Post-Exertional Malaise in Long COVID

I experience post-exertional malaise (PEM), which is an extremely common symptom of long COVID.

PEM is when I do something that seems perfectly normal and then later my energy crashes. Sometimes the crash happens immediately, but often I crash two days later. The magnitude of the crash is completely out of proportion to the exertion. I may need days of rest to recover.

For example, I went fishing from the bank for two hours. At the time this seemed like a leisurely activity. However, two days later I crashed and had to stay in bed for 2-3 days to recover.

For me, the activities that count as “exertion” can be

  • physical
  • mental
  • emotional or
  • social

Physical Exertion

The fact physical exertion wears me out makes complete sense. What doesn’t make sense is how little activity it takes to wear me out. For example, I have learned that taking a shower is a significant drain on my energy.

I started thinking of myself as an athlete competing in the Long COVID Micro-Olympics.

Mental Exertion

Mental exertion makes me tired. I know that because I’m a programmer and when I’m healthy, I’m often tired at the end of the workday. However PEM takes it to a whole new level.

The bureaucracy of being sick is a drain. Disability paperwork, asking doctors for forms, and meeting with HR all take a toll.

Concentration is also a big drain. For example, driving, being on a Zoom call, or writing this.

Even reading, listening to podcasts, or watching videos are a form of mental exertion. However, the genre seems to matter. I can usually watch people fish on YouTube, but intense movies are draining.

I remind myself that my brain is not declining. My body is just not producing enough energy to fully power my brain right now.

Emotional Distress

Long COVID is a traumatic event. It comes with questions like:

  • Will I ever be able to do X again?
  • How will I support my family?
  • Do the doctors believe me?
  • Will I qualify for disability?

Questions like that plus everyday emotional events can trigger PEM.

I recommend therapy to anyone living with long COVID.


I enjoy being with people, but they often make me tired. Friends have called me and after about 15 minutes I often have to hang up because I’m too tired. If we go to dinner with friends or family, I am exhausted by the end of the meal.

Delayed Symptoms

The crazy part about PEM is that the crash can happen up to two days later. So I do something, it seems okay, the next day I might feel very slightly off, but then the second day I’m so exhausted I have to stay in bed.

I told this to three doctors and they had never heard of it, yet it is the most common symptom of long COVID.

Pushing Through Makes Symptoms Worse

Nobody pushes through the wall and has a good result on the other side (reference).

The idea that pushing through is not the answer is completely counter to our culture. Work harder! Push yourself! You can do it! Use grit!

I am very adept at pushing myself very hard. Now I have to completely re-think how I approach challenges because pushing through is not the answer.

PEM is Not Being Out of Shape

In a 2010 research study, they took 23 couch potatoes and 25 people with PEM and had them ride an exercise bike to their max capacity two days in a row. The couch potatoes did about the same or even better the second day. The PEM folks all did worse the second day.

Also, the couch potatoes recovered in a day or so, but most of the PEM crowd were still feeling bad and had additional symptoms five days later.


PEM is Not New

PEM is a hallmark symptom of ME/CFS, which we have known about for many years. (reference).

After the 1918 Spanish Flu, there are many accounts of people with long-term symptoms. (reference).

I have a friend with Long Lyme Disease that has very similar symptoms.

PEM is not a new problem that stems just from COVID-19. What has changed is that many more people are impacted by it now, so PEM is getting much more attention.


Bateman Horne Center is a non-profit that tries to educate the healthcare community about ME/CFS, long COVID, and fibromyalgia. They have an excellent, 7 part video series on PEM. Each video is just a few minutes. If you get too bogged down in the medical terminology, then skip to the 7th video because it is about pacing.

Dr. Todd Davenport is an articulate researcher who has been studying people with fatigue-based illnesses for many years. Here is an excellent video that explains what we know about PEM: (55 minutes) That video is similar content to four blog posts that are linked on this page: