The present quasi-experimental study was designed in three phases, including pretest, posttest, and three-month follow-up. Participants were professional soccer players engaged in professional soccer leagues in Tehran.
The participants were selected based on 2 standard deviations above the mean of the players in the Persian version of the revised competitive state anxiety inventory-2 (rCSAI-2), a score above 15 in the subscale of cognitive anxiety, and a score above 12 in the subscale of anxiety. The participants were entered into the assessment stage, and after obtaining informed consent, they were entered into the randomization phase. Afterward, they were randomly assigned to one of the two experiment groups receiving MCT and MAC and also to the waiting list control group.
The study population included all professional soccer players participating in the U-19 league in Tehran in the year 2017 - 18.
The samples were collected using judgmental (purposing) sampling. The inclusion criteria included being employed in one of the soccer teams in the Tehran provincial league, having a minimum 9 grade high school, obtaining a score higher than 15 in the subscale of cognitive anxiety and above 12 in the scale of somatic anxiety in the Persian version of rCSAI-2, and being right-handed. The exclusion criteria were simultaneously gaining any psychiatric and/or psychological treatments and having a chronic mental disorder (substance abuse, schizophrenia spectrum disorders, and other psychotic disorders; neurodevelopmental disorders). Moreover, more than one session absence was determined as a dropout criterion.
The number of sessions for both MCT and MAC was seven (two sessions per week, for a total of four weeks), and the duration of each session was 90 minutes. At the end of the interventions, the participants were assessed with neurophysiological devices. Eventually, three months after the posttest, final assessments were carried out.
3.1. Procedures and Assessments
Psychophysiological signs included EEG, EMG of frontalis (forehead) muscle, HR, GSR, the temperature of finger of hand, and RR, which were obtained using the ewave 8-channel neuro-biofeedback device with 1000 sample rates per second. The data were analyzed in the eProbe7.8.3 software of Rubymind.us.
It is noticeable that the EEG assessment was recorded using three channels (F3, Fz, and F4) with electrodes according to the international 10/20 system. Data collected with left ear attached reference electrode and right ear attached ground electrode.
3.2. Randomization and Masking
The participants were randomly assigned to one of the three groups using a random number generator in Microsoft Office Excel. Moreover, randomization was stratified using rCASI-2.
3.3. Therapist
One certified clinical psychologist with 10 years of experience as a clinician and sport psychologist, who received extensive training in both MCT and ACT from national and international leading experts, was selected for the trial.
3.4. Treatments
The MCT plan for anxiety (
20) was the main resource for MCT-based intervention in the present study. This was intended as a guide for the treatment of the structure and content and should be applied flexibly as required by individual circumstances (
20).
The first session: Introduction of the metacognitive model, as well as competitive anxiety, anger, and sports aggression,
The second session: Socialization to the metacognitive model,
The third session: Verbal and behavioral reattribution; uncontrollability of worry and anger,
The fourth session: Challenging beliefs about the danger of worry and anger
The fifth session: Challenges with positive metacognitive beliefs on the risk of worry and anger,
The sixth session: Working on a new plan for worry and anger,
The seventh session: Relapse prevention.
The MAC manual (
11) is a semi-structured program, which offers several types of techniques to help performers (exercisers and/or players in our case) accept their inner thoughts and emotions as they pay attention to the linked stimuli and tasks in here and now situation for reaching personal meaningful goals and aims (
24). The program, therefore, typically takes between seven and 12 sessions (
25). The MAC protocol was revised from a fixed eight-session format to a flexible seven-module format, providing the opportunity to deliver any of the modules over any number of necessary sessions (
11,
17). The MAC protocol allows for the effective enhancement of performance and overall mental and generalized well-being among athletes (
16).
A short description of the MAC manual (
24) is given as follows:
The first session: Psycho-education for group preparation,
The second session: Introduction to cognitive diffusion and mindfulness,
The third session: Introduction to values and value-related behaviors,
The fourth session: Introduction to acceptance,
The fifth session: Commitment improvement,
The sixth session: Skill maintenance and MAC integration,
The seventh session: MAC maintenance and improvement.