Effectiveness and Health Benefits of a Nutritional, Chronobiological and Physical Exercise Intervention in Fibromyalgia and Chronic Fatigue Syndrome (SYNCHRONIZE +)

to be evaluated with the "Multidimensional Fatigue Inventory" (MFI) questionnaire (Smet et al., 1995). It will measure 20-items. MFI-20 has an even proportion of positively and negatively worded items that are rated on a 5-point Likert scale. Subscale scores (range 4-20) are calculated as the sum of item ratings and a total fatigue score (range 20-100) is calculated as the sum of subscale scores. Higher scores indicate a higher level of fatigue.

Sleep quality and insomnia will be assessed with the Pittsburgh Sleep Quality Index (PSQI-19 items) (Buysse et al., 1989). In scoring the PSQI, seven component scores are derived, each scored 0 (no difficulty) to 3 (severe difficulty). The component scores are summed to produce a global score (range 0 to 21). Higher scores indicate worse sleep quality.

To assess pain, the VAS questionnaire will be used (Marques et al., 2008). It will be measured by a scale Likert: 0 (absence of pain) to 10 (worst possible pain).

adherence to the Mediterranean diet will be assessed with the erMEDAS-17-item questionnaire (PREDIMED Plus; Schröder et al., 2021). Adherence to dietary habits characteristic of a MedDiet is scored, in each item, with 1 point and the opposite, with 0 points. Total scoring scale goes from 0 to 17 points, where 0 means no adherence and 17, maximum adherence. The score can be also classified into approximate tertiles: low (≤ 7), medium (8-10), and high (11-17).

physical exercise practice and sedentary lifestyle will be assessed with the REGICOR-Short questionnaire (Molina et al., 2017). The short questionnaire estimates energy expenditure in total physical activity and by intensity (light, moderate, vigorous) following REGICOR-Short algoritmes, and includes 2 questions about sedentary behavior and a question about occupational physical activity. We will evaluate change in amount of time dedicated to physical activity (minutes or hours) and physical activity intensity per week (energy expenditure or METs x min/week), and change in sedentarism (number of hours per week doing sedentary activities).

the circadian biological rhythm will be assessed with the "Biological Rhythms Interview of Assessment in Neuropsychiatry" (BRIAN) questionnaire (Giglio et al., 2008). The BRIAN includes 18-items to investigate four main areas related to circadian rhythm disturbance: sleep, activities, social rhythms and eating patterns. Items are rated using a 4-point scale, (1)= no difficulty, (2)= mild difficulty, (3)= moderate difficulty, and (4) =severe difficulty. The BRIAN scores thus range from 1 to 72, where the higher scores suggest severe circadian rhythm disturbance.

to be evaluatedwith the Revised Questionnaire on the Impact of Fibromyalgia (FIQR). It will be measured by a scale Likert: 0 (best) to 100 (worst).

To be evaluated with the Hospital Anxiety and Depression Scale (HADS) questionnaire. The scale llikert punctuates from 0 to 21 (8 to 10 indicates a doubtful case of anxiety; more than 11 indicates a probable case of anxiety)

Will be evaluate through R24h and FFQ (Rodríguez et al., 2008). The R24h will be evaluated qualitatively (number of intakes/day; intake composition, etc.) while the FFQ register weekly and monthly intake of different food (times per week; times per month), and will evaluated qualitatively.

Weight and height will be combined to report BMI in Kg/m2.

Body fat (measured in %) will be measured by bioimpedance with a OMRON BF511 body composition monitor.

Skeletal muscle (measured in %) will be measured by bioimpedance with a OMRON BF511 body composition monitor.

Endurance will be evaluated with the ''6-min walk test' (Rikli and Jones, 1999). This test involves determining the maximum distance (m) that can be walked in 6 min .

The ''30-s chair stand test''(Rikli and Jones, 1999) involves counting the number of times within 30 s that an individual can rise to a full stand from a seated position with the back straight and the feet flat on the floor, without pushing off with the arms.

The handgrip strength will be assessed using a "hand dynamometer". The subject continuously and gradually squeezes for at least 2 s. Each patient completes two attempts with each hand, with the arm fully extended, forming an angle of 30- with respect to the trunk. The maximum score in kilograms for each hand is recorded.