Mindfulness, Mental Fatigue, Inhibitory Control and Endurance Performance in Athletes: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Mindfulness, Mental Fatigue, Inhibitory Control and Endurance Performance in Athletes (NCT05466136), a randomized na study. The primary outcome is Inhibitory Control: Reaction Time.

2. Clinical Question

These elements describe the question and planned comparison, not a demonstrated effect. Trait mindfulness is a participant characteristic in this study, not one of the randomized conditions. The randomized sequence concerns the order in which the fatigue and control tasks were performed. The registry record does not state how mindfulness levels were determined, whether the analysis tested an interaction between mindfulness and condition, or which comparisons were prespecified. It also does not report a primary outcome result, so the direction and size of any difference in reaction time cannot be described.

3. Trial Design

The registry record describes a completed, randomized, unmasked crossover study sponsored by National Taiwan Normal University. Enrollment was 90. The study start date was 2022-04-20, and primary completion was 2022-10-31. The registered conditions were mental fatigue and control. Participants were assigned to one of two sequences: mental fatigue condition followed by control condition, or control condition followed by mental fatigue condition. The descriptions specify an incongruent Stroop task for 30min in the fatigue condition and a congruent Stroop task for 30min in the control condition.

In a crossover design, participants experience more than one condition, allowing comparisons within the same participant. As a general statistical principle, this can account for stable differences between participants, but analysis must also consider condition order and possible effects carried from one period into another. The registry record does not report the interval between conditions, whether a washout period was used, or how period and sequence effects were handled. Those details matter to interpretation and cannot be assumed from the crossover label alone.

The study was unmasked, meaning the registry does not describe masking of participants or study personnel. The registry record does not report who was aware of the assigned condition sequence, how allocation was generated or concealed, or whether outcome assessors were masked. It also does not report details of the athlete population beyond the focus on different levels of dispositional mindfulness.

Inhibitory control reaction time was the primary outcome. Secondary outcomes were subjective mental fatigue, reaction time and accuracy in the Stroop task, mood state and motivation. The record lists 10 outcome measures, but does not provide a complete analysis plan or explain how those measures relate to specific hypotheses. Although the study status is completed, the registry record reports no analyses of the primary outcome.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Before assignment: No participants were excluded from the study.

First Intervention

Washout (3 to 7 Days)

Second Intervention

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Inhibitory Control: Reaction Time, measured over From enrollment to the end of second intervention at 1 week. During Flanker task, up to 15 minutes..

The primary endpoint was mean reaction time, measured in milliseconds during a Flanker task. Participants saw five arrows and were instructed to respond as quickly and accurately as possible to the direction of the middle arrow. Congruent trials had arrows pointing in the same direction; incongruent trials placed the middle arrow against the direction of the surrounding arrows. The task is intended to assess inhibitory control because responding to the central arrow can require resisting conflicting visual information.

Reaction time captures the speed of responses, but speed alone does not describe performance fully. Accuracy is also relevant: a faster response could have a different interpretation if it were accompanied by less accurate responding. The registry record describes the primary outcome in terms of reaction time and lists Stroop accuracy, not Flanker accuracy, among secondary outcomes. It does not report how accuracy on the Flanker task was incorporated into the primary analysis, or whether only correct responses contributed to the reaction-time measure.

The stated timeframe runs from enrollment to the end of the second intervention at 1 week, with measurement during the Flanker task for up to 15 minutes. The registry description does not specify a single time point or a rule for combining measurements across trial types or periods. The record notes that the primary outcome has several categories or time points and was not reduced to one comparison. No primary endpoint estimate, uncertainty interval or test result is reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies the design as randomized and crossover. Randomization concerns assignment to the order of conditions, as reflected in the two sequences. It does not mean that participants were randomly assigned to a level of dispositional mindfulness. The record describes higher, intermediate and lower mindfulness groups, but the method of classification and any analytical use of those categories are not reported in the registry record.

What does a crossover comparison require?

As a general statistical principle, a crossover analysis compares outcomes across conditions while accounting for the fact that measurements from the same participant are related. Treating repeated measurements as if they came from unrelated participants can misstate uncertainty. A suitable analysis may also need to consider period and sequence, since the order of conditions can matter. In this study, the registry record does not report the statistical model, the handling of condition order, or any approach to possible carryover from the first intervention to the second. It also does not report whether the analysis used paired comparisons or another method.

The distinction between within-participant and between-participant comparisons is important for interpreting mindfulness. The condition sequence was randomized, whereas mindfulness level was a characteristic used to describe groups. An association between mindfulness group and reaction time would therefore not have the same randomized interpretation as a comparison of the randomized conditions. The registry record does not say whether the analysis tested condition differences separately by mindfulness group or tested an interaction between condition and mindfulness.

How should reaction time be understood?

The primary measure is a mean of a continuous outcome. Reaction-time observations can vary across trials and participants. As a general statistical consideration, their distribution may be skewed, and means can be influenced by unusually long responses. A statistical plan would normally specify how trial-level observations are cleaned or summarized and how repeated trials are used. The registry record does not report those decisions, any transformation of reaction times, or the model used for the primary endpoint.

The Flanker task contains congruent and incongruent trials. The registry description explains the arrow arrangement and response instruction, but does not state whether reaction time was analyzed separately by trial type, combined across types, or represented by a contrast between them. Since the record flags multiple categories or time points and does not reduce the primary outcome to one comparison, the intended primary contrast is not clear from the posted information.

What does uncertainty quantify?

In general, an estimate describes the size and direction of an observed association or contrast, while a confidence interval communicates uncertainty around that estimate under the chosen model. Neither is reported for the primary outcome. A p-value can address compatibility with a null hypothesis under specified assumptions, but it cannot replace an effect estimate or its interval. No primary inferential result is reported in the registry record. Therefore, there is no basis for describing statistical significance, precision or the magnitude of a reaction-time difference.

Over-dispersion is a general issue when observed variability exceeds what a statistical model expects. If a model fails to accommodate that variability, its uncertainty estimates may be too small. The registry record does not identify a model or report a dispersion assessment, so there is no basis to say whether over-dispersion was relevant to this analysis. More broadly, a model’s validity depends on its assumptions and on how the repeated measurements and outcome distribution are represented.

What can planning calculations establish?

Sample-size calculations are planning illustrations, not observed power. The assumptions described for planning illustrations use a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation and an effect set as a stated fraction of the observed effect. The instructions distinguish total events for time-to-event outcomes from participants per arm for other outcomes. These are general planning assumptions, not evidence of the trial’s original design rationale or a reported analysis. The registry record does not report the trial’s own sample-size justification. An observed-effect-based illustration should not be read as proof that the study was adequately powered or as a measure of the probability that the observed result is true.

For this crossover study, the record does not explain how any planning illustration relates to the randomized sequences or the repeated measurements. It also does not report a target sample size, an anticipated effect used during trial planning, or an interim-analysis plan. Those details are not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 10 outcome measures, including one primary outcome and secondary measures covering subjective mental fatigue, Stroop-task reaction time and accuracy, mood state and motivation. It also indicates that the primary outcome has several categories or time points and was not reduced to one comparison. When multiple outcomes, trial types, time points or subgroup contrasts are examined, the chance of obtaining an apparently notable result can increase. As a general statistical principle, a prespecified analysis plan can clarify which comparisons are primary and how multiplicity will be addressed.

The registry record does not report a multiplicity adjustment, a hierarchy of tests, or a prespecified strategy for selecting among outcome categories or time points. It also does not state which secondary analyses were planned or performed. Since no analyses are reported, it is not possible to determine whether multiplicity affected interpretation of the study’s results.

Missing-data information is also not reported. The registry record does not describe missing primary measurements, reasons for missingness, or how incomplete repeated measurements were handled. It does not report the number of participants included in the primary analysis or whether all enrolled participants were analyzed according to their assigned sequence. The analysis population and any exclusions are not reported in the registry record.

In general, missing outcomes can affect both the estimate and its uncertainty, especially if missingness is related to condition or performance. Statistical methods can address some forms of incomplete data, but their appropriateness depends on assumptions about why measurements are missing. Without a description of missingness and the analysis approach, the effect of incomplete data cannot be assessed.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The registry lists six groups defined by mindfulness level and condition order. For every listed group, the serious adverse-event count is 0, the other adverse-event count is 0, and the death count is 0. The at-risk counts shown for the groups range from 13 to 18. These are the posted safety figures for the listed groups.

Zero recorded events in the registry should be read narrowly: it means no events are reported in those categories for those groups. It does not establish that no symptoms or other experiences occurred, nor does it provide a comparison of event risk between the two conditions. The record does not give event descriptions, a follow-up definition for adverse events, or an explanation of how events were collected. No serious adverse-event terms are listed.

The safety figures are distinct from the primary endpoint, which concerns reaction time in a Flanker task. The registry record does not report an analysis linking adverse events to condition or mindfulness level. These counts therefore describe the recorded safety categories and should not be interpreted as an estimate of comparative safety.

12. What the Result Does, and Does Not, Mean

The registry record documents a randomized crossover study of mental fatigue and control tasks in athletes described by differing levels of dispositional mindfulness. It specifies the task conditions, condition order, primary reaction-time outcome and several secondary outcomes. Those details make the study question and broad design understandable.

However, the registry record does not report primary outcome estimates or analyses. It therefore does not show whether reaction times differed between the mental fatigue and control conditions, whether any difference varied across mindfulness groups, or how precisely such differences were estimated. The completed status and enrollment figure do not answer those questions. Without outcome estimates, the direction and magnitude of the findings cannot be characterized.

The design also does not make mindfulness level a randomized exposure. The randomized element is the order of the two task conditions. Any comparison across mindfulness groups would be observational with respect to that characteristic, and its interpretation would depend on the analysis and on other differences among the groups. The registry record does not report a model or adjusted estimates to clarify that interpretation.

General statistical interpretation requires attention to effect size, uncertainty, outcome definitions and analysis choices. A confidence interval can convey precision; a p-value alone cannot show whether a difference is large or meaningful. Here, neither is reported for the primary endpoint. The record also does not state how multiple trial categories or time points were combined or how missing measurements were handled.

Accordingly, the posted information supports conclusions about what was studied and how participants were assigned to condition order, but not about the observed effect of mental fatigue on inhibitory control or endurance performance. The registry record does not report an endurance performance estimate either. No conclusion about the presence, absence or importance of an effect can be drawn from the design description alone.

13. Why This Trial Matters Statistically

This study raises a statistical question about how mental fatigue, inhibitory control and individual differences in mindfulness can be examined together. Its randomized crossover structure is relevant because each participant experienced both the mental fatigue and control conditions. In general, repeated measurements can support within-participant comparisons, while requiring analysis that recognizes the dependence between observations and considers condition order.

The study also illustrates why randomization must be described precisely. Condition order was randomized, but dispositional mindfulness was used to define participant groups. The randomized comparison and the group-based comparison consequently answer different kinds of questions. Distinguishing them is important when interpreting any proposed association between mindfulness and performance.

The primary endpoint—Flanker-task reaction time—also brings measurement choices into focus. The task includes congruent and incongruent arrow patterns, yet the registry record does not specify how those categories or time points were combined for a primary comparison. A transparent statistical analysis would make the contrast, repeated-measures structure, uncertainty and handling of incomplete data explicit.

At present, the registry record offers no reported primary analysis. That absence matters statistically: a design can motivate a question, but results are needed to estimate the effect and its precision. The record’s status as completed does not resolve the missing outcome information. Its value for statistical interpretation is therefore mainly in documenting a randomized sequence design and a set of outcomes, while leaving the effect estimates and analysis decisions unreported.

14. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The main limitation for interpreting this trial from its registry record is the absence of reported outcome analyses. No primary reaction-time estimate, confidence interval or p-value is reported, and no endurance performance result is reported. As a result, the magnitude, direction and precision of the findings cannot be evaluated.

The primary outcome is described across several categories or time points, but the registry record does not reduce it to one comparison. It does not specify the primary contrast across condition, trial type, period or mindfulness group. The record also does not explain how the repeated Flanker observations were summarized or modeled, or how response accuracy was considered when calculating reaction time.

Important design and analysis details are not reported in the registry record: the interval between conditions, any washout procedure, the approach to period and sequence effects, the statistical model, and the analysis population. The method for classifying mindfulness levels, participant eligibility details, and the number with usable measurements are also not reported. These omissions prevent fuller assessment of internal validity and generalizability.

The unmasked design may be relevant to task behavior or outcome assessment, but the record does not identify who knew the condition or whether outcome assessors were masked. The record also does not report missing-data methods or multiplicity handling across its 10 outcome measures and the primary outcome’s categories or time points. These are limitations of the information recorded, not evidence that a particular procedure was or was not used outside the registry record.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Mindfulness, Mental Fatigue, Inhibitory Control and Endurance Performance in Athletes — NCT05466136.
• Registry record last updated 2026-09-09; status last verified 2026-08.
• Results first posted 2026-03-16.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

NCT05466136 is a completed, randomized, unmasked crossover study sponsored by National Taiwan Normal University, with enrollment of 90. The study examined mental fatigue, inhibitory control and endurance performance in athletes with different levels of dispositional mindfulness.

Participants were assigned to one of two condition sequences. The mental fatigue condition used an incongruent Stroop task for 30min; the control condition used a congruent Stroop task for 30min. The primary outcome was mean Flanker-task reaction time in milliseconds. Secondary outcomes included subjective mental fatigue, Stroop-task reaction time and accuracy, mood state and motivation.

The registry record reports zero analyses and does not report primary outcome estimates or inferential results. Details of the analysis plan, missing data, multiplicity handling and the trial’s sample-size justification are not reported in the registry record. Safety counts are zero for serious adverse events, other adverse events and deaths in each listed group.