Effect of Mindfulness Training on Mental Fatigue-Related Impairments of Endurance Performance and Inhibitory Control in Athletes: An Event-Related Potential Study
Phase: NA
Conditions: Mindfulness Training, Neurocognitive Function, Sports Performance, Mental Fatigue
Sponsor: National Taiwan Normal University

 
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Effect of Mindfulness Training on Mental Fatigue-Related Impairments of Endurance 
Performance and Inhibitory Control in Athletes: An Event-Related Potential Study 
 
Principal Investigator: Yu-Kai Chang, PhD 
NTC: NCT05452460  
Date: December 19, 2023 
 
ABSTRACT 
Purpose: This study utilized a longitudinal design to examine the effect of mindfulness 
training on mental fatigue-related impairments of endurance performance and inhibitory 
control aspect of neurocognitive functions in athletes. Methods: In this randomized 
controlled trial (RCT) study, specifically, fifty-three aged between 18 to 25 years of college 
athletes were randomly assigned to either a mindfulness training group (MT, n = 26) or a 
waiting-list control group (WC, n = 27) after completing the pre-test. MT group engaged 
mindfulness program in a 60-min session per week for eight weeks, whereas WC were asked 
to maintain regular life and routine training. The change in dispositional mindfulness was 
evaluated by Athlete Mindfulness Questionnaire (AMQ) before and after the intervention. 
Participants completed the two 30-min manipulation conditions by Stroop task [i.e., mental 
fatigue condition (MF) or control condition (CON)] in both baseline and post-intervention, 
respectively. Before (T1) and after (T2) the 30 min manipulations, subjective mental fatigue 
and mood were measured using a visual analogue scale for mental fatigue (VAS-MF) and 
Brunel mood scale-Chinese (BRUMS-C), respectively. The participants then completed the 
Flanker task [i.e., reaction time (RT) and accuracy (ACC)] and its induced ERP components 
(i.e., N2 and P3) were recorded, and subjective mental fatigue was evaluated by VAS-MF 
immediately after the Flanker task (T3). Following, endurance performance [i.e., time to 
exhaustion (TTE] and VO2max] of participants were evaluated using graded exercise test 
(GXT). Additionally, VAS for motivation in task (VAS-M) was used to evaluate motivation 
for completing tasks after the Flanker task and GXT. Expected results: It was hypothesized 
that MT will exhibit less subjective and objective of mental fatigue, and exhibit less mental 
fatigue-related changes in endurance performance and inhibitory control-aspect of 
neurocognitive functions. 
 
 

 
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METHODS 
Design and Sample 
This study examining mindfulness training on mental fatigue-related impairments of 
endurance performance and inhibitory control aspect of neurocognitive functions in athletes 
was registered at ClinicalTrials.gov (NCT05452460). The actual conduct of this study was 
from 17/2/2022 to 10/1/2023. Initially, one hundred and twenty-five potential participants 
were recruited via advertisements and personal contact form several sports team in Taiwan. 
After screening the eligibility and participation interested, the fifty-three were included in this 
study, and eligible participants who were (1) regular sports training at least 4 hours weekly, 
(2) normal or corrected-to-normal vision, (3) right-handedness, (4) no physical limitation or 
injury in lower limbs before and during the study, (5) no diagnosed or self-reported 
neurological disorders (e.g., epilepsy), (6) no diagnosed or self-reported major psychiatric 
illness (e.g., major depression, schizophrenia), and (6) no major previous experience with 
mindfulness training. 
 
Procedure 
In this study, participants visited the lab four time, they completed the two 30-min 
manipulation conditions by Stroop task [i.e., mental fatigue condition (MF) or control 
condition (CON)] in both baseline and post-intervention, respectively. Before (T1) and after 
(T2) the 30 min manipulations, subjective mental fatigue and mood were measured using a 
visual analogue scale for mental fatigue (VAS-MF) and Brunel mood scale-Chinese 
(BRUMS-C), respectively. The participants then completed the Flanker task [i.e., reaction 
time (RT) and accuracy (ACC)] and its induced ERP components (i.e., N2 and P3) were 
recorded, and subjective mental fatigue was evaluated by VAS-MF immediately after the 
Flanker task (T3). Following, endurance performance [i.e., time to exhaustion (TTE] and 
VO2max] of participants were evaluated using graded exercise test (GXT). Additionally, VAS 
for motivation in task (VAS-M) was used to evaluate motivation for completing tasks after 
the Flanker task and GXT.  
Prior to each visit, participants received the following instructions: do not do training 
vigorously the day before test, do not consume a food or beverage containing caffeine and 
alcohol 12 h before test, and do not sleep less than 7 h before the visit. 
 
Outcome measures 
Endurance performance assessment 
The graded exercise test (GXT) on treadmill (h/p/cosmos pulsar 3p, Germany) was used 
to assess participant’s endurance performance (i.e., VO2max and exhaustion time). Bruce 
protocol was adopted in the test (Bruce et al., 1973). The initial speed and grade of the GXT 
were set at 2.74 km/hr with grade of 10% and increases speed and grade every 3 min until 

 
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participants were voluntarily exhausted. Throughout endurance task, heart rate (HR) and 
perception of effort were measured every 2.5 min using an HR monitor (Polar H10, Finland) 
and Borg’s 6-20 rating of perceived exertion (RPE)(Borg, 1982) to check whether 
participants meet the criteria of volitional exhaustion (Beltz et al., 2016). The time to 
exhaustion (TTE) and Maximum oxygen consumption (VO2max) were recorded as indicator 
of endurance performance. 
 
Inhibitory control aspect of cognitive functions assessments 
Followed by the manipulation conditions (i.e., 30-min Stroop task), inhibitory control 
was evaluated by a Flanker task (Eriksen & Eriksen, 1974; Friedman & Robbins, 2021). 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). Types of trials are the congruent (i.e., > > > > >) and incongruent (i.e., < < > < 
<). The reaction time (RT) and accuracy (ACC) of incongruent trial were calculated as 
inhibitory control behaviors performance. 
Furthermore, the neuroelectric activities during the Flanker task was measured by 
electroencephalographic (EEG). The EEG data was recorded from a 32-electrode Quik-Cap 
Neo Net (Compummedics Neuroscan Inc., Charlotte, NC, USA) based upon the Neuroscan 
system. Additionally, the EEGLAB (V8.3)7 and ERPLAB (V8.0)8 plugins based upon 
MATLAB (R2022a, Mathworks Inc.) were used to perform the offline data processing. 
Specifically, frontally (F3/Fz/F4) mean N2 amplitude and parietally (P3/Pz/P4) mean P3 
amplitude for incongruent trial were extracted as neuroelectric marker of inhibitory control. 
 
Manipulation check 
Subjective mental fatigue assessment. Both in the baseline and post-intervention, the visual 
analog scale for mental fatigue (VAS-MF) was used to assess changes in perceived mental 
fatigue before (T1) and after (T2) two separate experimental conditions (i.e., 30-min of 100% 
incongruent Stroop task or 100% congruent version Stroop task), and after Flanker task (T3). 
The VAS has been used to extensively evaluate the change in perceived mental fatigue caused 
by prolonged cognitive task (Brown et al., 2020; Van Cutsem et al., 2017). 
 
Objective mental fatigue assessment. Both in the baseline and post-intervention, participants 
completed either a 30-min 100% incongruent Stroop task or 30-min 100% congruent Stroop 
task. Accuracy in both Stroop tasks was calculated as an index of objective mental fatigue 
(Filipas et al., 2018; Smith et al., 2015). 
 
Dispositional mindfulness assessment 
The changes in dispositional mindfulness was assessed using the 16-items (5-Likert 

 
4 
scale) athlete mindfulness questionnaire (AMQ)(Zhang et al., 2017). Higher mean scores 
indicate a higher level of dispositional mindfulness. Changes in mindfulness total scores and 
subscale scores from baseline to post-intervention were examined. 
 
Mood state assessment 
The change in mood state before and after manipulation conditions was assessed using 
the Brunel mood scale- Chinese (BRUMS-C), which contains 23 items and divided into six 
respective sub-scales such as anger, confusion, depression, fatigue, tension, and vigor (Zhang 
et al., 2014). 
 
Statistical Analysis Plan 
Specifically, all analyses followed intent-to-treat approach. The t-test (e.g., age, training 
experience) or chi-square test (e.g., gender, sports) were used separately to compare the 
difference in demographic characteristic between groups. For the manipulation check (e.g., 
subjective/objective mental fatigue), a four-way mixed-design ANOVA with 2 (GROUP: MT, 
WC) × 2 (CONDITION: MF condition, CON condition) × 3 (ASSESSMENT TIME: T1, T2, 
T3) × 2 (Phase: baseline, post-intervention) was conducted to check the effect of 
manipulation on VAS-MF (i.e., subjective mental fatigue). A similar four-way mixed-design 
ANOVA with 2 (GROUP: MT, WC) × 2 (CONDITION: MF condition, CON condition) × 5 
(BLOCK: B1, B2, B3, B4, B5) × 2 (Phase: baseline, post-intervention) was conducted to 
check the effect of manipulation on accuracy of Stroop task (i.e., objective mental fatigue). 
For the primary outcomes (e.g., endurance performance, inhibitory control), the condition 
differences (i.e., delta value) in TTE, VO2max, and RT, ACC, N2 amplitude and P3 
amplitude of Flanker task between MF condition and CON condition were calculated (CON 
− MF). Subsequently, the post-intervention of ∆TTE, ∆VO2, ∆RT, ∆ACC, ∆N2 and ∆P3 
between groups were separately compared by one-way ANCOVA while controlling baseline 
of delta value. Furthermore, the one-way ANCOVA was also separately conducted to 
compare the post-intervention of AMQ scores and mental fatigue-related change of BRUMS-
C scores between groups while controlling baseline of scores. All analyses were conducted 
using SPSS v.26 (SPSS Inc., Chicago, IL), with a significance level set at p < 0.05. 
 
 

 
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REFERENCE 
Beltz, N. M., Gibson, A. L., Janot, J. M., Kravitz, L., Mermier, C. M., & Dalleck, L. C. 
(2016). Graded exercise testing protocols for the determination of VO2max: 
Historical perspectives, progress, and future considerations. Journal of Sports 
Medicine, 2016, 3968393. https://doi.org/10.1155/2016/3968393  
Borg, G. A. (1982). Psychophysical bases of perceived exertion. Medicine & Science in 
Sports & Exercise, 14(5), 377–381. https://doi.org/10.1249/00005768-198205000-
00012  
Brown, D. M. Y., Graham, J. D., Innes, K. I., Harris, S., Flemington, A., & Bray, S. R. (2020). 
Effects of prior cognitive exertion on physical performance: A systematic review and 
meta-analysis. Sports Medicine, 50(3), 497-529. https://doi.org/10.1007/s40279-019-
01204-8  
Bruce, R. A., Kusumi, F., & Hosmer, D. (1973). Maximal oxygen intake and nomographic 
assessment of functional aerobic impairment in cardiovascular disease. American 
Heart Journal, 85(4), 546-562. https://doi.org/10.1016/0002-8703(73)90502-4  
Eriksen, B. A., & Eriksen, C. W. (1974). Effects of noise letters upon the identification of a 
target letter in a nonsearch task. Perception & Psychophysics, 16(1), 143-149. 
https://doi.org/10.3758/BF03203267  
Filipas, L., Mottola, F., Tagliabue, G., & La Torre, A. (2018). The effect of mentally 
demanding cognitive tasks on rowing performance in young athletes. Psychology of 
Sport and Exercise, 39, 52-62. https://doi.org/10.1016/j.psychsport.2018.08.002  
Friedman, N. P., & Robbins, T. W. (2021). The role of prefrontal cortex in cognitive control 
and executive function. Neuropsychopharmacology. https://doi.org/10.1038/s41386-
021-01132-0  
Smith, M. R., Marcora, S. M., & Coutts, A. J. (2015). Mental fatigue impairs intermittent 
running performance. Medicine and Science in Sports and Exercise, 47(8), 1682-
1690. https://doi.org/10.1249/mss.0000000000000592  
Van Cutsem, J., Marcora, S., De Pauw, K., Bailey, S., Meeusen, R., & Roelands, B. (2017). 
The effects of mental fatigue on physical performance: A systematic review. Sports 
Medicine, 47(8), 1569-1588. https://doi.org/10.1007/s40279-016-0672-0  
Zhang, C. Q., Chung, P. K., & Si, G. (2017). Assessing acceptance in mindfulness with 
direct-worded items: The development and initial validation of the Athlete 
Mindfulness Questionnaire. Journal of Sport and Health Science, 6(3), 311-320. 
https://doi.org/10.1016/j.jshs.2015.09.010  
Zhang, C. Q., Si, G., Chung, P. K., Du, M., & Terry, P. C. (2014). Psychometric properties of 
the Brunel Mood Scale in Chinese adolescents and adults. Journal of Sports Sciences, 
32(15), 1465-1476. https://doi.org/10.1080/02640414.2014.898184