Michiel Tack queries some conclusions of the recently published MAGENTA trial paper.
Physical activity patterns among children and adolescents with mild-to-moderate chronic fatigue syndrome/myalgic encephalomyelitis, by Emma Solomon-Moore, Russell Jago, Lucy Beasant, Amberly Brigden, Esther Crawley in BMJ Paediatrics Open Volume 3, Issue 1, 2019
- Children and adolescents with chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) are less active than the general child population, but not all are inactive. 9.4% of participants met physical activity recommendations.
- Compared with being ‘inactive’, ‘active’ children reported greater physical function but increased anxiety, while ‘lightly’ active children reported greater physical function and reduced fatigue.
- Paediatricians need to recognise that physical activity varies between patients with CFS/ME when they recommend treatment.
Comment: Targeting activity levels in ME/CFS, by Michiel Tack in BMJ Paediatrics Open [Published on: 15 July 2019]
Contrary to what is claimed by Solomon-Moore et al.,  the study by Van der Werf et al., (reference 17)  found little evidence of a boom and bust activity pattern in adult patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). The Dutch researchers measured physical activity using actimeters worn for 12 consecutive days. There was no significant difference in day-to-day fluctuations in physical activity between ME/CFS patients and controls. The peak amplitude and peak duration of physical activity were larger in controls than in ME/CFS patients while the latter had longer rest duration after an activity peak. Another actimeter study  found no supporting evidence of a more fluctuating activity pattern in patients with ME/CFS compared to controls, during the day, nor during consecutive days.
Now, Solomon-Moore et al. report that in children and adolescents with ME/CFS, no fluctuating active or boom-bust physical activity pattern could be identified.
It would be helpful if the authors could clarify how the actimeter data impacted the treatments in the MAGENTA trial. According to the trial protocol , one of the interventions aimed to “convert a boom–bust pattern of activity (lots 1 day and little the next) to a baseline with the same daily amount”. Was this aspect removed from the intervention now that participants showed little indication of a boom–bust activity pattern? Or were young ME/CFS patients instructed to correct illness behavior they did not display when tested objectively?
Solomon-Moore et al.,  also report that 9.4% of participants achieved government recommended levels of physical activity for children and adolescents, namely a minimum of 60 minutes of moderate to vigorous physical activity per day. This is of interest given that approximately half of healthy children and adolescents do not reach this target.  These results indicate that activity patterns are unlikely to be a key factor in perpetuating ME/CFS symptoms, at least for this subgroup. Nonetheless, one of the interventions in the MAGENTA trial aims for a gradual increase in physical activity by prescribing exercise targets. Were ME/CFS patients who already met government health recommendations for physical activity also instructed to increase their amount of exercise by 10-20% a week or were they exempted?
I look forward to reading the authors’ response to these questions.
 Solomon-Moore E, Jago R, Beasant L, Brigden A, Crawley E. Physical activity patterns among children and adolescents with mild-to-moderate chronic fatigue syndrome/myalgic encephalomyelitis. BMJ Paediatr Open. 2019 May 2;3(1):e000425. 2019.
 van der Werf SP, Prins JB, Vercoulen JH, et al. Identifying physical activity patterns in chronic fatigue syndrome using actigraphic assessment. J Psychosom Res 2000;49:373–9.
 Meeus M, van Eupen I, van Baarle E, De Boeck V, Luyckx A, Kos D, et al. Symptom fluctuations and daily physical activity in patients with chronic fatigue syndrome: a case-control study. Arch Phys Med Rehabil. 2011 Nov;92(11):1820-6.
 Brigden A, Beasant L, Hollingworth W, et al. Managed activity graded exercise iN teenagers and pre-Adolescents (magenta) feasibility randomised controlled trial: study protocol. BMJ Open 2016;6:e011255.