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Dettagli della rivista
Formato
Rivista
eISSN
1899-7562
Pubblicato per la prima volta
13 Jan 2009
Periodo di pubblicazione
5 volte all'anno
Lingue
Inglese

Cerca

Volume 70 (2019): Edizione 1 (November 2019)

Dettagli della rivista
Formato
Rivista
eISSN
1899-7562
Pubblicato per la prima volta
13 Jan 2009
Periodo di pubblicazione
5 volte all'anno
Lingue
Inglese

Cerca

28 Articoli

Section I – Kinesiology

Accesso libero

Effects of Batting Practice and Visual Training Focused on Pitch Type and Speed on Batting Ability and Visual Function

Pubblicato online: 30 Nov 2019
Pagine: 5 - 13

Astratto

Abstract

This study aimed to examine the effects of batting practice and visual training focused on the pitch type and speed on batting ability and visual function. A total of 46 participants took part in 12 training sessions for 4 weeks. The participants were divided into six groups according to the training type as follows: Group 1, batting practice with a fastball at 100 km/h; Group 2, tracking (watching) a fastball at 100 km/h; Group 3, batting practice with a fastball at 115 km/h; Group 4, tracking a fastball at 115 km/h; Group 5, batting practice with a curve ball at 100 km/h; and Group 6, tracking a curve ball at 100 km/h. Dynamic visual acuity, depth perception, hand-eye coordination, and batting ability were measured before and after training. Group 1 showed significant improvement in batting ability in the tests with 100 km/h fastballs and curve balls, while Groups 3 and 5 showed significant improvement in batting ability with 100 km/h fastballs and curve balls, respectively. Group 6 also showed significant improvement in batting ability with 100 km/h fastballs. Moreover, Groups 2 and 4 showed significant improvement in Dynamic visual acuity and hand-eye coordination, respectively. The results of the present study suggest that batting practice and visual training improve batting ability for the same pitch types and speeds as those encountered in practice. Therefore, visual training may be an effective method for improving batting ability and visual function in coaching settings.

Key words

  • tracking ball
  • dynamic visual acuity
  • fastball
  • curve ball
Accesso libero

Assessment of Lower Body and Abdominal Strength in Professional Soccer Players

Pubblicato online: 30 Nov 2019
Pagine: 15 - 23

Astratto

Abstract

The purpose of this study was to evaluate abdominal strength in professional soccer players and compare the findings to their lower body strength. An observational design was used to examine abdominal and lower body strength using two functional performance tests (a lower body isokinetic test and an isometric abdominal test, respectively). One hundred and thirty-two professional male soccer players from Cyprus’s first and second divisions participated in this study. Testing included three and twenty-five maximal concentric flexion and extension repetitions at angle speeds of 60°/s (degrees/second) and 300°/s, respectively. On a separate occasion, participants completed two trials on an isometric device (ABTEST Gen. 3 system) for evaluation of abdominal strength. At both isokinetic speeds of 300°/s and 60°/s, abdominal strength had low to moderate significant correlations (p < .05) with quadriceps and hamstring strength. Coefficients of determination (R2) demonstrated that the variability in isokinetic variables accounted for only 14-16% of the variability of abdominal strength. Abdominal strength appears to be high in professional soccer players, but is not dependent on the sports level and/or a playing position. The results of this study demonstrate that abdominal strength and knee joint strength need to be evaluated separately.

Key words

  • soccer
  • fitness testing
  • isokinetic strength
Accesso libero

How Do Spatiotemporal Parameters and Lower-Body Stiffness Change with Increased Running Velocity? A Comparison Between Novice and Elite Level Runners

Pubblicato online: 30 Nov 2019
Pagine: 25 - 38

Astratto

Abstract

This study aimed to examine the effect of running velocity on spatiotemporal parameters and lower-body stiffness of endurance runners, and the influence of the performance level on those adaptations. Twenty-two male runners (novice [NR], n = 12, and elite runners [ER], n = 10) performed an incremental running test with a total of 5 different running velocities (10, 12, 14, 16, 18 km/h). Each condition lasted 1 min (30 s acclimatization period, and 30 s recording period). Spatiotemporal parameters were measured using the OptoGait system. Vertical (Kvert) and leg (Kleg) stiffness were calculated according to the sine-wave method. A repeated measures ANOVA (2 x 5, group x velocities) revealed significant adaptations (p < 0.05) to increased velocity in all spatiotemporal parameters and Kvert in both NR and ER. ER showed a greater flight time (FT) and step angle (at 18 km/h) (p < 0.05), longer step length (SL) and lower step frequency (SF) (p < 0.05), whereas no between-group differences were found in contact time (CT) nor in the sub-phases during CT at any speed (p ≥ 0.05). ER also showed lower Kvert values at every running velocity (p < 0.05), and no differences in Kleg (p ≥ 0.05). In conclusion, lower SF and Kvert and, thereby, longer FT and SL, seem to be the main spatiotemporal characteristics of high-level runners compared to their low-level counterparts.

Key words

  • endurance runners
  • running kinematics
  • performance
Accesso libero

The Effect of Training Experience on Postural Control in Competitive Wrestlers

Pubblicato online: 30 Nov 2019
Pagine: 39 - 45

Astratto

Abstract

The aim of this study was to evaluate the effects of training experience in wrestling on postural control. Fourteen elite athletes with at least 8 years of wrestling training and competition experience participated in the study. The control group consisted of fifteen healthy adults who were not competitive athletes. The center of pressure (COP) trajectories were recorded with the use of an AMTI force plate at a sampling frequency of 50 Hz. The rambling-trembling decomposition method was used to analyze the COP trajectory data. The main finding was a significant effect of training experience on postural control in only the sagittal plane. Interestingly, significant differences in velocity were observed for the trembling component of the COP. All described variables were significantly higher in wrestlers. We hypothesized that balance training may lead to task-specific neural adaptations at the spinal and supraspinal levels. It was concluded that further research of high methodological quality is needed to determine the effect of training experience on balance control in elite athletes. Additionally, this effect should be observed in youth athletes, as it may be treated as a selection criteria in the training process.

Key words

  • balance
  • motor abilities
  • rambling/trembling analysis
  • combat sports
  • training experience
Accesso libero

Could Ankle Muscle Activation Be Used as a Simple Measure of Balance Exercise Intensity?

Pubblicato online: 30 Nov 2019
Pagine: 47 - 59

Astratto

Abstract

Few, if any, studies have reported the effects of intensity of balance exercise for balance training and rehabilitation. The aim of the present study was to find a relative measure of intensity of balance exercise. On this basis, we analysed ankle muscle activation in the sagittal plane with increasing difficulty for a one leg stance on a T-board. Ten adults (7 men, 24.1 ± 3.5 years; 3 women, 30.6 ± 5.8 years) performed 3 trials on a T-board within 6 randomly assigned stability levels. T-board swaying velocities in the sagittal plane were manipulated to attain different stability levels (conditions). Concurrently, angular distance of the T-board and active balance time (i.e., percentage of a total time balancing) under each condition were measured. Surface electromyography from the tibialis anterior, gastrocnemius and soleus were monitored during one leg stance. The surface electromyography amplitude in the time domain was quantified using the root-mean-square values. Significant effect of stability levels on angular distance (F5,45 = 3.4; p = 0.01) and velocity of the T-board (F5,45 = 4.6; p = 0.002) were obtained. Active balance time decreased by ∼15% (p = 0.001) from the maximal to the minimal stability conditions. The graded level of balance board stability conditions did not generate significantly higher root-mean-square values in any muscles and hence could not be used as a relative measure of intensity of balance exercise. These findings imply that there could be a plateau in difficulty of balance exercise for enhancement of ankle muscle activity.

Key words

  • soleus
  • tibialis anterior
  • lateral gastrocnemius
  • EMG

Section II – Exercise Physiology & Sports Medicine

Accesso libero

Physiological Responses and Swimming Technique During Upper Limb Critical Stroke Rate Training in Competitive Swimmers

Pubblicato online: 30 Nov 2019
Pagine: 61 - 68

Astratto

Abstract

The aim of this study was to examine how arm stroke swimming with critical stroke rate (CSR) control would influence physiological responses and stroke variables in an effort to identify a new swimming training method. Seven well-trained male competitive swimmers (19.9 ± 1.4 years of age) performed maximal 200 and 400 m front crawl swims to determine the CSR and critical swimming velocity (CV), respectively. Thereafter, they were instructed to perform tests with 4 × 400 m swimming bouts at the CSR and CV. The swimming time (CSR test: 278.96 ± 2.70 to 280.87 ± 2.57 s, CV test: 276.17 ± 3.36 to 277.06 ± 3.64 s), heart rate, and rated perceived exertion did not differ significantly between tests for all bouts. Blood lactate concentration after the fourth bout was significantly lower in the CSR test than in the CV test (3.16 ± 1.43 vs. 3.77 ± 1.52 mmol/l, p < 0.05). The stroke rate and stroke length remained stable across bouts in the CSR test, whereas the stroke rate increased with decreased stroke length across bouts in the CV test (p < 0.05). There were significant differences in the stroke rate (39.27 ± 1.22 vs. 41.47 ± 1.22 cycles/min, p < 0.05) and stroke length (2.20 ± 0.07 vs. 2.10 ± 0.04 m/stroke, p < 0.05) between the CSR and CV tests in the fourth bout. These results indicate that the CSR could provide the optimal intensity for improving aerobic capacity during arm stroke swimming, and it may also help stabilize stroke technique.

Key words

  • arm stroke swimming
  • stroke rate
  • stroke length
  • aerobic performance
  • swimming training
Accesso libero

Hematological, Hormonal and Fitness Indices in Youth Swimmers: Gender‐Related Comparisons

Pubblicato online: 30 Nov 2019
Pagine: 69 - 80

Astratto

Abstract

This study objective was to evaluate gender differences in hematological, hormonal and fitness variables among youth swimmers and to explore relationships between erythrocyte indices and aerobic and anaerobic capacity. 137 girls and 171 boys participated in the study and were divided into three groups based on their training experience. Blood samples were obtained to determine red blood cell counts, hemoglobin concentration, hematocrit, and plasma erythropoietin and testosterone levels. VO2max was assessed using a submaximal cycle protocol. 76 girls and 102 boys also undertook a Wingate test to determine their peak anaerobic power. Boys had higher (p < 0.05) means than girls for all hematological variables except for erythropoietin and these variables demonstrated an increase with training in boys. The average VO2max in l∙min-1 and peak anaerobic power in watts were also higher in boys (2.91 ± 0.08 and 547 ± 28, respectively) than girls (2.25 ± 0.07 and 450 ± 26, respectively). Modest but significant (p < 0.05) correlations were found between VO2max and red blood cell counts (r = 0.252), hemoglobin concentration (r = 0.345), or hematocrit (r = 0.345) and between peak anaerobic power and red blood cell counts (r = 0.304), hemoglobin concentration (r = 0.319) or hematocrit (r = 0.351). This study revealed relatively lower yet age- and gender-appropriate hematological, hormonal and fitness indices in youth swimmers. The gender-related differences in erythrocyte indices seem unrelated to erythropoietin and may be explained by the higher testosterone levels seen in boys. Given their correlation to both aerobic and anaerobic capacity, erythrocyte indices may be used as part of talent identification for sports.

Key words

  • erythrocytes
  • testosterone
  • aerobic capacity
  • anaerobic power
  • training
Accesso libero

Analysis of Daily Energy Expenditure of Elite Athletes in Relation to Their Sport, the Measurement Method and Energy Requirement Norms

Pubblicato online: 30 Nov 2019
Pagine: 81 - 92

Astratto

Abstract

The purpose of this study was to estimate the daily energy expenditure (DEE) of 30 Polish elite athletes (15 women and 15 men aged 20 to 34 years) representing aerobic-endurance sports and speed-strength sports and to compare the obtained values with energy requirement norms recommended for athletes. Participants’ DEE was measured for seven days using a chronometric-tabular method and a kinematic method. The kinematic method provided significantly lower values of DEE, by 25%. Mean DEEs obtained for female aerobic-endurance and speed-strength athletes were 3042.6 ± 389 and 3255.7 ± 359 kcal/24h (a chronometric-tabular method) and 2230.9 ± 209 and 2346.3 ± 355 (the kinematic method), respectively. The differences between the two groups were not statistically significant (p > 0.05). Male athletes’ mean DEEs were significantly higher (p < 0.05): 3778.0 ± 657 and 4036.7 ± 532 kcal/24h (a chronometric-tabular method) for aerobic-endurance athletes and 2983.3 ± 545 and 2970.4 ± 345 (the kinematic analysis) for speed-strength athletes. As in the case of female athletes, the differences were not significant (p > 0.05). While no evidence was found that the type of sport alone could cause significant differences in the overall mean DEE between aerobic endurance athletes and speed-strength athletes, athletes’ sex significantly differentiated women from men in that respect (the latter’s DEE was significantly greater). Such differences were not noted, though, when athletes’ relative DEE (adjusted for body mass and body composition) were compared. The study revealed that the actual energy requirements of individual athletes can vary in a wide range and that they can be different from recommended energy intake.

Key words

  • daily energy expenditure
  • athletes
  • accelerometer
  • questionnaire
Accesso libero

Hydration Status After an Ironman Triathlon: A Meta‐Analysis

Pubblicato online: 30 Nov 2019
Pagine: 93 - 102

Astratto

Abstract

The Ironman is one of the most popular triathlon events in the world. Such a race involves a great number of tactical decisions for a healthy finish and best performance. Dehydration is widely postulated to decrease performance and is known as a cause of dropouts in Ironman. Despite the importance of hydration status after an Ironman triathlon, there is a clear lack of review and especially meta-analysis studies on this topic. Therefore, the objective was to systematically review the literature and carry out a meta-analysis investigating the hydration status after an Ironman triathlon. We conducted a systematic review of the literature up to June 2016 that included the following databases: PubMed, SCOPUS, Science Direct and Web of Science. From the initial 995 references, we included 6 studies in the qualitative analysis and in the meta-analysis. All trials had two measures of hydration status after a full Ironman race. Total body water, blood and urine osmolality, urine specific gravity and sodium plasma concentration were considered as hydration markers. Three investigators independently abstracted data on the study design, sample size, participants’ and race characteristics, outcomes, and quantitative data for the meta-analysis. In the pooled analysis, it seems that the Ironman event led to a moderate state of dehydration in comparison to baseline values (SMD 0.494; 95% CI 0.220 to 0.767; p = 0.001). Some evidence of heterogeneity and consistency was also observed: Q = 19.6; I2 = 28.5%; τ2 = 2.39. The results suggest that after the race athletes seem to be hypo-hydrated in comparison to baseline values.

Key words

  • endurance
  • dehydration
  • swimming
  • cycling
  • running
Accesso libero

Changes in Performance and Morning‐Measured Responses in Sport Rock Climbers

Pubblicato online: 30 Nov 2019
Pagine: 103 - 114

Astratto

Abstract

The aim of this study was to determine changes in climbers’ hormonal, cardiovascular, neuromuscular, sleep and fatigue status, and their relationship with performance and workloads during a sport rock climbing camp. Mean difficulty of individual leading climbing routes (mean Difficulty) was calculated for six male, intermediate level sport rock climbers participating in a 2-week camp in Orpierre. Additionally, each morning climbers were tested for: cortisol (d-Cortisol) and testosterone (d-Testosterone) concentrations, testosterone/cortisol ratio (T/C), heart rate and heart rate variability in supine (d-L-HR, d-L-SD1, d-L-SD2) and standing positions (d-S-HR, d-S-SD1, d-S-SD2), difference in S-HR and L-HR (HR-S-L), maximal voluntary hand grip strength (MVC), sleep duration (Sleep) and the self-perception of fatigue (M-Fatigue). Only M-Fatigue and d-Testosterone did not change significantly during the camp. Changes in other variables were large and significant, especially in the second week of the camp when the mean Difficulty was > 70%. The greatest changes were noted on the last day, when T/C, HR-S-L, and Sleep decreased and d-Cortisol, d-L-HR, and d-SD1 increased. The monitoring of the uncoupling of neuromuscular, hormonal, and cardiovascular markers can be instrumental in determining the level of athletes’ morning fatigue and readiness during a climbing camp. An increase in d-Cortisol and a decrease in T/C and HR-S-L are relevant indicators of overreaching in sport climbers.

Key words

  • sport climbing
  • workload
  • hormonal markers
  • heart rate variability
  • maximal voluntary contraction
Accesso libero

Immunological Responses to a Brazilian Jiu‐Jitsu High‐Intensity Interval Training Session

Pubblicato online: 30 Nov 2019
Pagine: 115 - 124

Astratto

Abstract

The objective of the study was to characterize immunological responses to a Brazilian Jiu-Jitsu high-intensity interval training session. Neuromuscular function, blood, and salivary samples were obtained after a Brazilian Jiu-Jitsu high-intensity interval training session. Saliva and blood samples were collected at Pre- (before the warm-up) and immediately Post-training. Neuromuscular function was evaluated by lower body muscle testing. The horizontal countermovement jump was performed at Pre (after the warm-up) and immediately Post blood and saliva collection, and approximately 5 minutes Post-training. The horizontal countermovement jump performance did not present any significant changes Post-training, while blood leukocytes, urea, IgA and salivary alpha-amylase showed a significant increase. Salivary alpha-amylase activity increased more than six times immediately Post compared to Pre-training. Saliva volume, secretion rate, and uric acid were not significantly different between Pre and Post condition. A Brazilian Jiu-Jitsu high-intensity interval training session elicited an increase in the blood cells responsible for antibody production and muscle damage adaptation after exercise. On the other hand, neuromuscular performance was not significantly affected Post-training, suggesting that immunological and performance responses were not necessarily associated.

Key words

  • metabolism
  • neuromuscular function
  • martial arts
Accesso libero

Effects of Different Dietary Energy Intake Following Resistance Training on Muscle Mass and Body Fat in Bodybuilders: A Pilot Study

Pubblicato online: 30 Nov 2019
Pagine: 125 - 134

Astratto

Abstract

The purpose of this study was to determine the effects of different amounts of energy intake in combination with progressive resistance training on muscle mass and body fat in bodybuilders. Eleven male bodybuilders (26.8 ± 2.3 years, 90.1 ± 9.7 kg, and 176.9 ± 7.1 cm) were randomly assigned into one of two groups: a group that ingested higher amounts of energy (G1, 67.5 ± 1.7 kcal/kg/d, n = 6), and a group that ingested moderate amounts of energy (G2, 50.1 ± 0.51 kcal/kg/d, n = 5). Both groups performed resistance training 6 days per week over a 4-week study period. Measures of body composition were assessed before and after the intervention period. For body fat, only the G1 presented significant changes from pre- to post-training (G1 = +7.4% vs. G2 = +0.8%). For muscle mass, both groups showed significant increases after the intervention period, with G1 presenting a greater increase compared to G2 (G1 = +2.7% vs. G2 = +1.1%). Results suggest that greater energy intake in combination with resistance training induces greater increases in both muscle mass and body fat in competitive male bodybuilders.

Key words

  • strength training
  • bodybuilding
  • muscle mass
  • body fat
  • split routine
Accesso libero

Effects of Far‐Infrared Emitting Ceramic Material Clothing on Recovery After Maximal Eccentric Exercise

Pubblicato online: 30 Nov 2019
Pagine: 135 - 144

Astratto

Abstract

The purpose of this study was to determine whether Far-Infrared Emitting Ceramic Materials worn as Bioceramic pants would improve neuromuscular performance, biochemical and perceptual markers in healthy individuals after maximal eccentric exercise. Twenty-two moderately active men were randomized into Bioceramic (n = 11) or Placebo (n = 11) groups. To induce muscle damage, three sets of 30 maximal isokinetic eccentric contractions of the quadriceps were performed at 60°·s-1. Participants wore the bioceramic or placebo pants for 2 hours immediately following the protocol, and then again for 2 hours prior to each subsequent testing session at 24, 48 and 72 hours post. Plasma creatine kinase and lactate dehydrogenase activity, delayed-onset muscle soreness, perceived recovery status, and maximal voluntary contraction were measured pre-exercise and 2, 24, 48, and 72 hours post-exercise. Eccentric exercise induced muscle damage as evident in significant increases in delayed-onset muscle soreness at 24 - 72 hours (p < 0.05) and creatine kinase between Pre to 2, 24, 48 and 72 hours (p < 0.05). Despite the increased delayed-onset muscle soreness and creatine kinase values, no effect of Bioceramic was evident (p > 0.05). Furthermore, decreases in maximal voluntary contraction between Pre and immediately, 2, 24, 48 and 72 hours post (p < 0.05) were reported. However, the standardized difference was moderate lower for lactate dehydrogenase at 24 h (ES = 0.50), but higher at 48 h (ES = -0.58) in the Bioceramic compared to the Placebo group. Despite inducing muscle damage, the daily use of Far-Infrared Emitting Ceramic Materials clothing over 72 hours did not facilitate recovery after maximal eccentric exercise.

Key words

  • muscle damage
  • delayed-onset muscle soreness
  • bioceramic
  • neuromuscular performance
  • post-exercise recovery
Accesso libero

Changes in Anthropometric Traits and Body Composition Over a Four‐Year Period in Elite Female Judoka Athletes

Pubblicato online: 30 Nov 2019
Pagine: 145 - 155

Astratto

Abstract

The aim of the study was to determine changes in the structure and composition of the body in elite female athletes over a four-year period. The study involved 12 female judo athletes with 34 somatic variables evaluated. Anthropometric evaluation was performed twice, first, when the athletes were members of the national junior team (aged 16.64 ± 1.26 years), and second, after four years, when they were members of the national senior team (aged 20.78 ± 1.27 years). The measurements were taken in accordance with the recommendations of the IBP (International Biological Program) with a set of anthropometric instruments (GPM Swiss) while following the Martin-Saller technique. The average body mass, height, BMI, fat free mass (in kg) and body fat content significantly increased, while the percentage of fat free mass significantly decreased. All of the analyzed body circumferences also increased. Increases were recorded in the width of the upper limbs and they were the width of both hands and both elbows. There was also a statistically significant increase in the value of endomorphic and mesomorphic components, while the ectomorphic component value was similar. Body composition and a substantial number of somatic features of female judokas as seniors were not yet set at the junior stage. The predominant type of the body build was the endo-mesomorphic type and changes that occurred in the sample took place mainly in accordance with this tendency.

Key words

  • judo
  • female
  • somatic features
  • biological development
Accesso libero

Different Cleat Models do Not Influence Side Hop Test Performance of Soccer Players with and without Chronic Ankle Instability

Pubblicato online: 30 Nov 2019
Pagine: 156 - 164

Astratto

Abstract

The lateral ankle sprain is one of the most common sport injury, representing 10-30% of all musculoskeletal disorders. The lateral ankle sprain is induced by sport gestures involving changes of direction and landing manoeuvres and constitutes a risk factor for the occurrence of chronic ankle instability. Although cleat models and performance have been already explored, no study has evaluated this relationship in athletes with chronic ankle instability. Therefore, the purpose of the study was to analyse the influence of different soccer cleat models on Side Hop Test performance of athletes with and without chronic ankle instability. Thirty-nine athletes were divided into two groups, a chronic ankle instability group (n = 20) and a healthy group (n = 19). Each participant performed the Side Hop Test, executing 10 consecutive jumps on dry artificial grass with 4 cleat models. The Qualisys System and two force platforms were used to analyse the test runtime, the distance travelled and the mean velocity. No statistically significant interaction was observed between the group and the cleat model for all variables evaluated. In addition, no differences were observed between models or groups. In this specific test, performance does not seem to be influenced by different cleat models on dry artificial grass in athletes with and without chronic ankle instability.

Key words

  • soccer shoes
  • velocity
  • runtime
  • ankle sprain
  • artificial grass
Accesso libero

The Potential Relationship Between Leg Bone Length and Running Performance in Well‐Trained Endurance Runners

Pubblicato online: 30 Nov 2019
Pagine: 165 - 172

Astratto

Abstract

The present study aimed to determine the relationship between leg bone length and running performance in well-trained endurance runners. The lengths of the leg bones in 42 male endurance runners (age: 20.0 ± 1.0 years, body height: 169.6 ± 5.6 cm, body mass: 56.4 ± 5.1 kg, personal best 5000-m race time: 14 min 59 s ± 28 s) were measured using magnetic resonance imaging. The lengths of the femur and tibia were calculated to assess the upper and lower leg lengths, respectively. The total length of the femur + tibia was calculated to assess the overall leg bone length. These lengths of the leg bones were normalized with body height, which was measured using a stadiometer to minimize differences in body size among participants. The relative tibial length was significantly correlated with personal best 5000-m race time (r = -0.328, p = 0.034). Moreover, a trend towards significance was observed in the relative femoral length (r = -0.301, p = 0.053). Furthermore, the relative total lengths of the femur + tibia were significantly correlated with personal best 5000-m race time (r = -0.353, p < 0.05). These findings suggest that although the relationship between the leg bone length and personal best 5000-m race time was relatively minor, the leg bone length, especially of the tibia, may be a potential morphological factor for achieving superior running performance in well-trained endurance runners.

Key words

  • bone morphology
  • running economy
  • Achilles tendon length
  • step length
  • magnetic resonance imaging

Section III – Sports Training

Accesso libero

Analysis of Match Dynamics of Different Soccer Competition Levels Based on The Player Dyads

Pubblicato online: 30 Nov 2019
Pagine: 173 - 182

Astratto

Abstract

The purpose of this study was to analyse the dynamics of play based on dyads during soccer matches, according to the competition level, period of the matches, and playing positions. We recorded eight Brazilian soccer matches (four of the national and four of the regional level), using up to six digital cameras (30 Hz). The position information of the 204 players in the eight matches was obtained using an automatic tracking system. The Euclidean distance between the nearest opponents was calculated over time to define the dyads. The interaction between the components of dyads was assessed by the distances between players and was compared among the different positions (defender, full-back, defensive midfielder, midfielder, and forward), match periods (15, 30, 45, 60, 75, and 90 min), and competition levels. Results showed smaller distances for the national level dyads, compared to the regional matches. Greater distances between the players were found in the last 15 minutes of the matches, compared to the other periods. The full-backs were more distant from opposing players compared to players from other playing positions. Thus, coaches should consider the characteristics of each playing position and the greater proximity between opponents’ players in top-level competition for the development of tactical proficiency of the players.

Key words

  • automatic tracking
  • dynamical system
  • interpersonal interaction
  • sport performance
  • tactics
Accesso libero

Short-Term Repeated-Sprint Training (Straight Sprint vs. Changes of Direction) in Soccer Players

Pubblicato online: 30 Nov 2019
Pagine: 183 - 190

Astratto

Abstract

Repeated-sprint training (RST) is considered a critical training method in team sports. It is well known that RST effects may depend on several variables such as the duration of the protocol and repeated-sprint methodology. Few studies have evaluated very short-term protocols and compared different RST modalities. The aim of this study was to compare the effectiveness of 2 week RST including straight sprints or changes of direction (CODs) on physical performance in a sample of soccer players. This study used a randomised pre-post parallel group trial design. The participants were assigned to either an RST group using straight sprints (RST-SS = 18 players) or an RST group using CODs (RST-COD = 18 players). The protocols were: 3 sets of 7 x 30 m sprints for the RST-SS and 7 x 20 + 20 m (one COD of 180°) for the RST-COD, with 20 s and 4 min recovery between sprints and sets, respectively. The following evaluations were performed: 10 and 20 m sprint, agility test, repeated sprint test (RSTbest and RSTmean), and Yo-Yo Recovery Level 1. After the training period, the RST-SS did not report any performance variation, while the RST-COD showed improvements in the 10 m sprint and RSTbest (effect size = 0.70 and 0.65, respectively). The between-group analysis did not report any statistical difference between the RST-SS and the RST-COD. In conclusion, this study did not support the utilisation of a very short-term RST protocol with soccer players, however, the RST-COD presented some additional benefits in sprint performance compared to the RST-SS.

Key words

  • soccer
  • team sports
  • performance
  • training
  • changes of direction
Accesso libero

External Load Variations Between Medium- and Large-Sided Soccer Games: Ball Possession Games vs Regular Games with Small Goals

Pubblicato online: 30 Nov 2019
Pagine: 191 - 198

Astratto

Abstract

This study compared external load variations between 5 vs 5 and 10 vs 10 sided game formats played under two conditions: (i) a ball possession game with two floaters, and (ii) a regular game with goalkeepers and small goals. Twenty-two professional soccer players participated in this study: four central defenders, four wide defenders, nine central midfielders, three wide forwards, and three strikers. Total distance (TD), running distance (RD), sprinting distance (SD), number of sprints (NS), and player’s training load (PL) were recorded by GPS units. Within-format analyses revealed very likely large increases in TD (20.0%, [9.2; 31.9]; effect size (ES): 1.48, [0.71; 2.25]) and RD (130.9%, [20.2; 343.7]; ES: 1.32, [0.29; 2.35]) during the regular game when compared to the ball possession game in the 5 vs 5 format. In the 10 vs 10 format, large increases in TD (27.9%, [17.7; 39.1]; ES: 3.54, [2.34; 4.74]) and PL (27.4%, [12.6; 44.1]; ES: 2.46, [1.20; 3.72]) were observed in the regular condition when compared to the ball possession condition. Between-formats analyses revealed that, in the 10 vs 10 format, when compared to the 5 vs 5 format, RD was very likely larger (123.5%, [33.7; 273.7]), as was SD (195.8%, [20.5; 626.2]). However, very likely large decreases in PL were observed in the 10 vs 10 format (-19.6%; [-29.4; -8.3]) in the ball possession condition. Unclear differences were revealed based on variations in external load variables between formats in the regular condition. Smaller formats reduce the area available for running and sprinting and, thus, may be more adequate for increasing player’s training load (based on accelerometer data).

Key words

  • small-sided games
  • drill-based exercises
  • soccer
  • training
  • external load
Accesso libero

Influence of Contextual Variables on Performance of the Libero Player in Top-Level Women’s Volleyball

Pubblicato online: 30 Nov 2019
Pagine: 199 - 207

Astratto

Abstract

Sports performance changes dynamically according to multiple variables during a match. Contextual variables play an important role in complex situations and influence player’s performance depending on the player’s role. The aim of this study was to analyze performance of the libero player in terms of contextual variables in top-level women’s volleyball. The sample comprised 1,597 actions performed by libero players in 49 sets (13 matches) played in the Spanish Queen’s Cups from 2015 to 2017. The variables analyzed were: the game phase, the match period, the set period, match status, the type of the match, and action performance. The results revealed higher participation in the reception and digging, and top performance in reception and setting. The participation of the libero player decreased at the end of the match and the set as well as in advantage score situations, while performance got worse at the end of the set (especially in digs, p < .05) and improved in score advantage situations (especially in receptions, p < .05). Performance remained stable regardless of the type of the match (p > .05). These results may be useful to coaches in order to plan and design specific tasks coherent with libero competition demands and performance values.

Key words

  • team sports
  • performance analysis
  • game phase
  • player’s role
Accesso libero

Passing Network Analysis of Positional Attack Formations in Handball

Pubblicato online: 30 Nov 2019
Pagine: 209 - 221

Astratto

Abstract

The aim of this study was to characterize handball from a social network analysis perspective by analyzing 22 professional matches from the 2018 European Men's Handball Championship. Social network analysis has proven successful in the study of sports dynamics to investigate the interaction patterns of sport teams and the individual involvement of players. In handball, passing is crucial to establish an optimal position for throwing the ball into the goal of the opponent team. Moreover, different tactical formations are played during a game, often induced by two-minute suspensions or the addition of an offensive player replacing the goalkeeper as allowed by the International Handball Federation since 2016. Therefore, studying the interaction patterns of handball teams considering the different playing positions under various attack formations contributes to the tactical understanding of the sport. Degree and flow centrality as well as density and centralization values were computed. As a result, quantification of the contribution of individual players to the overall organization was achieved alongside the general balance in interplay. We identified the backcourt as the key players to structure interplay across tactical formations. While attack units without a goalkeeper were played longer, they were either more intensively structured around back positions (7 vs. 6) or spread out (5 + 1 vs. 6). We also found significant differences in the involvement of wing players across formations. The additional pivot in the 7 vs. 6 formation was mostly used to create space for back players and was less involved in interplay. Social network analysis turned out as a suitable method to govern and quantify team dynamics in handball.

Key words

  • social network analysis
  • temporal networks
  • centrality measures
  • performance analysis
  • tactical analysis
  • team sports
Accesso libero

The Effects of Conditioning Training on Body Build, Aerobic and Anaerobic Performance in Elite Mixed Martial Arts Athletes

Pubblicato online: 30 Nov 2019
Pagine: 223 - 231

Astratto

Abstract

The aim of the study was: 1. to evaluate the effects of conditioning training on body build and physical fitness in elite mixed martial athletes, 2. to investigate the training load structure and assess body build as well as the physiological profile of mixed martial arts athletes. Fifteen MMA male athletes (body mass: 79.8 ± 3.9 kg; body height: 178.7 ± 7.9 cm; body fat: 13.4 ± 1.6%) were involved in the study. The average training experience of athletes equalled 11 ± 1.1 years. Body composition, upper limb peak anaerobic power and aerobic performance were assessed before and after the preparatory phase. During each evaluation, athletes underwent two stress tests: the Wingate test for the upper limbs (upper limb anaerobic peak power measurement) and the graded exercise test until volitional exhaustion (maximal oxygen uptake measurement and second ventilatory threshold determination). Training means were investigated for the workload type, intensity and exercise metabolism. In the follow-up, body fat mass decreased, while anaerobic peak power and aerobic performance improved. Improvement in the time to obtain and maintain peak power in the upper limbs was noted. Training periodization resulted in advantageous body composition changes and improved physical fitness of the MMA athletes.

Key words

  • performance
  • physical fitness
  • aerobic capacity
  • anaerobic power
Accesso libero

Technical-Tactical Analysis of The Players of the Left and Right Wing in Elite Soccer

Pubblicato online: 30 Nov 2019
Pagine: 233 - 244

Astratto

Abstract

In today's soccer, teams are increasingly better trained both physically and tactically, hence different game styles can be identified and differences between them reduced. However, without an exhaustive analysis of reality, the view can lead to the extraction of erroneous conclusions, and what seems to be a team with a marked offensive profile is a mere illusion, resulting to be a team that develops a perfectly balanced game. In this paper, an analysis of technical-tactical performance of players who occupied both wings in an elite team was made, taking as reference the Spanish national soccer team as the model of international game to imitate in the last decade. The development of this paper was located within the observational methodology, using the polar coordinates technique for the analysis of the obtained data. The results showed how, despite identifying offensive profiles within technical-tactical performance of players that occupied the outer wings or lanes of the playing field, their tactical means and orientations diverged from each other. The results showed a more offensive profile and with higher technical complexity of players that occupied the left wing, while players that held the right wing showed a more defensive and recuperative profile, indicating a less vertical and complex style of play at a technical level with the forward as an offensive reference.

Key words

  • polar coordinates technique
  • performance
  • field position
  • team sport game

Section IV – Behavioural Sciences in Sport

Accesso libero

Associations Between Self-Determined Motivation, Team Potency, and Self-Talk in Team Sports

Pubblicato online: 30 Nov 2019
Pagine: 245 - 259

Astratto

Abstract

The current study aimed to evaluate the determinant factors of athletes´ internal positive self-talk that might lead to decreased anxiety and increased performance. The sample consisted of 191 male and female athletes ranging in age from 14 to 35 years old. They played soccer, volleyball and basketball and they were cadets (43%), juniors (29.6 %) and adults (27.4%). Results showed that satisfaction of the basic psychological needs was the strongest predictor of positive self-talk or positive thoughts during competition. Specifically, perception of autonomy was the strongest predictor, because it positively predicted concentration, control of anxiety and instructions, followed by perception of competence, which positively predicted confidence. Finally, team sports coaches should promote perception of autonomy and competence in their athletes, with the aim of enhancing more positive self-talk in competition, which may promote a better performance.

Key words

  • self-determination
  • autonomy
  • team potency
  • internal dialogue
  • sport performance
Accesso libero

The Effect of Virtual Training on Speed and Accuracy of Decision Making in Sport

Pubblicato online: 30 Nov 2019
Pagine: 261 - 273

Astratto

Abstract

The concept of expertise is an appealing topic in numerous domains, including sport. Research suggests that the path leading to expertise in sport is significantly influenced by the development of specific components, such as knowledge, skill, and game-performance (Thomas and Thomas, 1994). A relatively new technique in the field of teaching and coaching is the use of video games as a mode of instruction (Swing and Anderson, 2008). The purpose of this study was to address the question of whether video games can improve declarative and procedural sport knowledge. Twenty-seven volunteers were recruited through flyers and word of mouth at a university in a Midwest community. Measurements included an American football knowledge (pre- and post) test, survey of experience, and six football practice sessions using a Microsoft X-box. The project was approved by the Institutional Review Board (IRB), Human Subjects Review Committee. Knowledge test scores increased significantly from pre- to post-test [t (26) =-4.997, p = 0.0001]; the improvements were moderate (effect size = 0.66). From practice one to practice six (time) the average speed of decisions improved significantly, but accuracy did not. Knowledge increased regardless of the experience level, but the largest improvements in decision accuracy took place at the lowest experience level. This research supports the idea that video games could be an effective tool to increase sport specific knowledge, particularly in novices.

Key words

  • American Football
  • Decision-making
  • Procedural Knowledge
  • Xbox
  • Expertise
Accesso libero

In Search For Volleyball Entertainment: Impact of New Game Rules on Score and Time-Related Variables

Pubblicato online: 30 Nov 2019
Pagine: 275 - 285

Astratto

Abstract

The aim of this research was to analyse the impact of various game structures on score and time-related variables in elite volleyball. A total of 114 male matches and 76 female matches (38 matches for each tournament) were analysed in under-23 world championships. An observational design was implemented to measure match duration, points scored per match and set, set point differences, tournament phase, match balance, and set tendencies in various game structures (set to 21, to 25 or to 15 points) in male and female categories. Standardised differences in mean values showed that a 15-point set game structure led to shortest matches and smallest time variability in match duration, the largest number of points per match, and greatest equality in terms of set score differences in both the male and the female category. The use of various game structures in training may be useful to coaches and conditioning specialists when planning training schemes and sessions, by introducing different game structures to manage volume and intensity in training more effectively. These results may also be useful to local and/or national volleyball federations willing to attract new young players, to promote learning and to render volleyball a fun activity, by implementing S15 at initial stages. In addition, they could be useful to international federations or committees, so as to attract larger audiences and sponsors interested in more appealing matches with high levels of competitiveness and entertainment.

Key words

  • net sports
  • rule modifications
  • performance analysis
  • competition management
Accesso libero

Drive for Muscularity and Disordered Eating Behavior in Males: the Mediating Role of Cognitive Appraisal

Pubblicato online: 30 Nov 2019
Pagine: 287 - 295

Astratto

Abstract

There is mixed evidence for the relationship between increased levels of the drive for muscularity (DFM) and disordered eating behavior in males, therefore this study analysed the relationship between DFM and disordered eating behavior, giving particular relevance to the patterns of cognitive appraisal. A convenience sample was recruited from fitness centres and sport clubs with 308 participants, all males. Losing muscular mass represented a negative experience for participants, promoting a higher perception of threat appraisal. In addition, losing muscular mass was related to more muscularity-oriented behaviors and disordered eating behavior. Cognitive appraisal mediates the relation between DFM and disordered eating behavior. The results highlight the role of cognitive appraisal in DFM and disordered eating behavior in males in sport contexts.

Key words

  • mediation
  • sport
  • losing muscular mass
Accesso libero

Handball Goalkeeper Intuitive Decision-Making: A Naturalistic Case Study

Pubblicato online: 30 Nov 2019
Pagine: 297 - 308

Astratto

Abstract

Goalkeepers hold a key position for success in team sports competitions. They perform in dynamical contexts and are highly submitted to time pressure. The purpose of this naturalistic case study, therefore, was to explore how a handball expert goalkeeper deals with the uncertainty of the competition settings to make successful decisions. An individual self-confrontation interview was held with a goalkeeper while he watched duels with potential throwers in an official competition. A mixed method was used combining the first-person and third-person point of view. Verbal data were supplemented by observational data (distance measures between the goalkeeper and the potential thrower) in 83 short accounts of decision-making situations. Qualitative analysis resulted in 419 units of salient features, in three types of processes related to the Recognition-Primed Decision model, and in four micro-decisions. Non-parametrical statistical analysis indicated that there was a significant effect of distances between the potential thrower and the goalkeeper, on the micro-decision categories, but not on the recognition processes. These results provide insights into cognitive contents and processes an expert goalkeeper can use under uncertainty and time pressure. The mixed method furnishes a meaningful description and a subsequent understanding of expert performances in sport.

Key words

  • recognition processes
  • goalkeeping performance
  • elite
  • team sport
  • competition
28 Articoli

Section I – Kinesiology

Accesso libero

Effects of Batting Practice and Visual Training Focused on Pitch Type and Speed on Batting Ability and Visual Function

Pubblicato online: 30 Nov 2019
Pagine: 5 - 13

Astratto

Abstract

This study aimed to examine the effects of batting practice and visual training focused on the pitch type and speed on batting ability and visual function. A total of 46 participants took part in 12 training sessions for 4 weeks. The participants were divided into six groups according to the training type as follows: Group 1, batting practice with a fastball at 100 km/h; Group 2, tracking (watching) a fastball at 100 km/h; Group 3, batting practice with a fastball at 115 km/h; Group 4, tracking a fastball at 115 km/h; Group 5, batting practice with a curve ball at 100 km/h; and Group 6, tracking a curve ball at 100 km/h. Dynamic visual acuity, depth perception, hand-eye coordination, and batting ability were measured before and after training. Group 1 showed significant improvement in batting ability in the tests with 100 km/h fastballs and curve balls, while Groups 3 and 5 showed significant improvement in batting ability with 100 km/h fastballs and curve balls, respectively. Group 6 also showed significant improvement in batting ability with 100 km/h fastballs. Moreover, Groups 2 and 4 showed significant improvement in Dynamic visual acuity and hand-eye coordination, respectively. The results of the present study suggest that batting practice and visual training improve batting ability for the same pitch types and speeds as those encountered in practice. Therefore, visual training may be an effective method for improving batting ability and visual function in coaching settings.

Key words

  • tracking ball
  • dynamic visual acuity
  • fastball
  • curve ball
Accesso libero

Assessment of Lower Body and Abdominal Strength in Professional Soccer Players

Pubblicato online: 30 Nov 2019
Pagine: 15 - 23

Astratto

Abstract

The purpose of this study was to evaluate abdominal strength in professional soccer players and compare the findings to their lower body strength. An observational design was used to examine abdominal and lower body strength using two functional performance tests (a lower body isokinetic test and an isometric abdominal test, respectively). One hundred and thirty-two professional male soccer players from Cyprus’s first and second divisions participated in this study. Testing included three and twenty-five maximal concentric flexion and extension repetitions at angle speeds of 60°/s (degrees/second) and 300°/s, respectively. On a separate occasion, participants completed two trials on an isometric device (ABTEST Gen. 3 system) for evaluation of abdominal strength. At both isokinetic speeds of 300°/s and 60°/s, abdominal strength had low to moderate significant correlations (p < .05) with quadriceps and hamstring strength. Coefficients of determination (R2) demonstrated that the variability in isokinetic variables accounted for only 14-16% of the variability of abdominal strength. Abdominal strength appears to be high in professional soccer players, but is not dependent on the sports level and/or a playing position. The results of this study demonstrate that abdominal strength and knee joint strength need to be evaluated separately.

Key words

  • soccer
  • fitness testing
  • isokinetic strength
Accesso libero

How Do Spatiotemporal Parameters and Lower-Body Stiffness Change with Increased Running Velocity? A Comparison Between Novice and Elite Level Runners

Pubblicato online: 30 Nov 2019
Pagine: 25 - 38

Astratto

Abstract

This study aimed to examine the effect of running velocity on spatiotemporal parameters and lower-body stiffness of endurance runners, and the influence of the performance level on those adaptations. Twenty-two male runners (novice [NR], n = 12, and elite runners [ER], n = 10) performed an incremental running test with a total of 5 different running velocities (10, 12, 14, 16, 18 km/h). Each condition lasted 1 min (30 s acclimatization period, and 30 s recording period). Spatiotemporal parameters were measured using the OptoGait system. Vertical (Kvert) and leg (Kleg) stiffness were calculated according to the sine-wave method. A repeated measures ANOVA (2 x 5, group x velocities) revealed significant adaptations (p < 0.05) to increased velocity in all spatiotemporal parameters and Kvert in both NR and ER. ER showed a greater flight time (FT) and step angle (at 18 km/h) (p < 0.05), longer step length (SL) and lower step frequency (SF) (p < 0.05), whereas no between-group differences were found in contact time (CT) nor in the sub-phases during CT at any speed (p ≥ 0.05). ER also showed lower Kvert values at every running velocity (p < 0.05), and no differences in Kleg (p ≥ 0.05). In conclusion, lower SF and Kvert and, thereby, longer FT and SL, seem to be the main spatiotemporal characteristics of high-level runners compared to their low-level counterparts.

Key words

  • endurance runners
  • running kinematics
  • performance
Accesso libero

The Effect of Training Experience on Postural Control in Competitive Wrestlers

Pubblicato online: 30 Nov 2019
Pagine: 39 - 45

Astratto

Abstract

The aim of this study was to evaluate the effects of training experience in wrestling on postural control. Fourteen elite athletes with at least 8 years of wrestling training and competition experience participated in the study. The control group consisted of fifteen healthy adults who were not competitive athletes. The center of pressure (COP) trajectories were recorded with the use of an AMTI force plate at a sampling frequency of 50 Hz. The rambling-trembling decomposition method was used to analyze the COP trajectory data. The main finding was a significant effect of training experience on postural control in only the sagittal plane. Interestingly, significant differences in velocity were observed for the trembling component of the COP. All described variables were significantly higher in wrestlers. We hypothesized that balance training may lead to task-specific neural adaptations at the spinal and supraspinal levels. It was concluded that further research of high methodological quality is needed to determine the effect of training experience on balance control in elite athletes. Additionally, this effect should be observed in youth athletes, as it may be treated as a selection criteria in the training process.

Key words

  • balance
  • motor abilities
  • rambling/trembling analysis
  • combat sports
  • training experience
Accesso libero

Could Ankle Muscle Activation Be Used as a Simple Measure of Balance Exercise Intensity?

Pubblicato online: 30 Nov 2019
Pagine: 47 - 59

Astratto

Abstract

Few, if any, studies have reported the effects of intensity of balance exercise for balance training and rehabilitation. The aim of the present study was to find a relative measure of intensity of balance exercise. On this basis, we analysed ankle muscle activation in the sagittal plane with increasing difficulty for a one leg stance on a T-board. Ten adults (7 men, 24.1 ± 3.5 years; 3 women, 30.6 ± 5.8 years) performed 3 trials on a T-board within 6 randomly assigned stability levels. T-board swaying velocities in the sagittal plane were manipulated to attain different stability levels (conditions). Concurrently, angular distance of the T-board and active balance time (i.e., percentage of a total time balancing) under each condition were measured. Surface electromyography from the tibialis anterior, gastrocnemius and soleus were monitored during one leg stance. The surface electromyography amplitude in the time domain was quantified using the root-mean-square values. Significant effect of stability levels on angular distance (F5,45 = 3.4; p = 0.01) and velocity of the T-board (F5,45 = 4.6; p = 0.002) were obtained. Active balance time decreased by ∼15% (p = 0.001) from the maximal to the minimal stability conditions. The graded level of balance board stability conditions did not generate significantly higher root-mean-square values in any muscles and hence could not be used as a relative measure of intensity of balance exercise. These findings imply that there could be a plateau in difficulty of balance exercise for enhancement of ankle muscle activity.

Key words

  • soleus
  • tibialis anterior
  • lateral gastrocnemius
  • EMG

Section II – Exercise Physiology & Sports Medicine

Accesso libero

Physiological Responses and Swimming Technique During Upper Limb Critical Stroke Rate Training in Competitive Swimmers

Pubblicato online: 30 Nov 2019
Pagine: 61 - 68

Astratto

Abstract

The aim of this study was to examine how arm stroke swimming with critical stroke rate (CSR) control would influence physiological responses and stroke variables in an effort to identify a new swimming training method. Seven well-trained male competitive swimmers (19.9 ± 1.4 years of age) performed maximal 200 and 400 m front crawl swims to determine the CSR and critical swimming velocity (CV), respectively. Thereafter, they were instructed to perform tests with 4 × 400 m swimming bouts at the CSR and CV. The swimming time (CSR test: 278.96 ± 2.70 to 280.87 ± 2.57 s, CV test: 276.17 ± 3.36 to 277.06 ± 3.64 s), heart rate, and rated perceived exertion did not differ significantly between tests for all bouts. Blood lactate concentration after the fourth bout was significantly lower in the CSR test than in the CV test (3.16 ± 1.43 vs. 3.77 ± 1.52 mmol/l, p < 0.05). The stroke rate and stroke length remained stable across bouts in the CSR test, whereas the stroke rate increased with decreased stroke length across bouts in the CV test (p < 0.05). There were significant differences in the stroke rate (39.27 ± 1.22 vs. 41.47 ± 1.22 cycles/min, p < 0.05) and stroke length (2.20 ± 0.07 vs. 2.10 ± 0.04 m/stroke, p < 0.05) between the CSR and CV tests in the fourth bout. These results indicate that the CSR could provide the optimal intensity for improving aerobic capacity during arm stroke swimming, and it may also help stabilize stroke technique.

Key words

  • arm stroke swimming
  • stroke rate
  • stroke length
  • aerobic performance
  • swimming training
Accesso libero

Hematological, Hormonal and Fitness Indices in Youth Swimmers: Gender‐Related Comparisons

Pubblicato online: 30 Nov 2019
Pagine: 69 - 80

Astratto

Abstract

This study objective was to evaluate gender differences in hematological, hormonal and fitness variables among youth swimmers and to explore relationships between erythrocyte indices and aerobic and anaerobic capacity. 137 girls and 171 boys participated in the study and were divided into three groups based on their training experience. Blood samples were obtained to determine red blood cell counts, hemoglobin concentration, hematocrit, and plasma erythropoietin and testosterone levels. VO2max was assessed using a submaximal cycle protocol. 76 girls and 102 boys also undertook a Wingate test to determine their peak anaerobic power. Boys had higher (p < 0.05) means than girls for all hematological variables except for erythropoietin and these variables demonstrated an increase with training in boys. The average VO2max in l∙min-1 and peak anaerobic power in watts were also higher in boys (2.91 ± 0.08 and 547 ± 28, respectively) than girls (2.25 ± 0.07 and 450 ± 26, respectively). Modest but significant (p < 0.05) correlations were found between VO2max and red blood cell counts (r = 0.252), hemoglobin concentration (r = 0.345), or hematocrit (r = 0.345) and between peak anaerobic power and red blood cell counts (r = 0.304), hemoglobin concentration (r = 0.319) or hematocrit (r = 0.351). This study revealed relatively lower yet age- and gender-appropriate hematological, hormonal and fitness indices in youth swimmers. The gender-related differences in erythrocyte indices seem unrelated to erythropoietin and may be explained by the higher testosterone levels seen in boys. Given their correlation to both aerobic and anaerobic capacity, erythrocyte indices may be used as part of talent identification for sports.

Key words

  • erythrocytes
  • testosterone
  • aerobic capacity
  • anaerobic power
  • training
Accesso libero

Analysis of Daily Energy Expenditure of Elite Athletes in Relation to Their Sport, the Measurement Method and Energy Requirement Norms

Pubblicato online: 30 Nov 2019
Pagine: 81 - 92

Astratto

Abstract

The purpose of this study was to estimate the daily energy expenditure (DEE) of 30 Polish elite athletes (15 women and 15 men aged 20 to 34 years) representing aerobic-endurance sports and speed-strength sports and to compare the obtained values with energy requirement norms recommended for athletes. Participants’ DEE was measured for seven days using a chronometric-tabular method and a kinematic method. The kinematic method provided significantly lower values of DEE, by 25%. Mean DEEs obtained for female aerobic-endurance and speed-strength athletes were 3042.6 ± 389 and 3255.7 ± 359 kcal/24h (a chronometric-tabular method) and 2230.9 ± 209 and 2346.3 ± 355 (the kinematic method), respectively. The differences between the two groups were not statistically significant (p > 0.05). Male athletes’ mean DEEs were significantly higher (p < 0.05): 3778.0 ± 657 and 4036.7 ± 532 kcal/24h (a chronometric-tabular method) for aerobic-endurance athletes and 2983.3 ± 545 and 2970.4 ± 345 (the kinematic analysis) for speed-strength athletes. As in the case of female athletes, the differences were not significant (p > 0.05). While no evidence was found that the type of sport alone could cause significant differences in the overall mean DEE between aerobic endurance athletes and speed-strength athletes, athletes’ sex significantly differentiated women from men in that respect (the latter’s DEE was significantly greater). Such differences were not noted, though, when athletes’ relative DEE (adjusted for body mass and body composition) were compared. The study revealed that the actual energy requirements of individual athletes can vary in a wide range and that they can be different from recommended energy intake.

Key words

  • daily energy expenditure
  • athletes
  • accelerometer
  • questionnaire
Accesso libero

Hydration Status After an Ironman Triathlon: A Meta‐Analysis

Pubblicato online: 30 Nov 2019
Pagine: 93 - 102

Astratto

Abstract

The Ironman is one of the most popular triathlon events in the world. Such a race involves a great number of tactical decisions for a healthy finish and best performance. Dehydration is widely postulated to decrease performance and is known as a cause of dropouts in Ironman. Despite the importance of hydration status after an Ironman triathlon, there is a clear lack of review and especially meta-analysis studies on this topic. Therefore, the objective was to systematically review the literature and carry out a meta-analysis investigating the hydration status after an Ironman triathlon. We conducted a systematic review of the literature up to June 2016 that included the following databases: PubMed, SCOPUS, Science Direct and Web of Science. From the initial 995 references, we included 6 studies in the qualitative analysis and in the meta-analysis. All trials had two measures of hydration status after a full Ironman race. Total body water, blood and urine osmolality, urine specific gravity and sodium plasma concentration were considered as hydration markers. Three investigators independently abstracted data on the study design, sample size, participants’ and race characteristics, outcomes, and quantitative data for the meta-analysis. In the pooled analysis, it seems that the Ironman event led to a moderate state of dehydration in comparison to baseline values (SMD 0.494; 95% CI 0.220 to 0.767; p = 0.001). Some evidence of heterogeneity and consistency was also observed: Q = 19.6; I2 = 28.5%; τ2 = 2.39. The results suggest that after the race athletes seem to be hypo-hydrated in comparison to baseline values.

Key words

  • endurance
  • dehydration
  • swimming
  • cycling
  • running
Accesso libero

Changes in Performance and Morning‐Measured Responses in Sport Rock Climbers

Pubblicato online: 30 Nov 2019
Pagine: 103 - 114

Astratto

Abstract

The aim of this study was to determine changes in climbers’ hormonal, cardiovascular, neuromuscular, sleep and fatigue status, and their relationship with performance and workloads during a sport rock climbing camp. Mean difficulty of individual leading climbing routes (mean Difficulty) was calculated for six male, intermediate level sport rock climbers participating in a 2-week camp in Orpierre. Additionally, each morning climbers were tested for: cortisol (d-Cortisol) and testosterone (d-Testosterone) concentrations, testosterone/cortisol ratio (T/C), heart rate and heart rate variability in supine (d-L-HR, d-L-SD1, d-L-SD2) and standing positions (d-S-HR, d-S-SD1, d-S-SD2), difference in S-HR and L-HR (HR-S-L), maximal voluntary hand grip strength (MVC), sleep duration (Sleep) and the self-perception of fatigue (M-Fatigue). Only M-Fatigue and d-Testosterone did not change significantly during the camp. Changes in other variables were large and significant, especially in the second week of the camp when the mean Difficulty was > 70%. The greatest changes were noted on the last day, when T/C, HR-S-L, and Sleep decreased and d-Cortisol, d-L-HR, and d-SD1 increased. The monitoring of the uncoupling of neuromuscular, hormonal, and cardiovascular markers can be instrumental in determining the level of athletes’ morning fatigue and readiness during a climbing camp. An increase in d-Cortisol and a decrease in T/C and HR-S-L are relevant indicators of overreaching in sport climbers.

Key words

  • sport climbing
  • workload
  • hormonal markers
  • heart rate variability
  • maximal voluntary contraction
Accesso libero

Immunological Responses to a Brazilian Jiu‐Jitsu High‐Intensity Interval Training Session

Pubblicato online: 30 Nov 2019
Pagine: 115 - 124

Astratto

Abstract

The objective of the study was to characterize immunological responses to a Brazilian Jiu-Jitsu high-intensity interval training session. Neuromuscular function, blood, and salivary samples were obtained after a Brazilian Jiu-Jitsu high-intensity interval training session. Saliva and blood samples were collected at Pre- (before the warm-up) and immediately Post-training. Neuromuscular function was evaluated by lower body muscle testing. The horizontal countermovement jump was performed at Pre (after the warm-up) and immediately Post blood and saliva collection, and approximately 5 minutes Post-training. The horizontal countermovement jump performance did not present any significant changes Post-training, while blood leukocytes, urea, IgA and salivary alpha-amylase showed a significant increase. Salivary alpha-amylase activity increased more than six times immediately Post compared to Pre-training. Saliva volume, secretion rate, and uric acid were not significantly different between Pre and Post condition. A Brazilian Jiu-Jitsu high-intensity interval training session elicited an increase in the blood cells responsible for antibody production and muscle damage adaptation after exercise. On the other hand, neuromuscular performance was not significantly affected Post-training, suggesting that immunological and performance responses were not necessarily associated.

Key words

  • metabolism
  • neuromuscular function
  • martial arts
Accesso libero

Effects of Different Dietary Energy Intake Following Resistance Training on Muscle Mass and Body Fat in Bodybuilders: A Pilot Study

Pubblicato online: 30 Nov 2019
Pagine: 125 - 134

Astratto

Abstract

The purpose of this study was to determine the effects of different amounts of energy intake in combination with progressive resistance training on muscle mass and body fat in bodybuilders. Eleven male bodybuilders (26.8 ± 2.3 years, 90.1 ± 9.7 kg, and 176.9 ± 7.1 cm) were randomly assigned into one of two groups: a group that ingested higher amounts of energy (G1, 67.5 ± 1.7 kcal/kg/d, n = 6), and a group that ingested moderate amounts of energy (G2, 50.1 ± 0.51 kcal/kg/d, n = 5). Both groups performed resistance training 6 days per week over a 4-week study period. Measures of body composition were assessed before and after the intervention period. For body fat, only the G1 presented significant changes from pre- to post-training (G1 = +7.4% vs. G2 = +0.8%). For muscle mass, both groups showed significant increases after the intervention period, with G1 presenting a greater increase compared to G2 (G1 = +2.7% vs. G2 = +1.1%). Results suggest that greater energy intake in combination with resistance training induces greater increases in both muscle mass and body fat in competitive male bodybuilders.

Key words

  • strength training
  • bodybuilding
  • muscle mass
  • body fat
  • split routine
Accesso libero

Effects of Far‐Infrared Emitting Ceramic Material Clothing on Recovery After Maximal Eccentric Exercise

Pubblicato online: 30 Nov 2019
Pagine: 135 - 144

Astratto

Abstract

The purpose of this study was to determine whether Far-Infrared Emitting Ceramic Materials worn as Bioceramic pants would improve neuromuscular performance, biochemical and perceptual markers in healthy individuals after maximal eccentric exercise. Twenty-two moderately active men were randomized into Bioceramic (n = 11) or Placebo (n = 11) groups. To induce muscle damage, three sets of 30 maximal isokinetic eccentric contractions of the quadriceps were performed at 60°·s-1. Participants wore the bioceramic or placebo pants for 2 hours immediately following the protocol, and then again for 2 hours prior to each subsequent testing session at 24, 48 and 72 hours post. Plasma creatine kinase and lactate dehydrogenase activity, delayed-onset muscle soreness, perceived recovery status, and maximal voluntary contraction were measured pre-exercise and 2, 24, 48, and 72 hours post-exercise. Eccentric exercise induced muscle damage as evident in significant increases in delayed-onset muscle soreness at 24 - 72 hours (p < 0.05) and creatine kinase between Pre to 2, 24, 48 and 72 hours (p < 0.05). Despite the increased delayed-onset muscle soreness and creatine kinase values, no effect of Bioceramic was evident (p > 0.05). Furthermore, decreases in maximal voluntary contraction between Pre and immediately, 2, 24, 48 and 72 hours post (p < 0.05) were reported. However, the standardized difference was moderate lower for lactate dehydrogenase at 24 h (ES = 0.50), but higher at 48 h (ES = -0.58) in the Bioceramic compared to the Placebo group. Despite inducing muscle damage, the daily use of Far-Infrared Emitting Ceramic Materials clothing over 72 hours did not facilitate recovery after maximal eccentric exercise.

Key words

  • muscle damage
  • delayed-onset muscle soreness
  • bioceramic
  • neuromuscular performance
  • post-exercise recovery
Accesso libero

Changes in Anthropometric Traits and Body Composition Over a Four‐Year Period in Elite Female Judoka Athletes

Pubblicato online: 30 Nov 2019
Pagine: 145 - 155

Astratto

Abstract

The aim of the study was to determine changes in the structure and composition of the body in elite female athletes over a four-year period. The study involved 12 female judo athletes with 34 somatic variables evaluated. Anthropometric evaluation was performed twice, first, when the athletes were members of the national junior team (aged 16.64 ± 1.26 years), and second, after four years, when they were members of the national senior team (aged 20.78 ± 1.27 years). The measurements were taken in accordance with the recommendations of the IBP (International Biological Program) with a set of anthropometric instruments (GPM Swiss) while following the Martin-Saller technique. The average body mass, height, BMI, fat free mass (in kg) and body fat content significantly increased, while the percentage of fat free mass significantly decreased. All of the analyzed body circumferences also increased. Increases were recorded in the width of the upper limbs and they were the width of both hands and both elbows. There was also a statistically significant increase in the value of endomorphic and mesomorphic components, while the ectomorphic component value was similar. Body composition and a substantial number of somatic features of female judokas as seniors were not yet set at the junior stage. The predominant type of the body build was the endo-mesomorphic type and changes that occurred in the sample took place mainly in accordance with this tendency.

Key words

  • judo
  • female
  • somatic features
  • biological development
Accesso libero

Different Cleat Models do Not Influence Side Hop Test Performance of Soccer Players with and without Chronic Ankle Instability

Pubblicato online: 30 Nov 2019
Pagine: 156 - 164

Astratto

Abstract

The lateral ankle sprain is one of the most common sport injury, representing 10-30% of all musculoskeletal disorders. The lateral ankle sprain is induced by sport gestures involving changes of direction and landing manoeuvres and constitutes a risk factor for the occurrence of chronic ankle instability. Although cleat models and performance have been already explored, no study has evaluated this relationship in athletes with chronic ankle instability. Therefore, the purpose of the study was to analyse the influence of different soccer cleat models on Side Hop Test performance of athletes with and without chronic ankle instability. Thirty-nine athletes were divided into two groups, a chronic ankle instability group (n = 20) and a healthy group (n = 19). Each participant performed the Side Hop Test, executing 10 consecutive jumps on dry artificial grass with 4 cleat models. The Qualisys System and two force platforms were used to analyse the test runtime, the distance travelled and the mean velocity. No statistically significant interaction was observed between the group and the cleat model for all variables evaluated. In addition, no differences were observed between models or groups. In this specific test, performance does not seem to be influenced by different cleat models on dry artificial grass in athletes with and without chronic ankle instability.

Key words

  • soccer shoes
  • velocity
  • runtime
  • ankle sprain
  • artificial grass
Accesso libero

The Potential Relationship Between Leg Bone Length and Running Performance in Well‐Trained Endurance Runners

Pubblicato online: 30 Nov 2019
Pagine: 165 - 172

Astratto

Abstract

The present study aimed to determine the relationship between leg bone length and running performance in well-trained endurance runners. The lengths of the leg bones in 42 male endurance runners (age: 20.0 ± 1.0 years, body height: 169.6 ± 5.6 cm, body mass: 56.4 ± 5.1 kg, personal best 5000-m race time: 14 min 59 s ± 28 s) were measured using magnetic resonance imaging. The lengths of the femur and tibia were calculated to assess the upper and lower leg lengths, respectively. The total length of the femur + tibia was calculated to assess the overall leg bone length. These lengths of the leg bones were normalized with body height, which was measured using a stadiometer to minimize differences in body size among participants. The relative tibial length was significantly correlated with personal best 5000-m race time (r = -0.328, p = 0.034). Moreover, a trend towards significance was observed in the relative femoral length (r = -0.301, p = 0.053). Furthermore, the relative total lengths of the femur + tibia were significantly correlated with personal best 5000-m race time (r = -0.353, p < 0.05). These findings suggest that although the relationship between the leg bone length and personal best 5000-m race time was relatively minor, the leg bone length, especially of the tibia, may be a potential morphological factor for achieving superior running performance in well-trained endurance runners.

Key words

  • bone morphology
  • running economy
  • Achilles tendon length
  • step length
  • magnetic resonance imaging

Section III – Sports Training

Accesso libero

Analysis of Match Dynamics of Different Soccer Competition Levels Based on The Player Dyads

Pubblicato online: 30 Nov 2019
Pagine: 173 - 182

Astratto

Abstract

The purpose of this study was to analyse the dynamics of play based on dyads during soccer matches, according to the competition level, period of the matches, and playing positions. We recorded eight Brazilian soccer matches (four of the national and four of the regional level), using up to six digital cameras (30 Hz). The position information of the 204 players in the eight matches was obtained using an automatic tracking system. The Euclidean distance between the nearest opponents was calculated over time to define the dyads. The interaction between the components of dyads was assessed by the distances between players and was compared among the different positions (defender, full-back, defensive midfielder, midfielder, and forward), match periods (15, 30, 45, 60, 75, and 90 min), and competition levels. Results showed smaller distances for the national level dyads, compared to the regional matches. Greater distances between the players were found in the last 15 minutes of the matches, compared to the other periods. The full-backs were more distant from opposing players compared to players from other playing positions. Thus, coaches should consider the characteristics of each playing position and the greater proximity between opponents’ players in top-level competition for the development of tactical proficiency of the players.

Key words

  • automatic tracking
  • dynamical system
  • interpersonal interaction
  • sport performance
  • tactics
Accesso libero

Short-Term Repeated-Sprint Training (Straight Sprint vs. Changes of Direction) in Soccer Players

Pubblicato online: 30 Nov 2019
Pagine: 183 - 190

Astratto

Abstract

Repeated-sprint training (RST) is considered a critical training method in team sports. It is well known that RST effects may depend on several variables such as the duration of the protocol and repeated-sprint methodology. Few studies have evaluated very short-term protocols and compared different RST modalities. The aim of this study was to compare the effectiveness of 2 week RST including straight sprints or changes of direction (CODs) on physical performance in a sample of soccer players. This study used a randomised pre-post parallel group trial design. The participants were assigned to either an RST group using straight sprints (RST-SS = 18 players) or an RST group using CODs (RST-COD = 18 players). The protocols were: 3 sets of 7 x 30 m sprints for the RST-SS and 7 x 20 + 20 m (one COD of 180°) for the RST-COD, with 20 s and 4 min recovery between sprints and sets, respectively. The following evaluations were performed: 10 and 20 m sprint, agility test, repeated sprint test (RSTbest and RSTmean), and Yo-Yo Recovery Level 1. After the training period, the RST-SS did not report any performance variation, while the RST-COD showed improvements in the 10 m sprint and RSTbest (effect size = 0.70 and 0.65, respectively). The between-group analysis did not report any statistical difference between the RST-SS and the RST-COD. In conclusion, this study did not support the utilisation of a very short-term RST protocol with soccer players, however, the RST-COD presented some additional benefits in sprint performance compared to the RST-SS.

Key words

  • soccer
  • team sports
  • performance
  • training
  • changes of direction
Accesso libero

External Load Variations Between Medium- and Large-Sided Soccer Games: Ball Possession Games vs Regular Games with Small Goals

Pubblicato online: 30 Nov 2019
Pagine: 191 - 198

Astratto

Abstract

This study compared external load variations between 5 vs 5 and 10 vs 10 sided game formats played under two conditions: (i) a ball possession game with two floaters, and (ii) a regular game with goalkeepers and small goals. Twenty-two professional soccer players participated in this study: four central defenders, four wide defenders, nine central midfielders, three wide forwards, and three strikers. Total distance (TD), running distance (RD), sprinting distance (SD), number of sprints (NS), and player’s training load (PL) were recorded by GPS units. Within-format analyses revealed very likely large increases in TD (20.0%, [9.2; 31.9]; effect size (ES): 1.48, [0.71; 2.25]) and RD (130.9%, [20.2; 343.7]; ES: 1.32, [0.29; 2.35]) during the regular game when compared to the ball possession game in the 5 vs 5 format. In the 10 vs 10 format, large increases in TD (27.9%, [17.7; 39.1]; ES: 3.54, [2.34; 4.74]) and PL (27.4%, [12.6; 44.1]; ES: 2.46, [1.20; 3.72]) were observed in the regular condition when compared to the ball possession condition. Between-formats analyses revealed that, in the 10 vs 10 format, when compared to the 5 vs 5 format, RD was very likely larger (123.5%, [33.7; 273.7]), as was SD (195.8%, [20.5; 626.2]). However, very likely large decreases in PL were observed in the 10 vs 10 format (-19.6%; [-29.4; -8.3]) in the ball possession condition. Unclear differences were revealed based on variations in external load variables between formats in the regular condition. Smaller formats reduce the area available for running and sprinting and, thus, may be more adequate for increasing player’s training load (based on accelerometer data).

Key words

  • small-sided games
  • drill-based exercises
  • soccer
  • training
  • external load
Accesso libero

Influence of Contextual Variables on Performance of the Libero Player in Top-Level Women’s Volleyball

Pubblicato online: 30 Nov 2019
Pagine: 199 - 207

Astratto

Abstract

Sports performance changes dynamically according to multiple variables during a match. Contextual variables play an important role in complex situations and influence player’s performance depending on the player’s role. The aim of this study was to analyze performance of the libero player in terms of contextual variables in top-level women’s volleyball. The sample comprised 1,597 actions performed by libero players in 49 sets (13 matches) played in the Spanish Queen’s Cups from 2015 to 2017. The variables analyzed were: the game phase, the match period, the set period, match status, the type of the match, and action performance. The results revealed higher participation in the reception and digging, and top performance in reception and setting. The participation of the libero player decreased at the end of the match and the set as well as in advantage score situations, while performance got worse at the end of the set (especially in digs, p < .05) and improved in score advantage situations (especially in receptions, p < .05). Performance remained stable regardless of the type of the match (p > .05). These results may be useful to coaches in order to plan and design specific tasks coherent with libero competition demands and performance values.

Key words

  • team sports
  • performance analysis
  • game phase
  • player’s role
Accesso libero

Passing Network Analysis of Positional Attack Formations in Handball

Pubblicato online: 30 Nov 2019
Pagine: 209 - 221

Astratto

Abstract

The aim of this study was to characterize handball from a social network analysis perspective by analyzing 22 professional matches from the 2018 European Men's Handball Championship. Social network analysis has proven successful in the study of sports dynamics to investigate the interaction patterns of sport teams and the individual involvement of players. In handball, passing is crucial to establish an optimal position for throwing the ball into the goal of the opponent team. Moreover, different tactical formations are played during a game, often induced by two-minute suspensions or the addition of an offensive player replacing the goalkeeper as allowed by the International Handball Federation since 2016. Therefore, studying the interaction patterns of handball teams considering the different playing positions under various attack formations contributes to the tactical understanding of the sport. Degree and flow centrality as well as density and centralization values were computed. As a result, quantification of the contribution of individual players to the overall organization was achieved alongside the general balance in interplay. We identified the backcourt as the key players to structure interplay across tactical formations. While attack units without a goalkeeper were played longer, they were either more intensively structured around back positions (7 vs. 6) or spread out (5 + 1 vs. 6). We also found significant differences in the involvement of wing players across formations. The additional pivot in the 7 vs. 6 formation was mostly used to create space for back players and was less involved in interplay. Social network analysis turned out as a suitable method to govern and quantify team dynamics in handball.

Key words

  • social network analysis
  • temporal networks
  • centrality measures
  • performance analysis
  • tactical analysis
  • team sports
Accesso libero

The Effects of Conditioning Training on Body Build, Aerobic and Anaerobic Performance in Elite Mixed Martial Arts Athletes

Pubblicato online: 30 Nov 2019
Pagine: 223 - 231

Astratto

Abstract

The aim of the study was: 1. to evaluate the effects of conditioning training on body build and physical fitness in elite mixed martial athletes, 2. to investigate the training load structure and assess body build as well as the physiological profile of mixed martial arts athletes. Fifteen MMA male athletes (body mass: 79.8 ± 3.9 kg; body height: 178.7 ± 7.9 cm; body fat: 13.4 ± 1.6%) were involved in the study. The average training experience of athletes equalled 11 ± 1.1 years. Body composition, upper limb peak anaerobic power and aerobic performance were assessed before and after the preparatory phase. During each evaluation, athletes underwent two stress tests: the Wingate test for the upper limbs (upper limb anaerobic peak power measurement) and the graded exercise test until volitional exhaustion (maximal oxygen uptake measurement and second ventilatory threshold determination). Training means were investigated for the workload type, intensity and exercise metabolism. In the follow-up, body fat mass decreased, while anaerobic peak power and aerobic performance improved. Improvement in the time to obtain and maintain peak power in the upper limbs was noted. Training periodization resulted in advantageous body composition changes and improved physical fitness of the MMA athletes.

Key words

  • performance
  • physical fitness
  • aerobic capacity
  • anaerobic power
Accesso libero

Technical-Tactical Analysis of The Players of the Left and Right Wing in Elite Soccer

Pubblicato online: 30 Nov 2019
Pagine: 233 - 244

Astratto

Abstract

In today's soccer, teams are increasingly better trained both physically and tactically, hence different game styles can be identified and differences between them reduced. However, without an exhaustive analysis of reality, the view can lead to the extraction of erroneous conclusions, and what seems to be a team with a marked offensive profile is a mere illusion, resulting to be a team that develops a perfectly balanced game. In this paper, an analysis of technical-tactical performance of players who occupied both wings in an elite team was made, taking as reference the Spanish national soccer team as the model of international game to imitate in the last decade. The development of this paper was located within the observational methodology, using the polar coordinates technique for the analysis of the obtained data. The results showed how, despite identifying offensive profiles within technical-tactical performance of players that occupied the outer wings or lanes of the playing field, their tactical means and orientations diverged from each other. The results showed a more offensive profile and with higher technical complexity of players that occupied the left wing, while players that held the right wing showed a more defensive and recuperative profile, indicating a less vertical and complex style of play at a technical level with the forward as an offensive reference.

Key words

  • polar coordinates technique
  • performance
  • field position
  • team sport game

Section IV – Behavioural Sciences in Sport

Accesso libero

Associations Between Self-Determined Motivation, Team Potency, and Self-Talk in Team Sports

Pubblicato online: 30 Nov 2019
Pagine: 245 - 259

Astratto

Abstract

The current study aimed to evaluate the determinant factors of athletes´ internal positive self-talk that might lead to decreased anxiety and increased performance. The sample consisted of 191 male and female athletes ranging in age from 14 to 35 years old. They played soccer, volleyball and basketball and they were cadets (43%), juniors (29.6 %) and adults (27.4%). Results showed that satisfaction of the basic psychological needs was the strongest predictor of positive self-talk or positive thoughts during competition. Specifically, perception of autonomy was the strongest predictor, because it positively predicted concentration, control of anxiety and instructions, followed by perception of competence, which positively predicted confidence. Finally, team sports coaches should promote perception of autonomy and competence in their athletes, with the aim of enhancing more positive self-talk in competition, which may promote a better performance.

Key words

  • self-determination
  • autonomy
  • team potency
  • internal dialogue
  • sport performance
Accesso libero

The Effect of Virtual Training on Speed and Accuracy of Decision Making in Sport

Pubblicato online: 30 Nov 2019
Pagine: 261 - 273

Astratto

Abstract

The concept of expertise is an appealing topic in numerous domains, including sport. Research suggests that the path leading to expertise in sport is significantly influenced by the development of specific components, such as knowledge, skill, and game-performance (Thomas and Thomas, 1994). A relatively new technique in the field of teaching and coaching is the use of video games as a mode of instruction (Swing and Anderson, 2008). The purpose of this study was to address the question of whether video games can improve declarative and procedural sport knowledge. Twenty-seven volunteers were recruited through flyers and word of mouth at a university in a Midwest community. Measurements included an American football knowledge (pre- and post) test, survey of experience, and six football practice sessions using a Microsoft X-box. The project was approved by the Institutional Review Board (IRB), Human Subjects Review Committee. Knowledge test scores increased significantly from pre- to post-test [t (26) =-4.997, p = 0.0001]; the improvements were moderate (effect size = 0.66). From practice one to practice six (time) the average speed of decisions improved significantly, but accuracy did not. Knowledge increased regardless of the experience level, but the largest improvements in decision accuracy took place at the lowest experience level. This research supports the idea that video games could be an effective tool to increase sport specific knowledge, particularly in novices.

Key words

  • American Football
  • Decision-making
  • Procedural Knowledge
  • Xbox
  • Expertise
Accesso libero

In Search For Volleyball Entertainment: Impact of New Game Rules on Score and Time-Related Variables

Pubblicato online: 30 Nov 2019
Pagine: 275 - 285

Astratto

Abstract

The aim of this research was to analyse the impact of various game structures on score and time-related variables in elite volleyball. A total of 114 male matches and 76 female matches (38 matches for each tournament) were analysed in under-23 world championships. An observational design was implemented to measure match duration, points scored per match and set, set point differences, tournament phase, match balance, and set tendencies in various game structures (set to 21, to 25 or to 15 points) in male and female categories. Standardised differences in mean values showed that a 15-point set game structure led to shortest matches and smallest time variability in match duration, the largest number of points per match, and greatest equality in terms of set score differences in both the male and the female category. The use of various game structures in training may be useful to coaches and conditioning specialists when planning training schemes and sessions, by introducing different game structures to manage volume and intensity in training more effectively. These results may also be useful to local and/or national volleyball federations willing to attract new young players, to promote learning and to render volleyball a fun activity, by implementing S15 at initial stages. In addition, they could be useful to international federations or committees, so as to attract larger audiences and sponsors interested in more appealing matches with high levels of competitiveness and entertainment.

Key words

  • net sports
  • rule modifications
  • performance analysis
  • competition management
Accesso libero

Drive for Muscularity and Disordered Eating Behavior in Males: the Mediating Role of Cognitive Appraisal

Pubblicato online: 30 Nov 2019
Pagine: 287 - 295

Astratto

Abstract

There is mixed evidence for the relationship between increased levels of the drive for muscularity (DFM) and disordered eating behavior in males, therefore this study analysed the relationship between DFM and disordered eating behavior, giving particular relevance to the patterns of cognitive appraisal. A convenience sample was recruited from fitness centres and sport clubs with 308 participants, all males. Losing muscular mass represented a negative experience for participants, promoting a higher perception of threat appraisal. In addition, losing muscular mass was related to more muscularity-oriented behaviors and disordered eating behavior. Cognitive appraisal mediates the relation between DFM and disordered eating behavior. The results highlight the role of cognitive appraisal in DFM and disordered eating behavior in males in sport contexts.

Key words

  • mediation
  • sport
  • losing muscular mass
Accesso libero

Handball Goalkeeper Intuitive Decision-Making: A Naturalistic Case Study

Pubblicato online: 30 Nov 2019
Pagine: 297 - 308

Astratto

Abstract

Goalkeepers hold a key position for success in team sports competitions. They perform in dynamical contexts and are highly submitted to time pressure. The purpose of this naturalistic case study, therefore, was to explore how a handball expert goalkeeper deals with the uncertainty of the competition settings to make successful decisions. An individual self-confrontation interview was held with a goalkeeper while he watched duels with potential throwers in an official competition. A mixed method was used combining the first-person and third-person point of view. Verbal data were supplemented by observational data (distance measures between the goalkeeper and the potential thrower) in 83 short accounts of decision-making situations. Qualitative analysis resulted in 419 units of salient features, in three types of processes related to the Recognition-Primed Decision model, and in four micro-decisions. Non-parametrical statistical analysis indicated that there was a significant effect of distances between the potential thrower and the goalkeeper, on the micro-decision categories, but not on the recognition processes. These results provide insights into cognitive contents and processes an expert goalkeeper can use under uncertainty and time pressure. The mixed method furnishes a meaningful description and a subsequent understanding of expert performances in sport.

Key words

  • recognition processes
  • goalkeeping performance
  • elite
  • team sport
  • competition

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