Discussion
DISEASE, RECRUITMENT
This trial is the first trial trying to include a large number (The randomized controlled study design applied in our trial is a strength. Another strength related to this trial is that the protocol has been developed with guidelines from the SPIRIT and PREPARE guidelines, [Our trial has some limitations. Due to the nature of the exercise intervention blinding the research nurses, physiotherapists, and participants is not an option. Limitations according to the recruitment of participants do exist because we focus on patients with mild to moderate disease activity. These patients may be more cautious to participate due to symptoms or because of the possibility of not being randomized to the intervention or not being able to participate in the intervention because of their schedule. Another limitation of the trial is that we have not planned follow-up after week 12. However, we have chosen not to plan a long-term follow-up because we do not yet clearly know the short-term effect of exercise, which is the focus of this trial. Selection bias may be of concern when conducting a trial on exercise, and this may influence the generalizability of the study.