes in fatiguing conditions linked to cellular energy production problems. Such conditions include but are not limited to, myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), long COVID, fibromyalgia, Lyme disease, mitochondrial disorders, heart failure, chronic obstructive pulmonary disease (COPD), diabetes, and others.

Diagnosing and treating the underlying cause of fatigue is often challenging for healthcare providers. That’s where the utility of CPET is relevant. Workwell uses this cutting-edge diagnostic tool to identify the root cause of fatigue. 

What is CPET?

Cardiopulmonary exercise testing (CPET) is the most accurate non-invasive tool for assessing maximal aerobic capacity and determining submaximal sustained exercise performance. 

Let’s break this down into simpler terms. Our protocol consists of two CPETs separated by 24 hours. The purpose of the first CPET is to establish a baseline while applying a physical stressor (i.e., exercise). This will likely cause a flare of symptoms related to post-exertional malaise, i.e., worsening symptoms after physical activity (also referred to as post-exertional symptom exacerbation or PESE). The second CPET evaluates a person’s ability to function on consecutive days and often captures a decline in function associated with PEM/PESE.   

At the start of each test, we instruct patients to pedal on a stationary bicycle at a comfortable speed while workload gradually increases over time.  Within 8-12 minutes (sometimes less) maximal effort is achieved and the test is stopped. During the test, we sample each breath to quantify oxygen consumption, carbon dioxide production, and pulmonary ventilation.  These data reflect peak aerobic capacity and the point at which a person achieves their ventilatory/anaerobic threshold (V/AT).  Peak aerobic capacity is the maximal amount of oxygen the body can consume during intense exercise, whereas the V/AT is the point at which the body begins to shift from aerobic to anaerobic metabolism. When this occurs, lactic acid builds up faster than the body can remove it, and the activity cannot be sustained.

After testing, we compare the first and second CPET to evaluate a person’s ability to function on consecutive days.  A drop in performance on the second day can indicate problems with aerobic (oxidative) energy production. We also monitor heart rate, blood pressure, and oxygen saturation level using a 12-lead electrocardiogram (ECG), blood pressure cuff, and pulse oximeter. Patients track their recovery for a week after the test and record symptoms.

How can CPET help with diagnosis and disability?

CPET provides valuable information to identify the origins of aerobic impairment and can document PEM/PESE. Data collected during the test can pinpoint metabolic, cardiac, and pulmonary deficits associated with complex fatiguing illnesses. The test also provides an objective measure of a person’s functional capacity. 

We provide a comprehensive report with an interpretation of the CPET data. The report draws on decades of experience and expertise that combines exercise physiology with the legal aspects of disability evaluation. Patients can use this report when applying for disability or to develop a pacing/energy conservation program to improve quality of life. 

To learn more about how to prepare for CPET, please see our FAQ

CPET at Workwell Foundation

Workwell Foundation was the first group to research and publish a 2-day CPET procedure in people with ME/CFS.

We have expertise dealing with complex fatiguing conditions such as ME/CFS, long COVID, fibromyalgia, Lyme disease, and others.. We have been publishing in peer-reviewed scientific journals on this topic for over two decades.

Click here to read more about CPET or to download the information packet. It includes paperwork that must be filled out and returned prior to scheduling. Once the paperwork has been reviewed, a member of the Workwell staff will reach out to assist with scheduling. Contact us for more information: (661) 466-2545