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Definitions of key Pacing terms

Post Exertional Malaise (PEM):

One of the hallmark symptoms of both ME/CFS and Long-COVID is PEM (Post Exertional Malaise): a significant worsening of symptoms triggered by any type of exertion, including physical, mental, emotional, social. Worsening symptoms can start immediately or come on after hours or even a few days, making PEM triggers very difficult to identify. 

​The “push and crash” cycle: 

Repeating this pattern over and over, often leading to worse health over time:


  • On days when you feel a little better, you "push" to do more, work more, play more, socialize more

THEN... the PEM hits (immediately, in a few hours or after a few days) and you...


  • "crash," with bad, sometimes completely debilitating symptoms, often for several days or longer. 

​Energy Envelope:

The energy you have available to you to spend on any given day without triggering a worsening of symptoms. Everyone’s “energy envelope” is different and it is different for everyone every day.


If you have very mild ME or Long-COVID, you may have energy enough to work full or part time, cook, clean, care for children, socialize. However, 75% of people with ME cannot work/go to school, and 25% are house- or bed-bound. Very severe patients do not have energy enough to move, speak or eat by themselves.


You will need to learn for yourself what your own energy envelope looks like and how it changes with your environment, emotional state, level of health, certain biological markers (heart rate, e.g.), and other inputs. 


The term “crash” is often used interchangeably with PEM, but is sometimes used to mean a larger, more severe deterioration of symptoms, usually also lasting for an extended time - several days, weeks or even months.


Keeping your activities and exertions (physical, mental, emotional, social) below the level that causes worsening of symptoms.


Pacing is learning to listen carefully to your body and live minute-by-minute and day-by-day to prioritize, limit and adapt all activity, stimulus, and exertion so that you stay under the level that will trigger PEM.


This is often called “living within your energy envelope” (the energy you have available to you on any given day).

Graded Exercise Therapy (GET):

Gradually increasing one’s physical activity levels according to a plan. Though many healthcare providers still recommend GET for people with ME/CFS and Long-COVID because of outdated/incorrect information, GET has been shown to not help and even significantly harm people with ME/CFS and Long-COVID 🡪 GET seems to make the illness more severe for at least 75% of people and in one survey of 610 people, 89% indicated that increasing their level of exercise resulted in a worsening of their symptoms.

Most major health authorities (ex: CDC in the United States, NIH in the UK) have recently updated their guidelines and DO NOT recommend GET, advising caution against any exertion that may trigger or worsen PEM.

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