I also noticed Jo Nijs' name on the recent systematic review, "How to exercise people with chronic fatigue syndrome: evidence-based practice guidelines". I became concerned about it when I realized that the authors make claims about what patients can supposedly do without exacerbating symptoms, but usually relied on studies which do not require compliance to the durations and intensities described, drawing recommendations based on the intended goals of these studies rather than what patients actually did.
Only self-reported fatigue and self-reported physical function is considered in the outcomes, no objective data to help distinguish genuine improvements from perceptual conditioning due to encouragement/expectations. They mention common shortcomings of the evidence reviewed (including lack of data on compliance), but these limitations severely undermine the recommendations. The paper also lacks effect sizes and apparently misinterprets the FINE Trial as showing significant improvement for physical function.
"Based on the available studies, the appropriate exercise modalities were identified. [...] It is advocated that clinicians applying exercise therapy to people with CFS comply with these guidelines (summarized in Fig. 1).[Figure 1 paraphrased : time contingent home-based aerobic exercises eg walking/swimming/cycling, 5 times per week, starting 5-15 minutes per session, gradually increased to 30 minutes, 10-11 (professional sessions) spread over 4-5 months excluding home sessions] [...] Walking is especially recommended, but swimming or cycling should also be encouraged."
These recommendations might be OK for highly active or mildly affected patients, but they seem ridiculous to me and many other patients. They state that "The exercise intensity can be determined by using the individually derived target heart rate [(220 minus age). 0.75]. Target heart rates can be used to avoid overexertion." This means that I can supposedly do exercise up to 140bpm without exacerbations, which is untrue. Yes, I know, just anecdote +1, but still.
On the good side, they state that even with CBT/GET recovery is rare, and point out that time-contingent approach cannot be too strict and must account for post-exertional symptoms ie adapt to the exercise tolerance of the patient and recommend rests after exercises/activities "to account for the delayed recovery following physical activity". However, even the PACE therapy manuals for CBT/GET have similar recommendations, it is not strictly time-contingent either, they expect the patient to tolerate a temporary degree of increased symptoms while adapting to the new activity level but not if it interferes with function.
PACE is a classic example of how this systematic review makes recommendations based on presumed increases in activity rather than actual increases in activity. The mere goals of PACE style CBT/GET are incorporated into the actual recommendations, despite the fact that PACE did not require participants to increase activity as presumed nor did it publish evidence of increases in activity (if anything, the dismal average 6MWD scores suggest that the GET group never came remotely close to the goal of 30 minutes exercise 5 times a week despite having 12 months to do so).
Apologies if I sound overly critical, but anything presented as "evidence-based practice guidelines" may have serious implications on patients. I've already been through enough physio-rehabilitation-babble in real life.
Deconditioning has been pretty much debunked as a major factor in ME/CFS, and the notion of major boom-bust cycling as a common pathological feature of ME/CFS has been recently challenged in another systematic review on activity, which included the issue of activity variation. Since CBT/GET does not seem to increase activity much anyway it cannot be assumed that lofty exercise goals are being reached. The implication is that patients test their limit, feel worse, and then go back to their baseline level. Although some patients may increase exercise, there is also the problem of activity-substitution to consider.
There must be other mechanisms for the supposed self-reported improvements for the minority of patients, some of these may be genuine improvements due to reasons other than what the underlying rationale for the therapies assume, but it is also possible that a large degree are methodological artifacts which are difficult to distinguish. For example in the PACE Trial, APT group were told that improvement/recovery was unlikely while the CBT/GET groups were told improvement was likely and recovery was possible and even aimed for. The APT group were encouraged to do less and listen to their body while the CBT/GET groups were discouraged from doing that and encouraged to do more and probably instructed on how to perceive symptoms as less obnoxious.
I also take issue with the prevailing attitude in the medical community that ME/CFS patients by default "aren't doing enough" and need to exercise for the sake of exercise. This never helped me, and exercise should never interfere with basic living, there are far more important activities to do first, such as housework. In fact, unless it has a specific purpose which the patient really needs, exercise should not be a "priority". The activity ceiling is real and is not primarily "deconditioning", but I personally find the ceiling is not a fine line between black and white, it is more like a padded translucent rubber band, although sometimes it does snap back suddenly as if a threshold has been triggered, and further symptoms are much easier to manifest during states of relapse.
