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Journal Details
Format
Journal
eISSN
1899-7562
First Published
13 Jan 2009
Publication timeframe
5 times per year
Languages
English

Search

Volume 79 (2021): Issue 1 (July 2021)

Journal Details
Format
Journal
eISSN
1899-7562
First Published
13 Jan 2009
Publication timeframe
5 times per year
Languages
English

Search

26 Articles

Section I - Kinesiology

Open Access

MBboard: Validity and Reliability of a New Tool Developed to Evaluate Specific Strength in Rock Climbers

Published Online: 28 Jul 2021
Page range: 5 - 13

Abstract

Abstract

In the present study, we analysed the validity and reliability of a new tool designed to assist the measurement of maximal upper-limb strength in rock climbers in a specific way, named MBboard. The MBboard consists of an artificial small climbing hold affixed to a wooden board, which is connected to any cable-motion strength equipment to determine the maximum dynamic strength (MBboard-1RM). Ten male rock climbers (Rock Climbing Group, RCG = 10) and ten physically active men (Control Group, CG = 10) performed, on three separate occasions, a familiarization session with procedures adopted during MBboard-1RM testing and two experimental trials (i.e., test and retest) to determine the construct validity and reliability of the MBboard during unilateral seated cable row exercise. In the first trial, the electromyographic activity (EMG) was recorded from the flexor digitorum superficialis. The self-reported climbing ability was also recorded. The RCG had superior performance (i.e. 37.5%) and EMG activity (i.e. 51%) in MBboard-1RM testing when compared with the CG (p < 0.05). There was a significant correlation between the MBboard-1RM results and climbing ability (r > 0.72, p < 0.05). Intraclass correlation coefficient analysis revealed good reliability within trials (ICC > 0.79, p < 0.05). These findings suggest that the MBboard is a valid and reliable tool to assess rock climbing-specific maximal strength. The validity of MBboard-1RM appears to be related to the finger flexor muscles activation, probably reflecting the specific adaptations resulting from long-term practice of this sport discipline.

Key words

  • rock climbing
  • physical evaluation
  • maximum dynamic strength
  • electromyographic activity
Open Access

Assessing the Magnitude and Direction of Asymmetry in Unilateral Jump and Change of Direction Speed Tasks in Youth Female Team-Sport Athletes

Published Online: 28 Jul 2021
Page range: 15 - 27

Abstract

Abstract

The direction of inter-limb asymmetries and the change of direction (COD) deficit are two aspects that have increased in recent years. The main objective of the present study was to assess the magnitude of neuromuscular asymmetries in an elite youth female team-sports sample and determine its directionality. Secondary objectives were to evaluate the relationship between COD deficit, linear speed and COD time performance. Elite female youth basketball and handball players (n = 33, age = 16 ± 1.17 y) performed the Single Leg Countermovement Jump in vertical (SLCJ-V), horizontal (SLCJ-H), and lateral (SLCJ-L) directions, the COD and the 10-m sprint. Results showed statistical differences between limbs in all the neuromuscular tests (p < 0.001). The Kappa coefficient showed poor to fair levels of agreement between tasks (K range = -0.087 to 0.233), indicating that asymmetries rarely favoured the same limb between skills. Additionally, small and non-significant correlations were found between the linear sprint capacity and the COD ability. The findings of the present study highlight the independent directionality of asymmetries across tests. The COD deficit does not appear to be much more advantageous than COD total time to measure asymmetry. Practitioners are encouraged to use a fitness testing battery to detect existing side differences and each ability should be specifically trained with functional tasks.

Key words

  • imbalance
  • performance
  • youth
  • sprint
  • jumping
  • neuromuscular
Open Access

Effects of a Neuromuscular Warm-Up Program in Youth Female Soccer Players

Published Online: 28 Jul 2021
Page range: 29 - 40

Abstract

Abstract

The protective effects of different warm-up injury prevention routines in youth female soccer players have been demonstrated in the literature, however, there is a paucity of information regarding the effects that these kinds of programs have on soccer-specific physical performance variables. The purpose of this study was to assess the effectiveness of a 12-week neuromuscular warm-up program on physical performance in youth female soccer players. Players (age: 13.94 ± 0.82 years) were divided into two groups. One group performed a neuromuscular activation program (n = 21) twice per week whereas the other group (control, n = 17) continued with their habitual warm-up routine for the same duration. Both groups of players performed strength, jumping and balance tests before and after the intervention period. Substantially greater improvements were detected in the mean velocity for the squat (p < 0.001; Effect Size = 0.95) and the hip thrust (p < 0.001; Effect Size = 0.51) in the experimental group in comparison to the control group. In addition, after the intervention period players in the experimental group showed an increase in the jumping height in the unloaded double-leg and single-leg counter-movement jumps (p = 0.003-0.012; Effect Size = 0.42-0.46). The results of this study provide evidence that a 12-week neuromuscular warm-up program can be effective to improve different physical performance variables in youth female soccer players.

Key words

  • soccer
  • warm up
  • performance
  • fitness
  • injury prevention
Open Access

Assessing Inter-Limb Asymmetries in Soccer Players: Magnitude, Direction and Association with Performance

Published Online: 28 Jul 2021
Page range: 41 - 53

Abstract

Abstract

In this study, we aimed to analyze the magnitude and direction of inter-limb asymmetries in ankle dorsiflexion range of motion (ROM), power (using iso-inertial devices), and a neuromuscular skill (change of direction). Secondarily, we aimed to determine the relationship between inter-limb asymmetry scores for each test and also between these scores and the scores for the different performance tests. Sixteen semiprofessional male soccer players (age: 25.38 ± 6.08 years; body height: 1.78 ± 0.64 m; body mass: 79.5 ± 14.9 kg) participated in this study. We calculated inter-limb asymmetries using five tests: ankle dorsiflexion ROM, change of direction (COD 180º), and iso-inertial resistance tasks in the open (leg extension strength (LE), leg curl strength (LC)) and closed (crossover step (CRO)) kinetic chain. Our results showed that asymmetry magnitudes differed between all tests with highest inter-limb asymmetries displayed during iso-inertial overloading. In addition, we observed that the direction of asymmetries varied depending on the test-specificity, and that the CRO asymmetries had a negative association with LE and CRO performance. These findings highlight the independent nature of asymmetries and that CRO could be an appropriate test to detect asymmetries related with the performance of soccer-specific actions (such as changes of direction). Practitioners are encouraged to use multiple tests to detect existing inter-limb differences according to the specific characteristics of each sport.

Key words

  • change of direction speed
  • symmetry
  • iso-inertial
  • specificity

Section II - Exercise Physiology & Sports Medicine

Open Access

Hydration Status in Adolescent Alpine Skiers During a Training Camp

Published Online: 28 Jul 2021
Page range: 55 - 63

Abstract

Abstract

Maintaining euhydration is important for optimal health, performance and recovery, but can be challenging for alpine skiers when training in a relatively cold but dry environment. This study aimed to evaluate hydration status, fluid loss and fluid intake in adolescent alpine skiers during a training camp. Twelve athletes aged 14.3 ± 0.9 years volunteered to participate in the study. Athletes resided at an altitude of 1600 m and trained between 1614 and 2164 m. During eight consecutive days, urine specific gravity was measured before each morning training session using a refractometer. Changes in body weight representing fluid loss and ad libitum fluid intake during each morning training session were assessed using a precision scale. Mean pre-training urine specific gravity remained stable throughout the training camp. Individual values ranged between 1.010 and 1.028 g/cm3with 50 to 83% of athletes in a hypohydrated state (urine specific gravity ≥ 1.020 g/cm3). Mean training induced fluid loss remained stable throughout the training camp (range -420 to -587 g) with individual losses up to 1197 g (-3.5%). Fluid intake was significantly lower than fluid loss during each training session. To conclude, urine specific gravity values before training indicated insufficient daily fluid intake in more than half of the athletes. Furthermore, fluid intake during training in adolescent alpine skiers was suboptimal even when drinks were provided ad libitum. Coaches and athletes should be encouraged to carefully monitor hydration status and to ensure that alpine skiers drink sufficiently during and in between training sessions.

Key words

  • alpine skiing
  • dehydration
  • youth
  • fluid intake
Open Access

Anaerobic Capacity is Associated with Metabolic Contribution and Mechanical Output Measured During the Wingate Test

Published Online: 28 Jul 2021
Page range: 65 - 75

Abstract

Abstract

The study aimed to investigate the relationship between anaerobic capacity, mechanical and anaerobic contribution during the 30-s Wingate Anaerobic Test (30sWAnT). After familiarization, fifteen, male recreational mountain biking practitioners underwent the following sequence of tests: 1) a graded exercise test to determine maximal oxygen uptake and associated intensity i V ˙ O 2 m a x ; $\left(i \dot{V} O_{2 m a x}\right);$ 2 and 3) supramaximal exhaustive effort at 115% of iVO2max and 30sWAnT, performed randomly. The glycolytic and phosphagen pathways measured during the supramaximal effort were significantly correlated with peak power (r = 0.85; p < 0.01 and r = 0.57; p = 0.02, respectively), mean power (r = 0.78; p < 0.01 and r = 0.69; p < 0.01, respectively), and total work (r = 0.78; p < 0.01 and r = 0.69; p< 0.02, respectively) measured during the 30sWAnT. A significant correlation was also found between anaerobic capacity and peak power (r = 0.88; p < 0.01), mean power (r = 0.89; p < 0.01), and total work (r = 0.89; p < 0.01). Additionally, anaerobic capacity estimated during the supramaximal effort and the anaerobic contribution measured during the 30sWAnT were not different (p = 0.44) and presented significant good reliability and association (ICC = 0.84; p = 0.001) and good agreement, evidenced by the mean of differences and 95% limits of agreement near to zero (mean bias = 0.11). The results suggest that glycolytic and phosphagen capacity were associated with mechanical performance in the 30sWAnT. In addition, anaerobic contribution during the 30sWAnT seems to be valid for estimating anaerobic capacity in recreational mountain bike cyclists, as well as to estimate the glycolytic and phosphagen contributions.

Key words

  • glycolytic pathway
  • phosphagen pathway
  • anaerobic performance
  • exercise metabolism
  • cycling
Open Access

Does the PPARA Intron 7 Gene Variant (rs4253778) Influence Performance in Power/Strength‐Oriented Athletes? A Case‐Control Replication Study in three Cohorts of European Gymnasts

Published Online: 28 Jul 2021
Page range: 77 - 85

Abstract

Abstract

Athletic ability is influenced by several exogenous and endogenous factors including genetic component. Hundreds of gene variants have been proposed as potential genetic markers associated with fitness-related phenotypes as well as elite-level athletic performance. Among others, variants within the PPARA gene that code for the peroxisome proliferator activated receptor α are of potential interest. The main goal of the present study was to determine PPARA (G/C, rs4253778) genotype distribution among a group of Polish, Lithuanian and Italian international level male gymnasts and to compare our findings with those of previous research on the frequency of the PPARA intron 7 C allele/CC genotype in power/strength-oriented athletes. A total of 464 male subjects (147 gymnasts and 317 controls) from Poland (n = 203), Italy (n = 146) and Lithuania (n = 107) participated in the study. No statistically significant differences were found in any of the analyzed cohorts. However, a significantly higher frequency of the CC genotype of the PPARA rs4253778 polymorphism was observed when all gymnasts were pooled and compared with pooled control using a recessive model of inheritance (OR = 3.33, 95% CI = 1.18-10, p = 0.022). It is important to know that we investigated a relatively small sample of male European gymnasts and our results are limited only to male participants. Thus, it is necessary to validate our results in larger cohorts of athletes of different ethnicities and also in female gymnasts to find out whether there is a gender effect.

Key words

  • PPARα
  • athletic performance
  • genetic polymorphism
  • candidate gene
Open Access

The Impulse of Force as an Effective Indicator of Exercise Capacity in Competitive Rowers and Canoeists

Published Online: 28 Jul 2021
Page range: 87 - 99

Abstract

Abstract

The aim of the research was to present the importance of measuring the impulse of force in assessing exercise capacity in professional rowers and canoeists rather than conducting traditional physiological and biochemical analyses. A group of 20 athletes (12 rowers and 8 canoeists) underwent progressive intensity exercise tests in two testing sessions (before and after a training period). During the tests, maximal aerobic capacity, impulse of strength, metabolic indices, and markers of skeletal muscle damage were assessed. Total testosterone, free testosterone, cortisol, interleukin 1,6, and creatine kinase were evaluated in venous blood. The impulse of force at the ventilatory threshold and at the maximum load was correlated with free testosterone and a total testosterone/cortisol ratio during exercise (p ≤ 0.05) and was negatively correlated with cortisol concentration (p ≤ 0.05) in the first testing session (before training intervention). Values were positively correlated with concentration of total testosterone, free testosterone and total testosterone/cortisol, and free testosterone/cortisol ratios during exercise (p ≤ 0.05) in the second testing session (after training intervention). Biochemical indices of overtraining were correlated with maximum oxygen uptake in each session and with the impulse of force at the ventilatory threshold and the maximum load of exercise. Thus, there is an indirect relationship between maximal aerobic capacity and the impulse of force. The measurement of the impulse of force can become a simple and effective method for evaluating the overall exercise capacity of rowers because of its relationship with indices of the load and changes in hormonal indices of anabolic and catabolic processes during exercise. Therefore, it may constitute a replacement for the traditional laboratory measurement of VO2max in highly qualified rowers and canoeists.

Key words

  • maximal oxygen uptake
  • perithreshold impulse
  • inflammatory agents
  • antioxidant potential
Open Access

The Fifth Metatarsal Bone Fracture In Athletes ‐ Modalities of Treatment Related to Agility In Soccer Players

Published Online: 28 Jul 2021
Page range: 101 - 110

Abstract

Abstract

The 5th metatarsal fracture is a common foot fracture which could exclude a player from competition for several months and significantly affect his or her career. This manuscript presents the treatment and rehabilitation of professional soccer players who had acute fractures of the 5th metatarsal bone and a cannulated screw fixation. The main purpose of the analysis was to determine the minimum time necessary for a permanent return to the sport after a 5th metatarsal fracture among professional soccer players. We followed the surgical and rehabilitation path of 21 professional soccer players from the Polish League (Ist and IInd divisions) who suffered from the 5th metatarsal bone fracture. All players underwent standard percutaneous internal fixation with the use of cannulated screws. The total inability to play lasted for 9.2 (± 1.86) weeks among players treated only surgically (n = 10), 17.5 (± 2.5) weeks in the conservative and later surgery group, excluding players with nonunion (n = 6), and 24.5 (± 10.5) weeks for nonunion and switch treatment (n = 4) players. Prompt fracture stabilization surgery is recommended for athletes, enabling the implementation of an aggressive rehabilitation protocol as soon as possible. Early limb loading after surgery (from week 2) does not delay fracture healing or hinder the bone union, thus rehabilitation plays a crucial role in shortening the time of RTP (return to play) and is obligatory for each athlete who undergoes surgical treatment.

Key words

  • 5 metatarsal fracture
  • athletes
  • intramedullary screw fixation
  • surgical treatment
  • rehabilitation
Open Access

Hydration to Maximize Performance And Recovery: Knowledge, Attitudes, and Behaviors Among Collegiate Track and Field Throwers

Published Online: 28 Jul 2021
Page range: 111 - 122

Abstract

Abstract

Hydration plays an important role in performance, injury prevention, and recovery for athletes engaged in competitive sports. Therefore, it is important that strength and conditioning coaches understand an athlete’s hydration needs to prevent illness and enhance performance. The purpose of this study was to identify hydration knowledge, attitudes, and behaviors of collegiate track and field throwers, as well as identify barriers to hydration and sources of nutritional information. The Rehydration and Refueling in Collegiate Track and Field Throwers Survey was sent to 271 track and field thrower coaches with a request to forward the email to current track and field throwers. Pearson correlation coefficients were calculated regarding knowledge, attitude, and behavior scores among the participants in this sample. Differences among response patterns were assessed via Chi-square analysis. Alpha level was set at p = .05. Results demonstrated that 97.3% (n = 287) of respondents knew that dehydration would decrease performance, but 50.5% (n = 149) erroneously believed thirst was the best indicator of dehydration. Chi-square analysis demonstrated a significant difference in reported values between participants who intended to eat a performance-enhancing diet and those who consumed less fluid than recomended values (207 – 295 m)l in the 2-3 hours prior to competition (χ2 = 10.87, p < .05). Pearson correlation coefficients demonstrated a large association between knowledge and behavior (r = .70, p < .05), a medium association between knowledge and attitude (r = .41, p < .05), and a small association between attitude and behavior (r = .21, p < .05). This suggests that strength and conditioning coaches and health staff need to educate and monitor hydration behaviors among collegiate track and field throwers to optimize performance.

Key words

  • carbohydrates
  • hypohydration
  • thirst
Open Access

Outdoor Uphill Exercise Testing for Trail Runners, a More Suitable Method?

Published Online: 28 Jul 2021
Page range: 123 - 133

Abstract

Abstract

There is extensive knowledge about uphill running on a treadmill, although paucity regarding the influence of uphill trail running on exercise capacity in runners. The purpose of this study was to compare an uphill field test with a treadmill test with 1% inclination especially considering cardiopulmonary exercise variables. The difference in those tests between a group of trail runners and a group of road runners was tested for establishing a test specifically for trail runners. Ten male endurance road runners and ten male trail runners performed one maximal incremental treadmill test with 1% inclination and a maximal incremental field test on a hill at 16% inclination which they were instructed to run up four times for three minutes, each time with a higher pace. A mobile cardiopulmonary exercise testing unit was used to measure ventilation. There were no significant differences between trail runners and road runners. The equivalence factor was comparable between both groups. V ˙ O 2 p e a k $\dot{V} O_{2 p e a k}$ was comparable for both test protocols. However, there was a significant difference between the two test protocols regarding lactate concentration, the respiratory exchange ratio, running cost, heart rate, Breathing reserve, and O2pulse. The greater lactate concentration and running cost recorded uphill indicate a higher energy demand during trail running than level road running.

Key words

  • field running test
  • running physiology
  • exercise test protocol
  • mountain running
  • outdoor running

Section III - Sports Training

Open Access

Peak Running Intensities in Field Hockey - a Positional Analysis

Published Online: 28 Jul 2021
Page range: 135 - 144

Abstract

Abstract

The aim of this study was to investigate the positional mean peak running periods during a field hockey match using a moving average method. The secondary aim was to investigate how the peak periods changed between quarters and playing positions. The moving average method was used to analyse the data because of the nature of field hockey, which has natural fluctuations of high and low intensity periods of play. The time periods included periods from 1 to 10 minutes. The level of significance for results was set at p ≤ 0.05. The study found that forwards had a peak running intensity of 194 ± 24.2 m·min-1, midfielders 189 ± 11.9 m·min-1, and defenders 182.6 ± 17.9 m·min-1. These results showed that forwards had the highest maximum running speed, with defenders having the lowest one (p = 0.0025). Additionally, running output started to plateau after 7/8-min periods for each of the three positions. Forwards did not show any statistically significant changes across the four quarters. Midfielders showed effect sizes ranging from >0.6 to >2.0 (moderate, large and very large) significance when comparing the first three quarters to the fourth one. Defenders showed >0.6 to <2.0 (moderate to large) effect sizes to occur when comparing the first and second quarter to the fourth. There are three main practical implications from the results of this study: 1) the creation of conditioning drills, 2) substitution patterns, and 3) knowledge to be able to plan and train at or above peak match demands.

Key words

  • time motion analysis
  • GPS
  • match demands
Open Access

Post-Eccentric Flywheel Underwater Undulatory Swimming Potentiation in Competitive Swimmers

Published Online: 28 Jul 2021
Page range: 145 - 154

Abstract

Abstract

Underwater undulatory swimming (UUS) influences overall swimming performance, therefore swimmers should try to maximize it. This research aimed to: 1) assess the effects of an activation protocol based on post-activation performance enhancements upon UUS; and 2) evaluate the differences between males and females. Seventeen competitive swimmers (male = 10; female = 7) participated in a cross-sectional study designed to test performance in UUS at 10 m after a traditional swimming warm-up (TRA) and after adding to the TRA 4 maximal half-squat repetitions on an inertial flywheel device (PAPE). A speedometer and an electronic timing system were used to obtain kinematic variables such as time, frequency and velocity at 10-m, which were processed with MATLAB®. A paired sample t test was applied to determine the differences of the kinematic variables between the TRA and PAPE. An independent sample t test was used to determine the effects of the PAPE in males and females. Participants reduced the time to cover 10 m after PAPE compared to the TRA (males: 5.77 ± 0.44 to 5.64 ± 0.46; females 6.34 ± 0.80 to 6.09 ± 0.66; p < 0.05). In addition, trends towards improvements in UUS velocity were obtained for males and females. However, push-off velocity and frequency showed a different tendency between genders (p < 0.05). In conclusion, the warm-up including repetitions on the flywheel device improved UUS performance. Some differences were obtained between genders after PAPE. Further research should confirm if the benefits obtained after the eccentric overload would depend either on gender or on other components such as fiber type composition.

Key words

  • performance
  • strength
  • resistance
  • testing
  • training
Open Access

The Relationship Between Performance and Asymmetries in Different Multidirectional Sprint Tests in Soccer Players

Published Online: 28 Jul 2021
Page range: 155 - 164

Abstract

Abstract

Practitioners usually include change of direction (COD) and linear speed measurements in the testing batteries of soccer players; however, despite being a commonly occurring action, curve sprint (CS) ability is rarely assessed in soccer. The aims of this study were to analyze the association between linear sprint, CS, and COD speed performances, and compare the association and direction of asymmetries between these skills. Thirty-three male soccer players performed linear sprint (17 m), CS (17 m), and COD-90 speed tests (COD [8.5 + 8.5 m]). Our main findings were (a) a large relationship between linear and multidirectional tasks (COD-90 and CS tests) (r = from 0.6 to 0.64, p < 0.05), (b) a moderate relationship between CS and COD-90 tests (r = from 0.33 to 0.41, p < 0.05), with a certain opposite tendency (higher relationships between opposing directions [CurveLEFT - CODRIGHT; r = 0.41] than between equal directions [CurveLEFT – CODLEFT; r = 0.33]), and (c) no relationship (p > 0.05) between COD and CS asymmetries, with opposing directional dominance in ~70% of players (e.g., curve left and COD right dominance). These results indicate that performance in linear sprints is strongly related to performance in multidirectional trajectories, whereas CS and COD-90 seem to be more independent actions. Additionally, the direction of asymmetry or dominance is generally opposite between the non-linear tasks measured.

Key words

  • speed assessment
  • curvilinear speed
  • change of direction
Open Access

Average Game Physical Demands and the Most Demanding Scenarios of Basketball Competition in Various Age Groups

Published Online: 28 Jul 2021
Page range: 165 - 174

Abstract

Abstract

The purpose of this study was to compare average physical demands and the most demanding 60-s scenarios of basketball match-play between five different age groups. Sixty-four male basketball players from five different age groups were monitored across eight regular-season home games. Physical demands were examined using a local positioning system and included total distance covered, distance >18 km·h-1, the number of accelerations (≥2 m·s-2) and decelerations (≤-2 m·s-2). All four game performance variables increased significantly (58.4 - 639.2%) when calculated with rolling average techniques in comparison to average physical demand values. Furthermore, the current investigation found that while Under-12 presented the highest result in relative total distance covered (p < .001; effect size = 0.58-2.01), they also showed the lowest values in the most demanding scenarios of match play and small-to-moderate effect sizes compared with their older counterparts. Both average physical demands and the most demanding scenarios presented an increasing tendency with age when distance >18 km·h-1 in basketball players was assessed. More specifically, the Under-12 age group achieved the lowest values and showed significant differences with the other four teams in both game analysis techniques (p < .001; effect size = 0.53 - 1.32). In conclusion, average game demands are shown to remarkably underestimate the most demanding scenarios of basketball match-play, and there are multiple significant differences between particular age groups.

Key words

  • team sports
  • match demands
  • peak intensity
  • performance analysis
  • local positioning system
Open Access

Pacing Strategy in Men’s 400 m Hurdles Accounting for Temporal and Spatial Characteristics of Elite Athletes

Published Online: 28 Jul 2021
Page range: 175 - 186

Abstract

Abstract

The final result in a 400 m hurdles race (400mH) is relative to the motor preparation, technique of clearing hurdles as well as the adopted strategy of the race, including temporal aspects (split times in particular parts of the race) and spatial elements (the number of strides taken between subsequent hurdles). The objective of the study was to identify an optimal strategy for the 400mH race, including the stride pattern and split times. Data employed for this study were derived from results of 273 races held during the men’s finals of international events (Olympic Games, World and European Championships) held from 1968 to 2015. To determine the strategies in the race, three main hurdle sections were identified – 1-4H, 4-7H and 7-10H. In each part, the fast (best results), average and slow (worst results) performing groups of hurdlers were distinguished. The analysis of adopted strategies was carried out taking into account 26 variables (main, basic, temporal and spatial). Basic statistical data, correlations and analysis of variance (ANOVA) were used. Results highlight the use of a variety of strategies, of which selection depends, among others, on body composition and the level of motor abilities (speed, speed endurance and explosive strength), as well as hurdling technique. Especially, the endurance strategy appears to be the most effective one, as it is a characteristic of best performances of many hurdlers. The analysis demonstrates that at the highest sports level the strategy of 400 m hurdles should be analyzed individually.

Key words

  • 400 m hurdle strategy
  • typology of hurdlers
  • athletics, pace
Open Access

Effects of Plyometric Training on Soft and Hard Surfaces for Improving Running Economy

Published Online: 28 Jul 2021
Page range: 187 - 196

Abstract

Abstract

The present study investigated the effects of plyometric jump training on hard and soft surfaces on running economy (RE), maximal oxygen uptake (VO2max), running performance and the rate of force development in orienteers. Nineteen orienteers (11 women and 8 men, body mass 61.1 ± 7.3 kg, age 21 ± 5.8 yrs) were randomly stratified based on sex, age, VO2max and RE to plyometric jumping training (8 sessions over 4 weeks) on either a hard or a soft surface. RE, VO2max and running performance were assessed on a treadmill and outdoor on- and off-trail loops. Moreover, ground reaction forces and force development were assessed during a one leg drop-jump test. The training intervention led to an overall 2-7% improvement in treadmill and off-trail RE, independent of the jumping surface and running velocity assessed. These improvements were not explained by force development during drop jump tests, which remained unchanged following the intervention. The changes in time-trial performance were associated with changes in RE. Plyometric training improved RE with no difference between the hard or the soft training surface and improved RE was also independent of the running speed assessed. Furthermore, improved running performance was associated with changes in RE after the intervention.

Key words

  • running economy
  • plyometric jump training
  • surface
  • orienteers
Open Access

Prediction of Match Outcomes with Multivariate Statistical Methods for the Group Stage in the UEFA Champions League

Published Online: 28 Jul 2021
Page range: 197 - 209

Abstract

Abstract

The aim of this study was to analyse the win, draw, and loss outcomes of soccer matches with situational variables and performance indicators. Data from group stage matches spanning the ten years between the 2010/2011 and 2019/2020 seasons in the European Champions League, were used. One-way analysis of variance (ANOVA) and Tukey HSD (honestly significant difference) tests indicated performance indicators which affected the outcome of matches. K-mean clustering, with statistically significant variables, categorized the quality of the opposition into three clusters: weak, balanced, and strong. Multidimensional scaling (MDS) and decision tree analysis were applied to each of these clusters, highlighting that performance indicators of the teams differed according to the quality of their opponent. Furthermore, according to the decision tree analysis, certain performance indicators, including scoring first and shots on target, increased the chances of winning regardless of the quality of the opposition. Finally, particular performance indicators increased the chance of winning, while others decreased this, in accordance with the quality of the opposition. These findings can help coaches develop different strategies, before or during the match, based on the quality of opponents, situational variables, and performance indicators.

Key words

  • decision tree
  • soccer
  • quality of the opposition
  • performance indicators
  • situational variables
  • multidimensional scaling (MDS)
Open Access

Within-Match Performance Dynamics – Momentary Strength in Handball

Published Online: 28 Jul 2021
Page range: 211 - 219

Abstract

Abstract

Handball is an Olympic team sport characterized by changes of ball possession, where teams either play on offense or defense. In this paper, we model momentary strength in handball as scoring probabilities based on a double moving average. In this cross-sectional observational study, the aim was to describe the dynamics of momentary strength in handball from both theoretical and practical perspectives. Momentary strength can be used to further characterize the nuances of the sport by identifying different phases in a match. The momentary strength model was applied to the 2019 International Handball Federation (IHF) Men's World Championship. Ninety-six games were analyzed. The results showed that momentary strength could be used to better understand the dynamic interaction process between two teams. The Spearman correlation between the teams' median momentary strength and their final ranks at the Championship was -0.830. Virtually each team faced phases in its matches with a momentary scoring probability lower than 0.10 and with 4 exceptions also higher than 0.90. Twelve out of the 24 teams showed phases with a momentary scoring probability of exactly 0 as well as exactly 1

Key words

  • performance analysis
  • team sports
  • world championship
Open Access

The Influence of Sprint Mechanical Properties on Change of Direction in Female Futsal Players

Published Online: 28 Jul 2021
Page range: 221 - 228

Abstract

Abstract

The aim of the present study was to analyze the association of the sprint force-velocity profile [Hzt FV profile] variables with change of direction [COD] performance in female futsal players. Twelve female futsal players (age: 19.83 ± 4.2 years; body height: 160.75 ± 8.37 cm; body mass: 57.64 ± 8.3 kg) volunteered to be evaluated in the following assessments: Hzt FV profile, 505 test, modified 505 test [M505test] and V-cut test. The Spearman’s correlation coefficient [rs] (p < 0.05) was used to determine the relationship of the mechanical variables of the sprint (maximum power output [Pmax], maximum horizontal force production [F0] and maximum velocity [V0]) with COD performance. V0 showed a very large significant association with the 505 test (rs = -0.767; 90% CI: (-0.92 to -0.43); p < 0.01) and a large association with the V-cut test (rs = -0.641; 90% CI: (-0.86 to -0.21); p < 0.05), whereas Pmax was strongly associated with results of the 505 test (rs = -0.821; 90% CI: (-0.94 to -0.55); p < 0.01) and largely associated with the V-cut test results (rs = -0.596; 90% CI: (-0.84 to -0.14); p < 0.05). In conclusion, maximal power and velocity output during sprinting are determinant factors to successful COD in 180º and 45º cuts, thus, the Hzt FV profile should be assessed in female futsal players to better understand the influence of sprint mechanical properties on COD performance and prescribe individualized training programs

Key words

  • team sports
  • strength
  • acceleration
  • power
  • velocity
Open Access

Analysis of the Individual Set-Pieces Influence on the Teams’ Ranking in Rink Hockey

Published Online: 28 Jul 2021
Page range: 229 - 236

Abstract

Abstract

The main objective of this research was to analyze the individual set-pieces influence on the final season ranking in rink hockey. For this purpose, 6,920 individual set-pieces from 1,680 matches corresponding to free direct hits (n = 4,332) and penalty shots (n = 2,588) were analyzed during seven consecutive seasons (2012-13 to 2018-19) in the First Spanish League (Ok Liga). The variables recorded were the following for each team: total points, free direct hits attempted, free direct hits scored, penalties attempted, penalties scored, total goals scored during the season, free direct hits received, goals received from free direct hits, penalties received, goals received from penalties and total goals received in the season. Results showed that 21.08% of the goals were scored by free direct hits and penalty shots (11.58% and 9.49%, respectively). Likewise, teams ranked in a better position achieved higher effectiveness in individual set-pieces and their goalkeepers were more effective in defending the free direct hits and penalties. Furthermore, results showed significant correlations between team season points and better performance in individual set-pieces variables. Therefore, the results of this study demonstrated the importance of systematic practice of free direct hits and penalty shots for teams’ success in rink hockey. Additionally, it is suggested that teams possess special players to execute these particular elements of match play

Key words

  • performance analysis
  • roller hockey
  • match variables
  • shots
Open Access

Long-Term Trend Analysis of Playing Styles in the Chinese Soccer Super League

Published Online: 28 Jul 2021
Page range: 237 - 247

Abstract

Abstract

The aim of this study was to identify playing styles adopted by teams in the Chinese Soccer Super League (CSL) and to investigate their evolution across a 6-season period. Data were collected from 1,429 CSL matches from 2012 to 2017 seasons using the Amisco system. Seventeen technical performance-related indicators and eleven physical performance-related indicators were included in the factor analysis (PCA: principal components analysis) in order to group them into performance factors (styles of play). Seven factors were obtained (eigenvalues greater than 1) and explained 74.44% of the total variance. Multivariate analyses of covariance (MANCOVA) were used to check differences among seven styles of play (team’s ranking was used as a covariate) during the six seasons under study. The main findings showed that Factor 1 (high intensity play) and factor 3 (offensive actions) of CSL soccer increased substantially along the seasons. Coaches and sports scientists should take into consideration these performance trends when preparing training and controlling for matches

Key words

  • match analysis
  • factor analysis
  • Chinese soccer
  • longitudinal
  • evolution

Section IV - Behavioural Sciences in Sport

Open Access

Burnout and Coping Perceptions of Volleyball Players Throughout an Annual Sport Season

Published Online: 28 Jul 2021
Page range: 249 - 257

Abstract

Abstract

Burnout is a psychological syndrome of reaction to chronic stress that occurs in athletes who feel exhausted by a sport activity that was previously pleasurable and enjoyable. One technique to prevent and control the syndrome is through coping, which is the ability to deal with stressful situations. In contrast to traditional cross-sectional approaches, this study aimed to investigate burnout and coping strategy characteristics over time and to analyze the relationship between burnout dimensions and coping strategies. Fifty-four high-level volleyball athletes (twenty-eight men and twenty-six women, age M = 25.57, SD = 4.72, range 18-35) completed paper-and-pencil measures of burnout and coping four times throughout a sport season. The Friedman test presented a significant increase in the reduced sense of athletic accomplishment (X2 = 20.58; p < 0.01) and sport devaluation (X2 = 19.83; p < 0.01) perceptions during the season. However, no coping differences were observed through the longitudinal analysis. Burnout dimensions showed a moderate inverse correlation to confidence/motivation at all measurement points during the season. Overall, the findings suggest that burnout perceptions increase as the season progresses, highlighting the relevance for the periodization of burnout prevention and control

Key words

  • psychological skills
  • stress
  • longitudinal assessment
  • sport psychology
Open Access

Biopsychosocial Effects of Competition Preparation in Natural Bodybuilders

Published Online: 28 Jul 2021
Page range: 259 - 276

Abstract

Abstract

Bodybuilders are judged on the subjective visual assessment of their muscular size, proportion, and leanness. This case series tracked four drug-free bodybuilders (3 male) during the off-season, pre-competition and recovery phases. This study aimed to comprehensively profile key biopsychosocial changes occurring pre/post competition in a group of British natural bodybuilders. We measured: resting metabolic rate (RMR), body composition (via BIA, ultrasound and sum of 7 skinfolds), lipid profiles, fasted glucose, blood pressure, power output (Wingate), grip strength, and carried out psychometric questionnaires (EAT-26, STAI, BUT) over an eight-month period. Mean weight loss from 5 months (5M) to pre-contest (PRE) was 8.6 ± 4.1 kg, followed by an increase of 7.9 ± 1.6 kg two months post contest (POST). The mean RMR of the cohort was stable from 1899 ± 630 kcal (5M) to 1897 ± 598 kcal (PRE), before decreasing to 1797 ± 242 kcal (POST). Mean peak power declined from 770 ± 113.0 w (5M), to 700.0 ± 134.4 w (PRE), before increasing to 816.0 ± 116.2 w (POST). Competition dieting had no effect on EAT-26 or BUT scores, suggesting no body dysmorphic or eating disorder concerns, although trait anxiety was elevated in three out of the four participants throughout the observation. Many of the biopsychosocial changes that occur to bodybuilders as they prepare for competition return to baseline measurements 2 months post competition.

Key words

  • physique
  • body-dysmorphia
  • drug-free
  • reverse-diet
  • bigorexia
Open Access

Coach Encouragement During Soccer Practices Can Influence Players’ Mental and Physical Loads

Published Online: 28 Jul 2021
Page range: 277 - 288

Abstract

Abstract

This study analyzed the influence of the coaches’ encouragement on the mental and physical load in soccer practices. The participants were 36 semiprofessional Spanish soccer players (Mage = 22.40; SD = 2.25) belonging to two male teams and one female team. Following the same practices’ design and order, two training sessions of each team were completed. In one session, coaches maintained a passive verbal attitude, whereas in the other session, coaches intervened with an active attitude through continuous general encouragement. The mental load and fatigue were measured using self-reported questionnaires (Likert scales), and internal and external physical loads were quantified using the rating of perceived exertion and the Global Position System. A t-test for related samples and magnitude based on an inference spreadsheet was performed. The results demonstrated that mental and internal physical loads increased when coaches participated with active verbal encouragement. Especially, increases in performance satisfaction, mental effort, and RPE values, and decreases in unsafety values were detected due to encouragement interventions. Nevertheless, the external physical load did not show a clear trend. Based on these findings, coaches can use this information to manipulate their verbal encouragement during practices according to their physical and mental objectives with specific soccer strategies

Key words

  • coaching
  • constraints
  • soccer training
  • mental fatigue
  • training practice
Open Access

The Coaches’ Efficacy Expectations of Youth Soccer Players with Different Maturity Status and Physical Performance

Published Online: 28 Jul 2021
Page range: 289 - 299

Abstract

Abstract

This study aimed to report possible anthropometrical and physical performance differences between youth soccer players with different maturity status and to report the coaches’ expectations, hypothesizing that coaches would expect more from players with advanced maturity. One hundred twenty-two (122) players completed a physical performance battery. Their maturity status was estimated and the coaches’ efficacy expectations (CEEs) were assessed. Players with advanced maturation had better physical performance (F = 26.5-73.4; p < 0.01) and their CEEs for strength-related tasks were different according to the maturity status (F = 8.3-10.9; p < 0.01), but not for speed-related tests, nor for their general ability to play soccer. Normalized data showed significant differences between physical performance tests and their respective CEEs within each maturity group, especially in the Post-PHV group. This study confirms the physical advantages of players with advanced maturity while it shows controversial results of how maturation affects the coaches’ perceptions and, indirectly, the coaches’ identification and selection of talented players.

Key words

  • self-efficacy
  • youth
  • maturation
26 Articles

Section I - Kinesiology

Open Access

MBboard: Validity and Reliability of a New Tool Developed to Evaluate Specific Strength in Rock Climbers

Published Online: 28 Jul 2021
Page range: 5 - 13

Abstract

Abstract

In the present study, we analysed the validity and reliability of a new tool designed to assist the measurement of maximal upper-limb strength in rock climbers in a specific way, named MBboard. The MBboard consists of an artificial small climbing hold affixed to a wooden board, which is connected to any cable-motion strength equipment to determine the maximum dynamic strength (MBboard-1RM). Ten male rock climbers (Rock Climbing Group, RCG = 10) and ten physically active men (Control Group, CG = 10) performed, on three separate occasions, a familiarization session with procedures adopted during MBboard-1RM testing and two experimental trials (i.e., test and retest) to determine the construct validity and reliability of the MBboard during unilateral seated cable row exercise. In the first trial, the electromyographic activity (EMG) was recorded from the flexor digitorum superficialis. The self-reported climbing ability was also recorded. The RCG had superior performance (i.e. 37.5%) and EMG activity (i.e. 51%) in MBboard-1RM testing when compared with the CG (p < 0.05). There was a significant correlation between the MBboard-1RM results and climbing ability (r > 0.72, p < 0.05). Intraclass correlation coefficient analysis revealed good reliability within trials (ICC > 0.79, p < 0.05). These findings suggest that the MBboard is a valid and reliable tool to assess rock climbing-specific maximal strength. The validity of MBboard-1RM appears to be related to the finger flexor muscles activation, probably reflecting the specific adaptations resulting from long-term practice of this sport discipline.

Key words

  • rock climbing
  • physical evaluation
  • maximum dynamic strength
  • electromyographic activity
Open Access

Assessing the Magnitude and Direction of Asymmetry in Unilateral Jump and Change of Direction Speed Tasks in Youth Female Team-Sport Athletes

Published Online: 28 Jul 2021
Page range: 15 - 27

Abstract

Abstract

The direction of inter-limb asymmetries and the change of direction (COD) deficit are two aspects that have increased in recent years. The main objective of the present study was to assess the magnitude of neuromuscular asymmetries in an elite youth female team-sports sample and determine its directionality. Secondary objectives were to evaluate the relationship between COD deficit, linear speed and COD time performance. Elite female youth basketball and handball players (n = 33, age = 16 ± 1.17 y) performed the Single Leg Countermovement Jump in vertical (SLCJ-V), horizontal (SLCJ-H), and lateral (SLCJ-L) directions, the COD and the 10-m sprint. Results showed statistical differences between limbs in all the neuromuscular tests (p < 0.001). The Kappa coefficient showed poor to fair levels of agreement between tasks (K range = -0.087 to 0.233), indicating that asymmetries rarely favoured the same limb between skills. Additionally, small and non-significant correlations were found between the linear sprint capacity and the COD ability. The findings of the present study highlight the independent directionality of asymmetries across tests. The COD deficit does not appear to be much more advantageous than COD total time to measure asymmetry. Practitioners are encouraged to use a fitness testing battery to detect existing side differences and each ability should be specifically trained with functional tasks.

Key words

  • imbalance
  • performance
  • youth
  • sprint
  • jumping
  • neuromuscular
Open Access

Effects of a Neuromuscular Warm-Up Program in Youth Female Soccer Players

Published Online: 28 Jul 2021
Page range: 29 - 40

Abstract

Abstract

The protective effects of different warm-up injury prevention routines in youth female soccer players have been demonstrated in the literature, however, there is a paucity of information regarding the effects that these kinds of programs have on soccer-specific physical performance variables. The purpose of this study was to assess the effectiveness of a 12-week neuromuscular warm-up program on physical performance in youth female soccer players. Players (age: 13.94 ± 0.82 years) were divided into two groups. One group performed a neuromuscular activation program (n = 21) twice per week whereas the other group (control, n = 17) continued with their habitual warm-up routine for the same duration. Both groups of players performed strength, jumping and balance tests before and after the intervention period. Substantially greater improvements were detected in the mean velocity for the squat (p < 0.001; Effect Size = 0.95) and the hip thrust (p < 0.001; Effect Size = 0.51) in the experimental group in comparison to the control group. In addition, after the intervention period players in the experimental group showed an increase in the jumping height in the unloaded double-leg and single-leg counter-movement jumps (p = 0.003-0.012; Effect Size = 0.42-0.46). The results of this study provide evidence that a 12-week neuromuscular warm-up program can be effective to improve different physical performance variables in youth female soccer players.

Key words

  • soccer
  • warm up
  • performance
  • fitness
  • injury prevention
Open Access

Assessing Inter-Limb Asymmetries in Soccer Players: Magnitude, Direction and Association with Performance

Published Online: 28 Jul 2021
Page range: 41 - 53

Abstract

Abstract

In this study, we aimed to analyze the magnitude and direction of inter-limb asymmetries in ankle dorsiflexion range of motion (ROM), power (using iso-inertial devices), and a neuromuscular skill (change of direction). Secondarily, we aimed to determine the relationship between inter-limb asymmetry scores for each test and also between these scores and the scores for the different performance tests. Sixteen semiprofessional male soccer players (age: 25.38 ± 6.08 years; body height: 1.78 ± 0.64 m; body mass: 79.5 ± 14.9 kg) participated in this study. We calculated inter-limb asymmetries using five tests: ankle dorsiflexion ROM, change of direction (COD 180º), and iso-inertial resistance tasks in the open (leg extension strength (LE), leg curl strength (LC)) and closed (crossover step (CRO)) kinetic chain. Our results showed that asymmetry magnitudes differed between all tests with highest inter-limb asymmetries displayed during iso-inertial overloading. In addition, we observed that the direction of asymmetries varied depending on the test-specificity, and that the CRO asymmetries had a negative association with LE and CRO performance. These findings highlight the independent nature of asymmetries and that CRO could be an appropriate test to detect asymmetries related with the performance of soccer-specific actions (such as changes of direction). Practitioners are encouraged to use multiple tests to detect existing inter-limb differences according to the specific characteristics of each sport.

Key words

  • change of direction speed
  • symmetry
  • iso-inertial
  • specificity

Section II - Exercise Physiology & Sports Medicine

Open Access

Hydration Status in Adolescent Alpine Skiers During a Training Camp

Published Online: 28 Jul 2021
Page range: 55 - 63

Abstract

Abstract

Maintaining euhydration is important for optimal health, performance and recovery, but can be challenging for alpine skiers when training in a relatively cold but dry environment. This study aimed to evaluate hydration status, fluid loss and fluid intake in adolescent alpine skiers during a training camp. Twelve athletes aged 14.3 ± 0.9 years volunteered to participate in the study. Athletes resided at an altitude of 1600 m and trained between 1614 and 2164 m. During eight consecutive days, urine specific gravity was measured before each morning training session using a refractometer. Changes in body weight representing fluid loss and ad libitum fluid intake during each morning training session were assessed using a precision scale. Mean pre-training urine specific gravity remained stable throughout the training camp. Individual values ranged between 1.010 and 1.028 g/cm3with 50 to 83% of athletes in a hypohydrated state (urine specific gravity ≥ 1.020 g/cm3). Mean training induced fluid loss remained stable throughout the training camp (range -420 to -587 g) with individual losses up to 1197 g (-3.5%). Fluid intake was significantly lower than fluid loss during each training session. To conclude, urine specific gravity values before training indicated insufficient daily fluid intake in more than half of the athletes. Furthermore, fluid intake during training in adolescent alpine skiers was suboptimal even when drinks were provided ad libitum. Coaches and athletes should be encouraged to carefully monitor hydration status and to ensure that alpine skiers drink sufficiently during and in between training sessions.

Key words

  • alpine skiing
  • dehydration
  • youth
  • fluid intake
Open Access

Anaerobic Capacity is Associated with Metabolic Contribution and Mechanical Output Measured During the Wingate Test

Published Online: 28 Jul 2021
Page range: 65 - 75

Abstract

Abstract

The study aimed to investigate the relationship between anaerobic capacity, mechanical and anaerobic contribution during the 30-s Wingate Anaerobic Test (30sWAnT). After familiarization, fifteen, male recreational mountain biking practitioners underwent the following sequence of tests: 1) a graded exercise test to determine maximal oxygen uptake and associated intensity i V ˙ O 2 m a x ; $\left(i \dot{V} O_{2 m a x}\right);$ 2 and 3) supramaximal exhaustive effort at 115% of iVO2max and 30sWAnT, performed randomly. The glycolytic and phosphagen pathways measured during the supramaximal effort were significantly correlated with peak power (r = 0.85; p < 0.01 and r = 0.57; p = 0.02, respectively), mean power (r = 0.78; p < 0.01 and r = 0.69; p < 0.01, respectively), and total work (r = 0.78; p < 0.01 and r = 0.69; p< 0.02, respectively) measured during the 30sWAnT. A significant correlation was also found between anaerobic capacity and peak power (r = 0.88; p < 0.01), mean power (r = 0.89; p < 0.01), and total work (r = 0.89; p < 0.01). Additionally, anaerobic capacity estimated during the supramaximal effort and the anaerobic contribution measured during the 30sWAnT were not different (p = 0.44) and presented significant good reliability and association (ICC = 0.84; p = 0.001) and good agreement, evidenced by the mean of differences and 95% limits of agreement near to zero (mean bias = 0.11). The results suggest that glycolytic and phosphagen capacity were associated with mechanical performance in the 30sWAnT. In addition, anaerobic contribution during the 30sWAnT seems to be valid for estimating anaerobic capacity in recreational mountain bike cyclists, as well as to estimate the glycolytic and phosphagen contributions.

Key words

  • glycolytic pathway
  • phosphagen pathway
  • anaerobic performance
  • exercise metabolism
  • cycling
Open Access

Does the PPARA Intron 7 Gene Variant (rs4253778) Influence Performance in Power/Strength‐Oriented Athletes? A Case‐Control Replication Study in three Cohorts of European Gymnasts

Published Online: 28 Jul 2021
Page range: 77 - 85

Abstract

Abstract

Athletic ability is influenced by several exogenous and endogenous factors including genetic component. Hundreds of gene variants have been proposed as potential genetic markers associated with fitness-related phenotypes as well as elite-level athletic performance. Among others, variants within the PPARA gene that code for the peroxisome proliferator activated receptor α are of potential interest. The main goal of the present study was to determine PPARA (G/C, rs4253778) genotype distribution among a group of Polish, Lithuanian and Italian international level male gymnasts and to compare our findings with those of previous research on the frequency of the PPARA intron 7 C allele/CC genotype in power/strength-oriented athletes. A total of 464 male subjects (147 gymnasts and 317 controls) from Poland (n = 203), Italy (n = 146) and Lithuania (n = 107) participated in the study. No statistically significant differences were found in any of the analyzed cohorts. However, a significantly higher frequency of the CC genotype of the PPARA rs4253778 polymorphism was observed when all gymnasts were pooled and compared with pooled control using a recessive model of inheritance (OR = 3.33, 95% CI = 1.18-10, p = 0.022). It is important to know that we investigated a relatively small sample of male European gymnasts and our results are limited only to male participants. Thus, it is necessary to validate our results in larger cohorts of athletes of different ethnicities and also in female gymnasts to find out whether there is a gender effect.

Key words

  • PPARα
  • athletic performance
  • genetic polymorphism
  • candidate gene
Open Access

The Impulse of Force as an Effective Indicator of Exercise Capacity in Competitive Rowers and Canoeists

Published Online: 28 Jul 2021
Page range: 87 - 99

Abstract

Abstract

The aim of the research was to present the importance of measuring the impulse of force in assessing exercise capacity in professional rowers and canoeists rather than conducting traditional physiological and biochemical analyses. A group of 20 athletes (12 rowers and 8 canoeists) underwent progressive intensity exercise tests in two testing sessions (before and after a training period). During the tests, maximal aerobic capacity, impulse of strength, metabolic indices, and markers of skeletal muscle damage were assessed. Total testosterone, free testosterone, cortisol, interleukin 1,6, and creatine kinase were evaluated in venous blood. The impulse of force at the ventilatory threshold and at the maximum load was correlated with free testosterone and a total testosterone/cortisol ratio during exercise (p ≤ 0.05) and was negatively correlated with cortisol concentration (p ≤ 0.05) in the first testing session (before training intervention). Values were positively correlated with concentration of total testosterone, free testosterone and total testosterone/cortisol, and free testosterone/cortisol ratios during exercise (p ≤ 0.05) in the second testing session (after training intervention). Biochemical indices of overtraining were correlated with maximum oxygen uptake in each session and with the impulse of force at the ventilatory threshold and the maximum load of exercise. Thus, there is an indirect relationship between maximal aerobic capacity and the impulse of force. The measurement of the impulse of force can become a simple and effective method for evaluating the overall exercise capacity of rowers because of its relationship with indices of the load and changes in hormonal indices of anabolic and catabolic processes during exercise. Therefore, it may constitute a replacement for the traditional laboratory measurement of VO2max in highly qualified rowers and canoeists.

Key words

  • maximal oxygen uptake
  • perithreshold impulse
  • inflammatory agents
  • antioxidant potential
Open Access

The Fifth Metatarsal Bone Fracture In Athletes ‐ Modalities of Treatment Related to Agility In Soccer Players

Published Online: 28 Jul 2021
Page range: 101 - 110

Abstract

Abstract

The 5th metatarsal fracture is a common foot fracture which could exclude a player from competition for several months and significantly affect his or her career. This manuscript presents the treatment and rehabilitation of professional soccer players who had acute fractures of the 5th metatarsal bone and a cannulated screw fixation. The main purpose of the analysis was to determine the minimum time necessary for a permanent return to the sport after a 5th metatarsal fracture among professional soccer players. We followed the surgical and rehabilitation path of 21 professional soccer players from the Polish League (Ist and IInd divisions) who suffered from the 5th metatarsal bone fracture. All players underwent standard percutaneous internal fixation with the use of cannulated screws. The total inability to play lasted for 9.2 (± 1.86) weeks among players treated only surgically (n = 10), 17.5 (± 2.5) weeks in the conservative and later surgery group, excluding players with nonunion (n = 6), and 24.5 (± 10.5) weeks for nonunion and switch treatment (n = 4) players. Prompt fracture stabilization surgery is recommended for athletes, enabling the implementation of an aggressive rehabilitation protocol as soon as possible. Early limb loading after surgery (from week 2) does not delay fracture healing or hinder the bone union, thus rehabilitation plays a crucial role in shortening the time of RTP (return to play) and is obligatory for each athlete who undergoes surgical treatment.

Key words

  • 5 metatarsal fracture
  • athletes
  • intramedullary screw fixation
  • surgical treatment
  • rehabilitation
Open Access

Hydration to Maximize Performance And Recovery: Knowledge, Attitudes, and Behaviors Among Collegiate Track and Field Throwers

Published Online: 28 Jul 2021
Page range: 111 - 122

Abstract

Abstract

Hydration plays an important role in performance, injury prevention, and recovery for athletes engaged in competitive sports. Therefore, it is important that strength and conditioning coaches understand an athlete’s hydration needs to prevent illness and enhance performance. The purpose of this study was to identify hydration knowledge, attitudes, and behaviors of collegiate track and field throwers, as well as identify barriers to hydration and sources of nutritional information. The Rehydration and Refueling in Collegiate Track and Field Throwers Survey was sent to 271 track and field thrower coaches with a request to forward the email to current track and field throwers. Pearson correlation coefficients were calculated regarding knowledge, attitude, and behavior scores among the participants in this sample. Differences among response patterns were assessed via Chi-square analysis. Alpha level was set at p = .05. Results demonstrated that 97.3% (n = 287) of respondents knew that dehydration would decrease performance, but 50.5% (n = 149) erroneously believed thirst was the best indicator of dehydration. Chi-square analysis demonstrated a significant difference in reported values between participants who intended to eat a performance-enhancing diet and those who consumed less fluid than recomended values (207 – 295 m)l in the 2-3 hours prior to competition (χ2 = 10.87, p < .05). Pearson correlation coefficients demonstrated a large association between knowledge and behavior (r = .70, p < .05), a medium association between knowledge and attitude (r = .41, p < .05), and a small association between attitude and behavior (r = .21, p < .05). This suggests that strength and conditioning coaches and health staff need to educate and monitor hydration behaviors among collegiate track and field throwers to optimize performance.

Key words

  • carbohydrates
  • hypohydration
  • thirst
Open Access

Outdoor Uphill Exercise Testing for Trail Runners, a More Suitable Method?

Published Online: 28 Jul 2021
Page range: 123 - 133

Abstract

Abstract

There is extensive knowledge about uphill running on a treadmill, although paucity regarding the influence of uphill trail running on exercise capacity in runners. The purpose of this study was to compare an uphill field test with a treadmill test with 1% inclination especially considering cardiopulmonary exercise variables. The difference in those tests between a group of trail runners and a group of road runners was tested for establishing a test specifically for trail runners. Ten male endurance road runners and ten male trail runners performed one maximal incremental treadmill test with 1% inclination and a maximal incremental field test on a hill at 16% inclination which they were instructed to run up four times for three minutes, each time with a higher pace. A mobile cardiopulmonary exercise testing unit was used to measure ventilation. There were no significant differences between trail runners and road runners. The equivalence factor was comparable between both groups. V ˙ O 2 p e a k $\dot{V} O_{2 p e a k}$ was comparable for both test protocols. However, there was a significant difference between the two test protocols regarding lactate concentration, the respiratory exchange ratio, running cost, heart rate, Breathing reserve, and O2pulse. The greater lactate concentration and running cost recorded uphill indicate a higher energy demand during trail running than level road running.

Key words

  • field running test
  • running physiology
  • exercise test protocol
  • mountain running
  • outdoor running

Section III - Sports Training

Open Access

Peak Running Intensities in Field Hockey - a Positional Analysis

Published Online: 28 Jul 2021
Page range: 135 - 144

Abstract

Abstract

The aim of this study was to investigate the positional mean peak running periods during a field hockey match using a moving average method. The secondary aim was to investigate how the peak periods changed between quarters and playing positions. The moving average method was used to analyse the data because of the nature of field hockey, which has natural fluctuations of high and low intensity periods of play. The time periods included periods from 1 to 10 minutes. The level of significance for results was set at p ≤ 0.05. The study found that forwards had a peak running intensity of 194 ± 24.2 m·min-1, midfielders 189 ± 11.9 m·min-1, and defenders 182.6 ± 17.9 m·min-1. These results showed that forwards had the highest maximum running speed, with defenders having the lowest one (p = 0.0025). Additionally, running output started to plateau after 7/8-min periods for each of the three positions. Forwards did not show any statistically significant changes across the four quarters. Midfielders showed effect sizes ranging from >0.6 to >2.0 (moderate, large and very large) significance when comparing the first three quarters to the fourth one. Defenders showed >0.6 to <2.0 (moderate to large) effect sizes to occur when comparing the first and second quarter to the fourth. There are three main practical implications from the results of this study: 1) the creation of conditioning drills, 2) substitution patterns, and 3) knowledge to be able to plan and train at or above peak match demands.

Key words

  • time motion analysis
  • GPS
  • match demands
Open Access

Post-Eccentric Flywheel Underwater Undulatory Swimming Potentiation in Competitive Swimmers

Published Online: 28 Jul 2021
Page range: 145 - 154

Abstract

Abstract

Underwater undulatory swimming (UUS) influences overall swimming performance, therefore swimmers should try to maximize it. This research aimed to: 1) assess the effects of an activation protocol based on post-activation performance enhancements upon UUS; and 2) evaluate the differences between males and females. Seventeen competitive swimmers (male = 10; female = 7) participated in a cross-sectional study designed to test performance in UUS at 10 m after a traditional swimming warm-up (TRA) and after adding to the TRA 4 maximal half-squat repetitions on an inertial flywheel device (PAPE). A speedometer and an electronic timing system were used to obtain kinematic variables such as time, frequency and velocity at 10-m, which were processed with MATLAB®. A paired sample t test was applied to determine the differences of the kinematic variables between the TRA and PAPE. An independent sample t test was used to determine the effects of the PAPE in males and females. Participants reduced the time to cover 10 m after PAPE compared to the TRA (males: 5.77 ± 0.44 to 5.64 ± 0.46; females 6.34 ± 0.80 to 6.09 ± 0.66; p < 0.05). In addition, trends towards improvements in UUS velocity were obtained for males and females. However, push-off velocity and frequency showed a different tendency between genders (p < 0.05). In conclusion, the warm-up including repetitions on the flywheel device improved UUS performance. Some differences were obtained between genders after PAPE. Further research should confirm if the benefits obtained after the eccentric overload would depend either on gender or on other components such as fiber type composition.

Key words

  • performance
  • strength
  • resistance
  • testing
  • training
Open Access

The Relationship Between Performance and Asymmetries in Different Multidirectional Sprint Tests in Soccer Players

Published Online: 28 Jul 2021
Page range: 155 - 164

Abstract

Abstract

Practitioners usually include change of direction (COD) and linear speed measurements in the testing batteries of soccer players; however, despite being a commonly occurring action, curve sprint (CS) ability is rarely assessed in soccer. The aims of this study were to analyze the association between linear sprint, CS, and COD speed performances, and compare the association and direction of asymmetries between these skills. Thirty-three male soccer players performed linear sprint (17 m), CS (17 m), and COD-90 speed tests (COD [8.5 + 8.5 m]). Our main findings were (a) a large relationship between linear and multidirectional tasks (COD-90 and CS tests) (r = from 0.6 to 0.64, p < 0.05), (b) a moderate relationship between CS and COD-90 tests (r = from 0.33 to 0.41, p < 0.05), with a certain opposite tendency (higher relationships between opposing directions [CurveLEFT - CODRIGHT; r = 0.41] than between equal directions [CurveLEFT – CODLEFT; r = 0.33]), and (c) no relationship (p > 0.05) between COD and CS asymmetries, with opposing directional dominance in ~70% of players (e.g., curve left and COD right dominance). These results indicate that performance in linear sprints is strongly related to performance in multidirectional trajectories, whereas CS and COD-90 seem to be more independent actions. Additionally, the direction of asymmetry or dominance is generally opposite between the non-linear tasks measured.

Key words

  • speed assessment
  • curvilinear speed
  • change of direction
Open Access

Average Game Physical Demands and the Most Demanding Scenarios of Basketball Competition in Various Age Groups

Published Online: 28 Jul 2021
Page range: 165 - 174

Abstract

Abstract

The purpose of this study was to compare average physical demands and the most demanding 60-s scenarios of basketball match-play between five different age groups. Sixty-four male basketball players from five different age groups were monitored across eight regular-season home games. Physical demands were examined using a local positioning system and included total distance covered, distance >18 km·h-1, the number of accelerations (≥2 m·s-2) and decelerations (≤-2 m·s-2). All four game performance variables increased significantly (58.4 - 639.2%) when calculated with rolling average techniques in comparison to average physical demand values. Furthermore, the current investigation found that while Under-12 presented the highest result in relative total distance covered (p < .001; effect size = 0.58-2.01), they also showed the lowest values in the most demanding scenarios of match play and small-to-moderate effect sizes compared with their older counterparts. Both average physical demands and the most demanding scenarios presented an increasing tendency with age when distance >18 km·h-1 in basketball players was assessed. More specifically, the Under-12 age group achieved the lowest values and showed significant differences with the other four teams in both game analysis techniques (p < .001; effect size = 0.53 - 1.32). In conclusion, average game demands are shown to remarkably underestimate the most demanding scenarios of basketball match-play, and there are multiple significant differences between particular age groups.

Key words

  • team sports
  • match demands
  • peak intensity
  • performance analysis
  • local positioning system
Open Access

Pacing Strategy in Men’s 400 m Hurdles Accounting for Temporal and Spatial Characteristics of Elite Athletes

Published Online: 28 Jul 2021
Page range: 175 - 186

Abstract

Abstract

The final result in a 400 m hurdles race (400mH) is relative to the motor preparation, technique of clearing hurdles as well as the adopted strategy of the race, including temporal aspects (split times in particular parts of the race) and spatial elements (the number of strides taken between subsequent hurdles). The objective of the study was to identify an optimal strategy for the 400mH race, including the stride pattern and split times. Data employed for this study were derived from results of 273 races held during the men’s finals of international events (Olympic Games, World and European Championships) held from 1968 to 2015. To determine the strategies in the race, three main hurdle sections were identified – 1-4H, 4-7H and 7-10H. In each part, the fast (best results), average and slow (worst results) performing groups of hurdlers were distinguished. The analysis of adopted strategies was carried out taking into account 26 variables (main, basic, temporal and spatial). Basic statistical data, correlations and analysis of variance (ANOVA) were used. Results highlight the use of a variety of strategies, of which selection depends, among others, on body composition and the level of motor abilities (speed, speed endurance and explosive strength), as well as hurdling technique. Especially, the endurance strategy appears to be the most effective one, as it is a characteristic of best performances of many hurdlers. The analysis demonstrates that at the highest sports level the strategy of 400 m hurdles should be analyzed individually.

Key words

  • 400 m hurdle strategy
  • typology of hurdlers
  • athletics, pace
Open Access

Effects of Plyometric Training on Soft and Hard Surfaces for Improving Running Economy

Published Online: 28 Jul 2021
Page range: 187 - 196

Abstract

Abstract

The present study investigated the effects of plyometric jump training on hard and soft surfaces on running economy (RE), maximal oxygen uptake (VO2max), running performance and the rate of force development in orienteers. Nineteen orienteers (11 women and 8 men, body mass 61.1 ± 7.3 kg, age 21 ± 5.8 yrs) were randomly stratified based on sex, age, VO2max and RE to plyometric jumping training (8 sessions over 4 weeks) on either a hard or a soft surface. RE, VO2max and running performance were assessed on a treadmill and outdoor on- and off-trail loops. Moreover, ground reaction forces and force development were assessed during a one leg drop-jump test. The training intervention led to an overall 2-7% improvement in treadmill and off-trail RE, independent of the jumping surface and running velocity assessed. These improvements were not explained by force development during drop jump tests, which remained unchanged following the intervention. The changes in time-trial performance were associated with changes in RE. Plyometric training improved RE with no difference between the hard or the soft training surface and improved RE was also independent of the running speed assessed. Furthermore, improved running performance was associated with changes in RE after the intervention.

Key words

  • running economy
  • plyometric jump training
  • surface
  • orienteers
Open Access

Prediction of Match Outcomes with Multivariate Statistical Methods for the Group Stage in the UEFA Champions League

Published Online: 28 Jul 2021
Page range: 197 - 209

Abstract

Abstract

The aim of this study was to analyse the win, draw, and loss outcomes of soccer matches with situational variables and performance indicators. Data from group stage matches spanning the ten years between the 2010/2011 and 2019/2020 seasons in the European Champions League, were used. One-way analysis of variance (ANOVA) and Tukey HSD (honestly significant difference) tests indicated performance indicators which affected the outcome of matches. K-mean clustering, with statistically significant variables, categorized the quality of the opposition into three clusters: weak, balanced, and strong. Multidimensional scaling (MDS) and decision tree analysis were applied to each of these clusters, highlighting that performance indicators of the teams differed according to the quality of their opponent. Furthermore, according to the decision tree analysis, certain performance indicators, including scoring first and shots on target, increased the chances of winning regardless of the quality of the opposition. Finally, particular performance indicators increased the chance of winning, while others decreased this, in accordance with the quality of the opposition. These findings can help coaches develop different strategies, before or during the match, based on the quality of opponents, situational variables, and performance indicators.

Key words

  • decision tree
  • soccer
  • quality of the opposition
  • performance indicators
  • situational variables
  • multidimensional scaling (MDS)
Open Access

Within-Match Performance Dynamics – Momentary Strength in Handball

Published Online: 28 Jul 2021
Page range: 211 - 219

Abstract

Abstract

Handball is an Olympic team sport characterized by changes of ball possession, where teams either play on offense or defense. In this paper, we model momentary strength in handball as scoring probabilities based on a double moving average. In this cross-sectional observational study, the aim was to describe the dynamics of momentary strength in handball from both theoretical and practical perspectives. Momentary strength can be used to further characterize the nuances of the sport by identifying different phases in a match. The momentary strength model was applied to the 2019 International Handball Federation (IHF) Men's World Championship. Ninety-six games were analyzed. The results showed that momentary strength could be used to better understand the dynamic interaction process between two teams. The Spearman correlation between the teams' median momentary strength and their final ranks at the Championship was -0.830. Virtually each team faced phases in its matches with a momentary scoring probability lower than 0.10 and with 4 exceptions also higher than 0.90. Twelve out of the 24 teams showed phases with a momentary scoring probability of exactly 0 as well as exactly 1

Key words

  • performance analysis
  • team sports
  • world championship
Open Access

The Influence of Sprint Mechanical Properties on Change of Direction in Female Futsal Players

Published Online: 28 Jul 2021
Page range: 221 - 228

Abstract

Abstract

The aim of the present study was to analyze the association of the sprint force-velocity profile [Hzt FV profile] variables with change of direction [COD] performance in female futsal players. Twelve female futsal players (age: 19.83 ± 4.2 years; body height: 160.75 ± 8.37 cm; body mass: 57.64 ± 8.3 kg) volunteered to be evaluated in the following assessments: Hzt FV profile, 505 test, modified 505 test [M505test] and V-cut test. The Spearman’s correlation coefficient [rs] (p < 0.05) was used to determine the relationship of the mechanical variables of the sprint (maximum power output [Pmax], maximum horizontal force production [F0] and maximum velocity [V0]) with COD performance. V0 showed a very large significant association with the 505 test (rs = -0.767; 90% CI: (-0.92 to -0.43); p < 0.01) and a large association with the V-cut test (rs = -0.641; 90% CI: (-0.86 to -0.21); p < 0.05), whereas Pmax was strongly associated with results of the 505 test (rs = -0.821; 90% CI: (-0.94 to -0.55); p < 0.01) and largely associated with the V-cut test results (rs = -0.596; 90% CI: (-0.84 to -0.14); p < 0.05). In conclusion, maximal power and velocity output during sprinting are determinant factors to successful COD in 180º and 45º cuts, thus, the Hzt FV profile should be assessed in female futsal players to better understand the influence of sprint mechanical properties on COD performance and prescribe individualized training programs

Key words

  • team sports
  • strength
  • acceleration
  • power
  • velocity
Open Access

Analysis of the Individual Set-Pieces Influence on the Teams’ Ranking in Rink Hockey

Published Online: 28 Jul 2021
Page range: 229 - 236

Abstract

Abstract

The main objective of this research was to analyze the individual set-pieces influence on the final season ranking in rink hockey. For this purpose, 6,920 individual set-pieces from 1,680 matches corresponding to free direct hits (n = 4,332) and penalty shots (n = 2,588) were analyzed during seven consecutive seasons (2012-13 to 2018-19) in the First Spanish League (Ok Liga). The variables recorded were the following for each team: total points, free direct hits attempted, free direct hits scored, penalties attempted, penalties scored, total goals scored during the season, free direct hits received, goals received from free direct hits, penalties received, goals received from penalties and total goals received in the season. Results showed that 21.08% of the goals were scored by free direct hits and penalty shots (11.58% and 9.49%, respectively). Likewise, teams ranked in a better position achieved higher effectiveness in individual set-pieces and their goalkeepers were more effective in defending the free direct hits and penalties. Furthermore, results showed significant correlations between team season points and better performance in individual set-pieces variables. Therefore, the results of this study demonstrated the importance of systematic practice of free direct hits and penalty shots for teams’ success in rink hockey. Additionally, it is suggested that teams possess special players to execute these particular elements of match play

Key words

  • performance analysis
  • roller hockey
  • match variables
  • shots
Open Access

Long-Term Trend Analysis of Playing Styles in the Chinese Soccer Super League

Published Online: 28 Jul 2021
Page range: 237 - 247

Abstract

Abstract

The aim of this study was to identify playing styles adopted by teams in the Chinese Soccer Super League (CSL) and to investigate their evolution across a 6-season period. Data were collected from 1,429 CSL matches from 2012 to 2017 seasons using the Amisco system. Seventeen technical performance-related indicators and eleven physical performance-related indicators were included in the factor analysis (PCA: principal components analysis) in order to group them into performance factors (styles of play). Seven factors were obtained (eigenvalues greater than 1) and explained 74.44% of the total variance. Multivariate analyses of covariance (MANCOVA) were used to check differences among seven styles of play (team’s ranking was used as a covariate) during the six seasons under study. The main findings showed that Factor 1 (high intensity play) and factor 3 (offensive actions) of CSL soccer increased substantially along the seasons. Coaches and sports scientists should take into consideration these performance trends when preparing training and controlling for matches

Key words

  • match analysis
  • factor analysis
  • Chinese soccer
  • longitudinal
  • evolution

Section IV - Behavioural Sciences in Sport

Open Access

Burnout and Coping Perceptions of Volleyball Players Throughout an Annual Sport Season

Published Online: 28 Jul 2021
Page range: 249 - 257

Abstract

Abstract

Burnout is a psychological syndrome of reaction to chronic stress that occurs in athletes who feel exhausted by a sport activity that was previously pleasurable and enjoyable. One technique to prevent and control the syndrome is through coping, which is the ability to deal with stressful situations. In contrast to traditional cross-sectional approaches, this study aimed to investigate burnout and coping strategy characteristics over time and to analyze the relationship between burnout dimensions and coping strategies. Fifty-four high-level volleyball athletes (twenty-eight men and twenty-six women, age M = 25.57, SD = 4.72, range 18-35) completed paper-and-pencil measures of burnout and coping four times throughout a sport season. The Friedman test presented a significant increase in the reduced sense of athletic accomplishment (X2 = 20.58; p < 0.01) and sport devaluation (X2 = 19.83; p < 0.01) perceptions during the season. However, no coping differences were observed through the longitudinal analysis. Burnout dimensions showed a moderate inverse correlation to confidence/motivation at all measurement points during the season. Overall, the findings suggest that burnout perceptions increase as the season progresses, highlighting the relevance for the periodization of burnout prevention and control

Key words

  • psychological skills
  • stress
  • longitudinal assessment
  • sport psychology
Open Access

Biopsychosocial Effects of Competition Preparation in Natural Bodybuilders

Published Online: 28 Jul 2021
Page range: 259 - 276

Abstract

Abstract

Bodybuilders are judged on the subjective visual assessment of their muscular size, proportion, and leanness. This case series tracked four drug-free bodybuilders (3 male) during the off-season, pre-competition and recovery phases. This study aimed to comprehensively profile key biopsychosocial changes occurring pre/post competition in a group of British natural bodybuilders. We measured: resting metabolic rate (RMR), body composition (via BIA, ultrasound and sum of 7 skinfolds), lipid profiles, fasted glucose, blood pressure, power output (Wingate), grip strength, and carried out psychometric questionnaires (EAT-26, STAI, BUT) over an eight-month period. Mean weight loss from 5 months (5M) to pre-contest (PRE) was 8.6 ± 4.1 kg, followed by an increase of 7.9 ± 1.6 kg two months post contest (POST). The mean RMR of the cohort was stable from 1899 ± 630 kcal (5M) to 1897 ± 598 kcal (PRE), before decreasing to 1797 ± 242 kcal (POST). Mean peak power declined from 770 ± 113.0 w (5M), to 700.0 ± 134.4 w (PRE), before increasing to 816.0 ± 116.2 w (POST). Competition dieting had no effect on EAT-26 or BUT scores, suggesting no body dysmorphic or eating disorder concerns, although trait anxiety was elevated in three out of the four participants throughout the observation. Many of the biopsychosocial changes that occur to bodybuilders as they prepare for competition return to baseline measurements 2 months post competition.

Key words

  • physique
  • body-dysmorphia
  • drug-free
  • reverse-diet
  • bigorexia
Open Access

Coach Encouragement During Soccer Practices Can Influence Players’ Mental and Physical Loads

Published Online: 28 Jul 2021
Page range: 277 - 288

Abstract

Abstract

This study analyzed the influence of the coaches’ encouragement on the mental and physical load in soccer practices. The participants were 36 semiprofessional Spanish soccer players (Mage = 22.40; SD = 2.25) belonging to two male teams and one female team. Following the same practices’ design and order, two training sessions of each team were completed. In one session, coaches maintained a passive verbal attitude, whereas in the other session, coaches intervened with an active attitude through continuous general encouragement. The mental load and fatigue were measured using self-reported questionnaires (Likert scales), and internal and external physical loads were quantified using the rating of perceived exertion and the Global Position System. A t-test for related samples and magnitude based on an inference spreadsheet was performed. The results demonstrated that mental and internal physical loads increased when coaches participated with active verbal encouragement. Especially, increases in performance satisfaction, mental effort, and RPE values, and decreases in unsafety values were detected due to encouragement interventions. Nevertheless, the external physical load did not show a clear trend. Based on these findings, coaches can use this information to manipulate their verbal encouragement during practices according to their physical and mental objectives with specific soccer strategies

Key words

  • coaching
  • constraints
  • soccer training
  • mental fatigue
  • training practice
Open Access

The Coaches’ Efficacy Expectations of Youth Soccer Players with Different Maturity Status and Physical Performance

Published Online: 28 Jul 2021
Page range: 289 - 299

Abstract

Abstract

This study aimed to report possible anthropometrical and physical performance differences between youth soccer players with different maturity status and to report the coaches’ expectations, hypothesizing that coaches would expect more from players with advanced maturity. One hundred twenty-two (122) players completed a physical performance battery. Their maturity status was estimated and the coaches’ efficacy expectations (CEEs) were assessed. Players with advanced maturation had better physical performance (F = 26.5-73.4; p < 0.01) and their CEEs for strength-related tasks were different according to the maturity status (F = 8.3-10.9; p < 0.01), but not for speed-related tests, nor for their general ability to play soccer. Normalized data showed significant differences between physical performance tests and their respective CEEs within each maturity group, especially in the Post-PHV group. This study confirms the physical advantages of players with advanced maturity while it shows controversial results of how maturation affects the coaches’ perceptions and, indirectly, the coaches’ identification and selection of talented players.

Key words

  • self-efficacy
  • youth
  • maturation

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