Energy limit

A person's energy limit or energy bank budget is the amount of physical, cognitive/mental or other energy that they can spend within a particular period of time without it causing an increase in ME/CFS symptoms, such as post-exertional malaise.

Theory
Staying within their personal energy limit helps prevent post-exertional malaise (PEM), and reduces the risk of a permanent or long-term decrease in energy limit that PEM can cause.

Comparisons

 * Regularly exceeding limits is known as over-exertion, or pushing through symptoms
 * A repeating pattern of regularly exceeding energy limits followed by resulting post-exertional malaise of known as the boom and bust cycle
 * Avoiding even minimal exertion such as personal hygiene and dressing is known as bed rest or aggressive rest, although for patients with severe and very severe ME even digesting food or the presence of another person in the same room can exceed their energy limits, making PEM unavoidable

Potential treatments

 * Pacing is a management strategy that tries to minimize or avoid post-exertional malaise while maximizing activity, for instance stopping tasks early and continuing again another day or continuing after a considerable rest, and prioritizing or adapting tasks to reduce the change of over-exertion (exceeding energy limits) on a good day.