Mental Fatigue
Conditions
Keywords
Mindfulness, Athletes, Mental fatigue, Inhibitory control, Endurance performance
Brief summary
This study investigated whether trait mindfulness in athletes is associated with impairments in neurocognitive function and endurance performance resulting from mental fatigue.
Detailed description
Recent research suggests that mental fatigue by prolonged cognitive tasks would impair neurocognitive functions (e.g., executive functions, brain activity) and sports performance, especially inhibitory control and endurance performance. On the other hand, individuals with higher dispositional mindfulness have been linked to greater athletic performance and cognitive functions. Still, there is little known whether higher dispositional mindfulness counteracts the detrimental effects of mental fatigue on endurance performance and inhibitory control in athletes. Therefore, this study is conducted to investigate whether dispositional mindfulness mediates the effects of mental fatigue on neurocognitive functions and endurance performance in athletes. The qualified participants will visit the lab on two counterbalanced order occasions to complete either a modified incongruent Stroop task (mental fatigue condition, MF) or a modified congruent Stroop task (control condition, CON) for 30 minutes. Before and after each cognitive task, participants will be measured for their subjective mental fatigue by a visual analog scale (VAS). After each cognitive task, inhibitory control and endurance performance will be evaluated by a Flanker task and a graded exercise test (GXT), respectively. Furthermore, the general and athletic dispositional mindfulness will be measured using the Five Facet Mindfulness Questionnaire (FFMQ). Specifically, the targeted primary outcomes are neurocognitive functions (i.e., reaction time, accuracy and ERPs in Flanker task) and endurance performance (i.e., VO2max & time to exhaustion in GXT); The secondary outcomes are subjective (i.e., VAS score)/objective (i.e., reaction time, accuracy in Stroop task) mental fatigue, motivation in tasks, mood (i.e., BRUMS-C).
Interventions
BEHAVIORALMental fatigue condition
In mental fatigue condition, the mental fatigue manipulation will use a modified Stroop task with complete incongruent trials, which is wildly used to induce a mentally fatigued state in previous studies. The Stroop task included four colored words presented in traditional Chinese (i.e., red, green, blue, and yellow), the color of the word will paint inconsistent with the semantic meaning of the word (e.g., red word printed in green). The task consisted of five 6-minute blocks and 1080 incongruent trials for each block. The total duration will be 30-min.
BEHAVIORALControl condition
Similar to mental fatigue conditions, the modified Stroop task with complete congruent trials will be used, The Stroop task also included four colored words presented in traditional Chinese (i.e., red, green, blue, and yellow), but the color of the word will paint consistent with the semantic meaning of the word (e.g., red word printed in red) in order to set up the match condition of relative less cognitive demanding for participants. Same with the mental fatigue condition, the task consisted of five 6-minute blocks and 1080 congruent trials for each block. The total duration will be 30-min.
Sponsors
National Taiwan Normal University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
SCREENING
Masking
NONE
Intervention model description
The participants will visit the lab on two counterbalanced order occasions to complete either an incongruent version Stroop task (mental fatigue condition, MF) or a congruent version Stroop task (control condition, CON) for 30 minutes to induce the mental fatigue state.
Eligibility
Sex/Gender
ALL
Age
18 Years to 25 Years
Healthy volunteers
Yes
Inclusion criteria
1. Regular sports training at least 4 hours weekly 2. Normal or corrected-to-normal vision 3. Right-handed
Exclusion criteria
1. Physical limitation or injury in lower limbs before and during the study 2. Diagnosed or self-reported neurological disorders (e.g., epilepsy) 3. Diagnosed or self-reported major psychiatric illness (e.g., major depression, schizophrenia)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Inhibitory Control: Reaction Time | From enrollment to the end of second intervention at 1 week. During Flanker task, up to 15 minutes. | Inhibitory control will be evaluated by a Flanker task in terms of reaction time in this study, and the types of trials are the congruent (i.e., \> \> \> \> \>) and incongruent (i.e., \< \< \> \< \<). In the Flanker task, participants were presented with five arrows and instructed to respond as quickly and accurately as possible to the direction where the middle arrow is pointing (i.e., left or right). |
| Inhibitory Control: Accuracy | From enrollment to the end of second intervention at 1 week. During Flanker task, up to 15 minutes. | Inhibitory control will be evaluated by a Flanker task in terms of accuracy in this study, and the types of trials are the congruent (i.e., \> \> \> \> \>) and incongruent (i.e., \< \< \> \< \<). In the Flanker task, participants were presented with five arrows and instructed to respond as quickly and accurately as possible to the direction where the middle arrow is pointing (i.e., left or right). |
| Endurance Performance: Time to Exhaustion | From enrollment to the end of second intervention at 1 week. During graded exercise test, up to 30 minutes | The endurance performance in terms of time to exhaustion (TTE) will be assessed by graded exercise test (GXT) with Bruce protocol on treadmill (h/p/cosmos pulsar 3p, Germany). The initial speed and grade of the GXT will be set at 2.74 km/hr with grade of 10% and increase speed and grade every 3 min until participants are volitionally exhausted. |
| Endurance Performance: Maximum Oxygen Consumption | From enrollment to the end of second intervention at 1 week. During graded exercise test, up to 30 minutes. | The maximal oxygen consumption (VO2max) throughout the whole GXT will be recorded by a computerized indirect calorimetry system (SensorMedics Vmax 29C, USA), and until the participants reached volitional exhaustion. The VO2max in the study will be defined as the highest 30-s average value of VO2 measured during GXT. |
| Changes in Neuroelectrical Activities | From enrollment to the end of second intervention at 1 week. During Flanker task, up to 15 minutes. | Neuroelectrical activity during the Flanker task was recorded using electroencephalography (EEG) with continuous data acquisition throughout task performance. Changes in neuroelectrical activity were operationalized as differences in event-related potential (ERP) amplitudes during the Flanker task (e.g., N2 and P3 components). The mean amplitudes of the N2 and P3 were quantified within predefined time windows of 250-350 ms and 350-550 ms, respectively, following stimulus onset. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Subjective Mental Fatigue | From enrollment to the end of second intervention at 1 week. Before the Stroop task, immediately after Stroop task and immediately after the Flanker task. | Before, after Stroop task, and after Flanker task, changes in subjective mental fatigue was measured using a visual analog scale for mental fatigue (VAS-MF). Participants were asked the following questions "What is your mental fatigue level now?", and participants could indicate how mental fatigue on a scale from 0 (i.e., no mental fatigue at all) to 100 (i.e., completely mentally exhausted). |
| Objective Mental Fatigue: Reaction Time in Stroop Task | From enrollment to the end of second intervention at 1 week. During Stroop task, up to 30 minutes. | During the intervention, the reaction time in both Stroop tasks was calculated as an index of objective mental fatigue. |
| Objective Mental Fatigue: Accuracy in Stroop Task | From enrollment to the end of second intervention at 1 week. During Stroop task, up to 30 minutes. | During the intervention, the accuracy in both Stroop tasks was calculated as an index of objective mental fatigue. |
| Mood State | Two standardized time points within each experimental session at baseline and post-intervention: T0 (before the Stroop task) and T1 (after the Stroop task). | Mood state was determined by the difference in scores on the Brunel Mood Scale-Chinese (BRUMS-C) between before (i.e., T0) and after (i.e., T1) Stroop task. The BRUMS-C consists of 23 items rated on a 5-point Likert scale and comprises six subscales: anger, confusion, depression, tension, fatigue, and vigor. Each subscale score is calculated as the mean of its corresponding items, with possible scores ranging from 0 to 4. Higher mean scores indicate greater intensity of the respective mood state. |
| Motivation | From enrollment to the end of second intervention at 1 week. Immediately after completing Flanker task and GXT. | The level of effort exerted by participants during the Flanker task and GXT was assessed using the VAS for motivation (VAS-M). Immediately after completing each task, participants were also asked to mark a 100mm line to rate their motivation to perform at their best (i.e., "How motivated are you to perform to the best of your ability in the task?") on a scale ranging from 0, indicating "not at all," to 100, indicating "extremely motivated." |
Countries
Taiwan
Contacts
STUDY_DIRECTORYu-Kai Chang, Ph.D
Department of Physical Education and Sport Sciences, National Taiwan Normal University
Participant flow
Pre-assignment details
No participants were excluded from the study.
Baseline characteristics
| Characteristic | — |
|---|---|
| Age, Continuous | 20.22 years STANDARD_DEVIATION 1.97 |
| Education level | 14.67 years STANDARD_DEVIATION 1.78 |
| Height | 170.74 cm STANDARD_DEVIATION 7.95 |
| Race and Ethnicity Not Collected | 0 Participants |
| Region of Enrollment Taiwan | 28 Participants |
| Sex: Female, Male Female | 24 Participants |
| Sex: Female, Male Male | 24 Participants |
| Sport experience | 7.64 years STANDARD_DEVIATION 1.95 |
| Weight | 70.11 kg STANDARD_DEVIATION 11.86 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk | EG004 affected / at risk | EG005 affected / at risk |
|---|---|---|---|---|---|---|
| deaths Total, all-cause mortality | 0 / 14 | 0 / 13 | 0 / 17 | 0 / 18 | 0 / 14 | 0 / 14 |
| other Total, other adverse events | 0 / 14 | 0 / 13 | 0 / 17 | 0 / 18 | 0 / 14 | 0 / 14 |
| serious Total, serious adverse events | 0 / 14 | 0 / 13 | 0 / 17 | 0 / 18 | 0 / 14 | 0 / 14 |
Outcome results
None listed