Study limitations
comorbidity, headaches, migraines, hEDS, headaches/migraines
HEDS, MIGRAINES
Although this study added to the body of literature by evaluating the effects of an exercise program in comparison to the SOC in a randomized control trial and included those with hEDS, there were limitations, which require further research to answer. The weekly activity load was self-reported and dependent on participants tracking each session in the app, rather than using an activity monitor which would collect activity data continuously. The app with chest strap heart rate monitor was chosen to allow for heart rate monitoring in real time during training sessions, but does present a limitation as the tracked sessions may underrepresent total activity of participants as formal continuous aerobic exercise sessions may have been performed but never tracked. Future work should utilize an accelerometer or an activity monitor which could monitor changes in all activity not just tracked activity habits. Although the study was powered and designed to evaluate improvement in aerobic fitness, improvement in symptoms, quality of life, and functional ability is most valuable for clinicians. The questionnaires used in this study did try to assess this, but with the functional ability score, participants had to pick a discrete percentage according to the description that best described their current state; many found this difficult as they may have improved but did not meet all the requirements described in the next category (i.e., ability to start working or go to school part-time or full-time). As such, this may have limited the sensitivity to detect small, but meaningful improvements in functional ability and a longer intervention period may have been needed. The mechanism for improvement in aerobic fitness and endothelial function has been previously demonstrated, highlighting that additional research is needed to evaluate longer exercise intervention periods and should also include evaluation of endothelial function. Finally, with over 50% of the study population having headaches or migraines and this being a common comorbidity in this population, it would have been advantageous to evaluate the effect of the ET on severity or frequency of headaches/migraines.