Evaluating Combined Electromagnetic Stimulation for Enhanced Physical and Psychological Recovery in Athletes with DOMS

Primary outcomes

1. Big Five Personality Trait Short Questionnaire (Spanish version)

   Time frame: Participants will complete questionnaires at 2 time points: just before treatment and after de last treatment (3 days after the first time frame).

   This tool is used to evaluate five core personality dimensions: neuroticism, extraversion, openness, agreeableness, and conscientiousness (Airagnes et al., 2021). The abbreviated version contains 10 items rated on a 5-point Likert scale, where 1 indicates "completely disagree" and 5 represents "completely agree." An example item from this questionnaire is, "I see myself as a person who gets nervous easily." This measure provided insight into the stable personality characteristics of the athletes and their potential impact on recovery and pain perception.Each item is rated on a Likert scale, typically ranging from 1 (Strongly Disagree) to 5 (Strongly Agree).

   Scores for each trait are summed up separately, with higher scores indicating stronger presence of that personality trait.

2. State-Trait Anxiety Inventory (STAI, Spanish version)

   Time frame: Participants will complete questionnaires at 2 time points: just before treatment and after de last treatment (3 days after the first time frame)

   To assess anxiety levels, the STAI will be used. Participants rated their responses on a 4-point Likert scale, where 1 means "not at all" and 4 means "very much," reflecting their state and trait anxiety. This measure allowed for an analysis of how anxiety levels might correlate with recovery outcomes and subjective pain experiences. It consists of 40 items, divided into two subscales:

   STAI-S (State Anxiety, 20 items): Assesses temporary feelings of anxiety in a specific moment.

   STAI-T (Trait Anxiety, 20 items): Measures a person's general tendency to experience anxiety over time.

   Each item is rated on a 4-point Likert scale:

   STAI-S: 1 (Not at all) to 4 (Very much so) STAI-T: 1 (Almost never) to 4 (Almost always) Scores range from 20 to 80 for each subscale, with higher scores indicating greater anxiety levels. The STAI is widely used in both clinical and research settings to assess anxiety in different populations.

3. Acceptance and Action Questionnaire-II (AAQ-II, Spanish version)

   Time frame: Participants will complete questionnaires at 2 time points: just before treatment and after de last treatment (3 days after the first time frame)

   The AAQ-II measures psychological inflexibility and experiential avoidance, which are critical in understanding how individuals cope with discomfort and stress (Carreira-Míguez et al., 2022). The 7-item questionnaire uses a 7-point Likert scale (0 = "never true" to 7 = "always true"), with higher scores indicating greater levels of psychological distress.The total score ranges from 7 to 49, with higher scores indicating greater experiential avoidance and psychological inflexibility, while lower scores reflect higher psychological flexibility. This scale is commonly used in clinical and research settings to evaluate mental health and intervention outcomes.

4. UCLA Loneliness Scale (Spanish version):

   Time frame: Participants will complete questionnaires at 2 time points: just before treatment and after de last treatment (3 days after the first time frame)

   The Spanish version of the Three-Item Loneliness Scale will be administered to assess perceived social isolation. Participants rated each of the three items on a 3-point scale, with 1 meaning "never" and 3 meaning "frequently." This scale helped to explore the role of social support and perceived isolation in recovery from physical exertion.The scale consists of 20 items, each rated on a 4-point Likert scale:

   • (Never)
   • (Rarely)
   • (Sometimes)
   • (Often) The total score ranges from 20 to 80, with higher scores indicating greater levels of loneliness. There is no strict cutoff, but higher scores generally reflect more significant perceived loneliness.

5. Zung Self-Rating Depression Scale (Spanish version):

   Time frame: Participants will complete questionnaires at 2 time points: just before treatment and after de last treatment (3 days after the first time frame)

   This self-applied scale contains 20 items designed to assess the severity of depressive symptoms, with both positive and negative formulations. The Zung scale's high specificity (over 80%) makes it a reliable tool for evaluating depression levels in the study's population (Carreira-Míguez et al., 2022). These baseline psychological assessments enabled the researchers to correlate psychological variables with recovery markers throughout the study.t consists of 20 questions, each evaluating various aspects of depression, including mood, physical symptoms, and psychomotor activity.

   Scoring

   Each question is rated on a 4-point Likert scale:

   • (A little of the time)
   • (Some of the time)
   • (Good part of the time)
   • (Most of the time)

   The total score ranges from 20 to 80, with higher scores indicating more severe depression:

   20-44: Normal range 45-59: Mild depression 60-69: Moderate to marked depression 70-80: Severe depression