Chronic illness can be invisible, cause aerobic impairment

Dr. Todd Davenport’s empathetic understanding of chronic illness is profound and gratifying.

“The hard thing about all of this is that this is all invisible,” he explained. “So you wouldn’t know that somebody has a migraine unless you knew what you were looking for. And that kind of chronic level of headache that people walk around with in between migraines can impair function.”

Davenport is a doctor of physical therapy and professor at University of the Pacific (UOP). With numerous other credentials, Davenport knows of what he speaks.

In addition to migraines, Davenport said many other chronic conditions impair function. “Fatigue is invisible, and chronic pain, not just headache, but chronic widespread body pain is invisible. People don’t understand the concept of pacing [themselves] if they’ve never had to do it. That’s really hard. That’s hard to convey. It puts people in very difficult spaces.”

When asked what the primary distinctions are between ME/CFS (Chronic Fatigue Syndrome) and what an average individual may describe as day to day “fatigue,” Davenport explained, “It’s almost a disservice to put them on the same level. There’s a big difference between garden-variety tired, being stressed out, maybe not sleeping well at night, and the fatigue we call CFS or ME/CFS.”

Post exertional malaise (PEM) is one of the case definition criteria for ME/CFS.  Another definition criteria call it Post-exertional neuroimmune exhaustion (PENE).  The fatigue ME/CFS patients experience “is not really fatigue, it is fatigue plus, it is fatigue times infinity,” Davenport emphasized. 

PEM includes myriad unusual symptoms and there are three different types of PEM (immediate, short term, and long term). Davenport explained that symptoms include “brain fog (where people have limited or impaired short-term memory or maybe just don’t feel they can focus their attention well); widespread body pains, headaches, feelings of weakness, numbness and tingling; also dizziness with positional changes like just standing up from a seated position; heart palpitations.” 

Symptoms of PEM for ME/CFS patients can be triggered from taking a shower or unloading the dishwasher. It’s not only physical exertion that triggers PEM, but “mental exertion and emotional exertion can be triggering for people with ME/CFS,” he said.    

Davenport, who has been involved with the Workwell Foundation for the past dozen years, shared what physical therapy and treatments are and are not recommended for those in this situation.

“What we are aware of, through the exercise physiology data in this population, is people with ME/CFS have an altered metabolism. I mean an impaired ability to use oxygen in order to do prolonged work. So, we say the aerobic system is impaired.”

In summary, if a person’s aerobic system is impaired, there is a certain threshold that when reached or exceeded, is going to trigger symptoms.

Davenport likens it to having an electric car. “You have the gas side and you have the electric side; the gas side can be used to charge the electric side if the electric side wears down. If you didn’t have the gas side and only had the electric side, once the electric side runs out, you’re stuck at the side of the road. That’s what happens in ME/CFS.” 

“So as a result, you plan your trips differently, you plan how long you’re out, you plan how fast you can go, you plan how far you can go – literally – to recharge your batteries,” explained Davenport. 

Pacing is incredibly crucial when managing chronic fatigue.   

When it comes to physical therapy, Davenport said it can be tempting for industry professionals to “see tired and think exercise,” but that is assuming the patient has a normal-functioning metabolism.

Davenport explained that “instead of getting people in shape, we are trying to be respectful of the energy system problem, and try to use the energy system that works.”

Circling back to the electric car analogy, Davenport said, “We are not going to tax the battery so much that we rely on the gas that we don’t have.” 

What is the first step with physical therapy? “Educate people [regarding] what is happening,” said Davenport. Since being diagnosed with ME/CFS can take years, with unknowns and negative test results with “the underlying bad news that we don’t know what’s wrong with you, you still can’t work, you still can’t get out of bed, you still can’t do things that are meaningful to you as a person.” 

One of the primary things physical therapists can do is “provide some validation. Just knowing you have an aerobic system impairment that is causing or is correlated with all of this is just so helpful for people to understand,” said Davenport. This is helpful versus other people labeling those afflicted as lazy or crazy. 

Front-line treatment includes pacing and a heart rate monitor. In addition, if a patient has cardiopulmonary exercise test data (CPET) a physical therapist “can set the heart rate monitor to that point so they use the battery but not the gas.” This monitor sets off when a person goes into the ventilatory anaerobic threshold (VAT). VAT is the oxygen uptake right below the exercise intensity at which pulmonary ventilation increases disproportionally relative to oxygen consumption.   

Davenport explains the goal being to “reduce the time they spend above their VAT,” because the “longer the spend over their VAT taxing the gas that’s not there the more likely they are to crash (PEM day or several PEM days).”

Simple ways a patient can reduce the metabolic cost of an activity can be by “chopping vegetables by sitting down when you do it, you can get people a shower chair so they are not showering standing up, breaking up mental work – bookkeeping, tasks, can be very helpful for people.”

“Educate, and then we empower,” Davenport said. “We help people live differently based on a different understanding of their bodies and how their bodies are working.” 

Finding an important health care practitioner is invaluable. Davenport confirmed that “people with chronic diseases should find practitioners who will listen to them and consider them a partner.” From a physical therapy perspective, Davenport explained “that at all times the practitioner should be looking for interventions that do not subtract from daily activities.” 

He’s witnessed individuals who are following a prescribed exercise plan (i.e. walking program) who are unable to do their grocery shopping or weekly meal prep due to the program deducting energy / abilities from their lives, not adding to it. 

With physical therapy a person should feel “more consistent energy from day to day, that push-crash cycle is less, like its flattened out a bit,” he said.

“You may have to modify [your daily activities] but you’re not missing any,” he further explained. And with like any medical treatment, therapy program or new exercise program partnering with a health care professional that not only prescribes, but checks in throughout the journey is key.

Davenport said that as practitioners in general, “We need to make sure and come back and ask people how they are doing, instead of being prescriptive and moving on.” 

Physical therapy also has neurological benefits for a person with a chronic illness. 

Davenport emphasized that “the person with the chronic illness, the invisible disability, is the expert in the room.”

Having spent “a lot of time as a practitioner asking questions about headaches (which are not mutually exclusive),” Davenport explained “there may be some musculoskeletal triggers to some of these headaches.” 

Things like diaphragmatic breathing can be beneficial for a migraine patient because Davenport thinks “that manages the tension that might trigger a tension headache that might be construed as a migraine.” This breathing technique can be implemented “2 to 3 times a day for 5 minutes” and involves “monitoring your breath in a quiet location without your phone/screen,” he said. 

In addition to following your breath, “really gentle neck and arm exercises throughout the day can be helpful,” Davenport said. This includes “real gentle head rolls, just half head rolls, five of them, every hour or two.” 

Utilizing physical therapy in an appropriate way can improve one’s quality of life. Helping yourself find solutions for proper pacing of activities can be life-altering.

Most importantly, finding a medical practitioner who will partner with you and take your concerns seriously is key.

And remember, in many cases people’s problems or limitations are invisible. Don’t judge someone without knowing all the facts.

Dr. Todd Davenport serves as Professor in the Department of Physical Therapy in the School of Health Sciences at the University of the Pacific. He is a graduate of the University of Southern California’s DPT and Orthopedic Physical Therapy Residency programs. He is a past clinical research fellow at the Warren G. Magnusson Clinical Center at the National Institutes of Health in Bethesda, Maryland, where his work included construction and validation of function-based physical capacity tests for patients with chronic fatiguing illnesses. He is an Associate Editor with the Cardiopulmonary Physical Therapy Journal, International Editorial Review Board Member of the Journal of Orthopedic and Sports Physical Therapy, and a reviewer for several journals in the fields of rehabilitation and rheumatology.  

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