Using the term Energy Envelope helped me get a general idea of my limits, but I made much more progress in controlling my symptoms when I understood my limits in detail. 

I decided to focus on limits in different parts of my life when some fellow patients pointed out to me that mental activity and stress could be just as draining as physical activity. I began to ask myself a series of questions in order to get a fix on my limits and needs in different areas of my life. 

I asked myself: how much mental activity (reading or computer work, for example) can I do in a day? how much in a single session? what are the stressors in my life? how much sleep do I need at night? how much daytime rest? how long can I drive safely? how long can I stand at one time without intensifying my symptoms? how far can I walk?
 

I was also concerned to find my limits in other areas. In addition to those just mentioned, I included activity limits (which I define as how long I could do various activities like housework, shopping and spending time with people without intensifying my symptoms), food sensitivities, sensitivity to light and noise, and emotions.
 

Over time, I ended up with a list of about a dozen items that I listed for myself on a form I called “My Energy Envelope.” It took me at least a year to develop this more detailed understanding, but I felt rewarded all along the way because every limit I defined helped me gain more control. I filled out the form once every several months and found it a helpful way to assess how I was doing in some detail.

Later I added a section to the end of my definition, in which I summarized my abilities and limits, noted my greatest vulnerabilities (for example, stress, secondary illnesses and travel) and set goals for myself. This section was a helpful summary of my current situation and also suggested where work might give the biggest payoff in reduction of symptoms. 

One surprising discovery I made in studying my envelope was that my limits were more restrictive in some areas than in others. For example, when I thought I had recovered back to about 60% of my pre-illness level overall, I could do only about 30% as much exercise.
 

I found it very helpful to share my envelope definition with family and close friends. Getting outsiders’ views of my situation helped me to be more realistic in my self-assessment and also helped others to understand me better. So, I felt greatly rewarded by the time I had spent understanding my limits in detail.