Effects of long-term mindfulness meditation training on attentional capacity in professional male fencer athletes

Abstract

Attention is a crucial cognitive ability for sports performance. The current research aimed to investigate whether long-term mindfulness meditation (MM) intervention enhances male athletes’ attentional function and alters the activity of brain regions related to attention. In this experiment, we recruited 47 professional male fencer athletes completed two main trials—an MM trial and a control trial. In MM trial, the participants were provided with 3 sessions/wk (20 min/session) of mindfulness meditation training for 20 weeks. In control trial, the participants were instead assigned a mind-wandering related audio to listen to at that time. In each main trial, the five facets of mindfulness questionnaire (FFMQ), cognitive function (i.e. attention span, attention concentrativeness, attention stability, attentional network, distractibility and attentional blink), salivary cortisol, blood lactate and mental fatigue were measured at baseline (pretest) and after the intervention (posttest). The cerebral oxygenation status was recorded using functional near-infrared spectroscopy(fNIRS) during the cognitive function test. In cognition test, participants’ attention span, attention concentrativeness, attention stability, attentional networks on task-relevant information (targets) were better in the MM group, supported by eliciting increased oxygenated haemoglobin (HbO) concentration in the prefrontal cortex of the brain. Conversely, there are no remarkable different of distractibility and attentional blink on task-irrelevant information in the MM group than in the Con group (p > 0.05). Moreover, a lower mental fatigue level and lower salivary cortisol concentration were observed in the MM group than in the Con group after the intervention at posttest. Overall, 20-week MM training interventions after physical training improve attentive capacity and cerebral oxygenation concentration, decrease salivary cortisol concentrations and mental fatigue. The findings suggest that long-term MM training interventions after physical training facilitates focus during competition and improves athletic performance.

Introduction

Attention, the prioritization of goal-relevant stimuli, represent one of the most important main endogenous determinants of visual cognition, which is crucial in our perception of a stable world¹. Attention is often classified into the following elements: distractibility², attention span³, attention network⁴, selective attention⁵, attention stability⁶, attentional blink, attention shifting⁷. Previous research has proven to the importance of attention in sports performance^8,9, especially competitions that rely on precision, such as shooting, archery¹⁰, and golf¹¹. To get a good performance in contest, athletes are required to keep a high level of attention focusing and selective attention. For instance, during the competition, athletes actively focus attention on competition-related message (e.g., the objective) and avoid being distracted by competition-irrelated message (e.g., depress and /or anxiety status, environment). Compared with traditional behavioral paradigm and questionnaire survey^12,13, cognitive function test software is widely used in the field of psychology and brain science because of its direct, accurate and objective advantages^14–16.

Despite the important of traditional psychological skills training (PST) in the improving performance has been acknowledged in professional and semi-professional sports, a lack of convincing evidence and theoretical underpinning concerning PST to enhance performance in sports¹⁷. On the one hand, the efficacy of traditional PST do not meet the criteria for evidence-based empirical support¹⁸. On the other hand, traditional PST mainly controlling athletes’ mind by eliminating unexpected cognitive and emotional content, which has certain side effects, such as making the athletes unable to pay full attention to the competition¹⁹. On the contrary, mindfulness-based intervention is an orientation toward the present moment characterized by non-judgmental and opennes when suffering internal and/or external stimuli, including one’s feelings, thoughts, body states, awareness, and environment²⁰. The body of literature on mindfulness-based interventions has been widely applied in competitive sports for improving performance has increased exponentially in recent years^21–23. It was pointed out that two mainly important components of mindfulness, one is involves self-regulation of attention, and the other is involves an attitude of present-centred, curiosity, openness, and acceptance²⁴. Therefore, from a theoretical perspective, mindfulness-based intervention should affect attention, as attention is a key component of the conceptualization of mindfulness²⁵.

Mindfulness-based interventions are a promising approach and have received increasing attention in the field of competitive sports²⁶. Tóth and colleagues highlighted that mindfulness-based interventions can improve ice hockey athletes’ corrected shifting abilities in the SWITCH test and information processing speed in the trail making test that tested by a computer-based psychological testing system, the Vienna test system²⁷. Furthermore, mindfulness-related interventions are adopted in the field of sports psychology, including but not limited to competitive sports, such as brief mindfulness-based intervention^28,29, long-term mindfulness-based intervention^30–32, online mindfulness-based intervention^33,34, brief mindfulness-based intervention coupled with fluid intake³⁵, and so on. Among them, long-term meditation is the most common intervention by reviewing the literature, and those literature mainly focus on the benefits of mindfulness-based intervention on individual, such as improving athletic performance (e.g., free-throw accuracy in basketball, ranking points in table tennis, serve accuracy in tennis)^36,37. However, the effect of long-term mindfulness on enhancing attention in athletes has yet to be investigated. However, it is unknown whether brain correlates represent the process by which mindfulness enhances attention.

Mindfulness meditation theoretical frameworks conceptualise the cultivation of focused attention and emotional state management, as well as attitudinal underpinnings that promote nonjudgment and acceptance, in order to ease cognitive and affective processing and hence improve brain health³⁸. Several networks have been most consistently linked to mindfulness-related modulation of their functional connectivity. A review reported by Uddin et al. presented six common macro-scale brain network according taxonomy of functional brain networks: occipital network-visual, pericentral network-somatomotor, dorsal frontoparietal network-attention, lateral frontoparietal network-control, midcinguloinsular network-salience, mmedial frontoparietal network-default. We can learn from six common macro-scale brain network that attention is connected closely with dorsal frontoparietal network (DFPN)³⁹. The core regions of dorsal frontoparietal network, include the superior parietal lobule, middle temporal complex and the putative frontal eye fields (BA8), which is given the cognitive label “attention” because of its broad significance in visuospatial attention⁴⁰. The DFPN mainly regulates the activity of task-related in the brain to achieve top-down attention^41,42. The functional magnetic resonance imaging scanner in Go/NoGo tasks revealed that healthy participants increased their brain activations more over the right dorsolateral prefrontal cortex (DLPFC) and superior parietal lobe under gaming cue distraction⁴³. Conversely, an event-related electrophysiological study examined an auditory version of the delayed-match-to-sample task and found that neurological patients with focal lesions in the dorsolateral prefrontal cortex showed a failure in inhibitory control of sensory processing and reductions of neural activity as well as additional intrahemispheric reductions of attention-related frontal activity⁴⁴. Previous studies have demonstrated that mindfulness-based interventions are associated with changes in the DFPN⁴⁵. Based on above, we suppose that the neural mechanism of mindfulness improves attention in professional male fencer athletes may also be reflected in the activation or functional connectivity of the DFPN.

Therefore, the first objective of this study was to determine the influence of long-term mindfulness meditation intervention on male athletes’ attentional function. In addition to verifying the influence of mindfulness meditation on attention, understanding the mechanism underlying such an effect is vital. A functional near-infrared spectroscopy study revealed that long-term mindfulness practice led to the neural benefits of efficient activation in the prefrontal cortex, which is associated with the increase of cerebral blood oxygen levels⁴⁶. Mindfulness meditation is a psychological intervention that may change mental parameters. Therefore, the second objective of our study was to investigate the impact of long-term mindfulness meditation intervention on mental fatigue and/or the potential involvement of cortisol on mental fatigue and attention. We hypothesized that that compared with the Con group, the MM group would (1) benefit attention and be associated with higher oxygenated haemoglobin concentrations in the prefrontal cortex, supported by eliciting increased activation of the right dlPFC; (2) accompanied by a lower cortisol concentration and mental fatigue level.

Materials and methods

Study design and participants

Fifty professional male fencer athletes from China were enrolled in this study. All the participant were meet the following inclusion criteria: (1) All the participants are aged 18 to 30; and (2) No regular mindfulness practice in the past year; and (3) No participate in other organized mindfulness-related training in spare time; and (4) No cognitive, physical, or eyesight impairments; and (5) No surgery or drug use in the last six months. Three participants were excluded due to surgery issues. The 47 eligible participants were randomly assigned to the MM group (n = 25) and the Con group (n = 22) using a randomization sequence. The participants in the MM group were provided with 3 sessions/wk (20 min/session) of mindfulness meditation training for 20 weeks, while the participants in the Con group were instead assigned a travel-related audio to listen to at the same time. Finally, all the participants were required to attend FFMQ, cognitive function with fNIRS, salivary cortisol, blood lactate and mental fatigue test at pretest and posttest, details as shown in Fig. 1. Written informed consent was obtained from all the participants prior to participation. The experiment in this study was approved by Capital University of Physical Education and Sports ‘s Human Research Ethics Committee. The study was following the Declaration of Helsinki.

Fig. 1.

The detailed protocol.

Mindfulness interventions

The participants in the MM group were asked to concentrate their attention on a single object (i.e., their breath), keep an eye out for distractions, and nonjudgmentally redirect their attention back to the object if one occurred. For example, the participants in the MM group did a breath count task in which they counted their breathing cycles from 1 to 9, using the left arrow key to count and the right arrow key to reset the count after the ninth breath. When they lost count, they pressed the spacebar to reset the counter and began counting again using the left arrow. This intervention has been reported to induce mindfulness^47,48. While the participants in the Con group were required to read books related to the auditory system and press the right arrow key to navigate to the next page at the same time.

Measures

Body morphology

All the participants in this study were assessed for body height and weight as well as body mass index. Height and weight evaluations were conducted using the Holtain stadiometer and Inbody J10 (Biospace Corp., Seoul, Korea). Weight in kilograms divided by the square of height in meters (measured in kg/m²) to get each participant’s body composition.

Perception outcomes

FFMQ After long-term mindfulness meditation training or reading task, all the participants were asked to finish the five facets of mindfulness questionnaire (FFMQ), which was used as measure individual mindfulness states with regards to thoughts, experiences, and actions in daily life. Each of the 39-items uses a five-point scale: 1 (Never or very rarely true), 2(Rarely true), 3(Sometimes true), 4(Often true), 5(Very often or always true). In this test, a higher total score in the FFMQ of the participants means a better state of mindfulness^49,50.

Mental fatigue Mental fatigue was assessed using 1–10 point RPE scale, ranging from 1 (resting) to 10 (mmaximal).This evaluation method has also been used in previous studies⁵¹.

Attentional capacity test

Attentional abilities were evaluated by means of multitask computerized assessment. A test of cognitive function comprising the attention span, attention concentrativeness, attention stability, attentional network, distractibility and attentional blin in an event design was administered from one computer^52,53.

Attention span: This is a test of attention. After the test began, the subjects were asked to focus their attention on the center of the screen. Note that the target appears in a short time, after each viewing, the subjects should fill in the number of targets as soon as possible.

Attention concentrativeness: When the test starts, a character matrix will appear on the screen. Please check the matrix in order from left to right and from top to bottom. As long as the target character is found, it is marked with the left mouse button until this matrix is checked, click “Next page” to continue the check. Leaks and errors are recorded incorrectly. The subject needs to react as quickly as possible while remaining accurate.

Attention stability: After the test starts, several words will appear on the screen, some of which will blink several times. When they start to move, keep your eye on the picture that just flashed and keep track of them. After a while, all the words will change, and one of the words you’ve been tracking will become a “p” or a “q.” If you see “p”, press the P key on your keyboard as soon as possible, and if you see “q”, press the q key. Please react as quickly as possible while remaining correct.

Attentional network: After the test starts, a center point will appear in the center of the screen, and then a set of arrows will appear above or below it. Please identify the arrow in the middle of this set of arrows and press the corresponding arrow key on the keyboard.

Distractibility: In the following test, subjects will see three kinds of red, yellow and blue circles and four Chinese characters “up”, “down”, “left” and “right”. According to different conditions, the subjects’ left and right hands will complete three tasks respectively or together. Task 1 is to identify different colored circles with the left hand; The second task is to recognize the Chinese character representing the direction with the right hand; In Task three, both hands are required to respond to their respective goals, depending on the situation. Please react as quickly as possible while remaining correct.

Attentional blink: After the test starts, multiple letters will flash in sequence in the center of the screen, please remember the red letter, and pay attention to whether the letter X appears after the red letter, and then answer the relevant questions.

Hemodynamic changes

Spontaneous changes of cerebral oxygenation in prefrontal cortex is measured using functional near-infrared spectroscopy (fNIRS) as previously described^54,55. The system constituent part with dual wavelengths (760 and 850 nm) and a 3 cm source-detector separation comparison channel (NIRx Medical Technologies LLC, New York, US). The detectors are positioned on the participant’s prefrontal cortex (PFC). The system includes eight light sources and eight detectors, for a total of 16 channels. It is worth mentioning that the attention-relevant regions in this study and prior research were identified as Brodmann areas 9 (BA9) and BA10. BA9 includes the dorsolateral/anterior PFC, whereas BA10 includes the anterior PFC⁵⁶. Resting-state fNIRS data were collected after attention test 10 min, and the participants sat comfortably in a chair with their eyes closed. Raw fNIRS data were recorded for lasting 20 min at 5 Hz. The necessary collection software (MATLAB 2021Ra software and the Homer2 fNIRS processing package) was used to collect NIR spectral data and assess the signal-to-noise ratio⁵⁷.

Salivary cortisol

Saliva samples were collected using a mouth swab (Salivette® Cortisol, with synthetic swab) measured with salivary cortisol. A cotton swab is placed on the front of the tongue to collect saliva, then removed from the mouth and inserted into a syringe bucket. After centrifugation (CS150NX, Eppendorf, Hamburg, Germany), the saliva samples were stored in an ultra-low temperature refrigerator (906GP-ULTS, Thermo-fisher Scientific, Pittsburgh, USA) at – 80 °C and analyzed within 2 weeks. Salivary cortisol levels were assessed using a commercial enzyme-linked immunosorbent assay kit (96T, H094-1-2, Nanjing Jiancheng Bioengineering Institute, Nanjing, China) according to the manufacturer’s instructions⁵⁸.

Statistical analyses

All the baseline (pretest) and posttest data are presented as means standard deviations (SDs). SPSS was used for statistical analysis (version 26, IBM SPSS, Armonk, NY, USA). The sample size was conducted by G*Power analysis. The variances of the sample data for normality, homogeneity were evaluated by the Shapiro-Wilk and Levene, respectively. A paired sample t-test was used to determine group differences of mindfulness state based on their FFMQ scores. A 2 (conditions: MM and control) × 2 (times: pretest and posttest) repeated-measures analysis of variance (ANOVA) was conducted to examine the between- and within-condition effects. The significance level was set to 0.05.

Results

Long-term mindfulness meditation training

The mindfulness status in each group are shown in Fig. 2. Significant interaction and time effects were observed for mindfulness levels, (F (_{1, 90}) = 5.61, p < 0.05 for interaction effect; F(_{1, 90}) = 11.45, p < 0.05 for time effect). We can learn from the Fig. 2 that at the pretest stage, no significant group differences of the score in FFMQ test were observed in the MM and Con groups (p > 0.05). At the posttest, a significantly higher mindfulness state was observed on FFMQ in the MM group compared with the Con group (p < 0.001). There were no significant differences at pre- and post-test in Con group (p > 0.05), while a significant time effect was detected pre- and post-test in the MM group (p < 0.01). These results revealed that the participants in the MM group demonstrated higher mindfulness levels on the FFMQ than that in the Con group. Hence, the intervention was successful.

Fig. 2.

State mindfulness in each group. ^###p < 0.001 represent pre-test vs. post-test in the MM group. ^&&p < 0.01 represent compared with Con in the post-test stage.

Attention results

Figure 3 presents the attention data in each group. Significant interaction and time effects were observed for attention capacity, (attention span: F (_{1, 90}) = 5.782, p < 0.05, attention concentrativeness: F (_{1, 90}) = 5.524, p < 0.05, attention stability: F (_{1, 90}) = 35.05, p < 0.05, attentional network: F (_{1, 90}) = 46.95, p < 0.05, distractibility: F (_{1, 90}) = 1.215, p < 0.05, attentional blink: F (_{1, 90}) = 0.207, p < 0.05, for interaction effect; attention span: F (_{1, 90}) = 16.42, p < 0.05, attention concentrativeness: F (_{1, 90}) = 22.99, p < 0.05, attention stability: F (_{1, 90}) = 46.36, p < 0.05, attentional network: F (_{1, 90}) = 91.60, p < 0.05, distractibility: F (_{1, 90}) = 0.197, p < 0.05, attentional blink: F (_{1, 90}) = 0.65, p < 0.05, for time effect). There were no significant differences of attention span, attention concentrativeness, attention stability, and attentional network in attention test between the two groups at the pretest stage (p > 0.05). After 20 weeks interventions, a significant improvement was detected for attention span, attention concentrativeness, attention stability, and attentional network in the MM group when compared with Con group in the post-test stage (p < 0.05), but there was no significant difference between the two groups in terms of distractibility and attentional blink (p > 0.05).

Fig. 3.

Effect of mindfulness meditation training on attentive capacity in (A) attention span; (B) attention concentrativeness; (C) attention stability; (D) attentional network; (E) distractibility; (F) attentional blink. ^###p < 0.001 pre-test vs. post-test in the MM group. ^&&p < 0.01 represent represent compared with Con in the post-test stage.

A significant improvement in attention span, attention concentrativeness, attention stability, and attentional network subscores pre- to post-intervention (time effect) was seen for MM group (p < 0.05). In addition, no significant interaction effect or group effect was observed for distractibility and attentional blink (p > 0.05). In conclusion, the participants in the MM group demonstrated higher attentive capacity on the attentional test than that in the Con group. These data collectively suggested that a higher attentive capacity of athletes response to mindfulness meditation intervention observed in this study highlights the importance of mindfulness meditation intervention to training athletes.

fNIRS outcomes

Figure 4. revealed the fNIRS outcomes in each group. We conducted an analysis of variance to compare the HbO in different regions between the two groups during the attention test. We can learn from the Fig. 4. that there were no significant differences in terms of HbO before and after treatment between the two group in the left BA9 (p > 0.05) and the right BA9 (p > 0.05).

Fig. 4.

Effect of mindfulness meditation training on oxygenated haemoglobin concentration in (A) left BA9; (B) right BA9; (C) left BA10; (D) right BA10. ^#p < 0.05 represent pre-test vs. post-test in the MM group. ^&p < 0.05 represent compared with Con in the post-test stage.

However, significant interaction and time effects were observed for HbO (F (_{1, 90}) = 0.13, p < 0.05 for interaction effect; (F (_{1, 90}) = 13.33, p < 0.05 for time effect) in the left BA10 (p < 0.05,) and the right BA10 (p < 0.05). We can learn from the Fig. 4. that the pretest–posttest difference was significant in the MM group (p < 0.05) but not in the Con group (p < 0.05). Furthermore, the MM group had a greater HbO than did the Con group at the posttest p < 0.05). Figure 4 displays the differences in HbO₂ concentrations in the BA10 after physical exercise pretreatment, while no differ in the BA9. Such evidences collectively supported that mindfulness meditation intervention induced a remarkable increase of HbO in anterior PFC regions of professional male fencer athletes.

Salivary cortisol

Figure 5 depicts the changes in the salivary cortisol concentration in each group at pre-and-posttest in response to exercise. Significant interaction and time effects were observed for salivary cortisol, (F (_{1, 90}) = 8.069, p < 0.05 for interaction effect; F(_{1, 90}) = 8.14, p < 0.05 for time effect). The results indicated that the pretest–posttest difference was significant in the MM group (p < 0.01), but not in the Con group (p > 0.01). Furthermore, the MM group had a lower salivary cortisol concentration than did the Con group at the posttest (p < 0.05). This result indicated that the professional male fencer athletes exhibited lower cortisol concentrations after 20-week mindfulness meditation intervention, meaning that the athletes have a relaxing status after mindfulness meditation intervention, given its advantages.

Fig. 5.

Effect of mindfulness meditation training on salivary cortisol in each group. ^##p < 0.05 represent pre-test vs. post-test in the MM group. ^&p < 0.01 represent compared with Con in the post-test stage.

Mental fatigue

We observed from the Fig. 6. that regarding the RPE, the main effect of time was significant (F (_{1, 90}) = 11.4, p < 0.05) and that of interaction (F (_{1, 90}) = 21.65, p < 0.05) were significant. Findings suggest that participants’ mental fatigue significantly decreased after mindfulness meditation training (p < 0.001).

Fig. 6.

Effect of mindfulness meditation training on mental fatigue in each group. ^###p < 0.001 represent pre-test vs. post-test in the MM group. ^&&&p < 0.001 represent compared with Con in the post-test stage.

Discussion

This study explored the effects of long-term mindfulness meditation on the attention in professional male fencer athletes. Participants were required to finish 20-week mindfulness meditation interventions or to read books related to the auditory system at the same time. The key finding of this study is that long-term mindfulness meditation may potentially benefit fencer athletes’ attention, as the fNIRS results indicated significant changes in HbO concentration within specific brain areas after the intervention. In addition, the concentration of salivary cortisol and level of mental fatigue decreased after mindfulness meditation interventions. In general, our results supported our hypotheses at both the behavioural and neurological levels.

Previously studies provided adequately documented beneficial effects of mindfulness meditation on attentional capacity. The results in this study provides elementary evidence of the long-term mindfulness meditation on attentional capacity in professional male fencer athletes. Consistent with previous hypothesis, the results in this study demonstrated that the participants’ attention (i.e., attention span, attention concentrativeness, attention stability, attentional networks) on task-relevant information in the MM group was significantly improved after 20-week mindfulness meditation interventions in the post-test than those in the pre-test, conversely, the significant difference both distractibility and attentional blink on task-irrelevant information was not detected in the MM group at pre-and posttest. Our finding is consisted with a recent study that explored the effectiveness of long-term mindfulness meditation on attention⁵⁹, but this study was only an intra-group comparison because of no control group. However, in our study, we further demonstrated that the significant between-group difference of attentional capacity at posttest was detected, in other words, the MM group showed higher attentional capacity than the control group. This results also confirmed in previously study⁶⁰.

It is well known that it is essential for the brain to receive optimal oxygen and blood supply during the process of improving attentional capacity⁶¹. Studies have shown that brain oxygenation and hemodynamics can be altered by both internal and external interventions^62,63. Therefore, in order to better understand the relationship between brain oxyge nation/hemodynamics and attentional processing, we adopted fNIRS to quantify noninvasive changes in brain oxygenation, including oxygenated hemoglobin (HbO) in the human brain. Our results demonstrated that after 20-week mindfulness meditation interventions, the participants in the MM group exhibited a characteristic response of increased HbO in the right BA9 and BA10. Shakrawal and his colleague also consisted with this results that meditation was associated with significant increase in cortex oxygenation, including but not limited to a significant increase of HbO and significant decrease of HbR⁶⁴. We suspect that the increased of brain oxygenation level after long-term mindfulness meditation is associated with the increased of neural activity induced by attentional processing. This hypothesis has been tested by subsequent results. The fMRI results revealed that mindfulness meditation interventions caused increased neural activation in the right dorsolateral prefrontal cortex involved in sustaining and monitoring the focus of attention⁶⁵. This is explained by the fact that areas of high neural activity, including PFC, tend to have increased oxygen consumption and enhanced blood supply to ensure the required HbO supply⁶⁶. A recent study by Aly et al. showed that the neurophysiological evidence of the transient beneficial effects of a brief mindfulness exercise on cognitive processing using ERP measures. This study demonstrated that mindful exercise in healthy young adults could enhance the accuracy of cognitive performance and calm the neural response in P3 during the Flanker task, indicating more efficient cognitive processing, and enriching the effects of mindfulness meditation on attentional and cognitive performance⁶⁷. In addition, further study showed that the increased of brain oxygenation level after long-term mindfulness meditation is associated with cerebral blood flow (CBF), which plays a critical role in cognitive performance⁶⁸. For example, meditation experts pointed out that specific hemodynamic responses in the right temporo-parietal junction while meditating on an auditory stimulus⁶⁹. Another study by single photon emission computed tomography neuroimaging reveals that 5-days mindfulness meditation significantly enhanced cerebral blood flow (CBF) in subgenual/adjacent ventral anterior cingulate cortex, medial prefrontal cortex and insula⁷⁰.

A growing body of literature has documented that the relationship between mindfulness meditation and salivary cortisol^71–73. Cognitive decline is related with a higher levels of cortisol⁷⁴, while cognitive improvement (including but not limited to mindfulness meditation training)^75–77 is often associated with reduced cortisol. For example, Creswell and his colleague observed that mindfulness meditation training reduced individuals’ stress reactivity by regulating salivary cortisol reactivity⁷⁸; Ooishi et al. reported that mindfulness meditation training can improve physiological relaxation, or elevate physiological arousal, both of which are associated with a decrease in salivary cortisol levels⁷⁹, this result is similarly with other’s study⁸⁰. Zhu et al. also directly revealed that the reduced salivary cortisol after mindfulness meditation training is related with the improvement of attention in the Stroop congruent and incongruent tasks⁸¹. This conclusion is consistent with our results in present study that the participants showed a lower salivary cortisol after 20-week mindfulness meditation intervention. It was reported that even a single (e.g., 20-minute)⁸², or short-term^71–83 (e.g., seven 20-minute sessions or 3 days) mindfulness meditation intervention, all can significantly reduce cortisol levels. Thus, we concluded that the decreased salivary cortisol associated with increased attention after mindfulness meditation training.

In competitive sports, mental fatigue is considered as a psychological index that can affect athlete’s performance^84,85 and attention⁸⁶, which is essential because mental fatigue can influence decision accuracy and attentional flexibility in competition. The results in this study demonstrated that the athletes both in the MM and Con groups showed higher levels of mental fatigue at the pre-test, which is consistent with Gantois et al.,⁸⁷, who suggested that higher levels of mental fatigue are associated with worsening attention. Mechanistically, mental problem (e.g., chronic fatigue, depress) is closely related to the autonomic nervous system (including (sympathetic and parasympathetic) imbalances⁸⁸. And Sympathetic hyperactivity, due to decreased parasympathetic activity, is linked to mental fatigue caused by extended cognitive stress⁸⁹. However, mindfulness meditation can ameliorate the negative effect of mental fatigue in professional athlete population. The benefit of mindfulness meditation intervention on psychological statuses has been acknowledged in the field of athletic psychology and neurobiology, such as reduce the feeling of fatigue and stress, help adjust the mental state, and enhance satisfaction and happiness^90–92. A randomized controlled follow-up study indicated that mindfulness intervention effectively reduced mental fatigue caused by competing in volleyball athletes⁹³. Our results revealed that mental fatigue significantly decreased after mindfulness meditation intervention in fencer athletes. The findings of the current study support this hypothesis with participants in mindfulness meditation condition, in an accepting, openness mood and relaxed attitude, may be able to ameliorate mental fatigue by control the biological system and⁹⁴. in other words, mindfulness meditation can ameliorate induced mental fatigue by improving autonomic balance of sympatho-vagal, for instance, reducing sympathetic and increasing parasympathetic influence⁹⁵. As a result, implementing using a mindfulness meditation training to reduce mental fatigue appears viable.

In summary, this study demonstrated 20-week MM training interventions after physical training improve attentive capacity and cerebral oxygenation concentration, decrease salivary cortisol concentrations and mental fatigue. Therefore, we recommend the application of mindfulness practice in professional athletes, especially in closed-skill sports that require high attention participation (e.g., shooting, archery, darts, golf, gymnastics, skating etc.). But there are still some limitations in this study. First, all the participants in this study are male athletes. The lack of female athletes may have limited the generality of the results. Future studies should consider including female participants and further expand the sample size. Second, this paper demonstrates the positive effects of long-term mindfulness meditation on fencer athletes, but the effects on athletes in other sports (e.g., shooting, golf, etc.) need to be further demonstrated. Third, heart rate of athletes was not monitored in cognitive function tasks. Given that heart rate may affect cognitive performance, future research should involve human resource monitoring or cardiovascular index during cognitive tasks. Lastly, in our experiment, we use FFMQ was used to evaluate individual mindfulness states with regards to thoughts, experiences, and actions in daily life, which may product response bias because of the reliance on self-reported FFMQ data. More appropriate methods for assessing the state of mindfulness should be adopted in the next step research.

Conclusion

The results showed that after 20-week mindfulness meditation training interventions, participants exhibited better attentional capacity and lower salivary cortisol concentrations and mental fatigue. At the neural level, long-term mindfulness meditation induction significantly enhanced neural activity in PFC. Given these findings, we recommend that psychologists advocate long-term mindfulness mindfulness practices to enhance athletes’ attentive capacity prior to competitions.

Author contributions

“HD wrote the main manuscript text. LZ, MC helped complete the experiment.HBW prepared figures. XJZ revised the manuscript. All authors reviewed the manuscript.”

Funding

This work was supported by the Philosophy and Social Sciences Foundation of the Anhui Higher Education Institutions of China (2024AH052821 and 2024AH052823). Natural Science Foundation of the Higher Education Institutions of Anhui Province (2022AH051434).

Data availability

All data can be obtained from the corresponding author.

Competing interests

The authors declare no competing interests.