Table 1.

Description of the outcome measures

Measure	Construct	Description
Fibromyalgia Impact Questionnaire (FIQ) [30]	Fibromyalgia impact	10-item questionnaire. Item 1 contains 10 questions related to functionality, rated on a 4-point Likert scale ranging from 0 (always) to 3 (never). In items 2 and 3, the participants mark the number of days that they felt well and the number of days they were unable to work due to fibromyalgia in the last seven days. Items 4 to 10 are composed of numerical scales that rate work difficulty, pain, fatigue, morning tiredness, stiffness, anxiety, and depression. The FIQ score ranges from 0 to 100 points and higher values ​​indicate a greater impact of fibromyalgia on quality of life. In general, the scores of patients with fibromyalgia have an average of 50 points, but in those patients with severe impairment, values ​​exceed 70 points.
Pain Numerical Rating Scale (PNRS) [29]	Pain intensity	11-point numerical scale (0 to 10) that ranges from 0 (no pain) to 10 (pain as bad as it could be). In the baseline and follow-up assessments, the participants will rank their average pain in the last seven days. In assessing pain at each session, the participants will rate their pain before and after treatment.
Tampa Scale of Kinesiophobia (TSK) [31, 32]	Kinesiophobia	17-item questionnaire that addresses the fear that physical activity will cause pain or recurrence of the injury, with answers ranging from 1 (strongly disagree) to 4 points (strongly agree). For the final score, it is necessary to reverse the scores of questions 4, 8, 12, and 16. The total score varies between 17 and 68 points, and the higher the score is, the greater the degree of kinesiophobia.
Patient-Specific Functional Scale (PSFS) [29]	Specific disability	Scale in which participants will identify the three main activities that they feel incapable of doing or have difficulty doing because of fibromyalgia. Next, the participants will rate how able they feel capable of performing the activities identified on an 11-point scale, ranging from 0 (unable to perform activity) to 10 (able to perform the activity at preinjury level). The average of the three activities will be calculated, and the higher the score is, the greater the specific capacity of the patient.
Euroqol 5 dimensions (EQ-5D-3L) [41]	Health-related quality of life	Two-part questionnaire: the first part records the severity of the problem in each of the five dimensions of the questionnaire, and the second part contains a 20-cm vertical visual analogue scale ranging from 0 to 100, where 0 corresponds to the worst imaginable health states and 100 corresponds to the best imaginable health states. Its five dimensions are mobility, self-care, usual activities, pain/discomfort, and anxiety/depression, and each dimension has three levels of severity (no problems, moderate problems, and extreme problems). Health status is labeled with a five-digit number that represents the severity level in each dimension. For example, 11111 represents no problem in any dimension, whereas 33333 represents extreme problems in all five dimensions.
Short-Form 6 dimensions (SF-6D) [33, 34, 39, 40]	Health-related quality of life	Questionnaire with six domains: physical functioning, role limitations, social functioning, pain, mental health, and vitality. The SF-6D score represents the strength of a patient’s preference for a particular health condition and ranges from zero (worst health state) to one (best health state).
Pittsburgh Sleep Quality Index (PSQI) [38]	Sleep quality	Questionnaire composed of 19 self-report questions and five questions that must be answered by a roommate or bed partner (which will not be used in this assessment). The 19 questions are classified into seven components (subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction), which are classified into a score ranging from 0 (none in the last month) to 3 (three or more times/week). The sum of the scores for these seven components ranges from 0 to 21, where higher scores indicate poorer sleep quality. An overall score greater than 5 indicates great difficulty in at least two components, or moderate difficulty in more than three components.
Six-minute Walk Test (6MWT) [35–37]	Functional capacity	Before the test, the patient should rest for at least 10 min. The test will be performed on a flat, firm surface that is 30 m in length and seldom traveled. Two cones will be used to mark the starting point and the 30-m point where the participant must turn around and continue walking without hesitation. The surface will also have markings every 3 m with adhesive tape. The participants must walk for 6 min as fast as they can, without running, while the assessor times the walk (for 6 min) and counts how many laps are completed (each lap is 60 m). The participants will be allowed to slow down and/or stop during the test (including leaning against the wall) if necessary, but will be advised to walk again as soon as possible. Every minute of the test, the assessor will say the following words of encouragement: “You are doing well. You have x minutes to go”. With 15 s left to complete the test, the assessor will say: “In a moment I’m going to tell you to stop. When I do, just stop right where you are and I will come to you”. When the stopwatch is stopped, the assessor will say the word “stop”, go to the participant, and mark the point where he stopped with tape. After the test, the assessor will ask the patient to complete Borg scale. The distance traveled will be calculated by adding the number of laps to the meters walked until the participant stops.