Rewiring for Victory: Neuro-Athletic Training Enhances Flexibility, Serve Speed, and Upper Limb Performance in Elite Volleyball Players—A Randomized Controlled Trial

Abstract

This randomized controlled trial investigated the effects of neuro-athletic training (NAT) on flexibility, spike speed, and upper extremity stability in elite volleyball players. Thirty professional male athletes aged 18–23 years old (mean age of 19.5 ± 1.77 years old in the NAT group and 19.8 ± 1.87 years old in the control group) participated, with 26 completing this study. The participants were randomly assigned into an NAT intervention group or a control group continuing traditional training. Both groups trained three days per week for eight weeks, with the NAT program targeting neuromuscular adaptations while maintaining equal total training durations. Flexibility was assessed using the Sit and Reach Test, spike speed was evaluated using the Pocket Radar Ball Coach, and upper extremity stability was measured using the Closed Kinetic Chain Upper Extremity Stability Test (CKCUEST). The NAT group demonstrated significant improvements across all performance metrics. Flexibility increased significantly (p = 0.040; Cohen’s d = 0.845), indicating improved range of motion and musculoskeletal adaptability. Spike speed showed a highly significant improvement (p < 0.001; Cohen’s d = 1.503), reflecting enhanced neuromuscular coordination and power. Similarly, upper extremity stability exhibited substantial gains (p = 0.002; Cohen’s d = 1.152), highlighting improved shoulder stability and motor control. In contrast, the control group did not show statistically significant changes in their flexibility (p = 0.236; Cohen’s d = 0.045), spike speed (p = 0.197; Cohen’s d = 0.682), or upper extremity stability (p = 0.193; Cohen’s d = 0.184). Between-group comparisons confirmed the superiority of the NAT intervention, with significant differences across all metrics (p-values ranging from 0.040 to <0.001) and effect sizes spanning from moderate to large (Cohen’s d = 0.845–1.503). These findings demonstrate the effectiveness of NAT in enhancing volleyball-specific performance metrics, emphasizing its potential to target neuromuscular adaptations for improved flexibility, power, and stability. Future studies should explore the long-term effects of NAT and its applicability across various sports disciplines.

1. Introduction

The competitive landscape of elite volleyball requires continuous innovation in its training methodologies to enhance athletic performance. Neuro-athletic training (NAT) has recently gained traction as a novel paradigm that integrates neuroscience principles with athletic conditioning to optimize neuromuscular function. Traditional training regimens in volleyball have historically focused on biomechanical and physiological elements, often neglecting the neural components of athletic performance. However, the complex coordination of sensory and motor systems suggests a profound neural foundation for high-level athletic skills [1]. Neuro-athletic training (NAT) proposes that by fostering neuroplasticity and enhancing the efficiency of the neural pathways, it is possible to achieve improved motor output, coordination, and overall athletic performance [2,3].

NAT combines principles from both athletic training and neuroscience, suggesting that strengthening neural control mechanisms can significantly elevate physical performance beyond what is achievable through traditional methods alone. This approach emphasizes refining the movement control systems—namely the visual, vestibular, and proprioceptive systems—that govern an athlete’s interaction with their environment [4]. These systems form a foundational triad dictating the accuracy of motor responses and the fluidity of complex movements essential in volleyball, such as spiking and blocking [5]. The visual system is crucial for tracking the ball and anticipating opponents’ actions; the vestibular system supports balance and spatial orientation during rapid movements; and the proprioceptive system enables precise motor control, making each part of the triad indispensable to NAT’s effectiveness [2,3]. Effective communication between these systems ensures high-quality sensorimotor signals, which directly influence the performance outcomes [6]. Conversely, disruptions or suboptimal signals within these pathways can hinder training success and athletic performance, as highlighted by Gaerlan et al. [7].

Central to NAT is the vestibular system, which plays a significant role in balance, spatial orientation, and the fine-tuning of movements—all essential for volleyball-specific skills such as serving and spiking [7]. NAT’s impact on flexibility, a key attribute for volleyball athletes, can facilitate an increased range of motion and a more dynamic muscular response through neuromuscular conditioning Additionally, serve speed and upper limb strength, which are critical for powerful serves and effective defence, are hypothesized to be positively modulated by an athlete’s neural conditioning through NAT [8].

The importance of this randomized controlled trial lies in its potential to provide empirical evidence of the impact of neuro-athletic training (NAT) on volleyball-specific performance metrics, such as flexibility, serve speed, and upper limb strength and coordination. NAT aims to optimize neuromuscular performance by targeting the neural pathways involved in motor control and sensorimotor integration [9,10]. Traditional volleyball training programs primarily emphasize biomechanical and physiological aspects like strength and endurance, often overlooking the neural contributions essential for complex motor tasks [11]. As recent studies have highlighted, enhancing the nervous system’s efficiency in coordinating sensory inputs and motor outputs could unlock new performance gains in sports with high sensorimotor demands [12,13].

Neuro-athletic training combines principles from neuroscience and motor learning, emphasizing the enhancement of neural systems that govern movement accuracy, coordination, and reaction speed [14]. Specifically, NAT addresses the integration of the visual, vestibular, and proprioceptive systems, which are crucial for an athlete’s environmental awareness and movement execution [15]. These sensory systems form the foundation for coordinated motor responses in volleyball-specific skills, such as spiking, serving, and blocking [10]. Effective communication between these systems ensures high-quality sensorimotor signals, directly influencing athletic performance outcomes, while disruptions or inefficiencies in these pathways can lead to reduced performance and increased injury risk [16].

The vestibular system, a key component of NAT, plays a significant role in balance, spatial orientation, and the fine-tuning of motor tasks, all of which are critical for volleyball athletes who must maintain stability during rapid, multi-directional movements [10]. Additionally, NAT’s focus on improving neural efficiency may positively affect flexibility, serve speed, and upper limb strength by enhancing neuromuscular responses [17]. This aligns with recent findings that suggest neural conditioning can promote better motor output and coordination, essential for sports performance [18].

The clinical relevance of this study extends beyond performance enhancement. By improving sensorimotor integration, NAT may contribute to injury prevention, recovery, and long-term athletic resilience. Improved neural control over movement patterns may reduce the risk of coordination-related injuries, such as ankle sprains and shoulder strains, which are common in volleyball [19]. Moreover, the potential for NAT to retrain the neural pathways opens new possibilities for rehabilitation, supporting athletes in regaining optimal sensorimotor function post-injury [20].

Uniquely, this study positions NAT as an essential component of athletic conditioning, not merely a supplementary technique. By comparing NAT protocols to traditional training methods, this trial aims to determine whether NAT can produce significant improvements in flexibility, serve speed, upper limb strength, and coordination. The hypothesis is that NAT enhances sensorimotor signal quality and optimizes the neuromuscular pathways, thereby providing a more efficient platform for athletic execution [10]. If validated, NAT could represent a paradigm shift, placing the nervous system at the forefront of training methodologies for volleyball and potentially other sports with complex motor demands.

The aim of this study is to validate the theoretical framework of neuro-athletic training (NAT) and address a critical gap in the literature on sports performance by empirically examining NAT’s impact on specific volleyball performance metrics, including flexibility, serve speed, and upper limb strength and coordination. The primary hypothesis is that NAT will significantly enhance these volleyball-specific performance metrics compared to traditional training methods by optimizing neuromuscular function, with an emphasis on the nervous system’s role in athletic conditioning. A secondary hypothesis suggests that NAT’s neurocentric approach could contribute to a more efficient training platform, improving sensorimotor integration and overall athletic performance for elite volleyball players.

2. Materials and Methods

2.1. Study Design and Participants

This randomized controlled prospective trial was designed to evaluate the effects of a neuro-athletic training (NAT) program on flexibility, serve speed, and upper extremity performance in elite volleyball players. An initial sample of 30 professional male volleyball players, aged approximately 18.87 to 23.47 years old, was recruited. All of the participants were competing in the 2022–2023 Turkish Volleyball 1st League season and followed a similar standardized, high-performance training regimen, with their weekly training durations averaging 12–15 h. The average age of the participants was 19.5 ± 1.77 years old in the intervention group and 19.8 ± 1.87 years old in the control group. The players had an average of approximately 5 years of competitive volleyball experience, with 5.45 ± 2.29 years for the intervention group and 5.15 ± 1.45 years for the control group. Specific inclusion and exclusion criteria were applied to ensure participant eligibility. The inclusion criteria required players to be between 18 and 23 years old, hold an active professional volleyball license, have a minimum of three years of continuous competitive experience in the sport, and have no history of upper or lower limb injury or surgery within the previous three months. Players were also required to regularly attend training sessions throughout the study period and to have been free from illness or injury in the six months prior that could have impaired their performance. Additionally, to characterize the sample better, the players’ average time of deliberate volleyball practice was assessed, with the participants having a minimum of five years of structured training focused on skill development and performance improvement.

Players were excluded if they had sustained an injury within the past three months that had required more than two weeks away from training or if they had contracted COVID-19 within the past six months to prevent any potential residual impact on performance. An a priori power analysis conducted using G*Power 3.1.9.2 software with a Type I error rate of 0.05, a power of 80%, and an effect size of 0.5 determined that a sample size of 30 participants would be sufficient. Eligible participants were then randomly assigned into either the intervention group (neuro-athletic training) or the control group (traditional training) through a simple randomization process generated by computer software, with the allocation managed by a researcher not involved in the recruitment or assessment to prevent selection bias. This study began with 30 players who met the inclusion criteria, but during the intervention period, 2 players were lost to follow-up due to severe injuries that required their withdrawal, and 2 additional players discontinued participation due to irregular attendance. Consequently, this study was completed with a final sample of 26 players, who were evenly distributed between the intervention and control groups. All subjects gave their informed consent; this study was approved by the university ethics committee for human investigation, and all of its procedures were conducted in compliance with the Declaration of Helsinki.

2.2. Performance Assessments

Performance assessments were conducted at baseline (pre-intervention) and post-intervention to evaluate changes in flexibility, serve speed, and upper extremity performance—key physical attributes for volleyball.

2.2.1. Flexibility Measurement

Flexibility was assessed using the Sit and Reach Test, a validated measure for hamstring and lower back flexibility. The participants sat with their legs extended and feet flat against a sit-and-reach box. With their hands overlapping, they reached forward as far as possible while keeping their knees straight. Each player completed three attempts, with their best score recorded. The protocols followed were based on Ayala et al. [21] and Mayorga-Vega et al. [22].

2.2.2. Serve Speed Measurement

Serve speed was assessed using a Pocket Radar Ball Coach speed gun (Pocket Radar Inc., Santa Rosa, CA, USA), positioned 3 meters behind the player and aligned with their serve trajectory. Each player served three times with a 30 s rest between attempts, and their fastest recorded serve was used for further analysis. This protocol aligned with Conte et al. [23] and Sattler et al. [24].

2.2.3. Upper Extremity Performance Measurement

Upper extremity performance was measured using the Closed Kinetic Chain Upper Extremity Stability Test (CKCUEST), a validated test that assesses upper body stability, strength, and functional performance, particularly relevant for volleyball actions such as spiking and blocking. The participants assumed a push-up position with their hands 36 inches apart, alternatingly touching the opposite hand as quickly as possible within a 15 s period. The average score from three trials, with 1 min rest intervals, was used. The protocols were based on Lee and Kim [25] and Torabi et al. [26].

2.3. Neuro-Athletic Training Program

All of the participants, regardless of group assignment, followed a standardized baseline tactical–technical training program throughout this study. For both the NAT and control groups, training sessions were conducted over an 8-week period, with the participants training three days per week. In the NAT group, the neuro-athletic training intervention was integrated into this training period as an additional component, replacing specific sessions with neuro-athletic exercises designed to target neuromuscular adaptations. Importantly, the total training duration for both groups remained equal to ensure that the intervention did not increase or extend the overall training volume compared to that of the control group.

This approach was designed to maintain balanced training loads across the groups, isolating the effects of the NAT intervention while minimizing potential confounding factors. By aligning the training durations, frequencies, and schedules, this design ensured a fair and controlled comparison between the NAT and control groups. The progression of the NAT group’s exercise program is detailed in

Table 1. Progressive 8-week neuro-athletic training plan for enhancing performance and coordination.

Week	Station/Exercise	Sets and Reps	Rest Interval	Progression
1–2	Letter Saccade Station	3 sets × 10 reps	30 s	Focus on uppercase and lowercase letters
	Anti-Saccade Station	3 sets × 10 reps	30 s	Use basic color cues for direction
	Smart Optometry Station	3 sets × 5 reps	45 s	Track slow-moving red line
	Brock String Station	3 sets × 5 reps	45 s	Focus on beads at close distances
	Star Chart Station	3 sets × 8 reps	30 s	Track slow-moving objects
	Small Area Game (Pinhole Glasses)	5 sets × 1 min	1 min	Practice simple passing sequences
3–4	Letter Saccade Station	3 sets × 10 reps	30 s	Increase card distance for focus and reaction
	Anti-Saccade Station	3 sets × 10 reps	30 s	Add alternating color cues
	Smart Optometry Station	3 sets × 5 reps	45 s	Increase red line speed
	Brock String Station	3 sets × 5 reps	45 s	Use beads at further distances
	Star Chart Station	3 sets × 8 reps	30 s	Increase tracking speed
	Small Area Game (Pinhole Glasses)	5 sets × 1 min	1 min	Add complex passing patterns
5–6	Letter Saccade Station	3 sets × 10 reps	30 s	Add dual tasks with slight body movements
	Anti-Saccade Station	3 sets × 10 reps	30 s	Increase movement speed
	Smart Optometry Station	3 sets × 5 reps	45 s	Use random and fast-moving cues
	Brock String Station	3 sets × 5 reps	45 s	Add background distractions
	Star Chart Station	3 sets × 8 reps	30 s	Simulate quick visual scanning tasks
	Small Area Game (Pinhole Glasses)	5 sets × 1 min	1 min	Introduce rapid decision-making
7–8	Letter Saccade Station	3 sets × 10 reps	30 s	Add dynamic movements
	Anti-Saccade Station	3 sets × 10 reps	30 s	Combine visual cues with rapid direction changes
	Smart Optometry Station	3 sets × 5 reps	45 s	Integrate multiple reaction patterns
	Brock String Station	3 sets × 5 reps	45 s	Perform tasks with added distractions
	Star Chart Station	3 sets × 8 reps	30 s	Simulate game-like scenarios
	Small Area Game (Pinhole Glasses)	5 sets × 1 min	1 min	Add complex strategies under pressure

, providing a clear overview of the structured progression implemented throughout the 8-week intervention period.

2.3.1. Warm-Up Exercises

• Eye Massage

Eye massage was applied to various areas around the orbit to stimulate blood flow and relieve ocular tension, covering six specific areas (Figure 1) [2,3].

• Palming

The participants covered their eyes with both hands, either interlocking or layering their fingers. In this position, the participants may have experienced “fireworks” in their vision due to retinal stimulation. The goal was to relax and reduce visual “noise”. The exercise was conducted in darkness, with the participants focusing on achieving complete visual blackness, continuing for 30 s to 1 min (Figure 2) [2,3].

2.3.2. Volleyball-Specific Visual and Motor Coordination Stations

Letter Saccade Station: Each set consists of 10 repetitions, with a total of 3 sets performed. In this drill, the athlete holds a card with lowercase letters in one hand, while a card with uppercase letters is positioned at arm’s length in front of them. The player reads the letters aloud, moving from left to right, continuously alternating between the lowercase and uppercase letters. After a set period or upon a given command, a volleyball is passed from either the left or right side, prompting the athlete to quickly react, adjust their position, and prepare to receive or pass the ball accurately (Figure 3) [2,3].

Anti-Saccade Station: Each set comprises 10 repetitions, with a total of 3 sets performed. In this drill, the player begins by executing rapid footwork in place to initiate movement. Upon being shown a colored cue, the athlete moves in the opposite direction to the color indication. Subsequently, the coach passes a volleyball to the athlete, requiring them to respond with controlled reception or a directed pass to a predetermined target. This exercise emphasizes visual processing speed and directional response, training athletes to override their instinctual movement patterns in favor of task-directed actions (Figure 4) [2,3].

Smart Optometry Station: Each set includes 5 repetitions, with a total of 3 sets completed. In this station, players begin by performing rapid footwork while tracking a red line displayed on a screen with their eyes. The coach calls out colors in a random sequence, and players must swiftly locate and touch the corresponding colored markers before returning to the center and attempting to intercept or pass a centrally positioned volleyball. This station aims to enhance athletes’ visual tracking abilities, reaction speed, and spatial awareness, which are critical for high-level performance in volleyball (Figure 5) [2,3].

Brock String Station: Each set consists of 5 repetitions, each lasting 10 s, with a total of 3 sets performed. In this drill, players are instructed to sequentially focus on designated colored beads along a Brock string. Upon successfully following the coach’s commands without deviation, the players proceed to receive and pass a volleyball toward a specified target. This station reinforces depth perception, focus adjustment, and hand–eye coordination, all of which are essential for precise ball handling and positioning in volleyball (Figure 6) [2,3].

Star Chart Station: Each set comprises 8 repetitions, with a total of 3 sets conducted. In this exercise, a star-shaped chart is positioned at eye level for the players. While keeping their heads stationary, the athletes visually track each of the 8 points on the star in a designated sequence, completing three sets of eight repetitions. Following the visual tracking drill, the players immediately move to intercept or pass a volleyball to a target. This drill is designed to improve visual scanning, peripheral awareness, and spatial coordination, thereby enhancing players’ ability to track the ball and anticipate movements on the court (Figure 7) [2,3].

Small Area Game with Pinhole Glasses Station: This drill consists of five 1 min sets. Players engage in a “small area game” setup while wearing pinhole glasses that restrict their peripheral vision. The central player attempts to intercept the ball before their neighboring players complete a pass. If the central player successfully intercepts the ball, they switch positions with the player from whom the ball was taken. If unsuccessful, the central player quickly swaps places with the last passer. This station aims to improve athletes’ reaction time, visual acuity, and decision-making abilities in confined spaces, simulating the high-pressure scenarios encountered in competitive volleyball (Figure 8) [2,3].

2.4. Statistical Analyses

Statistical analyses were conducted using Python version 3.12.5 (Python Software Foundation, Wilmington, DE, USA) and SPSS version 25.0 (IBM Corp., Armonk, NY, USA). Descriptive statistics (means, standard deviations) were calculated for each variable. The data were screened for outliers, and normality was assessed using the Shapiro–Wilk test and Q-Q plots. Baseline comparisons between groups were performed using independent t-tests or Mann-Whitney U tests. For within-group changes (pre- and post-intervention), paired t-tests or Wilcoxon signed-rank tests were applied. Between-group differences in the change scores were analyzed using independent t-tests or Mann–Whitney U tests, depending on data normality. Effect sizes (Cohen’s d and Hedges’ g) were calculated to assess the magnitude of the changes.

A 2 × 2 repeated-measures ANOVA was performed in SPSS with “time” (pre vs. post) as the within-subject factor and “group” (intervention vs. control) as the between-subject factor to examine the interaction effects. Post hoc tests with Bonferroni correction were conducted if significant interaction effects were observed. All of the results, including the p-values, effect sizes, and confidence intervals (95%), were reported following the APA guidelines.

3. Results

The descriptive characteristics of the participants are shown in

Table 2. The descriptive characteristics.

Parameter	NAT Mean ± SD (N = 13)	Control Mean ± SD (N = 13)	p-Value
Age (year)	19.50 ± 1.77	19.80 ± 1.87	0.725
Height (m)	1.92 ± 0.04	1.92 ± 0.09	0.762
Weight (kg)	76.90 ± 9.45	78.10 ± 12.75	0.65
BMI (kg/m2)	20.71 ± 1.99	21.02 ± 2.22	0.821
Sport Experience (year)	5.45 ± 2.29	5.15 ± 1.45	0.781

BMI: body mass index; NAT: neuro-athletic training; SD: standard deviation.

.

This study did not end up with the initially indicated sample size due to unforeseen circumstances during the intervention period, resulting in a final sample size of 26 participants. However, a post hoc power analysis was conducted to assess the statistical power of the study at the final sample size. The results of the post hoc analysis indicated that this study maintained adequate power for the primary metrics. Specifically, the post hoc power for serve speed (mph) was 0.977, and for the CKCUET (normalized value), it was 0.982, both indicating that this study had sufficient power to detect meaningful effects using the final sample size.

Significant enhancements were observed in the neuro-athletic training (NAT) group across multiple performance metrics, demonstrating the effectiveness of the intervention. Specifically, the NAT group showed substantial gains in flexibility, with a statistically significant increase (p = 0.040) and a moderate effect size (Cohen’s d = 0.845), indicating meaningful improvements in their range of motion and musculoskeletal adaptability. Similarly, serve speed performance exhibited notable improvement in the NAT group, with these results reaching a high level of statistical significance (p < 0.001) and a large effect size (Cohen’s d = 1.503), highlighting the intervention’s substantial impact on the power and precision of serve actions. Furthermore, upper limb performance, measured through the CKCUET, showed a highly significant increase (p = 0.002) and a large effect size (Cohen’s d = 1.152), emphasizing the intervention’s role in improving upper body strength, stability, and motor coordination (

Table 3. Comparison of pre- and post-intervention metrics between NAT and control groups.

Metric	Group	Pre-Mean ± SD	Post-Mean ± SD	Within-Group				Between-Group
				F-Value	p1	95% CI	Effect Size (Cohen’s d)	p2	95% CI	Effect Size (Cohen’s d)
Flexibility (cm)	NAT Group	23.53 ± 6.91	27.85 ± 6.08	9.275	0.009 *	(21.40, 29.97)	0.663	0.040 *	(0.02–4.43)	0.845
	Control Group	19.86 ± 4.24	20.05 ± 4.13	1.023	0.236	(17.32, 22.58)	0.045
CKCUET (normalized value)	NAT Group	14.43 ± 2.06	18.6 ± 2.9	20.869	0.001 *	(15.23, 17.79)	1.657	0.002 *	(0.73, 3.72)	1.152
	Control Group	14.8 ± 1.72	15.13 ± 1.86	2.307	0.193	(13.898, 16.031)	0.184
Serve speed (mph)	NAT Group	48.0 ± 3.0	56.33 ± 6.63	5.759	0.030 *	(50.30, 54.024)	1.618	<0.001 *	(2.50, 6.13)	1.503
	Control Group	47.54 ± 3.45	50.21 ± 4.32	1.485	0.197	(46.73, 51.01)	0.682

* p < 0.05; p1: the p-value for within-group changes, calculated using paired t-tests or Wilcoxon signed-rank tests; p2: the p-value for between-group differences, determined using independent t-tests or Mann–Whitney U tests. F-value: indicates differences within a group (pre vs. post) from ANOVA analysis. CKCUET: Closed Kinetic Chain Upper Extremity Stability Test; NAT: neuro-athletic training; SD: standard deviation; CI: confidence interval.

).

In contrast, the control group did not demonstrate any statistically significant changes in their flexibility (p = 0.236), serve speed (p = 0.197), or upper limb performance (p = 0.193) from the pre- to post-training assessments, suggesting that traditional training alone was insufficient to produce similar outcomes. Between-group comparisons further confirmed the superiority of the NAT group across all of the parameters measured, with p-values ranging from 0.040 to <0.001 and effect sizes (Cohen’s d) spanning from 0.845 to 1.503. These results underscore the robust impact of the neuro-athletic training program on neuromuscular performance, demonstrating its potential to enhance specific athletic capabilities in a more targeted and effective manner than traditional training methods (see Table 3 and Figure 9 for detailed comparisons).

4. Discussion

This study investigated the effects of neuro-athletic training (NAT) on athletic performance, focusing on flexibility, spike speed in volleyball, and upper limb strength and coordination. Its findings demonstrated significant improvements across all of the outcomes measured in the NAT group compared to the control group. These improvements, indicated by substantial effect sizes, provide evidence for the efficacy of NAT in enhancing athletic performance. The results align with the emerging literature highlighting the importance of integrating neural mechanisms, such as neuroplasticity, proprioceptive feedback, and sensory–motor integration, into performance training paradigms.

The significant improvements in flexibility observed in the NAT group (p = 0.040; Cohen’s d = 0.845) underscore the role of neural adaptability in musculoskeletal performance. Previous studies, such as Magnusson et al. [27], demonstrated that flexibility is not merely a function of muscle length and elasticity but also of neural control, particularly the interaction between muscle spindles and proprioceptive feedback mechanisms. Proske and Gandevia [28] further emphasized that proprioception regulates body position and muscle force, which directly impact the range of motion. From a practical standpoint, increased flexibility contributes to smoother, more efficient movement patterns that are essential for executing key volleyball techniques. For example, during spiking, enhanced shoulder and hip flexibility allows for a more extensive range of motion, enabling athletes to generate higher power and accuracy without compromising joint stability. Similarly, during blocking actions, greater flexibility in the thoracic and shoulder regions helps players reach over the net more effectively, improving their defensive capabilities. Our results suggest that NAT enhances neural adaptability by improving the communication between the vestibular and proprioceptive systems, as noted by Horak [29] and Seemungal [8]. Clinically, this highlights the potential of NAT to prevent injuries such as muscle strains and improve joint health by promoting the optimal muscle tone and flexibility. This is particularly relevant for volleyball players, who frequently encounter high-intensity demands on their flexibility during spiking and diving actions, where excessive strain or a limited range of motion can compromise their performance or lead to injuries.

Spike speed in volleyball showed a significant improvement in the NAT group (p < 0.001; Cohen’s d = 1.503), reflecting gains in neuromuscular coordination, strength, and precision. Granacher et al. [30] demonstrated that neural training enhances motor unit recruitment and synchronization, which are critical for explosive actions like volleyball spikes. Furthermore, Hülsdünker et al. [11] linked enhanced neural visual processing to improved reaction times, which are vital for executing precise spikes under competitive conditions. While the improvement in spike speed is undoubtedly a positive indicator, its practical significance must be contextualized within match scenarios. Faster spikes can increase the likelihood of scoring points by reducing the reaction time available to opposing defenders. However, there is also the potential risk of increased errors, such as spikes or serves going out of bounds due to overexertion or decreased accuracy. These risks can be mitigated by incorporating precision-focused drills alongside NAT, ensuring that players develop not only power but also control. NAT likely improved spike speed by integrating the vestibular and visual sensory pathways, enabling the athletes to generate greater force and precision. Zhou et al. [14] reported similar results in volleyball players, where visual–motor training improved their spike accuracy and performance consistency. In match conditions, these improvements mean that players are better equipped to deliver decisive attacks under high-pressure situations, such as tie-break points or quick offensive plays, where the reaction time and execution are critical. Clinically, this underscores the value of NAT in developing the explosive power and hand–eye coordination essential for high-level volleyball while also reducing the risk of overuse injuries through optimized motor control.

Upper limb performance, measured through the CKCUET, showed a highly significant increase (p = 0.002; Cohen’s d = 1.152), highlighting the impact of NAT on upper body strength, stability, and coordination. These findings align with Grooms et al. [19], who emphasized that neuroplasticity-focused interventions improve motor control and functional recovery in athletes. Davies and Dickoff-Hoffman [12] further highlighted the importance of neuromuscular control in the rehabilitation of the shoulder complex, a critical area for volleyball players, who frequently experience shoulder overuse injuries. The practical implications of this finding are significant for volleyball performance. For instance, improved shoulder stability directly enhances the effectiveness and safety of repetitive actions such as spiking, serving, and blocking, which place substantial stress on the shoulder joint. With better upper limb coordination, players can achieve more precise ball placement during spikes and serves, leading to tactical advantages in matches. The vestibular system’s role in facilitating balance and upper body coordination, as described by Seemungal [8], likely contributed to these results. Clinically, NAT can be integrated into injury prevention and rehabilitation protocols to enhance shoulder stability and reduce the risk of rotator cuff injuries in volleyball athletes, particularly during repetitive high-impact actions like spiking and blocking. For example, players with enhanced upper limb coordination are able to adjust their arm positioning better during mid-air collisions or sudden movements, reducing the likelihood of acute injuries in dynamic match conditions.

The lack of significant improvements in the control group highlights the specificity of NAT in targeting the neural components that traditional training often overlooks. Gabriel et al. [10] emphasized that resistive training alone may not sufficiently address neural pathways, leaving room for innovative approaches like NAT. Dietz [31] reported that activating the vestibular system can enhance posterior chain stability, which is critical for maintaining postural control and generating power in volleyball movements. Behm et al. [18] also noted that training programs that neglect neural adaptations may leave athletes more susceptible to fatigue and injury. The practical applications of these findings suggest that NAT not only fills a critical gap in traditional training regimens but also offers a comprehensive approach to performance optimization. For instance, NAT’s focus on proprioceptive and sensory–motor integration directly translates into reduced error rates, improved reaction times, and enhanced decision-making in high-stress match environments. This makes NAT a valuable complement to conventional strength and conditioning programs.

Despite these promising findings, several limitations should be considered when interpreting these results. First, the relatively small sample size may limit the generalizability of our results, and future studies with larger and more diverse samples are necessary to confirm and extend these findings. Additionally, the cross-sectional nature of this study did not allow us to examine the long-term retention of the performance improvements following NAT. Future research should investigate whether the observed gains in flexibility, spike speed, and upper limb coordination persist over time and contribute to tangible competitive advantages, such as increased match win rates or improved player rankings. Understanding whether NAT’s benefits can be sustained over multiple seasons is critical for assessing its long-term value. Expanding future research to include broader metrics like injury prevention, recovery times, and mental resilience would provide a more comprehensive understanding of NAT’s impact on athletic performance and athlete well-being. Lastly, the lack of blinding in this study and the potential for placebo effects, as the participants were aware of their group allocation, may have introduced bias into their motivation and performance. Addressing this in future studies through double-blind designs and more randomized protocols would help to ensure the robustness and validity of these findings, providing a clearer picture of NAT’s true impact.

By addressing these limitations and integrating practical applications into future research, NAT’s role in advancing athletic performance can be fully realized, benefiting not only volleyball players but a wide range of athletes across different sport disciplines.

5. Conclusions

This investigation highlights the substantial benefits of neuro-athletic training (NAT) for key aspects of athletic performance, including flexibility, spike speed in volleyball, and upper limb strength and coordination. The significant improvements observed in the NAT group, in contrast to the stable performance in the control group, underline the effectiveness of NAT in enhancing athletic capabilities. These results emphasize the importance of incorporating neural components, particularly those involving the vestibular system and its connection with motor control, proprioception, and muscle activation, into athletic training protocols. By addressing the neurophysiological underpinnings of movement, NAT offers a holistic and neurologically informed approach that significantly enhances performance and reduces injury risks.

The improvements in flexibility observed with NAT demonstrate its ability to optimize neuromuscular adaptability and proprioceptive feedback, critical for volleyball athletes performing high-stress actions like spiking and diving. Similarly, the significant gains in spike speed and upper limb coordination reflect NAT’s efficacy in enhancing motor unit recruitment, sensory integration, and visual–motor coordination—key elements in achieving precision and power in volleyball performance. These findings align with the recent literature suggesting that targeted neural training not only improves athletic performance but also provides a protective effect against overuse injuries, particularly in the shoulder and lower back regions.

Future research should aim to elucidate the mechanisms by which NAT influences athletic performance further, focusing on its ability to induce neuroplastic changes and optimize sensory–motor pathways. Longitudinal studies with larger, more diverse samples could provide insights into the sustainability of NAT-induced performance gains and its broader applicability across various sports. Additionally, the integration of NAT into rehabilitation settings should be explored, particularly in preventing and recovering from repetitive strain injuries, which are common in volleyball. Research investigating the individual variability in the response to NAT could pave the way for personalized training programs tailored to specific neurophysiological profiles.

Finally, advancements in neuroimaging techniques, such as functional MRI and TMS-EEG, could offer direct evidence of the neural adaptations associated with NAT, providing deeper insights into the changes in brain activity and connectivity. Such investigations would not only validate the neural basis of NAT but also refine its application in both athletic and clinical contexts. By focusing on these areas, future studies can solidify NAT’s role as a versatile and effective tool for enhancing athletic performance and overall neuromuscular health.