Mindfulness Training, Mental Fatigue, Endurance Performance and Neurocognitive Functions

Followed by the manipulation conditions, inhibitory control will be evaluated by a Flanker task (i.e., either mental fatigue condition or control condition). In the Flanker task, participants will be presented with five arrows and will be instructed to respond as quickly and accurately as possible to the direction where the middle arrow is pointing (i.e., left or right). Types of trials are the congruent (i.e., > > > > >) and incongruent (i.e., < < > < <). The reaction time (RT) and accuracy (ACC) of the incongruent trials were calculated as inhibitory control performance, and the difference between conditions was further calculated to represent a mental fatigue-related impairment of inhibitory control in pre-test and post-test.

Followed by the manipulation conditions, inhibitory control will be evaluated by a Flanker task (i.e., either mental fatigue condition or control condition). In the Flanker task, participants will be presented with five arrows and will be instructed to respond as quickly and accurately as possible to the direction where the middle arrow is pointing (i.e., left or right). Types of trials are the congruent (i.e., > > > > >) and incongruent (i.e., < < > < <). The reaction time (RT) and accuracy (ACC) of the incongruent trials were calculated as inhibitory control performance, and the difference between conditions was further calculated to represent a mental fatigue-related impairment of inhibitory control in pre-test and post-test.

The neuroelectrical activities (i.e., N2, P3) during the Flanker task were recorded and analyzed using the Neuroscan system. The difference in neuroelectrical activities between conditions (i.e., mental fatigue condition & control condition) were calculated as mental fatigue-related impairment in neuroelectrical markers of inhibitory control.

The neuroelectrical activities (i.e., N2, P3) during the Flanker task were recorded and analyzed using the Neuroscan system. The difference in neuroelectrical activities between conditions (i.e., mental fatigue condition & control condition) were calculated as mental fatigue-related impairment in neuroelectrical markers of inhibitory control.

The graded exercise test (GXT) on treadmill was used to assess participant's endurance performance. Bruce protocol will be adopted in the test. The initial speed and grade of the GXT will be set at 2.74 km/hr with a grade of 10% and increase speed and grade every 3 min until participants are voluntarily exhausted. The time to exhaustion (TTE) was recorded as the endurance performance. The difference in TTE between conditions was further calculated (i.e., control condition minus mental fatigue condition) for both the pre-test and post-test.

The graded exercise test (GXT) on treadmill was used to assess participant's endurance performance. Bruce protocol will be adopted in the test. The initial speed and grade of the GXT will be set at 2.74 km/hr with a grade of 10% and increase speed and grade every 3 min until participants are voluntarily exhausted. The maximum oxygen consumption (VO2 max) was recorded as the endurance performance. The difference in VO2max between conditions was further calculated (i.e., control condition minus mental fatigue condition) for both the pre-test and post-test.

Both in the baseline and post-intervention, the visual analog scale for mental fatigue (VAS-MF) was used to assess changes in subjective mental fatigue before and after experimental manipulation. The scale ranges from 0 (not at all mentally fatigued) to 100 (extremely mentally fatigued).

Both at baseline and post-intervention, participants completed either a 30-min 100% incongruent version Stroop task (i.e., mental fatigue condition) or a 30-min 100% congruent version Stroop task (i.e., control condition). In the Stroop task, accuracy (ACC) was calculated as an index of objective mental fatigue. It is expressed as a percentage, determined by dividing the number of correct responses by the total number of responses.

The change in dispositional mindfulness was assessed using the 16-item (5-Likert scale) athlete mindfulness questionnaire (AMQ). The mean score range is between 1-5. Higher mean scores indicate a higher level of dispositional mindfulness.

Mood state change was determined by the difference in scores on the Brunel Mood Scale-Chinese (BRUMS-C) between before and after manipulation. The BRUMS-C contains 23 item (5-Likert scale) and is divided into six sub-scales: anger, confusion, depression, fatigue, tension, and vigour. The mean score range is between 0-4. Higher mean scores indicate a higher anger mood.

Mood state change was determined by the difference in scores on the Brunel Mood Scale-Chinese (BRUMS-C) between before and after manipulation. The BRUMS-C contains 23 item (5-Likert scale) and is divided into six sub-scales: anger, confusion, depression, fatigue, tension, and vigour. The mean score range is between 0-4. Higher mean scores indicate a higher confusion mood.

Mood state change was determined by the difference in scores on the Brunel Mood Scale-Chinese (BRUMS-C) between before and after manipulation. The BRUMS-C contains 23 item (5-Likert scale) and is divided into six sub-scales: anger, confusion, depression, fatigue, tension, and vigour. The mean score range is between 0-4. Higher mean scores indicate a higher depression mood.

Mood state change was determined by the difference in scores on the Brunel Mood Scale-Chinese (BRUMS-C) between before and after manipulation. The BRUMS-C contains 23 item (5-Likert scale) and is divided into six sub-scales: anger, confusion, depression, fatigue, tension, and vigour. The mean score range is between 0-4. Higher mean scores indicate a higher fatigue mood.

Mood state change was determined by the difference in scores on the Brunel Mood Scale-Chinese (BRUMS-C) between before and after manipulation. The BRUMS-C contains 23 item (5-Likert scale) and is divided into six sub-scales: anger, confusion, depression, fatigue, tension, and vigour. The mean score range is between 0-4. Higher mean scores indicate a higher tension mood.

Mood state change was determined by the difference in scores on the Brunel Mood Scale-Chinese (BRUMS-C) between before and after manipulation. The BRUMS-C contains 23 item (5-Likert scale) and is divided into six sub-scales: anger, confusion, depression, fatigue, tension, and vigour. The mean score range is between 0-4. Higher mean scores indicate a higher vigor mood.

During the graded exercise test, the perception of effort will be asked at beginning and every 2.5-min using Borg 6 to 20 scale, until the participant comes to voluntary exhaustion.