Training Load, Physical Performance, Biochemical Markers, and Psychological Stress During a Short Preparatory Period in Brazilian Elite Male Volleyball Players

The effect of time of day and menstrual cycle on physical performance and psychological responses in elite female Tunisian volleyball players

BACKGROUND

The influence of circadian rhythms and menstrual cycle phases on athletic performance and psychological responses is critical for optimizing training and competition strategies for female athletes. This study aimed to investigate the effects of time of day and menstrual cycle phases on the physical performance and psychological responses of elite female Tunisian volleyball players.

METHODS

Thirteen elite female volleyball players were assessed during three different phases of their menstrual cycle (menstrual, follicular, and luteal) and at two different times of day (morning and evening). Physical performance was evaluated using the Modified Agility Test (MAT), Reactive Agility Test (RAT), and Repeated Sprint Ability (RSA) Test. Psychological responses were measured using the Profile of Mood States (POMS), Hooper's Questionnaire, Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, Vis-Morgen Questionnaire, and Spiegel Questionnaire.

RESULTS

Significant effects of menstrual cycle, time of day, and competition on physical performance, cognitive function, mood, and sleep parameters were found. Physical performance, including the Countermovement Jump (CMJ), the Modified Agility T-test (MAT) and the Reactive Agility test (RAT), was higher in the afternoon than in the morning across all menstrual phases (CMJ: p < 0.001, η² = 0.836; MAT: p < 0.001, η² = 0.777; RAT: p < 0.001, η² = 0.859). After the competition, performance decreased significantly, especially in the follicular and luteal phases. As measured by the Stroop test, cognitive function showed significant diurnal effects (p < 0.001, η² = 0.910), with pre-competition performance being better in the afternoon. Mood disturbances (POMS) increased after the competition, especially in the morning and during the luteal phase (p < 0.001, η² = 0.961). Sleep parameters were significantly influenced by time and menstrual cycle, with higher fatigue (Hooper score: p < 0.001, η² = 0.754) and poorer sleep quality (PSQI: p < 0.001, η² = 0.627) in the morning, especially after the competition.

CONCLUSION

Our results suggest that aligning high-intensity training and competitions with afternoon circadian peaks may enhance physical and cognitive performance in elite female athletes. Recovery strategies and workload adjustments should account for menstrual phases, particularly reducing morning demands during the luteal phase to mitigate fatigue and mood disruptions. Integrating circadian timing with menstrual cycle monitoring offers a practical, evidence-based approach to optimize athlete readiness and resilience.

Peculiarities of cardio-respiratory relationships in qualified athletes with different types of heart rhythm regulation according to respiratory maneuver data

INTRODUCTION

Our goal was to determine the differences in changes in cardiovascular and cardiorespiratory interaction indicators during a respiratory maneuver with a change in breathing rate in athletes with different types of heart rate regulation.

METHODS

The results of a study of 183 healthy men aged 21.2 ± 2.3 years, who were systematically involved in various sports, were analyzed. According to the results of the analysis of the HRV study during spontaneous breathing, the athletes were divided into 4 groups taking into account the type of heart rate regulation (HRR). Group 1 (with type I) consisted of 53 people, group 2 (with type II)-29 people, group 3 (with type III)-85 people, group 4 (with type IV)-16 people. The methodology for studying the cardiorespiratory system included combined measurements of the respiratory and cardiovascular system activity indicators in a sitting position using a spiroarteriocardiorhythmograph. The duration of the study was 6 min.

RESULTS

According to changes in cardiorespiratory and cardiovascular interaction indicators during controlled breathing with a frequency of 6 and 15 per minute (CR6 and CR15), it is shown that with a pronounced predominance of parasympathetic influences (type IV) in conditions of excessive cardiorespiratory control and moderate hyperventilation, differences in changes in arterial baroreflex sensitivity (δBRLF and δBRHF) are noted in comparison with other HRR. Athletes with type IV at CR6 in δBRLF significantly differ from athletes with type III (p = 0.026) and do not differ from athletes with type II (p = 0.141). In δBRHF significantly (p = 0.038 and p = 0.043)-from athletes with types I and II. It is shown that with the predominance of sympathetic influences (types I and II), the reactivity of BRS (δBRLF and δBRHF) in response to moderate hyperventilation (CR15) is significantly lower. Changes in the Hildebrandt index and the volume synchronization index additionally differentiate HRR associated with a moderate and pronounced predominance of sympathetic and parasympathetic influences.

CONCLUSION

The use of a respiratory maneuver in a combined study of the cardiorespiratory system in the conditions of current control of athletes showed informativeness in the differentiation of HRR types and states of functional overstrain.

Is skin temperature associated with training load during preparatory period of a professional volleyball team?

The current study investigated if skin temperature (Tsk) measurement through infrared thermography could reflect the accumulation of training load during the preparatory period of a professional volleyball team. Sixteen athletes (20.1 ± 3.1 years, 88.1 ± 6.1 kg, 193 ± 0.1 cm e 13.3 ± 2.3 % body fat) were assessed over two weeks of the preparatory period (5 training days in each week) for the second division of the Brazilian Men's Volleyball Super League. After one week of familiarization with the study procedures, Tsk was measured in eight regions (anterior and posterior areas of arm, shoulder, thigh, and leg) on the first and last training days of each week, along with perceived recovery status (PRS) were measured on the first and last training days of each week. Training load for each session and total weekly training load (TWTL) were calculated using the session rating of perceived exertion (SRPE) method. Three days in the first week and four days in the second week had higher training loads (χ2 = 89.1, p < 0.001), as indicated by a significant reduction in recovery perception at the end of each week (F = 52.3, p < 0.001). Among the eight regions examined, five showed a decrease in Tsk after two rest days (weekend), while two regions exhibited an increase in Tsk at the end of the following training week (p < 0.05). Out of 44 associations examined between Tsk, PRS, and TWTL, only the associations between delta PRS and delta mean Tsk of the anterior and posterior leg were significant (β = -0.20, p < 0.045 for both). In conclusion, the data suggest that Tsk may be altered during the pre-competitive period of professional volleyball players; however, it does not appear to be associated with PRS and training load as assessed by the SRPE method.

The Role of Biomarkers in Monitoring Chronic Fatigue Among Male Professional Team Athletes: A Systematic Review

This systematic review synthesizes evidence on biomarker responses to physiological loads in professional male team sport athletes, providing insights into induced fatigue states. Structured searches across major databases yielded 28 studies examining various biomarkers in elite team sport players. Studies evaluated muscle damage markers, anabolic/catabolic hormones reflecting metabolic strain, inflammatory markers indicating immune activity and tissue damage, immunological markers tied to infection risk, and oxidative stress markers showing redox imbalances from excessive physiological load. Responses were examined in official matches and training across competitive seasons. The evidence shows that professional team sports induce significant alterations in all studied biomarkers, reflecting measurable physiological strain, muscle damage, oxidative stress, inflammation, and immunosuppression during intensive exercise. These effects tend to be larger and more prolonged after official matches compared to training. Reported recovery time courses range from 24-h to several days post-exercise. Monitoring biomarkers enables quantifying cumulative fatigue and physiological adaptations to training/competition loads, helping to optimize performance while mitigating injury and overtraining. Key biomarkers include creatine kinase, testosterone, cortisol, testosterone/cortisol ratio, salivary immunoglobulin-A, and markers of inflammation and oxidative stress. Further research should extend biomarker monitoring to cover psychological stress and affective states alongside physiological metrics for deeper insight into athlete wellness and readiness.

Quantifying internal and external training loads in collegiate male volleyball players during a competitive season

BACKGROUND

The long-term monitoring of internal and external training load is crucial for the training effectiveness of athletes. This study aims to quantify the internal and external training loads of collegiate male volleyball players during the competitive season. The internal and external training load variables were analyzed across mesocycles and playing positions.

METHODS

Fourteen participants with age of 20.2 ± 1.3 years, height of 1.81 ± 0.05 m, and body weight of 70.8 ± 5.9 kg were recruited. The data were collected over a 29-week period that was divided into four mesocycles: preparation 1 (P1, weeks 1-7), competition 1 (C1, weeks 8-14, including a 5-day tournament in week 14), preparation 2 (P2, weeks 15-23), and competition 2 (C2, weeks 24-29, including a 6-day tournament in week 29). Each participant wore an inertial measurement unit and reported the rating of perceived exertion in each training session. The internal training load variables included weekly session rating of perceived exertion, acute: chronic workload ratio, and training monotony and strain. The external training load variables included jump count and height and the percentage of jumps exceeding 80% of maximal height.

RESULTS

C2 had the highest average weekly internal training load (3022 ± 849 AU), whereas P2 had the highest average weekly acute: chronic workload ratio (1.46 ± 0.13 AU). The number of weekly jumps in C1 (466.0 ± 176.8) was significantly higher than in other mesocycles. Weekly jump height was significantly higher in C1, P2, and C2. Internal training load was positively correlated with jump count (ρ = 0.477, p < 0.001). Jump count was negatively correlated with jump height (ρ = -0.089, p = 0.006) and the percentage of jumps exceeding 80% of maximal height (ρ = -0.388, p < 0.001). The internal and external training load variables were similar among different playing positions.

CONCLUSION

The participants exhibited significantly higher internal training load in C2 and higher jump height after P1. A high jump count was associated with higher internal training load and lower jump height. Excessive jumps may result in fatigue and reduce height.

A Decrease in Branched-Chain Amino Acids after a Competitive Male Professional Volleyball Game-A Metabolomic-Based Approach

A competitive volleyball game is a highly metabolic and physically demanding event for professional players. This study aimed to investigate whether a single game at the end of a preseason promotes changes in the biochemical markers of physical exercise responses and the metabolomic profile of professional volleyball players. This cross-sectional study included 13 male Brazilian professional volleyball players. Food intake, body composition, heart rate, physical movement variables, and blood biochemical indicators were evaluated. For non-target metabolomic analysis, serum samples were subjected to 500 MHz Nuclear Magnetic Resonance. Data analysis showed no significant difference in the biochemical indicators after the game (p > 0.05). The level of metabolites present in the groups of the main components (β-hydroxybutyrate, arginine/lysine, isoleucine, leucine, and valine) had decreased after the game. However, formic acid and histidine levels increased. Among the compounds not part of the main components, hypoxanthine and tyrosine increased, whereas low-density lipoprotein and very low-density lipoprotein levels decreased. After the game, the metabolomic profiles of players showed significant negative variations in essential amino acids (leucine, valine, and isoleucine). These decreases might be influenced by athlete diet and reduced glycogen storage due to lower carbohydrate intake, potentially impacting serum-essential amino acid levels via oxidation in skeletal muscle. The study provides insights for developing metabolic compensation strategies in athletes.

Training stress, neuromuscular fatigue and well-being in volleyball: a systematic review

BACKGROUND

Volleyball, with its unique calendar structure, presents distinct challenges in training and competition scheduling. Like many team sports, volleyball features an unconventional schedule with brief off-season and pre-season phases, juxtaposed against an extensive in-season phase characterized by a high density of matches and training. This compact calendar necessitates careful management of training loads and recovery periods. The effectiveness of this management is a critical factor, influencing the overall performance and success of volleyball teams. In this review, we explore the associations between training stress measures, fatigue, and well-being assessments within this context, to better inform future research and practice.

METHODS

A systematic literature search was conducted in databases including PsycINFO, MEDLINE/PubMed, SPORTDiscus, Web of Science, and Scopus. Inclusion criteria were original research papers published in peer-reviewed journals involving volleyball athletes.

RESULTS

Of the 2535 studies identified, 31 were thoroughly analysed. From these 31 articles, 22 included professional athletes, seven included collegiate-level volleyball athletes, and two included young athletes. Nine studies had female volleyball players, while the remaining 22 had male volleyball athletes.

CONCLUSIONS

Internal training load should be collected daily after training sessions and matches with the session rating of perceived exertion method. External training load should also be measured daily according to the methods based on jump height, jump count, and kinetic energy. If force platforms are available, neuromuscular fatigue can be assessed weekly using the FT:CT ratio of a countermovement jump or, in cases where force platforms are not available, the average jump height can also be used. Finally, the Hooper Index has been shown to be a measure of overall wellness, fatigue, stress, muscle soreness, mood, and sleep quality in volleyball when used daily.

Rating of Perceived Exertion in Professional Volleyball: A Systematic Review

The rating of perceived exertion (RPE) is a non-invasive, cost effective, and time efficient strategy to measure training loads. However, data can be collected without following specific procedures and across a range of methods (e.g., different RPE scales and/or different operational questions). Consequently, practitioners working in professional volleyball can use this information in various ways with different assessment standards between them. Therefore, the purpose of the current review was to systematically and critically evaluate the use of RPE-based methods in professional volleyball athletes. Electronic searches were conducted in four databases (PubMed, SPORTDiscus, Scopus, and Web of Science). The electronic search yielded 442 articles, from which 14 articles were included in the systematic review. All included studies used the BORG-CR10 scale to calculate the session RPE. The main findings indicate that, to minimize the effect of the last exercise of the session, the athlete should be presented with the RPE question 10 to 30 minutes after the session is finished. Additionally, in order to evaluate the intensity of the training session, the question should be "how hard/intense was your session?", avoiding questions without these adverbs or adjectives such as "how was your training session/workout?". Future studies should analyse the collection of the localized RPE responses in professional volleyball athletes and their relationships with objective markers such as the number of jumps and accelerations.

Training Load, Neuromuscular Fatigue, and Well-Being of Elite Male Volleyball Athletes During an In-Season Mesocycle

PURPOSE

Most high-intensity bouts of exercise in volleyball consist of jumping activities, which are responsible for inducing muscle damage, high levels of fatigue, and muscle soreness. Therefore, the aim of the current study was to quantify and analyze the training loads, neuromuscular fatigue, and perceptual well-being of a 5-week in-season mesocycle carried out by a professional male volleyball team.

METHODS

Fifteen volleyball players (age 28.51 [5.39] y; height 193.19 [9.87] cm; body mass 88.46 [13.18] kg) participated in this study. Internal training load assessed through the rating of perceived exertion, external training load (ETL; evaluated using an inertial motion unit), countermovement jump (CMJ) height and peak power, and wellness questionnaire responses were obtained from all athletes.

RESULTS

Results indicated a progressive decrease of the internal training load during the week and by the undulatory pattern of the ETL during the microcycles. Moreover, training monotony increased across the microcycles and was negatively associated with CMJ peak power (r = -.681, P < .05). Finally, sleep quality (ρ = -.747, P < .01) and fatigue (ρ = -.789, P < .01) were negatively associated with weekly ETL.

CONCLUSIONS

This study indicated that sleep quality and fatigue were negatively associated with weekly ETL. Therefore, decreases in weekly ETL might be needed to improve sleep quality and decrease fatigue in professional volleyball players. Plus, higher values of training monotony were associated with lower values of CMJ peak power. Consequently, avoiding training monotony might be important to improve jumping performance in professional volleyball athletes.

Fatigue and Training Load Factors in Volleyball

The purpose of this article was to determine the internal and external loads experienced by volleyball players in a weekly cycle during the competitive season. Using accelerometers, as well as subjective rating perceived exertion (RPE) and total quality recovery scale (TQR) questionnaires, eleven female athletes were monitored during five days of training sessions over the course of the 2021 season. The data were evaluated for trends during the start period in preparation for the championship tournament. Analysis of the accelerometer data revealed a relationship between RPE and session rating perceived exertion (s-RPE), as well as the number of total accelerations. It was reported that on the training days of the same well-being level, the jump number values were significantly different. The results suggest that monitoring athletes for the number of accelerations can be used to understand the needs of volleyball players and to improve the design of training and recovery days to optimize athletes' well-being.

Effect of Physical Exertion on the effect of physical exertion on the concentration of copper and blood pressure in athletesn the Concentration of Copper and Blood Pressure in Athletes

Background and Study Aim. Several mineral elements are necessary for the athlete's body, which significantly impact the development of sports achievements because of their active role in bringing internal balance to the athlete's body. The study aims to determine the concentration of copper in the blood before and after the implementation of physical exertion at a level of 180 pulse/min on middle-distance runners. Material and Methods. Twelve athletes who are team members at Egyptian clubs were chosen deliberately as a research sample. The study participants were at the end of their special preparation. The experiment was conducted between July 12, 2021, and July 14, 2021, on the research sample, resting after exerting physical effort by running on a treadmill at a speed of 10 km / h. The runner continued at this speed for 3 minutes, after which the device's speed increased by 2 km / h every minute until reaching a heart rate of 180 pulse/ min. Results. The mineral differences in the copper element are attributed to the immediate induced by physical exertion by increasing the copper element in the blood within the normal level. This causes many changes and responses within the body cells. The copper element plays a significant role in oxidation and reduction processes via enzymes that require the copper element to produce energy in the cells and tissues due to the body's exposure to physical exertion. Athletes' exposure to physical exertion causes copper-dependent enzymes to produce energy in cells and tissues due to the element's requirement. Conclusions. Copper affected the physical effort of middle-distance runners at a heart rate of 180 pulse/min. In addition,  Middle-distance runners' blood pressure (systolic and diastolic) was affected by the physical exertion at a heart rate of 180 rpm.

Within-Week Variations and Relationships between Internal and External Intensities Occurring in Male Professional Volleyball Training Sessions

The purpose of the study was to test the within-week variations of the internal and external training intensity outcomes organized by days of the week. An 8-month observational period was conducted during the 2020-2021 season. The training sessions and matches of an elite volleyball team were monitored daily. The data comes from 14 players (two setters, five middle blockers, five outside hitters, and two opposites) of an elite team from the Portuguese 1st League (age: 21.7 ± 4.19 years of age; experience: 6.2 ± 3.8 years; body mass: 85.7 ± 8.69 kg; height: 192.4 ± 6.25 cm; BMI: 23.1 ± 1.40 kg/m2). The CR10 Borg scale was applied daily to measure the training intensity. The rate of perceived exertion (RPE) and the session-RPE were extracted as the internal outcomes. The external intensity was measured using an inertial measurement unit (IMU). The number of jumps, height average of jumps (JHA), minimum jump (MJ), maximal jump (MXJ), range jump (RJ), number of jumps (NJ), and training session density (D) were extracted as external intensity outcomes. The results showed that there was a difference between RPE and S-RPE (F (1.98) = 6.31, p = 0.01, η2 = 0.36, and F (1.73) = 28.30, p = 0.001, η2 = 0.72), as well as JHA and NJ (F (2.14) = 4.76, p = 0.02, η2 = 0.30, and F (1.77) = 4.77, p = 0.02, η2 = 0.30) within the microcycle. When analyzing the correlations between internal and external intensity, it was observed that there was a negative correlation between the Maximum Jump (4, 3, and 1 days before the Match day) (r2 = 0.34, r2 = 0.40, r2 = 0.41, respectively) and the Range Jump (3 and 1 days before the Match day (r2 = 0.33, r2 = 0.38, respectively) with the RPE (4 days before the Match day) and Maximum Jump (5, 4, 3, and 1 days before the Match day (r2 = 0.35, r2 = 0.39, r2 = 0.44, r2 = 0.34, respectively) and Range Jump (5, 4, 3, and 1 days before the Match day) (r2 = 0.34, r2 = 0.35, r2 = 0.40 and r2 = 0.36, respectively) with S_RPE (4 days before the Match day). Such findings show that higher internal intensities are correlated with lower external intensities in sessions further away from the game day. Such results could be an important tool for coaches to reflect, plan, monitor, and execute the training unit according to the temporal distance to the competition.

Acute Fatigue Responses to Occupational Training in Military Personnel: A Systematic Review and Meta-Analysis

INTRODUCTION

Military personnel are required to undertake rigorous physical training to meet the unique demands of combat, often leading to high levels of physiological stress. Inappropriate recovery periods with these high levels of physical stress may result in sub-optimal training and increased risk of injury in military personnel. However, no reviews have attempted to examine the magnitude of training-induced stress following military training activities. The aim of this systematic review was to assess the magnitude of physiological stress (physical, hormonal, and immunological) following task-specific training activities in military personnel.

METHODS

An extensive literature search was conducted within CINAHL, PubMed, Scopus, SportDiscus, and Web of Science databases with 7,220 records extracted and a total of 14 studies eligible for inclusion and evaluation. Study appraisal was conducted using the Kmet scale. Meta-analysis was conducted via forest plots, with standard mean difference (SMD, effect size) and inter-trial heterogeneity (I2) calculated between before (preactivity) and after (12-96 hours postactivity) military-specific activities for biomarkers of physiological stress (muscle damage, inflammation, and hormonal) and physical performance (muscular strength and power).

RESULTS

Military training activities resulted in significant levels of muscle damage (SMD = -1.28; P = .003) and significant impairments in strength and power (SMD = 0.91; P = .008) and testosterone levels (SMD = 1.48; P = .05) up to 96 hours postactivity. There were no significant differences in inflammation (SMD = -0.70; P = .11), cortisol (SMD = -0.18; P = .81), or insulin-like growth factor 1 (SMD = 0.65; P = .07) when compared to preactivity measures.

CONCLUSIONS

These findings indicate that assessments of muscle damage, anabolic hormones like testosterone, strength, and power are effective for determining the level of acute stress following military-specific activities. With regular monitoring of these measures, appropriate recovery periods may be implemented to optimize training adaptations and occupational performance, with minimal adverse training responses in military personnel.

Relationships between Fitness Status and Blood Biomarkers in Professional Soccer Players

Background

Physical conditions are recognized to be optimal after the pre-season (PS) phase in professional sports. Given that blood measures may also reveal variations, which in turn, may present associations with fitness changes.

Objective

The aim of this study is to test the changes of blood markers and physical fitness outcomes at the beginning and following the PS phase. Additionally, we aimed also to analyze the associations of training adaptations between blood markers and the physical fitness measures. Methodology. 25 professional male soccer players (28.1 ± 4.6 years old, 2.0 ± 7.8 kg, and 176.7 ± 4.9 cm) were assessed for hematological and biochemical parameters, and physical fitness measures in the baseline and after the phase of PS.

Results

Increases in platelets were observed after the PS phase (p = 0.001, η2 = 0.39). Regarding the biochemical parameters, significant increases between PS were found for creatinine (Cre) (p = 0.001, η2 = 0.66), alkaline phosphatase (ALP) (p = 0.001, η2 = 0.79), C-Reactive Protein (CRP) (p = 0.001, η2 = 0.74), cortisol (C) (p = 0.001, η2 = 0.63), and testosterone (T) (p = 0.001, η2 = 0.76), whereas significant decreases were found for albumin (Alb) (p = 0.004, η2 = 0.29), and calcium corrected (Ca Corr.) (p = 0.002, η2 = 0.32). Moderate correlations were found between albumin and the 5-meter linear sprint split (r = -0.44 (95%CI: -0.71; -0.05)) and CRP (r = -0.48 (95%CI: -0.74; -0.10)). Moderate correlations were found between VAMEVAL and hemoglobin (r = 0.44 (95%CI: 0.05; 0.71)).

Conclusions

The overall physical fitness measures improved after the PS phase. Also, significant variations (decreases/increases) were observed for the case of biomchemical and hematological outcomes. Coaches should carefully consider the adaptative changes observed in blood parameters as the changes in whole organism and metabolism after specific critical phases as the PS in professional players. Thus, optimal management of stimulus/recovery can be warranted to minimize illness and injury rate and to follow the direction and dynamics of adaptative changes.

Quantification of Workload and Wellness Measures in a Women's Collegiate Volleyball Season

The purpose of this paper was to quantify internal and external loads completed by collegiate volleyball athletes during a competitive season. Eleven players were sampled (using accelerometers and subjective wellness surveys) during the practice (n = 55) and game (n = 30) sessions over the 2019 season. Longitudinal data were evaluated for trends across the preseason, non-conference play, and conference play periods. Data were also analyzed with respect to positional groups. Longitudinal analysis of accelerometer data showed higher workload demand during practices than games. Positional group differences were most when evaluating jump count and height. Setters accrued over twice as many jumps in a practice than during a game and had similar overall jump counts in practice to attacking positions. Average team wellness values varied with time in the season, especially during times of congested travel. This is the first study to look at both game and practice workload and wellness measures in collegiate women's volleyball. The results suggest athlete monitoring can be used to understand the demands of volleyball and used in the future to enhance practice and recovery day design to optimize athlete well-being.

Acute Effects of Training Loads on Muscle Damage Markers and Performance in Semi-elite and Elite Athletes: A Systematic Review and Meta-analysis

BACKGROUND

The relationship between exercise-induced muscle damage (EIMD) indicators and acute training loads (TL) is yet to be reviewed extensively in semi-elite and elite athlete populations.

OBJECTIVES

The objectives of this systematic review and meta-analysis were threefold: (1) to evaluate studies of EIMD following the initial period of the preseason in semi-elite and elite athletes: (2) to examine acute physiological and performance responses across two periods of the season with similar TL; and (3) to examine acute physiological and performance responses to acute changes in TL during the season.

METHODS

The CINAHL, PubMed, Scopus, SPORTDiscus and Web of Science databases were systematically searched for studies that investigated: (1) semi-elite or elite athletes in team or individual sports following a periodised training programme; and (2) measured acute responses to training. Studies were excluded if: (1) conducted in animals; (2) non-English language; or (3) a conference abstract, review or case report. The Kmet Quality Scoring of Quantitative Studies tool was used for study appraisal.

SYNTHESIS METHODS

Data were quantitatively analysed by generating forest plots to report test statistics for statistical significance and inter-trial heterogeneity.

RESULTS

Of the included studies (n = 32), athletes experienced greater creatine kinase (CK) concentrations (Z = 4.99, p < 0.00001, I² = 74%), inflammatory factors and other indirect measures of muscle damage in the initial phase of the preseason period compared to the off-season; there were no changes in CK (Z = 1.43, p = 0.15, I² = 74%) across two time points of similar TL; and there were concurrent increases in CK with increases in TL (Z = 4.26, p < 0.0001, I² = 36%) and vice versa (Z = 4.33, p < 0.0001, I² = 79%).The qualitative analysis identified that the response of inflammatory factors and other indirect measures of muscle damage to changes in load were inconclusive.

LIMITATIONS

This review included varying age, sex, sports and competition levels. The group level meta-analysis failed to identify within-athlete or position-specific differences across time.

CONCLUSION

Blood biomarkers of EIMD may not differ across periods of similar TL, however can be considered a sensitive monitoring tool for assessing responses following acute TL changes in semi-elite and elite athletes.

Relationship between vertical jumping ability and endurance capacity with internal training loads in professional volleyball players during preseason

BACKGROUND

This study aimed to quantify internal training load and changes in vertical jumping ability and endurance capacity of professional volleyball players during the preseason, and to explore relationships between players` physical qualities at the beginning of the preseason with internal training load accumulated during the first two weeks of training.

METHODS

Sixteen male professional volleyball players from a team participating in the Brazilian National Super League took part in the study. Before and after a 10-week preseason, their vertical jumping ability and endurance capacity were assessed by squat jump, countermovement jump without and with arm swing, and YoYo endurance test, level 1. The internal training load was quantified by the session rating of perceived exertion method. Results were analyzed using analysis of variance, magnitude-based inference and Pearson's correlation.

RESULTS

The internal training load varied between 1388 ± 111 a.u. and 3852 ± 149 a.u., and performance in all the tests was positively changed (small to moderate effect sizes) at end of preseason training. Significant (P < 0.05) very large and large correlations were observed between squat jump (r = -0.81) and YoYo endurance test (r = -0.64) performances and internal training load accumulated during the first two training weeks, respectively.

CONCLUSIONS

In conclusion, the internal training load and training strategies undertaken by the investigated team were effective to improve players` vertical jumping ability and endurance capacity. Coaches need to improve these physical qualities of volleyball players in order to improve their tolerance to training.

Stress and recovery perception, creatine kinase levels, and performance parameters of male volleyball athletes in a preseason for a championship

Background

Training load and adequate recovery have been identified as essential elements to improve well-being and performance in team sports and avoid non-functional overreaching and overtraining.

Objective

This cohort study sought to analyze the stress and recovery perceptions, creatine kinase levels (CK), and vertical jump performance of volleyball athletes at different training times during a championship preseason.

Methods

Thirteen high-level male volleyball players (23.80 ± 5.40 years, 91.50 ± 8.80 kg, and 193.10 ± 6.40 cm) completed the RESTQ-Sport questionnaire on stress and recovery perception, and blood samples were collected to evaluate CK levels. These measures were performed six times over 16 weeks, while jumps such as squat jump (SJ), countermovement jump (CMJ), and countermovement jump arm (CMJA) were performed at three of those times for specific performance evaluation.

Results

The stress perception and recovery perception indices increased and decreased, respectively, in the pre-competitive phase, while CK levels presented an initial rise, maintenance over the training period, and a drop. Vertical jump heights increased significantly throughout the preparatory period regardless of the type of jump. In all training phases, CMJA values exceeded CMJ and SJ values, and CMJ values exceeded SJ values.

Conclusions

Positive adaptations were elicited by training stimuli, resulting in improvements in performance. Conversely, load training variables indicated higher levels of stress and muscle damage, together with lower perceptions of recovery during the championship preseason.

Monitoring Internal Training Load, Stress-Recovery Responses, and Immune-Endocrine Parameters in Brazilian Jiu-Jitsu Training

Campos, F, Molina Correa, JC, Canevari, VCM, Branco, BHM, Andreato, LV, and de Paula Ramos, S. Monitoring internal training load, stress-recovery responses, and immune-endocrine parameters in Brazilian jiu-jitsu training. J Strength Cond Res XX(X): 000-000, 2020-This study aimed to evaluate the relationship between training loads, stress, and immune-endocrine markers during a precompetitive period in Brazilian jiu-jitsu (BJJ) athletes. For this, 12 athletes were submitted to 1 physical and 1 technical-tactical training session per day, 5 days a week, for 7 weeks. The saliva sampling and physical tests (countermovement jump [CMJ] and squat jump [SJ]) were performed before starting the training period (pre) and at the fourth week (4-week) and eighth week (post). Session rating of perceived exertion (sRPE) and the Recovery-Stress Questionnaire-Sport (RESTQ) were applied, and the training load was calculated weekly. Repeated-measures analysis of variance and the Friedman test were used, with significance levels set at p < 0.05. Increased training loads were recorded by the sRPE method in technical-tactical training sessions (p < 0.05). Higher physical loads were reported by athletes during weeks 1-4, contributing to overall higher training load, monotony, and strain during this period (p < 0.05). Increased perception of stress, by the RESTQ, and cortisol were detected, whereas decreased salivary testosterone and salivary immunoglobulin A were observed at 4 weeks (p < 0.05). No significant differences were detected in CMJ and SJ tests, suggesting that training neither elicited significant fatigue and underperformance nor improved strength performance. However, decreasing physical training loads appeared to reduce symptoms of stress and improved recovery, favoring immune recovery and anabolic balance. Thus, the sRPE seems to be a reliable and simple method to monitor training loads in BJJ athletes because variation in values was related to the RESTQ and physiological responses to training loads.

Syzygium cumini Nectar Supplementation Reduced Biomarkers of Oxidative Stress, Muscle Damage, and Improved Psychological Response in Highly Trained Young Handball Players

The purpose of this study was to investigate the effects of Syzygium cumini (SC) nectar supplementation on performance, markers of oxidative stress, muscle damage, and psychological response in Handball players. Twenty-five young athletes (age = 18.6 ± 2.4 years) from an elite high school national level Brazilian Handball team were randomized into two study groups: SC/Jamelon nectar (SC, n = 12) and placebo (n = 13). The subjects ingested 10 mL/kg/day of Jamelon nectar or placebo 30 min before the training sessions and immediately after training cessation, for 28 days. Body mass index (BMI) and percentage of fat mass were assessed using bioelectrical impedance analysis. Biomarkers of oxidative stress were measured by lipid peroxidation, which was quantified by malondialdehyde (MDA). Total antioxidant capacity (TAC), creatine kinase (CK) activity, and lactate dehydrogenase (LDH) were determined. The 20 m shuttle run test, vertical jump, and running anaerobic sprint test were assessed to verify performance and the fatigue index was calculated. The Profile of Mood States (POMS) questionnaire was used for psychological evaluation. Both groups demonstrated improved vertical jump performance and a decreased fatigue index over time but without significant differences between them regarding performance. There was statistically significance only for SC in CK, LDH, and MDA, and TAC was greater in the SC compared to placebo. Furthermore, only the SC group demonstrated improved mood disturbance and confusion after the intervention. In conclusion, the present study suggests that SC nectar supplementation reduced biomarkers of oxidative stress and muscle damage, and improved psychological response in young handball players.