You think that people with ME form some sort of special group that hasn't a clue? That's why many of us suggest rest--because it doesn't come naturally and it's bloody well not easy. Try lying down and doing nothing-- unless you can fall asleep (I can't) it's mind numbingly dull. Exercise can and does prove useful if it can be managed but the BIG issue for me is that people are naturally going to try and do just that. We are not layabouts. We need to be told to rest because no-one else will offer that advice needed for people with ME. Even the experts feel the need to qualify the 'oh yes, you must rest' advice with an immediate follow-up on doing exercise.
Rest is extremely important in my own experience as one who has never suffered with ME as well as in our son's case who has suffered with it. I agree with
@Snowdrop that it always seems to be presented as a second rated treatment or lifestyle strategy when in my experience it should be equally important and maybe should be over-emphasized based on the culture we live in.
My own experience as a competitive runner (in the past) was fraught with injury until I learned the importance of purposeful rest. When that was taken into account and I worked to correct any physical dysfunctions, I trained for several years without injury for the only time in my athletic career. My experience as a Physical Therapist also showed me the value of rest leading me to say "Stress (the correct dosage and type of activity) with Rest is Best". In ME or any other systemic disorder, it has to be even more purposeful in my opinion.
In our son's experience he was instructed by Dr Lerner to do absolutely no exercise or exertional activity during his 12 week treatment. I have to admit the "athlete" and "Therapist" within me struggled with this, but we followed his advice. Our son gained a significant amount of weight during that time period and it took him over a year to lose it, but
he did have a successful treatment outcome which is most important. Whether knowingly or not, Dr Lerner's advice now makes sense in that the treatment itself was probably stressful enough to the body without adding more stress by trying to exercise or exert. I am confident it was the total treatment package that "shut the switch off" for our son and allowed him then to "rehabilitate" himself over the next 2-3 years.
Once the switch was "off", he did benefit from a correctly applied combination of CBT and GET that was individualized to him (not a generic form applied blindly as appears to be the case at Mayo and in the UK).
Rest supplies what is needed for recovery, allows the body/Nervous system to re-charge and prepares the body to make improvement. It also provides emotional and spiritual margin in my opinion which is an extremely important matter in the case of chronic disease. It is very unfortunate that so few people hold it to be of such extreme value. This is particularly true for those who say "if you believe it, you can achieve it" and our "more is better" culture that is so pervasive in the US. Those mindsets are counter-productive in the long term and in particular it seems with ME.