Kinesiology

EFFECTS OF A MOBILITY AND DYNAMIC STRENGTH INTERVENTION PROGRAM ON THE RANGE OF MOTION, STRENGTH, AND STRENGTH ASYMMETRY IN PEOPLE WITH NECK OR LOW BACK PAIN

Estibaliz Romaratezabala — 2023-12-31

The purpose was to ascertain the effects of a 12-week intervention program based on exercises of mobility and dynamic strength on the stabilization of neck and trunk muscles in people with neck or low back pain according to gender. Forty-two subjects (n = 25 males and n = 17 females; age 49.62±8.82 years) with neck or low back pain completed a recovery-training program focused on improving mobility and strength in the stabilizing muscles of the trunk and neck. A range of motion test, a strength (maximum voluntary contraction) test and the muscle strength asymmetry of the muscle groups analyzed were assessed at the beginning (T1), after six (T2) and after 12 (T3) weeks of intervention. Improvements were seen in nine out of the 12 range of motion variables at T2 (ES=0.52 to 1.26, moderate-high; p<.05) and T3 (ES=-0.28 to -0.44, low; p<.05 or p<.01). Improvements were also evident in all the strength variables at T2 (ES=-0.81, high; p<.01) and T3 (ES=-1.08 to -0.95, high; p<.01). In contrast, in the strength asymmetry variables improvements were found in one out of the five variables analyzed at T2 (ES=-0.81, high; p<.01) and two out of five at T3 (ES=- 1.08 to -0.95, high; p<.01). In conclusion, the intervention was effective for improving range of motion and strength. However, to improve muscle strength asymmetry it may be necessary to include specific exercises.

Key words: mobility, force, training, pathology, spine

ANALYSIS OF TRAINING LOAD AND PERFORMANCE IN DESIGNING SMART BODYWEIGHT POWER TRAINING: EFFECTS OF SET STRUCTURE IN VERTICAL JUMP SESSIONS

Radenko Arsenijević — 2023-12-31

The purpose of this study was to investigate the role of set structures in designing bodyweight power training (BWPT). Specifically, we compared the effects of Cluster set structure undulating variant (CSS_UV) and Traditional set structure (TSS) on training load and performance during vertical jumping sessions. Sixteen active males participated in this study. We designed four training sessions that consisted of 144 countermovement jumps distributed into 12 sets, where number of repetitions varied for CSS_UV sessions’, and for TSS sessions’ was fixed. In addition, both of the applied set structures included sessions with short (i.e., 60 seconds) and long rest periods (i.e., 120 seconds), while training volume was separately analysed for the first six sets (i.e., small volume) and last six sets (i.e., large volume). We calculated external load, internal load and performance variables. The obtained results suggest that CSS_UV allows superior utilization of applied external load, reduction of internal load and overall higher performances that are maintained during entire training session compared to TSS. The present study provides important findings about advantages of CSS_UV over TSS in terms of external load, internal load and performances during vertical jumping sessions, and therefore, it might be more suitable approach for designing BWPT.

THE USE OF PRINCIPAL COMPONENT ANALYSIS FOR REDUCTION OF TRAINING LOAD DATA IN PROFESSIONAL SOCCER

Perry Nosek — 2023-12-31

The aim of this study was to explore the use of principal component analysis (PCA) in understanding multivariate relationships in soccer training load data. Training load data were collected from 20 professional male soccer players during a 28-week in-season period. Twelve training load variables (total distance, PlayerLoadTM, low-speed running distance, moderate-speed running distance, high-speed running distance, sprint distance, moderate-speed running efforts, high-speed running efforts, sprint efforts, accelerations, decelerations, and changes of direction) were collected during training sessions, with correlation analysis revealing high intercorrelation between most variables (r = 0.04-0.98). Principal component analysis was performed on datasets containing all players and on individual players. On the whole dataset, two principal components were retained explaining a total of 81% of data variance. The first component comprised variables associated with distances in speed zones and the second component changes of direction. Whilst some individual variation existed among players, distances in speed zones were loaded on the first component and inertial movement analysis variables, such as accelerations, decelerations, and changes of direction, were loaded on the second component. These findings evidence the strong relationships between several common training load variables and highlight the risk of data redundancy. By selecting variables from each component, practitioners can reduce the number of variables reported whilst retaining as much of the variation in data as possible.

Key words: training load, Global Positioning Units (GPS), multivariate analysis, football, feedback

IS SPORT AND EXERCISE PARTICIPATION RELATED TO THE ENVIRONMENTAL AND POLICY FACTORS OF PHYSICAL ACTIVITY IN CROATIA? A CROSS-SECTIONAL POPULATION-BASED STUDY

Anja Maria Jukić — 2023-12-31

Physical activity is a complex behaviour influenced by individual, social, environmental, and policy factors. Understanding these factors of specific populations is a prerequisite for effective public health interventions. The main aim of this study was to determine the relationship between participation in sports, exercise, and other physical activities and the perception of environmental and policy correlates of physical activity in Croatia. The sample consisted of 1031 randomly selected Croatian citizens and data were collected within the “Special Eurobarometer 472” using questions about: a) participation in sport, exercise, and other physical activities and b) the environmental and policy factors of physical activity including opportunities for engaging in physical activities, the offer of sports clubs, and level of the support from local authorities. The results of the logistic regression analysis showed that people who perceived their local sports clubs and other service providers as offering more opportunities and those who felt that their local government supported physical activity were more likely to be actively involved in sports and exercise (p<.05 for all). Furthermore, the perception of greater opportunities for physical activity in the local environment is associated with increased involvement in recreational physical activities that are not related to sports (p<.05). Future strategies aiming at encouraging citizens to engage in sports and exercise should be based on strengthening cooperation between local authorities and local sports clubs, while the promotion of other physical activities should incorporate providing adequate infrastructure for engaging in physical activities and informing citizens about the provided opportunities.

Key words: physical inactivity, motor activity, correlates, policy impact, environmental influences, exercise engagement

GENDER AND LIMB EFFECTS ON ADULT NORMATIVE DATA FOR THE BIODEX BALANCE SYSTEM

Simonè Ferreira — 2023-12-31

Posturography normative data in healthy populations is crucial for several reasons including monitoring the independence issues related to activities of daily living (ADLs), fall and incapacity avoidance, and residual injury impairment. The Biodex Balance System requires updated normative data regarding healthy persons because of recent revisions to the Biodex Balance System. Further, this study aimed to determine and compare gender and limb performance of 161 adults aged 18-55 years (n = 80 males; n = 81 females). Assessments involved both static and dynamic stability tests such as double-leg and single-leg balance tests at platform stability which served as outcome measurements. Females performed significantly (p≤.05) better on double-leg static balance (p=.031), double-leg dynamic balance (p=.002), and single-leg dynamic balance on both the left (p=.003) and right legs (p=.013) when compared to males. The normative values and findings of this study not only enable the evaluation of individual performance regarding the balance of adults but also suggest the need to use gender-stratified normative data when using the Biodex Balance System to interpret double- and single-leg, static and dynamic balance test performance.

Key words: postural balance, posturography, health, reference values

METABOLIC RESPONSE DURING HIGH-INTENSITY INTERVAL EXERCISE AND RESTING VASCULAR AND MITOCHONDRIAL FUNCTION IN CROSSFIT PARTICIPANTS

Regis C. Pearson — 2023-12-31

High-intensity functional training (HIFT) can play a major role in preventing cardiometabolic disease. The majority of HIFT interventions incorporate CrossFit (CF) training. We measured aerobic capacity, metabolic response during high-intensity interval exercise (HIIE), resting mitochondrial oxidative capacity, and resting vascular function in adults who participated in CF training (> one year) vs. a sedentary group completing <2 h·wk-1 of structure exercise for > one year (SED). Twenty-one participants were recruited (CF n = 13 vs. SED n = 8). CF participants had a 33.0% greater relative VO2 peak (p<.001) and lower body fat percentage (CF = 18.6 [3.8] vs. SED = 30.3 [8.4]; p<.001). CF participants had higher exercising substrate oxidation when expressed as absolute and body weight relative values (p<.013), but not when expressed relative to lean mass (p>.200). CF participants had greater mitochondrial oxidative capacity (p=.014). There were no differences in large artery function, but CF participants had greater baseline arterial diameter (p=.004) and faster reperfusion following arterial occlusion (p<.05). These data support HIFT programs’ effectiveness in improving fitness, weight status, and metabolic, mitochondrial, and vascular function.

Key words: high-intensity functional training, CrossFit, metabolism, vascular function

EXCESSIVE USE OF THE PREFERRED FOOT IN ON-THE-BALL SKILLS EXECUTION COMPROMISES PERFORMANCE AND TACTICAL BEHAVIOUR OF FOOTBALL PLAYERS

Marcos Antônio Mattos dos Reis — 2023-12-31

This study aimed to compare tactical behaviour and performance of football players with different on-theball skills execution functional technical asymmetry levels and to verify whether functional technical and tactical performance indexes of football players are associated. The sample included 59 football players (14.2 ± 1.5 years of age). FUT-SAT and SAFALL-FOOT were used as instruments for performance analysis. Participants were divided in two groups: higher and lower functional technical asymmetry. Student’s t-test was used to compare the behaviour and tactical performance of the groups, and the Pearson test was used to verify associations between functional technical asymmetry and tactical performance indexes. A significance level of 5% was adopted. The higher functional technical asymmetry group showed less tactical efficiency (t57 = 1.9; p = .05; d = .17) and low performance results in the execution of defensive actions (t57 = 2.1; p = .04; d = .55; t57 = 2.1; p = .04; d = .61) compared to the lower functional technical asymmetry group. No association was found between the functional technical asymmetry and tactical performance indexes (r = -.06; p = .66). It is concluded that the levels of functional technical asymmetry affected the behaviour and tactical performance of players although functional technical asymmetry and tactical performance indexes values are not associated. Future investigations may verify how football players with high and low levels of functional technical asymmetry change their behaviour and tactical performance from different kinds of training.

Key words: decision-making, motor behaviour, motor skills, performance analysis, team sports

DOES THE LOAD-VELOCITY RELATIONSHIP PREDICT MAXIMUM DYNAMIC STRENGTH IN POWER CLEAN FROM THE KNEE?

Demostenys David da Silva — 2023-12-31

This study investigated the predictive validity and reliability of the load-velocity relationship with the one-repetition maximum test (1RM) in power clean from the knee exercise (PC). Initially, 12 healthy young males, with no PC experience, underwent eight sessions to learn the PC technique. After the learning period, the participants visited the laboratory on four more occasions with intervals between the visits from 72 to 96 h. The first two sessions were dedicated to the actual 1RM tests, while the last two sessions were performed to measure the barbell’s load-velocity relationship at 30%, 45%, 60%, 75%, and 90% of PC 1RM. The highest peak velocity recorded at each load was used to establish the linear regression equation and, consequently, to predict 1RM values. As a result, a low validity was observed between the highest actual 1RM value and the predicted 1RM in sessions 1 and 2 (typical errors = 3.6 to 5.0 kg, coefficients of variation = 6.03 to 8.21%, effect sizes = -1.23 to -1.00, and Bland-Altman bias = 8.5 to 11.7 kg). For reliability, higher measurement errors (intraclass correlation coefficient, typical error, coefficient of variation, and width of limits of agreement at 95%) were observed for the predicted 1RM compared to the actual 1RM test. In conclusion, the load-velocity relationship was not able to predict the 1RM value with high accuracy in the PC from the knee. Moreover, the predicted 1RM presented inferior reliability than the actual 1RM test.

Key words: maximum strength, weightlifting, velocity, velocity-based training, performance

RELATIONSHIP BETWEEN UNILATERAL AND BILATERAL COUNTERMOVEMENT JUMP PERFORMANCE AND FORCE-VELOCITY-POWER OUTCOME VARIABLES

Darjan Spudić — 2023-12-31

The main objective of the present study was to check the relationship between commonly used unilateral and bilateral countermovement jump (CMJ) performance variables (jump heights, unilateral CMJ jump/ bilateral CMJ jump height index, reactive strength index modified and bilateral deficit) and Force-velocity- Power (F-v-P) outcomes from loaded CMJs. Seventeen physical education students performed unilateral CMJ jumps, bilateral CMJ jumps and two-load (20 and 70% of the participant’s body mass) F-v-P tests. The results show that bilateral CMJ jump, unilateral CMJ jump height and the reactive strength index modified calculated from the bilateral CMJ jump are moderately correlated (r = 0.567-0.633, p<.05) to F0. No statistically significant correlations were found between F-v-P outcomes and unilateral CMJ jump height to bilateral CMJ jump index, reactive strength index modified calculated from the unilateral CMJ jump and bilateral deficit. Multiple linear stepwise regressions between F-v-P outcomes and performance variables revealed that only F0 can be statistically significantly predicted by CMJ height (R2 = 40 %). Although the unilateral and bilateral CMJ tests are less time-consuming and less fatiguing than the progressive loaded CMJ jump test, the results of our study show that the mechanical properties of the lower extremities obtained by unilateral CMJ jump and bilateral CMJ jump cannot be generalized to those measured by F-v-P profiling.

Key words: unilateral, F-v-P profiling, strength, power, ballistic

EFFECTS OF PLYOMETRIC JUMP TRAINING ON RUNNING ECONOMY IN ENDURANCE RUNNERS: A SYSTEMATIC REVIEW AND META-ANALYSIS

Ekaitz Dudagoitia Barrio — 2023-12-31

Running economy (RE) has a strong relationship with distance running performance and is defined as the energy demand for a given velocity. Plyometric jump training may improve RE. The present study aimed to assess the effects of plyometric jump training on endurance runners’ running economy and to estimate the effectiveness of program duration, training frequency, total sessions, age, training status and velocity. A literature search was performed using PubMed/MEDLINE, Web of Science, and SCOPUS databases. Subgroup and single training factor analyses of program duration, frequency, total sessions, chronological age, training status, and running velocity were performed. A random-effects model for meta-analyses was used. Eighteen studies were selected for the systematic review and 10 for the meta-analysis. A trivial effect was noted for plyometric jump training on running economy (ES=0.19). However, plyometric jump training combined with resistance training revealed a large effect on running economy (ES=1.34). Greater running economy improvements were noted after training interventions with >15 total sessions (ES=1.00), >7 weeks (ES=0.95) and >2 days/week (ES=0.89). The youngest (ES=0.95) and highly trained participants (ES=0.94) with faster velocities (ES=0.95) obtained better results. Our findings highlight the effect of plyometric jump training that may improve running economy, particularly in combination with resistance training, after longer-term interventions (i.e., >15 total sessions, >7 weeks), with greater frequency, and among younger and more highly trained runners, especially during running at higher competitive velocities.

Key words: running performance, human biomechanics, stretch-shortening cycle, high-intensity interval training, resistance training

KNEE WRAPS ARE DETRIMENTAL TO THE MAXIMAL SQUAT PERFORMANCE OF POWERLIFTERS COMPETING IN LOWER WEIGHT CLASSES

Andrew Naylor — 2023-12-31

The aim of the study was to evaluate the efficacy of knee wraps for competitive powerlifters. To achieve this, an analysis of powerlifting results dating back to 1964 has been conducted. From these results the one repetition max (1RM) squat was evaluated, specifically examining the influence of competitors using knee wraps versus raw (allowing only neoprene knee sleeves). Student’s t-test was used to compare the 1RM squat for male raw competitors (n=270,268) to those using wraps (n=26,576); and likewise for female raw (n=136,530) versus wraps (n=11,468). Overall, the males using wraps yielded significantly higher (p<.05) 1RM squat values (203 kg ± 46.8) than their raw counterparts (195 kg ± 45.7). The females yielded modest, but significantly higher (p<.05) 1RM squat values for raw (112 kg ± 29.3), compared to wraps (111 kg ± 29.8). The results were stratified by weight classes, and it was found that males in heavier classes (105, 120, and 120+ kg) significantly benefited (p<.05) from using knee wraps (+1.3, +4.8, and +6.9 kg respectively). For the lighter weight classes (59, 66, and 74 kg) knee wraps appeared significantly detrimental (p<.05) to the 1RM squat (-8.4, -4.4, and -3.6 kg, respectively). Only the heaviest female weight class (84 kg+) saw a significant benefit (p<.05) in the use of wraps with a net gain in 1RM squat of 4.5 kg. Again, wraps were shown to be significantly detrimental (p<.05) to the lighter weight classes (47, 52, 57, and 63 kg) with a net loss in 1RM squat (-3, -5.3, -3.6, and -3.3 kg, respectively). Considering these findings, it is suggested that only males in the heaviest three weight classes (105, 120, and 120+ kg), as well as females in the heaviest weight class (84+ kg), stand to gain any benefit from the use of knee wraps in competition.

Key words: strength training, powerlifting, supportive gear

VALIDITY AND RELIABILITY OF THE DAILY ACTIVITY BEHAVIOURS QUESTIONNAIRE (DABQ) FOR THE ASSESSMENT OF 24-H MOVEMENT BEHAVIOURS AMONG ADOLESCENTS

Kaja Kastelic — 2023-12-31

Measurement of the time spent in sleep, sedentary behaviour, and physical activity across the full 24-h day (i.e. 24-h movement behaviours) is essential for time-use research among adolescents. However, self-reported questionnaires for the assessment of 24-h movement behaviours are scarce. The aim of this study was to examine the validity and reliability of recently developed Daily Activity Behaviours Questionnaire (DABQ) for the assessment of time spent in sleep, sedentary behaviour, light physical activity, and moderate-to-vigorous physical activity among adolescents. A convenience sample of 59 high-school students (34 female, age range: 15–18 years) was recruited. Participants were asked to complete a web-based DABQ at two occasions (two-weeks apart) to examine test-retest reliability of the DABQ, and to wear activPAL accelerometer to examine convergent validity of the DABQ. The test-retest reliability correlation coefficients (ICC) for the durations of sleep, sedentary behaviour, light physical activity, and moderate-to-vigorous physical activity were 0.49, 0.64, 0.51, and 0.66, respectively. Convergent validity correlation coefficients (Spearman’s ρ) were 0.51, 0.38, 0.25, and 0.53, respectively. Our findings are comparable with the reliability and validity of most existing sleep, sedentary behaviour, or physical activity questionnaires among adolescents. However, DABQ is one of the first validated questionnaires that resonates with the emerging 24-h movement paradigm. The observed reliability and validity are indicating satisfactory measurement properties of the DABQ to be used in time-use research among adolescents.

Keywords: time-use questionnaire, time-use composition, physical behaviours, time-use epidemiology

PLYOMETRIC TRAINING PROGRAMS IN HANDBALL: A SYSTEMATIC SCOPING REVIEW

José Rocha Henrique — 2023-12-31

This systematic scoping review aimed to comprehensively identify and analyze the available evidence pertaining to the effects of plyometric training interventions on handball players. The search for relevant literature was conducted across prominent databases, including PubMed, Scopus, SPORTDiscus, and Web of Science Core Collection. The eligibility criteria focused on healthy handball players, without restrictions on age, sex, or competitive level, who were exposed to plyometric training interventions, either alone or in combination with other training methods. A meticulous screening process was conducted, whereby 3,195 titles were carefully evaluated, resulting in the inclusion of 35 eligible studies in this systematic scoping review, involving a total of 891 participants. Most studies on plyometric training in handball focused on indoor settings, conducted during the in-season period, and involved tier two athletes. The training frequency typically ranged from twice per week, with a duration of between 5 and 12 weeks, and incorporated some form of progressive overload. The number of total floor contacts varied between 20 and 600. There was a considerable variation in outcomes across the included studies, but most of them demonstrated a positive impact of plyometric training on improving jumping ability, sprinting speed, change of direction, strength, and balance. In conclusion, the predominant focus of the studies was on the lower limb, specifically aiming to assess the intervention influence on variables associated with strength and power. Notably, these investigations consistently highlighted favorable effects on enhancing these parameters among handball players. However, further research is needed to explore the effects of plyometric training in handball, particularly regarding exercise selection, optimal volume and intensity, rest intervals, and tapering protocols.

Key words: team sports, muscle strength, resistance training, stretch-shortening cycle

HOW COMPETITIVE PERFORMANCE DATA CAN INFORM THE TRAINING PROCESS? AN ACTION-RESEARCH STUDY BASED ON THE CONSTRAINT-LED APPROACH

Carmen Fernández-Echeverría — 2023-12-31

By implementing an insider action-research (AR) design throughout a competitive volleyball season, this study sought to examine qualitatively how competitive data, extracted from match analysis, may support the development of a coaching intervention based on the principles of the constraint-led approach. Twelve elite players, one head coach and one assistant coach participated in two AR cycles, each one involving the processes of planning, monitoring, reflecting, and fact-finding. The first author, who was also the assistant coach and the insider-researcher, collected data over 20 weeks using interviews, training videotaped records, and field notes. Data were analysed using thematic analysis, and inductive procedures were adopted to deepen an understanding of how a constraint-led coaching intervention evolved over the season. The results highlighted competitive data as a relevant tool for supporting the underlying pedagogical process in the design of representative learning tasks via constraints manipulation. Grounded on competitive data, the learning designs progressed from an initial point where constraints manipulation was scarce, non-representative, and without stimulating players’ problem-solving abilities, to an endpoint where tasks were conceived based on the next opposition’s features (i.e., task representativeness) and focused on the development of functional and co-adaptative skills. In conclusion, the competitive data supported the development of a coaching practice based on the constraint-led approach. Methodologically, the insider AR-design offered contextualized insights into how the pedagogical coaching intervention evolved over the season. Thus, we highlight the importance of sampling the most relevant information from competition, through match analysis reports, so that coaches can design representative and contextualized learning tasks ongoingly aligned with players’ needs.

Key words: ecological dynamics, sports pedagogy, qualitative analysis, volleyball

THE EFFECT OF MAXIMAL AEROBIC SPEED TRAINING COMBINED WITH SMALL-SIDED GAMES ON PERFORMANCE PARAMETERS IN SOCCER

Yılmaz Yüksel — 2023-12-31

The purpose of this research was to compare the effects of maximal aerobic speed (MAS) training, small-sided games (SSG) training, and combined training (CT) on sprint, agility, lactate accumulation, repeated sprint, aerobic, and anaerobic endurance performances. Thirty under-16 male players participated in a 6-week randomized training study. Pre- and post-training all players completed a test battery involving body composition (body height and Dual Energy X-Ray Absorptiometry-DEXA), sprint tests (10 m, 20 m, and 30 m), Yo-Yo 1 test, Arrowhead agility test, blood lactate test, and Yo-Yo 2 test. A global positioning system (GPS) was used for monitoring. After the pre-tests, the players were randomly assigned to three groups as MAS, SSG, and CT. Mixed two-way ANOVA was used to compare the pre-test and post-test performance of the three groups. While the CT group had higher changes in body composition, repeated sprint, aerobic, and anaerobic endurance parameters compared to the MAS training group (p<.05), the SSG training group had similar changes as the CT group (p>.05). In conclusion, coaches and sports scientists are advised to choose CT for more efficient training, considering the differences between the MAS training and CT methods.

Key words: small-sided games, maximal aerobic speed, game-based training, young male players, football

LOW-LOAD RESISTANCE EXERCISE COMPLETED TO VOLITIONAL FAILURE DECREASES PAIN PERCEPTION POST-EXERCISE IN FEMALES AND MALES

Christopher E. Proppe — 2023-12-31

Exercise-induced hypoalgesia (EIH) is the acute pain reduction post-exercise. Typically, high-intensity and/or long-duration exercise is required to elicit EIH. Alternatively, low-load resistance exercise with blood flow restriction (LL+BFR) may elicit EIH. However, there is conflicting evidence regarding the necessary repetitions and volume load. This study evaluated EIH after 75 repetitions (1×30, 3×15) (BFR-75) and four sets to volitional failure (BFR-F) protocols. Twenty-six participants completed unilateral knee extensions at 30% of maximal strength using a BFR-75 and BFR-F protocol. Pain pressure threshold (PPT) of the rectus femoris was assessed before and after exercise. Repetitions completed, volume load, occlusion time, and PPT were analyzed. Participants completed more repetitions (91.4±30.5), volume load (5,204.9±2,367.0 Nm), and had a longer occlusion time (345.8±76.2 seconds) during BFR-F compared to BFR-75 (73.2±3.7 repetitions, 4,451.1±1,498.1 Nm, 300.5±52.2 seconds, respectively). Collapsed across sex, PPT increased from pre- (3.24±1.91 kgf) to post-exercise (3.76±2.27 kgf) for BFR-F but not for BFR-75 (3.51±1.67 to 3.68±2.04 kgf). The results indicated that BFR-F, but not BFR-75, elicited EIH, as assessed by an increase in PPT. Lower loads used during LL+BFR may be a clinically relevant alternative to high-intensity and/or long-duration exercise in populations that may not tolerate high-intensity or prolonged exercise to induce EIH.

Key words: exercise-induced hypoalgesia, pain pressure threshold, blood flow restriction, muscle pain, resistance exercise, pain measurement

A TWO-FACTOR MODEL OF PERFECTIONISM IN SPORTS: RELATIONS WITH PERSONALITY TRAITS AND MOTIVATIONAL STRATEGIES

Tijana Radulović — 2023-12-31

The main goal of the research was to examine the correlation between personality traits (conscientiousness and neuroticism), perfectionistic strivings and concerns, and achievement motives (hope of success and fear of failure). In this research, 348 respondents (111 women, 237 men) from Serbia, Montenegro, Bosnia and Herzegovina, aged 16 to 54 years, filled out the questionnaires. Personality traits were measured by the Big Five plus 2 (VP + 2) questionnaire. The Sport Multidimensional Perfectionism Scale 2 (Sport-MPS 2) and the Multidimensional Inventory of Perfectionism in Sports (MIPS) were used for measuring perfectionism, while the revised version of the Achievement Motivation Scale (AMS-R) was used for motivational strategies determination. The relations were investigated with the method of structural equations. The theoretical model showed satisfactory concordance with the empirical data (RMSEA = .021, SRMR = .019, CFI = .999, TLI = .996). The model predicts the mediating effect of perfectionistic strivings on the relationship between conscientiousness and hope of success, as well as neuroticism and hope of success, and the mediating effect of perfectionistic concerns on the relationship between neuroticism and fear of failure.

Key words: perfectionism, personality traits, motivational strategies

UNDERSTANDING THE IMPACT OF HAMSTRING INJURIES ON MATCH PERFORMANCE IN SPANISH PROFESSIONAL SOCCER PLAYERS: TWO FULL SEASONS FOLLOW-UP

Javier Raya-González — 2023-12-31

This study aimed to analyze the changes in match physical performance in professional soccer players after sustaining a hamstring injury, which was categorized based on injury severity. Seventy-two hamstring injuries involving sixty-four professional soccer players from the Spanish LaLiga™ were considered for this study. All injuries were classified according to their severity as moderate (resulting in eight to 28 missed days) and major (resulting in more than 28 missed days). Mediacoach video-tracking system collected time and external load variables and subsequently compared them between the pre-injury and return-to-play periods. The analyzed variables included distance covered at different velocities (i.e., total distance, at 18-21 km.h−1, at 21-24 km.h−1, and at more than 24 km.h-1), the number of sprints, accelerations, decelerations, and high metabolic load distance (HMLD). The results showed that players with both the moderate and major injuries played fewer minutes after injury (p<.001 to p<.05) and experienced a decrease in maximum speed (p<.01 to p<.05), covering less total distance (p<.05) and exhibiting a decrease (p<.05) in average speed (only observed in players with major injuries). Additionally, moderately injured players experienced a reduction in the number of maximum accelerations (p<.05) and decelerations (p<.05), high metabolic load distance/min (p<.05), and average accelerations (p<.05). Furthermore, a significant reduction in the magnitude of maximum decelerations was observed in players with major injuries (p<.05). These findings highlight the importance of implementing strategies that enable the attainment of initial levels of high-intensity actions and maximum speed in reconditioning programs following hamstring injuries.

Key words: physical conditioning, thigh muscles, external load, playing time, video tracking, return to play, football