Post Exertional Malaise (PEM)

by Larisa Hockey – Last updated:

For the last three years, Covid long haulers have had to become their own advocates and researchers as they lobby for recognition, funding and proper healthcare. Their knowledge has been hard-won against a backdrop of sickness. They’ve pushed through symptoms that ravaged their previously able-bodies and become the experts of their own disease. 

That is why we decided that all the symptoms on this website should be written by patients, for patients.  As our co-founder Jenene Crossan says “They poured their hearts, their souls and their deep determination to find just enough energy to put their experiences down for others to benefit from”. 

Although we do not intend to give medical advice, the articles have been fact-checked by a wonderful doctor who is suffering from Long Covid too. 

About the author

I was an active guy in my early 30s who liked to run, socialise, mahi | work hard and play music. Since getting Long Covid in mid-2021, including Post Exertional Malaise (PEM), I lost huge parts of my identity because of my disability. My body would ‘crash’ at the drop of a hat and I’d often fall asleep mid-conversation.

To cope, I had to move back in with my wonderful parents. I still play a little music for enjoyment, in rest homes – very appropriate, given my energy levels!

I have found a new sense of identity through online tautoko | support groups and as an advocate for Long Covid and ME/CFS. This happens via blogging, writing and as a board member for MECFS Canterbury. I had ME/CFS when I was younger and had mostly recovered, but Covid triggered it again.

I have been doing better in recent months, and my symptoms are now mild.

– Male, NZ European, Ōtautahi/Christchurch

“Exertion Extortion” by Tracey Thorp

A brief explanation of PEM

  • PEM is when you crash (ie. your symptoms get significantly worse) after minimal physical OR mental activity.

  • It’s often accompanied by severe brain fog, or pain, and is more like having the flu than just having ordinary tiredness.

  • It can often take 24–72 hours to kick in, which makes it very hard to manage. You don’t know whether you’ve overdone it until you’ve overdone it!

  • If you have PEM, exercise can be harmful.

There are many symptoms associated with Kowheori Roa | Long Covid, but most people with Long Covid get PEM. According to this international survey, three out of four Long Covid sufferers have it. If you do get PEM, you should be very careful about exercising as it will make you sicker. You can’t ‘push through’ PEM – the only cure is rest, and learning to pace.

PEM is a core symptom of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), so if you have Long Covid and get PEM, you can be described as having ‘ME/CFS-like’ Long Covid.

PEM symptoms include:

  • profound, disabling fatigue

  • cognitive dysfunction (also known as brain fog)
  • moe | sleep disturbance

  • racing heart rate
  • dizziness

  • fevers, sweats and chills

  • sore throat and swollen glands

  • headaches

  • low mood. This may look like depression, but unlike depression it is not helped by ‘pushing through’ or exercising.

You might also hear PEM referred to as Post Exertional Symptom Exacerbation.

What others say PEM is like

The experience of PEM can range hugely in terms of symptoms, how little is needed to trigger it, the time it takes to kick in, and sensitivity to activity. Even ‘mild’ PEM can have a massive impact on your quality of life. Here are several perspectives from people in New Zealand’s Long Covid community:

“I feel like I am wearing a wet sack, walking through mud in gumboots that are too big for me or I’m eight months pregnant. Sleep feels like a drug calling my ingoa | name, and the tiredness is crushing. Luckily I’m getting this less and less these days.”

– Andrea

“You don’t know if you’ve overdone it until you’ve overdone it. I think that’s the most frustrating thing — we don’t know how far we can test the waters without the fear of going backwards.”

– Jenna

“The key thing for me was learning to stop *before* I feel like I’ve done enough, because the PEM won’t hit me till hours later or even the next day. On the downside, I then got scared to try anything in case it triggered a crash. 😥 It’s a tough tightrope to walk.”

– Marcella

“I find I can’t manage any exercise. My pulse is really high due to POTS see article. Just walking from my car to my work gets my pulse racing, and I’m breathless walking up the stairs.”

– Briana

“I will usually get PEM 48 hours after overdoing it – too much laughter or socialising or bending or walking, or daring to do some dishes. The latest bout was after walking about 50 metres and taking off a horse cover, and the next day cleaning a bunny cage. Only minimal effort will set it off. If I don’t stop and completely rest, symptoms can get worse, getting to the point where I feel it’s too hard to breathe. It is a horrible thing – a punishment for having fun or trying to live your life.”

– Steph

What I have tried

These things have helped me manage my PEM:

  • stopping exercise and keeping my heart rate low (below 110 for me)

  • accepting that PEM is unpredictable, and I need to cautiously ration all my efforts

  • lying horizontal when I need a rest

  • adding planned rests to my day, and having them even before I’m tired

  • drinking plenty of water, and adding electrolytes (I like this one)

  • avoiding temperature extremes by having shorter, tepid showers

  • avoiding noisy environments, and using noise-cancelling headphones or earplugs when needed

  • calming my system by breathing out more slowly than I breathe in (breathe in for 4, out for 6), OR doing yoga nidra (I love this video/app), OR napping with a pet or plushie soft toy

  • using online support groups to feel part of a community (eg. Reddit and Facebook)

  • moving in with supportive family, and communicating my situation with them

  • very occasionally having a blowout (eg. social time with friends) where I overdo it and get PEM, but feel better for connecting with the world.

What others have tried

“What works for one person may not work for another. You have to learn to listen closely to your own body and set rules. For me, that meant no exercise.”

– Matthew

“I use a heart-rate monitor (on my Apple Watch) to know when I’m pushing it too hard and my heart rate gets too high, but I can also feel when it’s too much. If I exercise one day, I don’t do anything for the next 1–2 days. I also try to only get my heart rate up for 2–3 minutes, no longer. I don’t even aim to increase my heart rate, but that’s what happens almost immediately when I try to exercise, so I don’t do it for long.”

– Lorna

“It seems to be related to heart rate. If my heart gets up above 60% of the normal maximum for my age, there will be consequences. It also seems to be related to how long I stay vertical – so if my body is saying lie down and I don’t, there will be consequences.”

– Kim

You. Have. To. Pace. Yourself. Make #stoprestpace your mantra!

  • A very helpful rule of thumb is to ask yourself, could I do whatever I just did over again? If the answer is no, you’ve done too much.

  • Know that going into PEM too severely or too often can permanently increase the severity of your illness.

  • Have a place to lie down when you’re out, working or at events.

  • Use a shower chair or install hand rails in your bathroom.

  • If you have severe PEM, you could apply for a mobility parking permit from CCS Disability Action (you will need a letter from your GP).

  • Investigate hiring mobility aids, such as a wheelchair, walking frame or stick. It might be an unpleasant thought, but if it helps you get out and about, it’s worth it.

How others can help

Friends, family and workmates can āwhina | help by:

  • reading this letter (PDF) to a loved one from the perspective of a person with chronic illness

  • being understanding, and accepting our lived experience even if it feels counterintuitive

  • allowing us to cancel plans at the last minute if we need to rest

  • providing tautoko | support but without giving too much advice. A little is fine, but a lot is tiring and may not match our lived experience.

For a deeper dive and truly great advice about PEM and pacing, watch this video.

How is PEM diagnosed?

Currently there is no quick medical test for PEM. Usually, a health professional will see if you meet the criteria for Long Covid and/or ME/CFS. For instance, they may ask if you crash after minimal exertion, and if you have unrefreshing moe | sleep. They may also look to rule out other fatiguing illnesses.

A good rule of thumb: PEM is the only condition where exercise makes you worse.

Two-day cardiopulmonary exercise test (CPET): researchers have found that when they get people with PEM to do an exercise test on one day and then repeat the test the next day, their performance gets significantly worse. This is different for people with other fatiguing illnesses, or unfit people.

In other words, it’s definitely not all in your head! The two-day CPET test is not used for diagnosis, and it can be damaging to those with PEM, but knowing about it can validate your own experiences.

Conditions associated with PEM

The common thread between these conditions is that they are all ‘post-viral’ or ‘post-infection’ illnesses. Until Long Covid began affecting so many people, modern medicine largely ignored these conditions, and they were not part of medical-school education.

While this is changing for the better, it is still important to arm yourself with knowledge, so you can work with an informed health practitioner. An ill-informed health practitioner may try and get you to push through PEM with exercise, which backfires.

Different levels of severity

Mild: PEM is triggered by a run or a busy mahi | work day, and may last for a day to a week.

Moderate: PEM is triggered by a short walk or a long conversation, and may last for days to weeks.

Severe: PEM is triggered by standing up for a minute, and may last for days, weeks, months or longer.

Support and resources

  • Seek out online support groups, including for people with ME/CFS.
  • Occupational therapists are experienced at helping people pace. Your GP can refer you.
  • Start an activity diary. It will help you get a clearer idea of what’s causing your crashes, and how to divide your time between activity and rest. Try the Emerge Pacing app.
  • Monitor your heart rate with a smart watch (I like my Garmin vivosmart 4), to minimise spikes and crashes. Check out this Heart Rate Monitor factsheet (PDF) and consider joining the Facebook group Beat Long Covid with a smartwatch!

DISCLAIMER: THIS WEBSITE DOES NOT PROVIDE MEDICAL ADVICE

Content shared on this website is for informational purposes only. It should not be taken as a substitute for professional medical advice. Always seek the advice of a qualified healthcare professional regarding a medical condition, diagnosis or possible treatments. Long Covid Support Aotearoa is not liable for risks associated with using or acting upon the information provided on this website.

Back to top