Managing rest and activity to reduce the incidence and severity of
post-exertional malaise (PEM).
PEM can be mitigated by activity management (pacing). The goal is to avoid PEM flare-ups and illness relapses by balancing rest and activity.
ME/CFS, CDC, 2019
The goal of pacing is to manage energy in order to stabilise symptoms and reduce the risk of post-exertional malaise (PEM) or long-term relapse. By consistently avoiding PEM through pacing, people with ME/CFS may develop an increase in functional capacity in the longer term.
Pacing for ME/CFS relies on internal and observable symptoms, and not on activity goal-setting. Differentiating between these two types of pacing is important.
- Symptom-contingent pacing, as used in ME/CFS, aims to conserve energy and avoid symptom exacerbation.
- Quota-contingent pacing, such as graded exercise therapy (GET), aims to gradually increase activity and improve function; this risks provoking PEM in people with ME/CFS and has consistently been reported to cause harm, including reduced functional capacity.
It is important to identify how each symptom feels when symptoms are stable. This is called the baseline level of symptoms.
The type and intensity of symptoms at baseline become the reference point for recognising:
- a change in symptoms
- an exposure to a trigger (see PEM)
- whether or not an activity is safe
- how much rest is needed
- the onset of PEM or a relapse
Most people find that they have one or more symptoms that act as an early warning sign that all symptoms are about to get worse. These markers act as cues, indicating the need for rest to allow the body to recover to baseline.
If symptoms are constantly unstable, this may be an indication of frequent, rolling or unremitting PEM. Extended rest will be needed to enable the body to stabilise and establish a baseline.
If identifying a baseline level of symptoms seems confusing, keeping a symptom diary may be helpful.
Living within available energy reserves
It is important for each individual to recognise how far symptoms can deviate safely from their baseline, knowing that symptoms will return to baseline with a short-term rest, and that the worsening symptoms are not PEM.
To clarify what can be attempted with a degree of confidence that PEM won't be induced, monitor the following:
- symptoms, while undertaking an activity or being exposed to a trigger
- symptoms following the activity or trigger
- if symptoms have worsened, how quickly they return to baseline
The largest single component of energy expenditure is the energy the body needs to carry out basic metabolic functions, such as breathing or circulation. This is called the basal metabolic rate (BMR). The lower an individual's energy reserves, the larger the proportion of those reserves that are required for BMR. For someone whose ME/CFS is very severe, BMR may approach, or even exceed, their available energy reserves.
There will always be situations when energy reserves are insufficient to meet energy demands. When additional demands are placed on the body before a return to baseline, the impact on energy reserves will be compounded and the return to baseline will take much longer.
Living within available energy reserves will reduce the incidence of PEM, leading to a more stable daily life. Over time, consistent pacing may lead to an improvement in the baseline level of symptoms and an ability to do more.
My treating physician ... always told me to do 50% of what I think I can do. It was the best advice I got.
Gabby Klein, 7 Aug 2018
In people with ME/CFS, all activity draws on already limited energy reserves. An activity can be as little as brushing teeth, having a brief conversation or listening to music.
People with ME/CFS need to constantly consider and prioritise how their energy will be spent. It can be difficult to leave important, valued or enjoyed tasks undone. Stopping an activity mid-task can be frustrating and difficult, especially when there is an adrenaline surge that allows the activity to continue beyond energy reserves, leading to PEM.
Some people may be able to do one important activity by eliminating or severely reducing activities in other aspects of their life. For example, some people prioritise social contact over showering, or food preparation over time spent online.
..will I sit in the garden for 15 minutes or will I wash my hair today.
Jennifer Brea, TED Talk, Jan 2017
Resting, when symptoms are amplified, can be very uncomfortable and bear little resemblance to resting when healthy.
Resting is an essential, proactive measure that allows the body to stay at, or recover to, baseline. Complete rest involves resting the body, mind and senses. Even for people with mild ME/CFS, more complete rest will allow a more rapid return to baseline.
The most restful circumstances will differ for each individual. For example, guided relaxation may be restful for one person, while for another, the sound of someone's voice will drain energy reserves.
Many patients have found that reducing sensory input by lying quietly in a dimly lit place is the most helpful.
Resting can be challenging due to:
- a desire to engage in activity, as a distraction from the heightened awareness of symptoms whilst resting
- a natural inclination to begin moving as soon as energy becomes available
- pressure to resume usual activities too soon
Waiting for the body to replenish its energy stores requires discipline and patience.
PEM is unique to ME/CFS and requires a paradigm shift in thinking.
There can be a natural inclination to want to fight against and push through the symptoms of the illness. Cultural and societal expectations can reinforce this tendency. People with ME/CFS learn quickly that pushing through worsens symptoms in the short term, and in the longer term, may result in more severe illness, with reduced functional capacity.
This illness requires acceptance of energy limitations and the strength to resist pressure to push through.
To manage other conditions that involve pain, fatigue and/or deconditioning, health practitioners often recommend quota-contingent pacing, such as graded exercise therapy (GET). ME/CFS patients report significant harm from ignoring symptoms in order to pursue activity goals.
People with ME/CFS must be guided by their symptoms and not by activity goals.
The common attitude to rest is that it is time off, a break, and a pleasant experience. It can be associated negatively with laziness, wasting time, and being unproductive.
Rest is the cornerstone of management in ME/CFS.
Difficulty in making decisions is a symptom that worsens as energy is depleted, so pre-planning is essential.
Leave or delegate tasks
Few people with ME/CFS are able to manage the full array of activities of daily living (ADLs) on a daily basis. It may be necessary to identify tasks that can be left undone or delegated to other people. For example, buying prepared meals instead of cooking, or asking a neighbour to put out the rubbish bin.
Break down tasks
Some people with ME/CFS may be able to complete a task if it is broken down into short activities that don’t exhaust their energy supplies, for example, breaking activities such as cleaning teeth, preparing a meal, or taking a shower into manageable stages. Completing a task may occur across a day or across multiple days.
Stop before overdoing it
Irrespective of planning, people with ME/CFS must be prepared to stop in the middle of a task if it begins to provoke a worsening of symptoms. It may be useful to set a timer as a reminder to check on how symptoms are going.
Pre-emptive and post-activity resting
When facing an activity where it will not be possible to avoid PEM, such as a scheduled hospital visit, planning can reduce the extent of PEM. Resting before the activity can maximise energy stores and thus reduce the intensity of the subsequent crash (PEM). Planning for complete rest following the event may shorten the time to a return to a baseline level of symptoms and usual functioning.
Tools for monitoring
Wearable devices can measure activity levels and/or their impact on the body. Some devices and apps also record data and provide reports.
- Heart rate monitors provide immediate feedback about staying below your anaerobic threshold. Data, including morning heart rate, resting heart rate and heart rate variability, provide additional information about overall levels of health and changes in health status. Workwell Foundation has produced a helpful fact sheet on ME/CFS Activity Management with a Heart Rate Monitor, and other educational materials.
- Pedometers provide an objective measure of steps taken.
- Activity trackers can provide information on activity and sleep patterns. However, some people with ME/CFS find that their activity trackers misinterpret their rest and activities.
- Other devices and apps are used by some with ME/CFS to track activity, symptoms and health status, for example, an oximeter to monitor oxygen saturation levels.
A diary may be helpful in providing a record of symptoms and triggers, including activity.
Learn more about pacing
Dialogues for ME/CFS includes a 15 minute video on pacing, with a transcript, accompanied by links to educational materials and references.
This video also includes helpful information on pacing with a heart rate monitor.
Last edited: 02 April, 2023