2005 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1280928/ Abstract In a previous study we demonstrated that while people with CFS had lower daily activity levels than control subjects, they were able to increase daily activity via a daily walking program. We reanalyzed our data to determine the time course of activity changes during the walking program. Daily activity assessed via an accelometer worn at the hip was divided into sleep, active, and walking periods. Over the first 4–10 days of walking the subjects with CFS were able to reach the prescribed activity goals each day. After this time, walking and total activity counts decreased. Sedentary controls subjects were able to maintain their daily walking and total activity goals throughout the 4 weeks. Unlike our previous interpretation of the data, we feel this new analysis suggests that CFS patients may develop exercise intolerance as demonstrated by reduced total activity after 4–10 days. The inability to sustain target activity levels, associated with pronounced worsening of symptomology, suggests the subjects with CFS had reached their activity limit.
This brief note was mentioned by @strategist. It's interesting in terms of exercise physiology evidence, but the sample size is very small. I think it's most interesting in terms of history. In 2005, Black and McCully realised that their initial analysis had led them to a faulty conclusion, and they were attempting to inform others.
Patients using accelerometers for 4 weeks strongly refutes the claim by PACE that they are an undue burden for patients.
That was always a "dog at my homework" excuse. It was insulting in itself, far more that it was accepted. Especially as it's noted by the steering group that it was initially performed, without any mention of burden, and that the only comment they had related to the other study that found no benefits. Impunity breeds ineptitude.
I looked up the original paper on the study. It's interesting that only a few months (March to October 2005) after they published their analysis and drew conclusions, they took another look at the data and realised they hadn't noticed the decline in activity after the initial uptick. I think it's very interesting seeing the contrast in conclusions. . 2005 Mar 3;4:3. doi: 10.1186/1476-5918-4-3 Increased daily physical activity and fatigue symptoms in chronic fatigue syndrome Christopher D Black 1, Patrick J O'Connor 1, Kevin K McCully 1,✉ PMCID: PMC555551 PMID: 15745455 Abstract Individuals with chronic fatigue syndrome (CFS) have been shown to have reduced activity levels associated with heightened feelings of fatigue. Previous research has demonstrated that exercise training has beneficial effects on fatigue-related symptoms in individuals with CFS. Purpose The aim of this study was to sustain an increase in daily physical activity in CFS patients for 4 weeks and assess the effects on fatigue, muscle pain and overall mood. Methods Six CFS and seven sedentary controls were studied. Daily activity was assessed by a CSA accelerometer. Following a two week baseline period, CFS subjects were asked to increase their daily physical activity by 30% over baseline by walking a prescribed amount each day for a period of four weeks. Fatigue, muscle pain and overall mood were reported daily using a 0 to 100 visual analog scale and weekly using the Profile of Mood States (Bipolar) questionnaire. Results CFS patients had significantly lower daily activity counts than controls (162.5 ± 51.7 × 103 counts/day vs. 267.2 ± 79.5 × 103 counts/day) during a 2-week baseline period. At baseline, the CFS patients reported significantly (P < 0.01) higher fatigue and muscle pain intensity compared to controls but the groups did not differ in overall mood. CFS subjects increased their daily activity by 28 ± 19.7% over a 4 week period. Overall mood and muscle pain worsened in the CFS patients with increased activity. Conclusion CFS patients were able to increase their daily physical activity for a period of four weeks. In contrast to previous studies fatigue, muscle pain, and overall mood did not improve with increased activity. Increased activity was not presented as a treatment which may account for the differential findings between this and previous studies. The results suggest that a daily "activity limit" may exist in this population. Future studies on the impact of physical activity on the symptoms of CFS patients are needed.
Google Scholar says the original has been cited 94 times: https://scholar.google.com/scholar_...es=3&pmid=15745455&doi=10.1186/1476-5918-4-3&
But this correction paper has been cited 8 times. Notably in The Draft Report by the Institute for Quality and Efficiency in Healthcare Does Not Provide Any Evidence That Graded Exercise Therapy and Cognitive Behavioral Therapy Are Safe and Effective Treatments for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (2023, Diseases)
That claim is ridiculous to me. I literally have had an accelerometer on my wrist for two years while being bedridden and unable to speak and I barely notice it until I sometimes check the data on my phone.
I am surprised people averaged increasing their activity. If I did this I would instantly drop to almost no activity due to PEM where I defended my health over achieving what the nice person in a white coat wanted due to the crippling pain. I would enter the dark place too for many days to weeks my mood goes off a cliff and my pain shoots up. There is no increasing my activity from baseline its an instant crash to almost nothing.
From the original paper: “Daily count” appears to just be general movements that would register as a change in velocity on an accelerometer. 24% lower than sedentary control is probably what I could maintain for a few weeks at my best mild condition, provided I had access to my stimulant meds, was getting consistent great sleep, could space that activity throughout the day, and didn’t have to go any higher than that level at any point. But I would definitely have crashed after a while like they saw in the follow up paper. So it seems like the study selected for rather mild participants to begin with.
Selecting for mild patients seems to be the usual study bias, that and selecting patients that a doctor thinks has ME/CFS which selects based on who their GP and local clinic is rather than actual disease presentation. So many papers require patients to come into a lab or hospital at the beginning and end of a study at least and this instantly deselects moderates and especially the severe and often starts things off with a crash too which helps reduce the apparent impact of their interventions too.
Indeed. They are lighter than a cotton t-shirt. Are they seriously suggesting that the weight of summer clothes is too much of a burden? It is a blatant demonstrably fraudulent claim, and should never have been accepted by the trial steering committee. The real story, of course, is that they saw the complete lack of correlation between actimeters and self-report outcomes in previous CBT studies on ME/CFS and panicked, because that alone could have negated their claims about efficacy (for CBT). This info became formally available in 2010, but they almost certainly knew about it informally before then. Wiborg, et al (2010). How does cognitive behaviour therapy reduce fatigue in patients with chronic fatigue syndrome? The role of physical activity. Psychological Medicine, 40, pp 12811287 doi:10.1017/S0033291709992212 IIRC, there is also another odd part to this story. It was a long time back, but somebody took a look at the resources they had for doing the actimetery at outcome, which strongly suggested that there was no way they could collect the relevant data in any reasonable length of time. That is, they either mismanaged it, or never had any intention of collecting that data. Can't find that discussion, was probably on PR, but might have been elsewhere.
