Mental Fatigue and Performance in Young Soccer Players

Tokat Gaziosmanpasa University16 enrolled

Overview

The study employed a randomized, parallel-group, between-subjects design in which participants were assigned to either the MF+ or MF- condition and completed a single testing session accordingly. All test sessions were conducted on synthetic turf pitches and comprised three stages of testing, which included assessments of aerobic and anaerobic endurance, jumping, agility, and balance. During the familiarization session, players were briefed on the study procedures, practiced the main tasks, and became accustomed to the equipment and environment used during the intervention. During the MF+ session, prior to each physical testing stage, participants completed a 30-minute Color-word Stroop task (CST) to induce MF. To minimize external influence, players were not prompted or verbally encouraged during testing. Immediately, after each session, ratings of perceived exertion (RPE 6--20) were recorded using the category-level Borg scale (29), and enjoyment was assessed using the exercise enjoyment scale, a bipolar instrument consisting of eight items scored on a 1-7 Likert scale.

The study employed a randomized, parallel-group, between-subjects design in which participants were assigned to either the MF+ or MF- condition and completed a single testing session accordingly. Players were recommended to sleep for at least 7-8 hours, refrain from exercising at moderate to high intensity, and avoid consuming alcoholic or caffeinated beverages during the 24 hours before the intervention. Indoor and outdoor temperatures (25-28°C) and humidity levels (35-40%) were kept consistent across all intervention sessions. All test sessions were conducted on synthetic turf pitches and comprised three stages of testing, which included assessments of aerobic and anaerobic endurance, jumping, agility, and balance. During the familiarization session, players were briefed on the study procedures, practiced the main tasks, and became accustomed to the equipment and environment used during the intervention. During the MF+ session, prior to each physical testing stage, participants completed a 30-minute Color-word Stroop task (CST) to induce MF. Four color words (red, blue, green, and yellow) were randomly printed, and participants were required to verbally name the color of each word. During the control (MF-) session, prior to each physical testing stage, participants watched emotionally neutral documentaries for 30 minutes. Each testing session began with a standardized 15-minute warm-up, consisting of 5 minutes of low- to moderate-intensity running followed by 10 minutes of upper- and lower-extremity-specific dynamic stretching, mobility exercises, and change-of-direction drills. To minimize external influence, players were not prompted or verbally encouraged during testing. Immediately, after each session, ratings of perceived exertion (RPE 6--20) were recorded using the category-level Borg scale, and enjoyment was assessed using the exercise enjoyment scale, a bipolar instrument consisting of eight items scored on a 1-7 Likert scale.

Interventions

MF+OTHER

During the MF+ session, before each physical testing phase, participants completed a 30-min Colour Word Stroop task (CST) to trigger MF. The paper-based version of the CST was completed in quiet rooms following the same protocol as in previous studies. This prolonged cognitive task was reported to require sustained attention and automatic response inhibition and effectively induced MF through cognitive manipulation. ThyIt had ben Four colour words (red, blue, green and yellow) were randomly printed and participants were asked to verbalise the colour of each word.

MF-OTHER

During the control session, before each physical testing phase, participants watched emotionally neutral documentaries for 30 min.

Outcomes

Primary Outcomes

Aerobic performance assessment

The test consisted of shuttle runs between two landmarks placed 20 metres apart, and athletes were required to complete a short active recovery period by running or walking within 10 seconds after each shuttle run. The testing protocol typically includes a standardised warm-up followed by progressive shuttle runs until exhaustion. The distance travelled or the level reached before exhaustion is used to measure performance. The test was carried out on an artificial turf field according to the recommended procedures.