College Volleyball Players Research Articles

Ejercicios de perfeccionamiento para atacadores de voleibol del Club Universidad Central del Ecuador. Validación teórica

Introducción: El ataque es una técnica fundamental desde el punto de vista técnico-táctico. El perfeccionamiento técnico-táctico del ataque requiere varias estrategias dónde la selección de ejercicios potenciadores pudiera perfeccionar su rendimiento. Objetivo: Validar teóricamente mediante consulta de especialistas un plan de ejercicios para perfeccionar la efectividad en el ataque de los voleibolistas universitarios pertenecientes al club de voleibol Universidad Central del Ecuador. Métodos: La investigación es de tipo Descriptivo-analítica de orden correlativa, estudiando el fenómeno mediante consulta de especialistas (33 sujetos) divididos en tres grupos independientes. Se transitará por tres fases: Diagnóstico Preliminar, Elaboración y Evaluación Teórica de la propuesta, permitiendo estudiar el contenido de forma prospectiva, así como las posibles mejoras que podría tener en el ataque del equipo de voleibol de la Universidad Central del Ecuador. Resultados: Las medias obtenidas en la segunda evaluación fueron mayores que en la primera evaluación, siendo significativamente diferentes en todos los casos. Para el caso de los criterios emitidos por cada grupo independiente la mayoría no presentan diferencias significativas “Objetividad” (p=0.185), “Asequibilidad” (p=0.081), “Progresión” (p=0.589), “Variedad” (p=0.724), “Integralidad” (p=1.000), “Especialización” (p=0.378) y “Especialización Progresiva” (p=0.641), exceptuando el indicador “Originalidad” (p=0.043). Conclusiones: Se constata teóricamente una mejora notable en los ocho indicadores que evalúan la propuesta de intervención a favor del segundo diseño, además de un alto nivel de concordancia entre expertos relacionados con los alcances y limitaciones de la futura propuesta de intervención.

사회연결망 분석을 통한 남자대학배구선수의 스트레스 요인 탐색

The purpose of this study is to investigate stress of male college volleyball players. To analyze and identify the stress factors perceived by male college volleyball players, this study analyzed the volleyball of 11 teams participating in the 2019 U league among male college volleyball players registered in the Korean National University Federation. An investigation was conducted. The subjects of this study were the centrality analysis of a total of 121 university athletes using NetMiner program. The stress factors of male college volleyball players derived from the analysis were as follows: First, academic, assignment, grades, money, injury, free time, and career were derived from daily life. Second, stress factors in athletes" lives are centered on improving their skills and preventing injuries, and at the same time, factors such as improving the accommodation environment, career counseling, and surrounding human relationships were derived. Lastly, volleyball players were the most stressed on their careers and career paths. The implications of this study gave significant implications for the deepening of research topics related to athletes and the refinement of research areas in that they analyzed the various stresses experienced by male university volleyball players with relatively little previous studies. It is considered that the data of this study will be used as a basis for future athlete stress research and exploration.

Attacking and Scoring by College Volleyball Players: A Matching Analysis

We applied the generalized matching equation to examine the relation between attacks attempted and points scored by the top five attackers on 36 Division 1 National Collegiate Athletic Association women’s volleyball teams during the 2017–2018 season. Twelve of the teams were highest-ranked at season’s end, 12 were mid-ranked, and 12 were lowest-ranked. The equation accounted for at least 70% of the variance in responding for 31 teams. Of them, 16 teams demonstrated undermatching, 4 demonstrated overmatching, and 11 approached strict matching. Eight of these teams were biased towards attempts by a single player and four towards attempts by the other four players combined. Team ranking did not consistently affect performance. These findings are significant in extending the provenance of matching to another sport and to a naturalistic setting involving three or more response options.

Heart Rate Variability As Psychophysiological Stress Indicator In Mexican College Volleyball Players

PURPOSE: To compare the response of Heart Rate Variability (HRV) during induced stress as a psychophysiological stress indicator in Mexican college volleyball players. METHODS: We evaluated 16 male college volleyball players (18 to 26 y). Psychophysiological assessment of stress consisted of 7 stages lasting 2 min each (baseline, exposed to a physiological stressor [unpleasant sounds], 1st rest, exposed to a cognitive stressor [mathematical task], 2nd rest, exposed to stressor emotional [talk about a stressful memory] and 3rd rest). It was done by a ProCompTM Infiniti Biofeedback System. Short-term HRV was obtained by a Blood Volume Pulse (BVP) Sensor and analyzed using time-domain: SDRR (standard deviation of RR intervals) and pNN50 (percentage of successive RR intervals that differ by more than 50 ms); and frequency-domain: HRV peak frequency, Very Low Frequency (VLF) total power, Low Frequency (LF) total power, High Frequency (HF) total power, VLF % power, LF % power and HF % power measurements. Statistical analysis was performed by repeated measures ANOVA and non-parametric Friedman test. RESULTS: Significant differences in HRV were observed when we compared the seven stages of the assessment (with stress stimulus and without stress stimulus). During the COGNITIVE stage there was a difference with the BASELINE (p= .01) and EMOTIONAL (p= .004) stage in HRV peak frequency; in VLF% between PHYSIOLOGICAL and 1st REST (p= .01) stage; among the BASELINE and the EMOTIONAL (p= .04) stage on SDRR; and with pNN50 on COGNITIVE and 3rd REST (p= .02) stage. (Table 1). CONCLUSIONS: The results show significant changes in the variables associated with sympathetic activity in stages that had stressors compared to baseline and rests, which may indicate psychophysiological response to stress. These results support the idea of HRV is a useful psychophysiological stress indicator and maybe a helpful tool to identify and have better stress management in Mexican college athletes.Table 1: Heart Rate Variability indicators comparison between each stage.

Effect of plyometric and circuit training on selected muscular strength and explosive power among engineering college volleyball players

Effect of plyometric and circuit training on selected muscular strength and explosive power among engineering college volleyball players

Use Of Plyometric Training To Offset Fatigue In Division I Collegiate Female Volleyball Players

Volleyball is a demanding sport consisting of multiple passages of play with a high priority on jumping, including attacking, blocking, jump serving and setting. Heavy resistance training and plyometric training have been shown to increase vertical jump in volleyball players, as well as high intensity interval training to increase conditioning, however, there is a lack of information on the use of plyometric training to decrease indexes of fatigue. PURPOSE: To determine if plyometric training can decrease repeated jump fatigue in NCAA Division I female college volleyball players METHODS: 8 female collegiate volleyball players (Age: 18.4 ± 0.7, height: 179.7 ± 9.2cm, weight: 71.8 ± 10.0kg), cleared of injuries completed a vertical jump test, squat jump test, repeat squat jump, and repeat block jump test while wearing velocity and height measuring devices. Participants were split into a control group (CON) and a plyometric group (PLYO), which completed a 3 day a week/ 8 week program consisting of dot drill and box drop jump exercise variations. After 8 weeks, participants were retested. Fatigue Index for the repeat tests were analyzed for statistical significance, [(Initial Jump-Final Jump)/Initial Jump)] x 100. RESULTS: Significant differences were seen in the PLYO group in the repeat squat jump test at posttest compared to the CON (10.98 ± 4.69 vs -5.41 ± 4.65 p<.015), and in the repeat block jump test compared to pretesting values within the PLYO group (6.41 ± 8.47 vs-4.24 ± 14.77, p<.042). CONCLUSIONS: Utilization of plyometric training may help offset fatigue as seen in multiple jump bouts in volleyball players, potentially attributing to increased athletic performance.

Effects of Plyometric Training on Surface Electromyographic Activity and Performance during Blocking Jumps in College Division I Men’s Volleyball Athletes

In volleyball matches, there are three minute intervals between sets. Therefore, the improvement of the muscle output ratio is one of the most import foundational physical elements for the players. The purpose of this study was to investigate the effects of plyometric training on the changes in electrical signals in the lower limb muscles of male college volleyball players during continuous blocking and to examine the benefits of plyometric training on blocking agility and maximum vertical jump height. In this study, twenty elite male college volleyball players were recruited and divided into a plyometric training group (PTG) and a control group (CG). The wireless electromyography was used for data acquisition, and the electrodes were applied to the left and right rectus femoris, biceps femoris, tibialis anterior, and gastrocnemius. The median frequency was used as the measurement of the electromyographic signals during the jumping blocks. This study used covariate analysis methods, with previously measured results used as covariates to perform a two-way analysis of covariance for the independent samples. Based on the results of this study, after 6 weeks of training, the median frequency of the rectus femoris (2.13% to 4.75% improved) and that of the tibialis anterior muscles (4.14% to 7.71% improved) were significantly lower in the PTG than in the CG. Additionally, the blocking agility increased by 6.26% and the maximum vertical jump height increased by 3.33% in the PTG compared to the CG. The findings provide important insights on the neuromuscular status for volleyball players during continuous blocking jumps. Six weeks of appropriate plyometric training can facilitate the performance of volleyball players.

CHANGES IN INFRASPINATUS AND LOWER TRAPEZIUS ACTIVATION IN VOLLEYBALL PLAYERS FOLLOWING REPETITIVE SERVES

Prolonged and repetitive overhead use of the arm, such as during the volleyball serve, has been linked to overuse injuries. To examine changes in activation of the infraspinatus and lower trapezius following performance of repetitive jump-float serves. Descriptive Cohort study. Six asymptomatic female Division I college volleyball players (age = 19.2 ± 1.1 years, height = 182.9 ± 2.5 cm, weight = 82.1 ± 12.2 kg) performed 87 jump-float serves in 13 intervals of seven serves each on an NCAA regulated indoor volleyball court. Electromyography (EMG) electrodes were connected to TeleMyo DTS wireless sensor with the DTS EMG lead sampling at 1000 Hz. Dependent variables included Median Power Frequency (MPF) of the infraspinatus (IF) and lower trapezius (LT), as well as rating of perceived exertion (RPE), perceptual fatigue measured using the Borg scale, and heart rate (HR). Paired t-tests were performed to examine differences in variables between interval 1 (serves 1-3) and interval 13 (serves 85-87). Pearson's r Correlation Coefficients were calculated to examine relationships between the dependent variables across all 13 intervals. IF MPF demonstrated a significant and clinically meaningful decrease from interval 1 to interval 13, indicating muscular fatigue. The decrease in LT MPF from interval 1 to interval 13 was not statistically significant, though it met criteria for clinical meaningfulness and was underpowered. RPE and perceptual fatigue were strongly correlated (r = 0.889. p < 0.01) as were RPE and HR (r = 0.679, p < 0.01) and HR and fatigue (r = 0.631, p < 0.01). IF MPF was weakly related to LT MPF (r = 0.227, p < 0.05). LT MPF was weakly related to RPE (r = 0.352, p < 0.01), perceptual fatigue (r = 0.313, p < 0.01), and HR (r = 0.322, p < 0.01). Repeated overhead jump-float serves, common in volleyball players, required high effort and induced clinically meaningful muscular fatigue that was not perceived by the participant. Significant changes were observed in IF MPF and percent change and effect size suggest that a meaningful change occurred in LT MPF related to jump-float serving. 2.

Effect of long-term training adaptation on isokinetic strength in college male volleyball players

Background and Study Aim: Most of this study focused on endurance, power, and anthropometric measurements but no research declared isokinetic strength changes during two years. The purpose of this study was to assess the effect of resistance exercises on two seasonal alters in isokinetic strength of knee muscles at different angular velocities, in college volleyball players. Material and Methods: Thirteen college volleyball players, (age: 21.75 years, body mass: 78.60 kg, and height: 187.0 cm) participated in the study. All college volleyball players take part in the two-year (8 month each year) volleyball-specific training and competitions. The measurement of peak isokinetic concentric knee extension and knee flexion torque in both legs were taken at 2 angular velocities of movement, low at 60° s-1, and intermediate at 180° s-1. Results: The pre- and post-test values of the peak isokinetic strength found that statistical significance difference, at 60° s-1 and 180° s-1 for knee extensor-flexor both dominant and non-dominant in favor of post-tests. Significant enhances were observed in the baseline dominant knee extensor-flexor muscle strength (extensor knee strength 60° s-1: 19.0%, 180° s-1: 20.5%, flexor knee strength, 60° s-1: 33.4%, 180° s-1: 31.4%) respectively. Non-dominant knee extensor-flexor muscle strength increased significantly over the two-year period (extensor knee strength 60° s-1: 21.3%, 180° s-1: 23.0%, flexor knee strength, 60° s-1: 37.4%, 180° s-1: 33.9%) respectively. Conclusion: As a result, our data suggests that the two-year planned program of specific volleyball and resistance training can increase the knee muscle extensor-flexor strength and H:Q ratios of volleyball players. Especially, at a 60° s-1 and 180° s-1 angular velocities, whilst the knee muscle extensor-flexor strength and H:Q ratios for dominant and non-dominant legs were increasing, also H:Q ratios disproportion were decreasing. Therefore, these alters indicated that regular specific-volleyball and resistance training can increase knee muscle extensor-flexor strength and H:Q ratios for dominant and non-dominant legs.

Effect of Eight Weeks of FIFA 11+ Training on the Agility and Explosive Power of Male College Volleyball Players

BackgroundFIFA 11+ training is a warm-up program for the prevention of athletic injuries, including slow running, active stretching, and player-controlled collisions designed to focus on central muscle stability, neuromuscular control, eccentric hamstring strength, and agility, and can improve sports performance.ObjectivesThis study aimed to investigate the effect of eight weeks of FIFA 11+ training on the agility and explosive power of male volleyball players.MethodsIn this quasi-experimental study, 24 male volleyball players from the Islamic Azad University of Marvdasht were selected as the statistical sample and divided into two groups of 11+ training and control. The 11+ training group performed FIFA 11+ training for eight weeks, three sessions per week and 20 minutes each session. The control group only had their usual activities in this period. Agility and explosive power were measured before the start of training and 24 hours after the last session of training through Illinois test, horizontal jump test, and vertical Sargent test. The Shapiro-Wilk test and independent/dependent samples t-tests were used to analyze the data (P ≤ 0.05).ResultsEight weeks of 11+ training had a significant effect on agility (P = 0.008), horizontal jump (P = 0.001), and vertical jump (P = 0.001).ConclusionsIt seems that 11+ training can be used to improve the agility and explosive power of male college volleyball players.

Effects of Relative Drop Heights of Drop Jump Biomechanics in Male Volleyball Players.

Previous cross-sectional studies have reported that higher drop heights do not always result in improved performance, and may increase injury risk during drop jumps (DJ). The purpose of this study was to analyze the kinematics and kinetics during the DJ in order to determine the relative drop height that maximize performance without exposing the lower extremity joints to unnecessary loads. Twenty male Division I college volleyball players volunteered. Data were collected using 11 infrared cameras and two force platforms. Participants performed three maximal effort countermovement jumps (CMJ). Subsequently, 50, 75, 100, 125, and 150% CMJ height (CMJH) was used to scale their relative drop height for three DJ trials per height. There was a significant increase in the landing phase impulse when the drop height exceeded 100%CMJH (p<0.05). At 125% and 150%CMJH, the negative work of knee and ankle significantly increased. The incoming velocity, kinetic energy, landing depth, maximum ground reaction force, landing impulse and power absorption of knee and ankle all increased with drop height (p<0.05). DJ height and reactive strength index following the drop landing were not statistically different between any of the drop heights (p>0.05). 50% to 100%CMJH may be the appropriate individual relative drop height for the DJ.

A cross-level moderating effect of team trust on the relationship between transformational leadership and cohesion

ABSTRACTWe draw on the concept of the shared mental model to explain the cross-level direct and moderating effects of team trust on the relationship between coach transformational leadership and cohesion. Using hierarchical linear modelling, we analysed 597 national level high school and university volleyball players to test our research model. Our results revealed that, (a) at the individual level, coach transformational leadership has a positive effect on athletes’ perceptions on cohesion and (b) team trust, a group-level construct, is positively related to social cohesion and moderates the coach transformational leadership-cohesion relationship. The moderating effect demonstrates that the positive effect of coach transformational leadership on cohesion could be enhanced when high levels of team trust are shared within the group. Implications for coach education and sport psychology in terms of theory and research are discussed.

Preseason Functional Performance Test Measures Are Associated With Injury in Female College Volleyball Players.

Preseason functional performance test measures have been associated with noncontact time-loss injury in some athletic populations. However, findings have been equivocal with many studies consisting of heterogeneous populations. To determine if preseason standing long jump and/or single-leg hop test scores are associated with a noncontact time-loss injury to the lower quadrant (LQ = low back or lower-extremities) in female Division III college volleyball (VB) players. Prospective cohort study. National Collegiate Athletic Association Division III female VB teams. A total of 82 female college VB players (age = 18.9 [1.0]y). Standing long jump and single-leg hop test measures were collected at the start of the official preseason. Athletic trainers tracked all time-loss injuries and their mechanisms. Athletes were categorized as at risk if their preseason standing long jump <80% height, bilateral single-leg hop <70% height, and had a SLH side-to-side asymmetry >10%. The noncontact time-loss overall injury rate for the LQ region in at-risk athletes was 13.5 (95% confidence interval [CI], 4.3-31.5) per 1000 athletic exposures. At-risk athletes were significantly more likely to experience a noncontact time-loss injury than VB players in the referent group (rate ratio = 6.2; 95% CI, 1.9-17.2; P = .008). The relative risk of sustaining a noncontact time-loss injury to the LQ was 4 times greater in the at-risk group (relative risk = 4.6; 95% CI, 2.1-10.1; P = .01). At-risk athletes were 6 times more likely to experience a foot or ankle injury (relative risk = 6.3; 95% CI, 2.1-19.2; P = .008). Suboptimal performance on a battery of functional performance tests is associated with a significantly greater risk of noncontact time-loss injury to the LQ in female Division III college VB players.

Relationship between Repeated Sprint Ability and Aerobic Fitness in College Volleyball Players

The main purpose of this study was to investigate the relationship between physiological variables related to aerobic fitness and repeated sprint ability (RSA) in college volleyball players. Sixteen male volleyball players (21.1±1.4 years) took part in the study. Players first performed an incremental treadmill run test to determine their maximal oxygen uptake (VO2max ), ventilatory threshold (VT), peak incremental test speed and time to exhaustion. After at least 48 hours, subjects performed an RSA test consisting of 10 × 20-m sprints interspersed with 20 seconds of active recovery, to determine the mean sprint time (RSAmean), the best sprint time (RSAbest) and the fatigue index (FI). RSAmean was significantly negatively correlated with VO 2max (r= −0.73, p 0.05). The results of this study demonstrated that high VO 2max as well as VT has an important contribution to performance during repeated-sprint efforts. These findings suggest that training practices for the development of aerobic components may improve also RSA.

Similar Strength and Power Adaptations between Two Different Velocity-Based Training Regimens in Collegiate Female Volleyball Players.

This study investigated the effects of two different velocity-based training (VBT) regimens on muscular adaptations. Fifteen female college volleyball players were randomly assigned into either progressive velocity-based training (PVBT) or optimum training load (OTL). Both groups trained three times a week for seven weeks. PVBT performed a 4-week strength block (e.g., 0.55–0.70 m·s−1) followed by a 3-week power block (e.g., 0.85–1.0 m·s−1), whereas OTL performed training at ~0.85–0.9 m·s−1. 1RM and peak power output (PP) assessments on the back squat (BS), bench press (BP) and deadlift (DL) exercises were assessed pre and post training. There was a main time effect (p ≤ 0.05) for BS and BP 1RM, (PVBT: 19.6%, ES: 1.72; OTL: 18.3%, ES: 1.57) and (PVBT: 8.5%, ES: 0.58; OTL: 10.2%, ES: 0.72), respectively. OTL increased DL 1RM to a greater extent than PVBT (p ≤ 0.05), (OTL: 22.9%, ES: 1.49; PVBT: 10.9%, ES: 0.88). Lastly, there was a main time effect (p ≤ 0.05) for BS, BP and DL PP, (PVBT: 18.3%, ES: 0.86; OTL: 19.8%, ES: 0.79); (PVBT: 14.5%, ES: 0.81; OTL: 27.9%, ES: 1.68); (PVBT: 15.7%, ES: 1.32; OTL: 20.1%, ES: 1.77) respectively. Our data suggest that both VBT regimens are effective for improving muscular performance in college volleyball players during the offseason period.

Analysis of Team Relationship using Self-Organizing Map for University Volleyball Players

In Japan, sports efforts are actively being carried out to host the 2020 Olympic Games. Especially in the field of sports science, researches on ergonomics, development of sports equipment and pattern recognition technology using artificial intelligence are actively researched. In previous research, we developed a clustering algorithm for positioning adaptation and relationships in team sports using self-organizing maps in university rugby players. However, I have not yet confirmed whether the developed algorithm can be applied to other team sports. For this reason, we applied the same algorithm to a university volleyball player. Then, as an algorithm, we verify whether it can be generally used for team sports.

Biomechanical Comparisons of One-Legged and Two-Legged Running Vertical Jumps.

The purpose of this study was to determine the differences in biomechanical characteristics between one- and two-legged running vertical jumps (1-LRVJ and 2-LRVJ). Ten male college volleyball players voluntarily participated in this study. Two running vertical jumps used in volleyball were randomly performed. Three trials for each type of the running vertical jump were recorded for each participant. Data were collected using six infra-red Qualisys motion-capture cameras at a 180-Hz sampling rate and two AMTI force platforms at an 1800-Hz sampling rate. Jump height in the 2-LRVJ was significantly higher than that in the 1-LRVJ (p < 0.05). In the take-off phase, knee and hip extension impulses for the 1-LRVJ were significantly greater than those for the 2-LRVJ (p < 0.05). These results suggest that the 1-LRVJ produced greater leg stiffness than the 2-LRVJ did. We found that the 1-LRVJ caused greater lower-extremity stiffness and impulse compared to the 2-LRVJ, which is beneficial in the stretch-shortening cycle, and thus the more focus on practicing 1-LRVJs is recommended for coaches and athletes.

고등학교, 대학교 배구선수의 심리적 안녕감이 경쟁상태 불안과 경기력에 미치는 영향에 관한 연구

The purpose of this study is to analyze the effects of psychological well - being of high school and university volleyball players on competitive anxiety and performance, and to utilize them as basic data for improving positive emotions, releasing competitive state anxiety, and increasing performance of high school and university volleyball players. To measure this, 119 high school and university volleyball players from Seoul and Kyunggi province were surveyed for two months from January 3 to March 2, 2018. First, as a result of analyzing the effects of psychological well - being on competitive anxiety, life satisfaction, which is a sub - variable of psychological well - being, has a negative effect on competitive anxiety, but happiness has no effect. Second, the analysis of the effects of psychological well - being on the performance showed that the satisfaction of life, which is a sub - variable of psychological well - being, has a positive effect on the performance, but the happiness did not affect the performance. Fourth, the effects of demographic characteristics (school type, grade, career) on psychological well - being, competitive anxiety, and performance were found to be different. As a result of analyzing the effects of psychological well - being according to demographic characteristics (school type, grade, and career) on competitive anxiety, psychological well - being on performance and competitive anxiety on performance, the characteristics of school type and career were found to affect competitive anxiety and performance, but academic ability did not affect competitive anxiety and performance.

대학U리그에 참가한 대학배구선수들의 포지션별 상해유형 분석 연구

The purpose of this study is to analyze injury types at each position in college volleyball players who participated in the University Volleyball League. This study focused on the analysis of the place of injury, the part of injury, the kind of injury, and injury motion at each position of players who participated in the Men’s University Volleyball League. The questionnaire consisted of 9 items and was distributed to 80 players who participated in the 2017 Men’s University Volleyball League. 59 effective samples were obtained and statistical processing was done. The chi-square test of sports injury types at each position was performed to obtain study results. Finally, the following conclusions were drawn. First, the place of injury was analyzed at each position in college volleyball players who participated in the University Volleyball League. As a result, the place for training and practicing was the most common place of injury in all positions. However, there was no statistically significant difference in frequency. Second, the part of injury was analyzed at each position in college volleyball players who participated in the University Volleyball League. As a result, the frequency of an ankle injury was the highest, followed by that of a knee. However, there was no statistically significant difference in frequency. Third, the kind of injury was analyzed at each position in college volleyball players who participated in the University Volleyball League. As a result, the frequency of ligament injury was the highest, followed by that of sprain injury. However, there was no statistically significant difference in frequency. Fourth, injury motion was analyzed at each position in college volleyball players who participated in the University Volleyball League. As a result, the injury frequency in spiking was the highest, followed by that of blocking. There was a statistically significant difference in frequency (χ²=59.238a, p.001). In conclusion, the frequency of the place of injury at each position was high in the place for training and practicing in college volleyball players who participated in the university volleyball league. They suffered from ligament injury and sprain caused by ankle and knee injurie s during spiking or blocking.

EFFECTS OF REPEATED SPRINT TRAINING ON ISOCAPNIC BUFFERING PHASE IN VOLLEYBALL PLAYERS

ABSTRACT Introduction: The region between the ventilatory threshold (VT) and respiratory compensation point (RCP) is defined as the isocapnic buffering (ICB) phase and represents a phase of compensation for exercise-induced metabolic acidosis. There is sparse literature examining the effects of physical training on ICB phase in athletes. Objectives: The purpose of this study was to examine the effects of a repeated sprint training program on the ICB phase of college volleyball players. Methods: Eighteen male volleyball players were randomly assigned to either an experimental group (n=9) or a control group (n=9) and followed a traditional volleyball training program three times per week for six weeks. The experimental group additionally performed a repeated sprint training protocol immediately before each volleyball training session. Before and after the 6-week training period, all participants performed an incremental treadmill test to determine VT, RCP, and maximal oxygen uptake (VO2max). The ICB phases were calculated as VO2 (ml/kg/min) and sprint speed (km/h). Results: The experimental group showed significant improvements in ICB phase, RCP, VO2max and maximal sprint speed after training (p&lt;0.01). There were no significant changes in VT after training in the experimental group (p&gt;0.05). None of these variables changed significantly in the control group (p&gt;0.05). Conclusions: These findings indicate that repeated sprint training can enhance the ICB phase of volleyball players, which may be attributable to an improvement in buffering capacity leading to a shift in RCP towards higher intensities without any change in VT. The increase in the ICB phase may an important factor in terms of improvement in the high-intensity exercise tolerance of athletes. Level of Evidence II; Therapeutic studies - Investigating the results of treatment.