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Aquatic Sports and Activities

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Zeitschriftendaten
Format
Zeitschrift
eISSN
1899-7562
Erstveröffentlichung
13 Jan 2009
Erscheinungsweise
5 Hefte pro Jahr
Sprachen
Englisch

Suche

Volumen 82 (2022): Heft 1 (April 2022)

Zeitschriftendaten
Format
Zeitschrift
eISSN
1899-7562
Erstveröffentlichung
13 Jan 2009
Erscheinungsweise
5 Hefte pro Jahr
Sprachen
Englisch

Suche

25 Artikel

Section I - Kinesiology

Uneingeschränkter Zugang

Inter-Limb Muscle Property Differences in Junior Tennis Players

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 5 - 15

Zusammenfassung

Abstract

The goal of this study was to investigate side-to-side differences and asymmetries regarding muscle characteristics in young tennis players. Thirty-four participants performed contractile property measurements (stiffness, tone, elasticity and time to relaxation) on the dominant and non-dominant extremities including nine muscle groups involved in the kinetic chain of main tennis strokes. Significant differences (p≤0.05) and small-to-moderate effect sizes for greater stiffness and tone were found for the dominant biceps femoris (-11.1% and -5.6%; ES=0.53 and 0.54) and the non-dominant vastus medialis (5.4% and 3.2%; ES=-0.33 and -0.41), while greater tone was present in the non-dominant pectoralis major (4.0%; ES=-0.56). Time to relaxation was increased in the dominant biceps femoris (10.3%; ES=-0.58), the non-dominant pectoralis major (5.1%; ES=-0.56) and the gastrocnemius (9.1%; ES=-0.5). The non-dominant infraspinatus and dominant rectus abdominis showed greater elasticity than contralateral muscles (9.9% and -8.0%; ES=-0.58 and 0.6, respectively). These results reflect the existence of small-to-moderate differences when comparing side-to-side values of contractile characteristics in a small amount of the muscle groups tested. However, passive measurements of a relaxed muscle do not seem to fully reflect possible adaptation and changes derived from gameplay in young tennis players.

Key words

  • asymmetries
  • stiffness
  • tone
  • elasticity
  • relaxation
Uneingeschränkter Zugang

The Pre-Exhaustion Method Does Not Increase Muscle Activity in Target Muscle During Strength Training in Untrained Individuals

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 17 - 26

Zusammenfassung

Abstract

This study investigated the effects of the pre-exhaustion method on electromyographic activity (root mean square and median frequency) at different interval sets. Twenty adults with little or no experience in strength training performed the seated row exercise until muscular failure, with or without completing a previous pre-exhaustion set in a pullover exercise. Surface electrodes were placed over the latissimus dorsi, teres major, biceps brachii, and posterior deltoid muscles of the dominant side. The results showed no effect of pre-exhaustion on EMG activity of latissimus dorsi target muscle for any interval sets. Regarding median frequency, our results showed a consistent decrease throughout the sets (p>0.05). Also, our results revealed a decrease in posterior deltoid median frequency with pre-exhaustion (p=0.001). We conclude that the pre-exhaustion method seems ineffective in increasing the EMG activity of the desired muscle throughout all repetitions of strength training. Furthermore, pre-exhaustion seems to be a good way to increase fatigue in the posterior deltoid muscle.

Key words

  • resistance training
  • muscle activation
  • muscle recruitment
  • exercise order
  • pre-activation
Uneingeschränkter Zugang

Neuromuscular Impact of Acute Hypertrophic Resistance Loading With and Without Blood-Flow Restriction

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 27 - 37

Zusammenfassung

Abstract

Exploring acute neuromuscular fatigue induced by different modalities of resistance exercise would help understand the adaptation subsequent to specific training programs. Therefore, we investigated the acute impact of high-intensity and low-intensity blood flow-restricted resistance exercise on the development of explosive torque throughout the torque-time curve. Seventeen healthy, young participants were included in a randomized, counterbalanced within-subjects design study, in which participants underwent two experimental conditions, separated by a 1-wk period. Low-intensity blood-flow restricted exercise and high-intensity resistance exercise were performed using dynamic elbow flexion at 20 and 75% of 1 repetition maximum, respectively. Maximal voluntary contraction (MVC) and the sequential rate of torque development (absolute and relative) were measured before and after exercise. Both protocols elicited a similar decrement in MVC (~ 25%) and in the peak rate of torque development after exercise (~ 45%). The absolute rate of torque development (0-50 and 50-100 ms) was also reduced (p<0.05) similarly between conditions. After normalizing torque values to MVC, this was only sustained for the rate of torque development 0-50ms (p<0.05). We found that both exercise protocols induced similar acute attenuation of the absolute rate of torque development up to the first 100 ms of MVC. We also demonstrated that the reduction in the rate of torque development between 50-100ms (in both protocols) was largely explained by an acute deficit in muscle strength post-exercise. Conversely, the impact of each protocol on the first 50ms of muscle torque did not depend on lower levels of muscle strength after exercise.

Key words

  • strength
  • fatigue
  • physiology
  • weightlifting
  • exercise
Uneingeschränkter Zugang

A Study Comparing Gait and Lower Limb Muscle Activity During Aquatic Treadmill Running With Different Water Depth and Land Treadmill Running

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 39 - 50

Zusammenfassung

Abstract

Aquatic treadmill running is a partial weight-bearing exercise for rehabilitation. The purpose of this study was to investigate the surface electromyography activities of the rectus femoris, tibialis anterior, biceps femoris and medial head of gastrocnemius, and gait kinematics during aquatic treadmill running in water levels at waist, mid-thigh and mid-shin and on land. Seventeen healthy subjects (9 males and 8 females) were recruited by convenience sampling. Participants performed 2-min aquatic treadmill running at a specific speed for each water depth. The test speed was selected based upon the speed that elicited 110 steps per min. The surface electromyography data of lower limb muscles and the joint angles at three different water depths and on land were collected to evaluate the muscle activity and gait kinematics using a waterproofed surface electromyography system and inertial measurement unit for each muscle. Results showed that rectus femoris electromyography was different between depths during the swing and stance phases. Likewise, biceps femoris and tibialis anterior electromyography were different between depths for the swing phase. However, it was not the case for gastrocnemius electromyography. Peak flexion angles in both left and right hips were different between depths. A significant increase in a stance/swing ratio was observed with rising water depths. Water depth influenced muscle activity as well as kinematics. Aquatic treadmill running in the mid-thigh level should be further evaluated for its effectiveness, training value and applicability.

Key words

  • aquatic treadmill running
  • muscle activity
  • motion analysis
  • electromyography
Uneingeschränkter Zugang

Validity and Reliability of the Smart Groin Trainer for Measuring Hip Adduction Strength

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 51 - 59

Zusammenfassung

Abstract

We analyzed the Smart Groin Trainer device's validity and reliability to measure the isometric hip adduction strength during the adductor squeeze strength test. Fifteen professional soccer players (25.33±4.06 years) and fifteen university students (21.60±1.76 years) participated in this study. All participants performed the squeeze strength test using two portable dynamometers: Smart Groin Trainer and Globus Ergometer. Three maximal isometric hip adduction contractions lasting 5s, interspersed by 3min rest intervals, were performed. Reliability was analyzed with intraclass correlation coefficients, standard error of measurements, and minimal detectable change. The absolute percent error and inter-device accuracy were also analyzed. Correlation analysis assessed the inter-device concurrent validity. The results found no significant differences (p>0.05) between devices in the squeeze strength test values in soccer players and university students. Inter-device comparisons revealed excellent levels of reliability and accuracy in soccer players. Concurrent validity measures revealed strong inter-device relationships in soccer players (r=0.89) and very strong relationships in university students (r=0.99). Intra-device analysis using the Smart Groin Trainer showed excellent relative and absolute reliability in tested soccer players. Our data demonstrated excellent levels of agreement between both dynamometers during the squeeze strength test, suggesting the Smart Groin Trainer as a valid, reliable, and accurate device to measure isometric hip adduction strength.

Key words

  • portable dynamometer
  • squeeze test
  • groin
  • accuracy
  • measurement error

Section II - Exercise Physiology & Sports Medicine

Uneingeschränkter Zugang

Changes in Heart Rate Variability and Post‐Exercise Blood Pressure from Manipulating Rest Intervals Between Sets of Resistance Training

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 61 - 73

Zusammenfassung

Abstract

The purpose of this study was to compare blood pressure and heart rate variability responses in physically active men after performing resistance training sessions with rest intervals of 1 min, 2 min and 3 min. Eighteen men (age, 21.6±1.1 years; body mass, 74.1±8.1 kg; body height, 175.3±7.1 cm) who performed 180min of physical activity per week participated in this study. After determining the 15RM loads for the squat, bench press, bent-over row and deadlift, participants performed a resistance training session. Participants performed three resistance training protocols in randomized counterbalanced order. Each experimental protocol comprised different rest intervals between sets of resistance training exercises (1min, 2min or 3min). During each experimental session, participants performed three sets with a 15RM load. Blood pressure and heart rate variability were measured before and for 2h after each session. The results demonstrated a greater blood pressure (p<0.05) reduction with a longer rest interval. There was no statistically significant difference in heart rate variability changes between groups. These results indicate that 2min and 3min rest intervals while using a 15RM load provide the best stimulus for a blood pressure reduction response after a resistance training session. Our findings suggest that strength and conditioning professionals should prescribe 2min or 3min rest intervals when resistance training is performed with a 15RM load if the aim is to obtain an acute reduction in blood pressure after a resistance training session.

Key words

  • systolic pressure
  • diastolic pressure
  • autonomic nervous systems
Uneingeschränkter Zugang

Evidence‐Based Recovery in Soccer – Low‐Effort Approaches for Practitioners

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 75 - 99

Zusammenfassung

Abstract

Strategies to improve recovery are widely used among soccer players at both amateur and professional levels. Sometimes, however, recovery strategies are ineffective, improperly timed or even harmful to players. This highlights the need to educate practitioners and athletes about the scientific evidence of recovery strategies as well as to provide practical approaches to address this issue. Therefore, recent surveys among soccer athletes and practitioners were reviewed to identify the recovery modalities currently in use. Each strategy was then outlined with its rationale, its physiological mechanisms and the scientific evidence followed by practical approaches to implement the modality. For each intervention, practical and particularly low-effort strategies are provided to ensure that practitioners at all levels are able to implement them. We identified numerous interventions regularly used in soccer, i.e., sleep, rehydration, nutrition, psychological recovery, active recovery, foam-rolling/massage, stretching, cold-water immersion, and compression garments. Nutrition and rehydration were classified with the best evidence, while cold-water immersion, compression garments, foam-rolling/massage and sleep were rated with moderate evidence to enhance recovery. The remaining strategies (active recovery, psychological recovery, stretching) should be applied on an individual basis due to weak evidence observed. Finally, a guide is provided, helping practitioners to decide which intervention to implement. Here, practitioners should rely on the evidence, but also on their own experience and preference of the players.

Key words

  • football
  • performance
  • practical interventions
  • intermittent exercise
  • strength and conditioning
Uneingeschränkter Zugang

Prevalence of Dehydration and the Relationship with Fluid Intake and Self‐Assessment of Hydration Status in Czech First League Soccer Players

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 101 - 110

Zusammenfassung

Abstract

The objective of this cross-sectional study was to evaluate the hydration status of Czech First League soccer players, and to compare the reported fluid intake, perceived fluid intake and thirst sensation of euhydrated (EU) and dehydrated (DE) players. The study involved 124 Czech male professional soccer players (age 25.2±5.0 years) participating in annual winter, pre-season laboratory testing. Hydration status was assessed based on urine specific gravity (USG), euhydration was set at USG≤1.020. Fluid intake and thirst perception were evaluated by a questionnaire. The sample mean for USG was 1.021±0.008, 56% of players were dehydrated. Reported daily fluid intake was significantly (p<0.001, d=0.95, large effect) higher in EU compared to DE players. Daily fluid intake negatively correlated with USG (rS=-0.46, p<0.001, medium effect). The fluid intake perception score was significantly (p=0.005, d=0.54, medium effect) better in EU compared to DE players. Reported intake perception scores negatively correlated with USG (rS=-0.32, p<0.001, medium effect). However, there was no correlation (rS=-0.09, p=0.34, trivial effect) between thirst perception scores and USG. Thirst perception scores were not significantly different between EU and DE players (p=0.35, d=0.18, trivial effect). Our results indicated that self-assessment of both daily fluid intake and perceived fluid intake matched with objective hydration status, while self-assessment of thirst perception was not an appropriate indicator of hydration status in elite soccer players.

Key words

  • dehydration
  • athletes
  • urine specific gravity
  • self-assessment questionnaire
Uneingeschränkter Zugang

Addition of in‐Play Cooling Breaks During Intermittent Exercise while Wearing Lacrosse Uniforms in the Heat Attenuates Increases in Rectal Temperature

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 111 - 121

Zusammenfassung

Abstract

To reduce the risk of heat-related illness, appropriate body cooling strategies are needed during men’s lacrosse competitions in hot-humid environments. The current study investigated whether additional in-play cooling breaks would attenuate the core (rectal) body temperature rise during exercise designed to mimic the activity patterns of a men’s lacrosse match while wearing uniform in hot-humid environments. In randomized and counterbalanced order, ten physically active men completed two experimental trials comprising four quarters of 15-min intermittent cycling exercises separated by a 10-min simulated half-time break and two 2-min quarter breaks in a climate chamber (35°C, 50% relative humidity). The two trials included a regular simulated match condition (REG) and a water break time out condition (WBTO) that included additional 2-min breaks 7.5-min into each quarter. Rectal temperature was significantly lower (p=0.017) in the WBTO condition (38.23±0.23°C) compared with the REG condition (38.50±0.46°C) at the end of the 4th quarter. In addition, ratings of perceived exertion, thermal sensation, heart rate and the physiological strain index were significantly lower (all p<0.05) in the WBTO condition compared with the REG condition. The current results indicated that, even when wearing lacrosse uniforms, the implementation of WBTO attenuated the core body temperature elevation only in the latter stages of an intermittent cycling exercise protocol designed to mimic the exercise pattern of a men’s lacrosse match. Therefore, WBTO may provide a feasible and effective cooling strategy for lacrosse players to reduce the risk of heat-illness.

Key words

  • protective equipment
  • heat-related illness
  • exertional heat stroke
  • cold drink.
Uneingeschränkter Zugang

The Effects of Preferred Music and Its Timing on Performance, Pacing, and Psychophysiological Responses During the 6‐min Test

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 123 - 133

Zusammenfassung

Abstract

The aim of this study was to investigate the effects of listening to preferred music during a warm up or exercise, on performance during a 6-min all-out exercise test (6-MT) in young adult males. Twenty-five healthy males volunteered to participate in this study. Following a within subject design, participants performed three test conditions (MDT: music during the test; MDW: music during the warm-up; WM: without music) in random order. Outcomes included mean running speed over the 6-min test (MRS6), total distance covered (TDC), heart rate responses (HRpeak, HRmean), blood lactate (3-min after the test), and the rating of perceived exertion (RPE); additionally, feeling scale scores were recorded. Listening to preferred music during running resulted in significant TDC (Δ↑10%, p=0.006, ES=0.80) and MRS6 (Δ↑14%, p=0.012, ES=1.02) improvement during the 6-MT, improvement was also noted for the warm-up with music condition (TDC:Δ↑8%, p=0.028, ES=0.63; MRS6:Δ↑8%, p=0.032, ES=0.61). A similar reverse “J-shaped” pacing profile was detected during the three conditions. Blood lactate was lower in the MDT condition by 8% (p=0.01, ES=1.10), but not the MDW condition, compared to MW. In addition, no statistically significant differences were found between the test sessions for the HR, RPE, and feeling scale scores. In conclusion, listening to music during exercise testing would be more beneficial for optimal TDC and MRS6 performances compared to MDW and WM.

Key words

  • rating of perceived exertion
  • work-rate distribution
  • blood lactate
  • aerobic exercise

Section III - Sports Training

Uneingeschränkter Zugang

Influence of Tactical Behaviour on Running Performance in the Three Most Successful Soccer Teams During the Competitive Season of the Spanish First Division

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 135 - 144

Zusammenfassung

Abstract

The purpose of this study was to analyze the influence of tactical behavior on physical performance of the three best Spanish soccer teams. Team 1 employed a 1-4-4-2 formation with compact defence and direct attacks, Team 2 employed an indirect style of play with a 1-4-3-3 formation and Team 3 used a 1-4-3-3 formation with elaborate attacks and strong counter-attacks. 816 individual situations of 54 professional soccer players categorized as fullbacks (FB), central defenders (CD), central midfielders (MF), wide midfielders (WM), and strikers (S) were included in the analysis. Their performance was examined with a player-tracking system. The analyzed variables included total distance covered, distance covered above 14, 21 and 24 km·h-1, as well as distance covered in possession of the ball and without possession of the ball. Team 2 covered a substantially lower distance >14 km·h–1 than Team 1 and substantially lower distances >14, >21, and >25km·h–1 than Team 3. No differences in running activity were found between Teams 1 and 3. However, there were substantial differences between the specific positions of the three teams. CD in Team 1 covered the lowest distance by a substantial margin in almost all variables analysed, whereas MF travelled substantially greater distances than did other positions. WM in Team 1 covered the greatest distance >18 and >21km·h– 1, while S in Team 2 had the lowest distance covered in almost all the variables, and FB in Team 3 showed the lowest total distance covered and distance covered >14km·h–1. WM in Team 2 had the greatest distance covered in possession, while S in Team 3 had the greatest distance covered out of possession. The results indicate that different team formations and associated tactical demands have a significant influence on running performance.

Key words

  • time-motion
  • soccer
  • match-analysis
  • training
  • physical demands
Uneingeschränkter Zugang

Effects of Postactivation Performance Enhancement on the Vertical Jump in High-Level Volleyball Athletes

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 145 - 153

Zusammenfassung

Abstract

The objective of this study was to evaluate the effects of a training session with and without an intervention of postactivation performance enhancement (PAPE) on countermovement jump (CMJ) height, perceived recovery status (PRS), and ratings of perceived exertion (RPEs), followed by a specific volleyball training session. The sample consisted of sixteen professional male volleyball players, with an average age of 26.8±6.1 years and average height of 195.9±6.7 cm, randomly divided into a group with PAPE intervention (GPAPE) (n=8), and a control group (CTRL) without PAPE intervention (n=8). The control group carried out the training session with plyometric exercises, and the GPAPE added conditioning protocols for PAPE to plyometric training, followed by a technical tactical volleyball session. At the end of the training session, there was an increase of 16.3% in the height of the CMJ in the GPAPE, while the CTRL showed a decrease of 5% in the height of the CMJ. PRS and RPE variables did not differ between the groups. It was concluded that PAPE had a positive effect on the height of the vertical jump after plyometric training, which was maintained until the end of the technical and tactical volleyball session.

Key words

  • team sports
  • countermovement jump
  • performance
  • plyometrics
  • postactivation performance enhancement
Uneingeschränkter Zugang

On-Court Change of Direction Test: An Effective Approach to Assess COD Performance in Badminton Players

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 155 - 164

Zusammenfassung

Abstract

The aim of this research was to assess the reliability of a specific change of direction test (i.e., “On-Court COD test”) in youth badminton players, evaluate the effect of age on On-Court COD performance, and examine its correlations with linear speed, change of direction speed, and vertical jump tests. Forty-two young badminton players (27 males and 15 females; age: 17.3±1.6 years, body height: 170.3±7.5 cm, body mass: 59.0±9.7 kg) were divided into two age groups (Under 17 years and under 19 years). Tests included: linear sprints (5, 10, and 20-m), bilateral/unilateral countermovement jumps, a hexagon test, traditional and modified 505 change of direction tests; and On-court COD. Results showed an excellent intraclass correlation coefficient score (0.90) and a very low coefficient of variation values (1.6%) for the On-Court COD test. Comparing age groups, under 19 players were significantly faster in linear sprints (i.e., 5, 15 and 20-m; small to moderate effect sizes) and in all change of direction tests (moderate to large effect sizes). Moreover, the On-Court COD test showed moderate to large (r=.513-.779) relationships with both acceleration and COD abilities in under 17 players, and with linear sprints, COD, and jump performances in under 19 players. These data indicate that the On-Court COD test is a useful and reliable means to assess COD performance in youth badminton players and it is associated with acceleration, sprint and jump performance.

Key words

  • racket sports
  • specific movement
  • neuromuscular performance
  • testing
Uneingeschränkter Zugang

The Creation of Goal-Scoring Opportunities at the 2019 FIFA Women’s World Cup

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 165 - 172

Zusammenfassung

Abstract

The aim of this study was to analyse how goal-scoring opportunities (GSOs) were created at the 2019 FIFA Women’s World Cup. The sample consisted of 868 GSOs that led to a shot at the goal throughout all 52 games during the tournament. All games were downloaded from the InStat platform. Descriptive statistics, chi-square of association and binary logistic regression analysis were used to analyse the data. Of the 868 GSOs, 81 (9.1%) resulted in goals. A significant association was observed between GSOs and the type of attack (χ2=6.38, p=0.01, V=0.09), with more goals being scored from a counter-attack (12.7%) than an organised attack (7.5%). Counter-attacks recorded a higher odds ratio in univariate analysis (OR=0.56; 95%CI:0.35–0.88; p=0.01) than in multivariate analysis (OR=0.46; 95%CI:0.28–0.76; p=0.002). The multivariate analysis further indicated a significant probability of scoring when ball possession started in the middle third of the field (OR=0.19; 95%CI:0.44–0.88; p= 0.01). The current study has practical implications for soccer coaches to develop and implement training sessions to improve goal-scoring chances of women’s teams at international competitions.

Key words

  • counter-attack
  • organised attack
  • passes
  • attacking
  • defending
Uneingeschränkter Zugang

Post-Activation Performance Enhancement in Sprinters: Effects of Hard Versus Sand Surfaces

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 173 - 180

Zusammenfassung

Abstract

This study aimed to compare the post-activation performance enhancement induced by successive drop-jumps performed on hard and sand surfaces in sprint and jump performance of top-level sprinters. Athletes were tested on two occasions. On each visit they were allocated to one of the experimental protocols, which consisted of performing 2x5 drop-jumps from a box with the height of 60-cm on hard or sand surfaces in randomized order, seven days apart. Prior to and 7 and 15-min after executing drop-jumps, sprinters performed countermovement jumps and 60-m sprint tests. Differences between sprinting splits and surfaces were assessed using a two-way analysis of variance with repeated measures. No significant differences in jump height or sprint time were observed (p>0.05), regardless of the surface used (i.e., hard or sand) during the conditioning activity (effect sizes [95% confidence intervals] ranging from 0.01 [-0.84;0.84] to 0.44 [-0.42;1.27]). Performing drop-jumps on sand or hard surfaces immediately before maximum sprinting bouts does not provide any advantage or disadvantage to top-level sprinters. Sprint coaches may prescribe short-plyometric training activities on sand surfaces even close to competitions, bearing in mind that this strategy will not compromise sprint-specific performance.

Key words

  • athletic performance
  • plyometrics
  • potentiation
  • track and field
  • muscle strength
Uneingeschränkter Zugang

The Repeated Curve Sprint Test Appears to be an Appropriate Tool for Estimating Anaerobic Fitness in Young Trained Male Futsal Players

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 181 - 189

Zusammenfassung

Abstract

This study aimed to determine the magnitude of correlation between the repeated curve sprint test (RCST), the running-based anaerobic sprint test (RAST) and the Wingate anaerobic test (WAnT) in elite male futsal players to determine whether the field test can be a futsal-specific alternative assessment tool compared to the other tests. Fifteen trained futsal players (20±3 yrs) performed the RCST, RAST and WAnT in a crossover design over three weeks. Peak power (PP), average power (AP) and the fatigue index (FI) were obtained from the tests. Finger-prick blood-lactate measurements were performed before and after the tests, and heart rate loading was recorded. To assess the magnitude and direction of the relationship between variables the Pearson’s correlation coefficient (r) was calculated. In respect of AP, there was a significant correlation between the RCST and both the WAnT (r=0.63, p=0.012) and the RAST (r=0.67, p=0.006). In respect of PP, the RCST only correlated with the RAST (r=0.71, p=0.003). In respect of the FI, the RCST did not correlate with either the RAST or the WAnT (p>0.05). Post-test heart rate values in the RCST correlated with those in both the WAnT (r=0.88, p=0.001) and the RAST (r=0.77, p=0.001). Also, post-test blood-lactate levels in the RCST correlated with those in both the RAST (r=0.58, p=0.025) and the WAnT (r=0.54, p=0.039). In conclusion, the RCST can be a valid and practical field test for measuring anaerobic fitness in competitive futsal players.

Key words

  • anaerobic test
  • fatigue index
  • peak power
  • average power
  • field test
Uneingeschränkter Zugang

Training with a Heavy Puck Elicits a Higher Increase of Shooting Speed Than Unloaded Training in Midget Ice Hockey Players

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 191 - 200

Zusammenfassung

Abstract

A method of load variability is a common way of developing specific skills in various sports, however, not explored considering the use of different ice-hockey pucks. Therefore, the purpose of this study was to compare shooting speed, shooting accuracy, and handgrip strength changes after training with variable training loads (lighter 60g pucks and heavier 260g pucks) in the wrist shot and snapshot. Sixteen male ice hockey players (13.62±0.35y; 167.67±7.71cm; 53.87±7.55kg) were subjected to a 12 week experiment during which they trained six weeks with a light puck and six weeks with a heavy puck and were tested for shooting speed, shooting accuracy and handgrip strength. The variable load training increased shooting speed (the long hand snapshot by 7.4%, the shorthand snapshot by 8.5%, and the wrist shot by 13%), shooting accuracy (by 14%), and handgrip strength (by 8.7%) of the bottom hand; all at p<0.001. Training with heavy pucks was more effective (d=0.50-0.86) than training with lighter pucks (d=23-25) for increasing puck speed. Shooting accuracy was increased by variable load training with a similar effect of heavy and light puck training. The variable training load had a positive effect on shooting speed and accuracy and the use of a heavier load was more effective than using the unloaded puck. Variable load shooting training in youth ice-hockey players is more effective with heavier pucks than lighter ones, and the improvements are greater in players with better shooting skills.

Key words

  • variable load
  • motor learning
  • heavy-weight puck
  • light-weight puck
  • contrast training
Uneingeschränkter Zugang

Accuracy of Predicting One-Repetition Maximum from Submaximal Velocity in the Barbell Back Squat and Bench Press

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 201 - 212

Zusammenfassung

Abstract

This study examined the accuracy of predicting a free-weight back squat and a bench press one-repetition maximum (1RM) using both 2- and 4-point submaximal average concentric velocity (ACV) methods. Seventeen resistance trained men performed a warm-up and a 1RM test on the squat and bench press with ACV assessed on all repetitions. The ACVs during the warm-up closest to 1.0 and 0.5m.s-1 were used in the 2-point linear regression forecast of the 1RM and the ACVs established at loads closest to 20, 50, 70, and 80% of the 1RM were used in the 4-point 1RM prediction. Repeated measures ANOVA and Bland-Altman and Mountain plots were used to analyze agreement between predicted and actual 1RMs. ANOVA indicated significant differences between the predicted and the actual 1RM for both the 2- and 4-point equations in both exercises (p<0.001). The 2-point squat prediction overestimated the 1RM by 29.12±0.07kg and the 4-point squat prediction overestimated the 1RM by 38.53±5.01kg. The bench press 1RM was overestimated by 9.32±4.68kg with the 2-point method and by 7.15±6.66kg using the 4-point method. Bland-Altman and Mountain plots confirmed the ANOVA findings as data were not tightly conformed to the respective zero difference lines and Bland-Altman plots showed wide limits of agreement. These data demonstrate that both 2- and 4-point velocity methods predicted the bench press 1RM more accurately than the squat 1RM. However, a lack of agreement between the predicted and the actual 1RM was observed for both exercises when volitional velocity was used.

Key words

  • resistance training
  • movement
  • performance
  • biomechanics
  • strength testing

Section IV - Behavioural Sciences in Sport & Sport for the Disabled

Uneingeschränkter Zugang

Cognitive Factors in Elite Handball: Do Players’ Positions Determine their Cognitive Processes?

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 213 - 221

Zusammenfassung

Abstract

For an athlete to be successful at the professional level, he or she should be characterized by extraordinary preparation in four areas: physical, technical, cognitive (related to game strategy, perception, and decision-making), and emotional (coping, emotional control). This study aimed to determine the level of selected cognitive traits in handball players while considering their sports level and assigned position on the court. Fifty handball players participated in the study. Participants consisted of 35 national team players, six first-division players, and nine second-division players. There were no significant differences between players from the elite (national team) and the sub-elite (I and II divisions) group. The results identified major differences in selective attention and short-term memory between handball players assigned to different positions (goalkeepers, compared to players in other positions, had lower attention and short-term memory). Thus, it is possible to develop a more effective psychological training program. However, it must be remembered that the results showed great variability among handball players. With this in mind, individual differences should be taken into account when planning psychological interventions.

Key words

  • cognitive skills
  • attention and concentration
  • Vienna test system
  • handball
Uneingeschränkter Zugang

Movement Patterns of Polish National Paralympic Team Wheelchair Fencers with Regard to Muscle Activity and Co-Activation Time

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 223 - 232

Zusammenfassung

Abstract

The aim of this study was to determine muscle co-activation and muscle activity time using EMG in Paralympic wheelchair fencers categorized into two disability-level groups: A (n= 7) and B (n= 9). The study was carried out with the use of a 16-channel EMG system. The surface EMG electrodes were placed on the fencer’s body along nine channels: arm muscles - deltoideus middle head (DEL), triceps brachii (TRI) and biceps brachii (BC); forearm muscles - extensor carpi radialis longus (ECR), flexor carpi radialis (FCR); postural (abdominal and back) muscles - the right and the left external oblique abdominal (EOA RT and LT) and latissimus dorsi (LD RT and LT). To assess the relative level of co-activation (simultaneous contraction of both muscles) for the TRI-BC, ECR-FCR, LD RT-EDA RT and LD LT-EDA LT muscle pairs, the co-activation index (CI) was calculated. The collected data were processed using Jamovi. The study hypotheses were verified at the level of significance of p≤0.05 (Welch’s t-test). The normal distribution of analyzed statistical features was checked with the Shapiro-Wilk test. The analysis of muscle activation time, as a percent ratio of three attempts executed in a series, confirmed the study assumptions. Fencers from Group A had a shorter activation time in all tested muscles, with the exception of the ECR (58.24), than fencers from Group B. This confirms that the activation of antagonist muscles representing a centrally programmed anticipatory mechanism stabilizing technical actions was particularly intensified in Group A fencers. The study results indicate that the standard co-activation index (CI) of key muscles involved in wheelchair fencing ranges from 48 to 51%.

Key words

  • wheelchair fencing
  • EMG muscle co-activation
  • movement pattern
  • antagonist muscle group
  • muscle activation time
Uneingeschränkter Zugang

Handcycling Training in Men with Spinal Cord Injury Increases Tolerance to High Intensity Exercise

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 233 - 241

Zusammenfassung

Abstract

Individuals with spinal cord injury are characterised by reduced physical capacity as compared to able-bodied persons, and are at risk of developing cardiovascular disease. The study aimed to evaluate the differences in physiological responses to an exercise test in handcycling-trained vs. able-bodied-trained and non-trained men. Eight males with spinal cord injury who were trained in handcycling, eighteen able-bodied males who were trained in powerlifting, and fourteen physically active non-athletes performed a graded arm crank ergometer test. The following physiological indices were measured before and during the test: heart rate, oxygen uptake, and blood lactate concentrations. Aerobic capacity was significantly higher in athletes with spinal cord injury compared to able-bodied athletes (p<0.01) and the control group (p<0.01). The heart rate achieved by handcycling-trained athletes was significantly lower as compared to powerlifters (p<0.01), however, the oxygen pulse was significantly higher (p<0.05). Handcycling-trained athletes reached significantly higher peak power (Pmax) during the graded arm exercise in comparison with powerlifters, and significantly higher post exercise blood lactate concentration (p<0.05). The lactate threshold was observed at a significantly higher P in individuals with spinal cord injury compared to able-bodied-trained (p<0.05) and non-trained men (p<0.001). Athletes with spinal cord injury were found to have excellent aerobic capacity and better physiological adaptation to the maximal graded exercise test as compared to able-bodied-trained men. These findings emphasize the importance of regular physical exercise and its potential therapeutic role in the prevention of cardiovascular disease in patients with spinal cord injury.

Key words

  • aerobic capacity
  • disabilities
  • physique enhancement
  • paraplegic endurance athletes
Uneingeschränkter Zugang

Anaerobic Variables as Specific Determinants of Functional Classification in Wheelchair Basketball

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 243 - 252

Zusammenfassung

Abstract

Every parasport is currently encouraged to consider evidence-based classification to develop their respective classification system. Therefore, the aims of this study were to: (1) assess the relationship between trunk function and anaerobic power determining proficiency in wheelchair basketball, and (2) define “natural classes” in wheelchair basketball based on anaerobic power. Fifty-nine elite players (representing five national teams) were divided into four main functional classes: Group 1 (n=17), Group 2 (n=14), Group 3 (n=16), Group 4 (n=12). They performed the 6x10s Anaerobic Power Test using an arm crank ergometer. Average values of mean power, peak power, relative mean power, relative peak power, and power decrement were calculated for the 6x10s and 3x10s tests. The Spearman’s correlation matrix revealed significant correlations between classes and values recorded in the 6x10s test. This confirmation between anaerobic power and players’ classification endorses the division of players into different classes. Furthermore, cluster analysis (with fair quality) divided players into two “natural classes”. The first resulting class was mainly formed of participants from Group 1 (71%). An important complement to this research could be to consider wheelchair acceleration and the volume of trunk action in wheelchair basketball classification.

Key words

  • evidence-based classification
  • cluster
  • paralympics
Uneingeschränkter Zugang

Assessing the Sprint Force-Velocity Profile in International Football Players with Cerebral Palsy: Validity, Reliability and Sport Class’ Profiles

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 253 - 262

Zusammenfassung

Abstract

This study assessed and described the Sprint Force-velocity (SFv) profile, and its validity and reliability in international cerebral palsy (CP) football players. Twenty international male CP football players (age: 26.9±7.4) performed a 30-m sprint, a vertical jump (CMJ), a change of direction (MAT), a dribbling and an intermittent endurance (Yo-YoIR1) test. The SFv profile and physical performance variables were shown according to the players’ sport class with the estimation of the effect sizes between classes. The SFv showed high reliability (ICC=0.77 to 0.99; SEM=0.89 to 8.66%). Validity for the SFv was provided by its positive correlation with the players’ sport class (r=0.53 to 0.75; p=.02 to <.01) and the rest of the physical performance tests (r=0.45 to 0.99; p=.04 to <.01). The RFmax was the main SFv profile variable that explained players’ performance in the rest of the tests (β=0.77 to 1.0; p<.05; R2=0.59 to 0.99). The SFv profile seems to be an efficient test to assess international CP football players’ physical performance. This provides information about the players’ individual sprint mechanical characteristics and their sprint strengths and weaknesses, allowing coaches and conditioning trainers to individualize their training interventions to optimize sprint performance.

Key words

  • CP football
  • para-sports
  • physical performance
  • disability
Uneingeschränkter Zugang

The Importance of Posture And Body Composition for the Stability and Selected Motor Abilities of Professional Handball Players

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 264 - 273

Zusammenfassung

Abstract

The aim of the research was to analyze body composition, body posture and postural stability of professional male handball players and to determine the differences between players with correct and incorrect body posture, considering power of the lower limbs and agility, speed, and change of direction deficit. The study comprised 16 professional handball players. Body composition analysis was performed using the method of electrical bioimpedance. Body posture was examined using the Diers formetric III 4D optoelectronic method. Postural stability was tested via the Biodex Balance System. Players performed the following fitness tests assessing lower limb muscle power (LP, HS, CMJ), linear speed (SLS 20 m), and COD speed (Zig-Zag test, COD deficit). Only 31.25% of players demonstrated body posture with correct physiological curvatures, while 68.75% showed changes in body asymmetry. The group with correct body posture performed better in SLS 20m than the group with incorrect posture, yet in the Zig-Zag agility test, the difference in the results was not significant and this affected the COD deficit, which was higher. The vast majority of participants demonstrated postural defects and incorrect physiological curvatures of the spine. The occurrence of scoliotic posture was also observed. The body deflection angles indicated that athletes’ postural stability was good. However, it is worth noting that the majority demonstrated a tendency towards asymmetrical body deflections to the right or to the left, backwards direction. One-sided sports specialization leads to disturbances in the statics of the body, therefore, it becomes necessary to include postural re-education exercises in training.

Key words

  • body composition
  • body posture
  • postural stability
  • handball players
Uneingeschränkter Zugang

Hand Grip Strength vs. Locomotor Efficiency in Sitting Volleyball Players

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 275 - 282

Zusammenfassung

Abstract

The objective of this paper was to determine the relationship between hand grip strength and movement time (locomotor efficiency in a seated position using the upper and lower extremities) in sitting volleyball players. In addition, a comparison was made between the velocity curves for forward and backward locomotion. Nine male members of the sitting volleyball team participated in the study. Hydraulic and spring manual dynamometers were used to measure hand grip strength. Movement times were registered for distances of 1, 2, 3, 4, 5, 6 and 10-m with the use of the Smart Speed System photocells. Significant relationships between hand grip strength of the left (rs=-0.78) and right (rs=-0.73) hands and the forward movement time over a distance of 1-m were found. Hand grip strength had no significant relationship with either forward movement times at other distances or backward movement times. Results suggest that hand strength is linked to locomotor efficiency of sitting volleyball players. High hand grip strength makes the start easier by pushing away from the ground with the upper limbs.

Key words

  • disabled athletes
  • locomotor efficiency
  • motor abilities
  • sitting volleyball
25 Artikel

Section I - Kinesiology

Uneingeschränkter Zugang

Inter-Limb Muscle Property Differences in Junior Tennis Players

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 5 - 15

Zusammenfassung

Abstract

The goal of this study was to investigate side-to-side differences and asymmetries regarding muscle characteristics in young tennis players. Thirty-four participants performed contractile property measurements (stiffness, tone, elasticity and time to relaxation) on the dominant and non-dominant extremities including nine muscle groups involved in the kinetic chain of main tennis strokes. Significant differences (p≤0.05) and small-to-moderate effect sizes for greater stiffness and tone were found for the dominant biceps femoris (-11.1% and -5.6%; ES=0.53 and 0.54) and the non-dominant vastus medialis (5.4% and 3.2%; ES=-0.33 and -0.41), while greater tone was present in the non-dominant pectoralis major (4.0%; ES=-0.56). Time to relaxation was increased in the dominant biceps femoris (10.3%; ES=-0.58), the non-dominant pectoralis major (5.1%; ES=-0.56) and the gastrocnemius (9.1%; ES=-0.5). The non-dominant infraspinatus and dominant rectus abdominis showed greater elasticity than contralateral muscles (9.9% and -8.0%; ES=-0.58 and 0.6, respectively). These results reflect the existence of small-to-moderate differences when comparing side-to-side values of contractile characteristics in a small amount of the muscle groups tested. However, passive measurements of a relaxed muscle do not seem to fully reflect possible adaptation and changes derived from gameplay in young tennis players.

Key words

  • asymmetries
  • stiffness
  • tone
  • elasticity
  • relaxation
Uneingeschränkter Zugang

The Pre-Exhaustion Method Does Not Increase Muscle Activity in Target Muscle During Strength Training in Untrained Individuals

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 17 - 26

Zusammenfassung

Abstract

This study investigated the effects of the pre-exhaustion method on electromyographic activity (root mean square and median frequency) at different interval sets. Twenty adults with little or no experience in strength training performed the seated row exercise until muscular failure, with or without completing a previous pre-exhaustion set in a pullover exercise. Surface electrodes were placed over the latissimus dorsi, teres major, biceps brachii, and posterior deltoid muscles of the dominant side. The results showed no effect of pre-exhaustion on EMG activity of latissimus dorsi target muscle for any interval sets. Regarding median frequency, our results showed a consistent decrease throughout the sets (p>0.05). Also, our results revealed a decrease in posterior deltoid median frequency with pre-exhaustion (p=0.001). We conclude that the pre-exhaustion method seems ineffective in increasing the EMG activity of the desired muscle throughout all repetitions of strength training. Furthermore, pre-exhaustion seems to be a good way to increase fatigue in the posterior deltoid muscle.

Key words

  • resistance training
  • muscle activation
  • muscle recruitment
  • exercise order
  • pre-activation
Uneingeschränkter Zugang

Neuromuscular Impact of Acute Hypertrophic Resistance Loading With and Without Blood-Flow Restriction

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 27 - 37

Zusammenfassung

Abstract

Exploring acute neuromuscular fatigue induced by different modalities of resistance exercise would help understand the adaptation subsequent to specific training programs. Therefore, we investigated the acute impact of high-intensity and low-intensity blood flow-restricted resistance exercise on the development of explosive torque throughout the torque-time curve. Seventeen healthy, young participants were included in a randomized, counterbalanced within-subjects design study, in which participants underwent two experimental conditions, separated by a 1-wk period. Low-intensity blood-flow restricted exercise and high-intensity resistance exercise were performed using dynamic elbow flexion at 20 and 75% of 1 repetition maximum, respectively. Maximal voluntary contraction (MVC) and the sequential rate of torque development (absolute and relative) were measured before and after exercise. Both protocols elicited a similar decrement in MVC (~ 25%) and in the peak rate of torque development after exercise (~ 45%). The absolute rate of torque development (0-50 and 50-100 ms) was also reduced (p<0.05) similarly between conditions. After normalizing torque values to MVC, this was only sustained for the rate of torque development 0-50ms (p<0.05). We found that both exercise protocols induced similar acute attenuation of the absolute rate of torque development up to the first 100 ms of MVC. We also demonstrated that the reduction in the rate of torque development between 50-100ms (in both protocols) was largely explained by an acute deficit in muscle strength post-exercise. Conversely, the impact of each protocol on the first 50ms of muscle torque did not depend on lower levels of muscle strength after exercise.

Key words

  • strength
  • fatigue
  • physiology
  • weightlifting
  • exercise
Uneingeschränkter Zugang

A Study Comparing Gait and Lower Limb Muscle Activity During Aquatic Treadmill Running With Different Water Depth and Land Treadmill Running

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 39 - 50

Zusammenfassung

Abstract

Aquatic treadmill running is a partial weight-bearing exercise for rehabilitation. The purpose of this study was to investigate the surface electromyography activities of the rectus femoris, tibialis anterior, biceps femoris and medial head of gastrocnemius, and gait kinematics during aquatic treadmill running in water levels at waist, mid-thigh and mid-shin and on land. Seventeen healthy subjects (9 males and 8 females) were recruited by convenience sampling. Participants performed 2-min aquatic treadmill running at a specific speed for each water depth. The test speed was selected based upon the speed that elicited 110 steps per min. The surface electromyography data of lower limb muscles and the joint angles at three different water depths and on land were collected to evaluate the muscle activity and gait kinematics using a waterproofed surface electromyography system and inertial measurement unit for each muscle. Results showed that rectus femoris electromyography was different between depths during the swing and stance phases. Likewise, biceps femoris and tibialis anterior electromyography were different between depths for the swing phase. However, it was not the case for gastrocnemius electromyography. Peak flexion angles in both left and right hips were different between depths. A significant increase in a stance/swing ratio was observed with rising water depths. Water depth influenced muscle activity as well as kinematics. Aquatic treadmill running in the mid-thigh level should be further evaluated for its effectiveness, training value and applicability.

Key words

  • aquatic treadmill running
  • muscle activity
  • motion analysis
  • electromyography
Uneingeschränkter Zugang

Validity and Reliability of the Smart Groin Trainer for Measuring Hip Adduction Strength

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 51 - 59

Zusammenfassung

Abstract

We analyzed the Smart Groin Trainer device's validity and reliability to measure the isometric hip adduction strength during the adductor squeeze strength test. Fifteen professional soccer players (25.33±4.06 years) and fifteen university students (21.60±1.76 years) participated in this study. All participants performed the squeeze strength test using two portable dynamometers: Smart Groin Trainer and Globus Ergometer. Three maximal isometric hip adduction contractions lasting 5s, interspersed by 3min rest intervals, were performed. Reliability was analyzed with intraclass correlation coefficients, standard error of measurements, and minimal detectable change. The absolute percent error and inter-device accuracy were also analyzed. Correlation analysis assessed the inter-device concurrent validity. The results found no significant differences (p>0.05) between devices in the squeeze strength test values in soccer players and university students. Inter-device comparisons revealed excellent levels of reliability and accuracy in soccer players. Concurrent validity measures revealed strong inter-device relationships in soccer players (r=0.89) and very strong relationships in university students (r=0.99). Intra-device analysis using the Smart Groin Trainer showed excellent relative and absolute reliability in tested soccer players. Our data demonstrated excellent levels of agreement between both dynamometers during the squeeze strength test, suggesting the Smart Groin Trainer as a valid, reliable, and accurate device to measure isometric hip adduction strength.

Key words

  • portable dynamometer
  • squeeze test
  • groin
  • accuracy
  • measurement error

Section II - Exercise Physiology & Sports Medicine

Uneingeschränkter Zugang

Changes in Heart Rate Variability and Post‐Exercise Blood Pressure from Manipulating Rest Intervals Between Sets of Resistance Training

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 61 - 73

Zusammenfassung

Abstract

The purpose of this study was to compare blood pressure and heart rate variability responses in physically active men after performing resistance training sessions with rest intervals of 1 min, 2 min and 3 min. Eighteen men (age, 21.6±1.1 years; body mass, 74.1±8.1 kg; body height, 175.3±7.1 cm) who performed 180min of physical activity per week participated in this study. After determining the 15RM loads for the squat, bench press, bent-over row and deadlift, participants performed a resistance training session. Participants performed three resistance training protocols in randomized counterbalanced order. Each experimental protocol comprised different rest intervals between sets of resistance training exercises (1min, 2min or 3min). During each experimental session, participants performed three sets with a 15RM load. Blood pressure and heart rate variability were measured before and for 2h after each session. The results demonstrated a greater blood pressure (p<0.05) reduction with a longer rest interval. There was no statistically significant difference in heart rate variability changes between groups. These results indicate that 2min and 3min rest intervals while using a 15RM load provide the best stimulus for a blood pressure reduction response after a resistance training session. Our findings suggest that strength and conditioning professionals should prescribe 2min or 3min rest intervals when resistance training is performed with a 15RM load if the aim is to obtain an acute reduction in blood pressure after a resistance training session.

Key words

  • systolic pressure
  • diastolic pressure
  • autonomic nervous systems
Uneingeschränkter Zugang

Evidence‐Based Recovery in Soccer – Low‐Effort Approaches for Practitioners

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 75 - 99

Zusammenfassung

Abstract

Strategies to improve recovery are widely used among soccer players at both amateur and professional levels. Sometimes, however, recovery strategies are ineffective, improperly timed or even harmful to players. This highlights the need to educate practitioners and athletes about the scientific evidence of recovery strategies as well as to provide practical approaches to address this issue. Therefore, recent surveys among soccer athletes and practitioners were reviewed to identify the recovery modalities currently in use. Each strategy was then outlined with its rationale, its physiological mechanisms and the scientific evidence followed by practical approaches to implement the modality. For each intervention, practical and particularly low-effort strategies are provided to ensure that practitioners at all levels are able to implement them. We identified numerous interventions regularly used in soccer, i.e., sleep, rehydration, nutrition, psychological recovery, active recovery, foam-rolling/massage, stretching, cold-water immersion, and compression garments. Nutrition and rehydration were classified with the best evidence, while cold-water immersion, compression garments, foam-rolling/massage and sleep were rated with moderate evidence to enhance recovery. The remaining strategies (active recovery, psychological recovery, stretching) should be applied on an individual basis due to weak evidence observed. Finally, a guide is provided, helping practitioners to decide which intervention to implement. Here, practitioners should rely on the evidence, but also on their own experience and preference of the players.

Key words

  • football
  • performance
  • practical interventions
  • intermittent exercise
  • strength and conditioning
Uneingeschränkter Zugang

Prevalence of Dehydration and the Relationship with Fluid Intake and Self‐Assessment of Hydration Status in Czech First League Soccer Players

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 101 - 110

Zusammenfassung

Abstract

The objective of this cross-sectional study was to evaluate the hydration status of Czech First League soccer players, and to compare the reported fluid intake, perceived fluid intake and thirst sensation of euhydrated (EU) and dehydrated (DE) players. The study involved 124 Czech male professional soccer players (age 25.2±5.0 years) participating in annual winter, pre-season laboratory testing. Hydration status was assessed based on urine specific gravity (USG), euhydration was set at USG≤1.020. Fluid intake and thirst perception were evaluated by a questionnaire. The sample mean for USG was 1.021±0.008, 56% of players were dehydrated. Reported daily fluid intake was significantly (p<0.001, d=0.95, large effect) higher in EU compared to DE players. Daily fluid intake negatively correlated with USG (rS=-0.46, p<0.001, medium effect). The fluid intake perception score was significantly (p=0.005, d=0.54, medium effect) better in EU compared to DE players. Reported intake perception scores negatively correlated with USG (rS=-0.32, p<0.001, medium effect). However, there was no correlation (rS=-0.09, p=0.34, trivial effect) between thirst perception scores and USG. Thirst perception scores were not significantly different between EU and DE players (p=0.35, d=0.18, trivial effect). Our results indicated that self-assessment of both daily fluid intake and perceived fluid intake matched with objective hydration status, while self-assessment of thirst perception was not an appropriate indicator of hydration status in elite soccer players.

Key words

  • dehydration
  • athletes
  • urine specific gravity
  • self-assessment questionnaire
Uneingeschränkter Zugang

Addition of in‐Play Cooling Breaks During Intermittent Exercise while Wearing Lacrosse Uniforms in the Heat Attenuates Increases in Rectal Temperature

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 111 - 121

Zusammenfassung

Abstract

To reduce the risk of heat-related illness, appropriate body cooling strategies are needed during men’s lacrosse competitions in hot-humid environments. The current study investigated whether additional in-play cooling breaks would attenuate the core (rectal) body temperature rise during exercise designed to mimic the activity patterns of a men’s lacrosse match while wearing uniform in hot-humid environments. In randomized and counterbalanced order, ten physically active men completed two experimental trials comprising four quarters of 15-min intermittent cycling exercises separated by a 10-min simulated half-time break and two 2-min quarter breaks in a climate chamber (35°C, 50% relative humidity). The two trials included a regular simulated match condition (REG) and a water break time out condition (WBTO) that included additional 2-min breaks 7.5-min into each quarter. Rectal temperature was significantly lower (p=0.017) in the WBTO condition (38.23±0.23°C) compared with the REG condition (38.50±0.46°C) at the end of the 4th quarter. In addition, ratings of perceived exertion, thermal sensation, heart rate and the physiological strain index were significantly lower (all p<0.05) in the WBTO condition compared with the REG condition. The current results indicated that, even when wearing lacrosse uniforms, the implementation of WBTO attenuated the core body temperature elevation only in the latter stages of an intermittent cycling exercise protocol designed to mimic the exercise pattern of a men’s lacrosse match. Therefore, WBTO may provide a feasible and effective cooling strategy for lacrosse players to reduce the risk of heat-illness.

Key words

  • protective equipment
  • heat-related illness
  • exertional heat stroke
  • cold drink.
Uneingeschränkter Zugang

The Effects of Preferred Music and Its Timing on Performance, Pacing, and Psychophysiological Responses During the 6‐min Test

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 123 - 133

Zusammenfassung

Abstract

The aim of this study was to investigate the effects of listening to preferred music during a warm up or exercise, on performance during a 6-min all-out exercise test (6-MT) in young adult males. Twenty-five healthy males volunteered to participate in this study. Following a within subject design, participants performed three test conditions (MDT: music during the test; MDW: music during the warm-up; WM: without music) in random order. Outcomes included mean running speed over the 6-min test (MRS6), total distance covered (TDC), heart rate responses (HRpeak, HRmean), blood lactate (3-min after the test), and the rating of perceived exertion (RPE); additionally, feeling scale scores were recorded. Listening to preferred music during running resulted in significant TDC (Δ↑10%, p=0.006, ES=0.80) and MRS6 (Δ↑14%, p=0.012, ES=1.02) improvement during the 6-MT, improvement was also noted for the warm-up with music condition (TDC:Δ↑8%, p=0.028, ES=0.63; MRS6:Δ↑8%, p=0.032, ES=0.61). A similar reverse “J-shaped” pacing profile was detected during the three conditions. Blood lactate was lower in the MDT condition by 8% (p=0.01, ES=1.10), but not the MDW condition, compared to MW. In addition, no statistically significant differences were found between the test sessions for the HR, RPE, and feeling scale scores. In conclusion, listening to music during exercise testing would be more beneficial for optimal TDC and MRS6 performances compared to MDW and WM.

Key words

  • rating of perceived exertion
  • work-rate distribution
  • blood lactate
  • aerobic exercise

Section III - Sports Training

Uneingeschränkter Zugang

Influence of Tactical Behaviour on Running Performance in the Three Most Successful Soccer Teams During the Competitive Season of the Spanish First Division

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 135 - 144

Zusammenfassung

Abstract

The purpose of this study was to analyze the influence of tactical behavior on physical performance of the three best Spanish soccer teams. Team 1 employed a 1-4-4-2 formation with compact defence and direct attacks, Team 2 employed an indirect style of play with a 1-4-3-3 formation and Team 3 used a 1-4-3-3 formation with elaborate attacks and strong counter-attacks. 816 individual situations of 54 professional soccer players categorized as fullbacks (FB), central defenders (CD), central midfielders (MF), wide midfielders (WM), and strikers (S) were included in the analysis. Their performance was examined with a player-tracking system. The analyzed variables included total distance covered, distance covered above 14, 21 and 24 km·h-1, as well as distance covered in possession of the ball and without possession of the ball. Team 2 covered a substantially lower distance >14 km·h–1 than Team 1 and substantially lower distances >14, >21, and >25km·h–1 than Team 3. No differences in running activity were found between Teams 1 and 3. However, there were substantial differences between the specific positions of the three teams. CD in Team 1 covered the lowest distance by a substantial margin in almost all variables analysed, whereas MF travelled substantially greater distances than did other positions. WM in Team 1 covered the greatest distance >18 and >21km·h– 1, while S in Team 2 had the lowest distance covered in almost all the variables, and FB in Team 3 showed the lowest total distance covered and distance covered >14km·h–1. WM in Team 2 had the greatest distance covered in possession, while S in Team 3 had the greatest distance covered out of possession. The results indicate that different team formations and associated tactical demands have a significant influence on running performance.

Key words

  • time-motion
  • soccer
  • match-analysis
  • training
  • physical demands
Uneingeschränkter Zugang

Effects of Postactivation Performance Enhancement on the Vertical Jump in High-Level Volleyball Athletes

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 145 - 153

Zusammenfassung

Abstract

The objective of this study was to evaluate the effects of a training session with and without an intervention of postactivation performance enhancement (PAPE) on countermovement jump (CMJ) height, perceived recovery status (PRS), and ratings of perceived exertion (RPEs), followed by a specific volleyball training session. The sample consisted of sixteen professional male volleyball players, with an average age of 26.8±6.1 years and average height of 195.9±6.7 cm, randomly divided into a group with PAPE intervention (GPAPE) (n=8), and a control group (CTRL) without PAPE intervention (n=8). The control group carried out the training session with plyometric exercises, and the GPAPE added conditioning protocols for PAPE to plyometric training, followed by a technical tactical volleyball session. At the end of the training session, there was an increase of 16.3% in the height of the CMJ in the GPAPE, while the CTRL showed a decrease of 5% in the height of the CMJ. PRS and RPE variables did not differ between the groups. It was concluded that PAPE had a positive effect on the height of the vertical jump after plyometric training, which was maintained until the end of the technical and tactical volleyball session.

Key words

  • team sports
  • countermovement jump
  • performance
  • plyometrics
  • postactivation performance enhancement
Uneingeschränkter Zugang

On-Court Change of Direction Test: An Effective Approach to Assess COD Performance in Badminton Players

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 155 - 164

Zusammenfassung

Abstract

The aim of this research was to assess the reliability of a specific change of direction test (i.e., “On-Court COD test”) in youth badminton players, evaluate the effect of age on On-Court COD performance, and examine its correlations with linear speed, change of direction speed, and vertical jump tests. Forty-two young badminton players (27 males and 15 females; age: 17.3±1.6 years, body height: 170.3±7.5 cm, body mass: 59.0±9.7 kg) were divided into two age groups (Under 17 years and under 19 years). Tests included: linear sprints (5, 10, and 20-m), bilateral/unilateral countermovement jumps, a hexagon test, traditional and modified 505 change of direction tests; and On-court COD. Results showed an excellent intraclass correlation coefficient score (0.90) and a very low coefficient of variation values (1.6%) for the On-Court COD test. Comparing age groups, under 19 players were significantly faster in linear sprints (i.e., 5, 15 and 20-m; small to moderate effect sizes) and in all change of direction tests (moderate to large effect sizes). Moreover, the On-Court COD test showed moderate to large (r=.513-.779) relationships with both acceleration and COD abilities in under 17 players, and with linear sprints, COD, and jump performances in under 19 players. These data indicate that the On-Court COD test is a useful and reliable means to assess COD performance in youth badminton players and it is associated with acceleration, sprint and jump performance.

Key words

  • racket sports
  • specific movement
  • neuromuscular performance
  • testing
Uneingeschränkter Zugang

The Creation of Goal-Scoring Opportunities at the 2019 FIFA Women’s World Cup

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 165 - 172

Zusammenfassung

Abstract

The aim of this study was to analyse how goal-scoring opportunities (GSOs) were created at the 2019 FIFA Women’s World Cup. The sample consisted of 868 GSOs that led to a shot at the goal throughout all 52 games during the tournament. All games were downloaded from the InStat platform. Descriptive statistics, chi-square of association and binary logistic regression analysis were used to analyse the data. Of the 868 GSOs, 81 (9.1%) resulted in goals. A significant association was observed between GSOs and the type of attack (χ2=6.38, p=0.01, V=0.09), with more goals being scored from a counter-attack (12.7%) than an organised attack (7.5%). Counter-attacks recorded a higher odds ratio in univariate analysis (OR=0.56; 95%CI:0.35–0.88; p=0.01) than in multivariate analysis (OR=0.46; 95%CI:0.28–0.76; p=0.002). The multivariate analysis further indicated a significant probability of scoring when ball possession started in the middle third of the field (OR=0.19; 95%CI:0.44–0.88; p= 0.01). The current study has practical implications for soccer coaches to develop and implement training sessions to improve goal-scoring chances of women’s teams at international competitions.

Key words

  • counter-attack
  • organised attack
  • passes
  • attacking
  • defending
Uneingeschränkter Zugang

Post-Activation Performance Enhancement in Sprinters: Effects of Hard Versus Sand Surfaces

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 173 - 180

Zusammenfassung

Abstract

This study aimed to compare the post-activation performance enhancement induced by successive drop-jumps performed on hard and sand surfaces in sprint and jump performance of top-level sprinters. Athletes were tested on two occasions. On each visit they were allocated to one of the experimental protocols, which consisted of performing 2x5 drop-jumps from a box with the height of 60-cm on hard or sand surfaces in randomized order, seven days apart. Prior to and 7 and 15-min after executing drop-jumps, sprinters performed countermovement jumps and 60-m sprint tests. Differences between sprinting splits and surfaces were assessed using a two-way analysis of variance with repeated measures. No significant differences in jump height or sprint time were observed (p>0.05), regardless of the surface used (i.e., hard or sand) during the conditioning activity (effect sizes [95% confidence intervals] ranging from 0.01 [-0.84;0.84] to 0.44 [-0.42;1.27]). Performing drop-jumps on sand or hard surfaces immediately before maximum sprinting bouts does not provide any advantage or disadvantage to top-level sprinters. Sprint coaches may prescribe short-plyometric training activities on sand surfaces even close to competitions, bearing in mind that this strategy will not compromise sprint-specific performance.

Key words

  • athletic performance
  • plyometrics
  • potentiation
  • track and field
  • muscle strength
Uneingeschränkter Zugang

The Repeated Curve Sprint Test Appears to be an Appropriate Tool for Estimating Anaerobic Fitness in Young Trained Male Futsal Players

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 181 - 189

Zusammenfassung

Abstract

This study aimed to determine the magnitude of correlation between the repeated curve sprint test (RCST), the running-based anaerobic sprint test (RAST) and the Wingate anaerobic test (WAnT) in elite male futsal players to determine whether the field test can be a futsal-specific alternative assessment tool compared to the other tests. Fifteen trained futsal players (20±3 yrs) performed the RCST, RAST and WAnT in a crossover design over three weeks. Peak power (PP), average power (AP) and the fatigue index (FI) were obtained from the tests. Finger-prick blood-lactate measurements were performed before and after the tests, and heart rate loading was recorded. To assess the magnitude and direction of the relationship between variables the Pearson’s correlation coefficient (r) was calculated. In respect of AP, there was a significant correlation between the RCST and both the WAnT (r=0.63, p=0.012) and the RAST (r=0.67, p=0.006). In respect of PP, the RCST only correlated with the RAST (r=0.71, p=0.003). In respect of the FI, the RCST did not correlate with either the RAST or the WAnT (p>0.05). Post-test heart rate values in the RCST correlated with those in both the WAnT (r=0.88, p=0.001) and the RAST (r=0.77, p=0.001). Also, post-test blood-lactate levels in the RCST correlated with those in both the RAST (r=0.58, p=0.025) and the WAnT (r=0.54, p=0.039). In conclusion, the RCST can be a valid and practical field test for measuring anaerobic fitness in competitive futsal players.

Key words

  • anaerobic test
  • fatigue index
  • peak power
  • average power
  • field test
Uneingeschränkter Zugang

Training with a Heavy Puck Elicits a Higher Increase of Shooting Speed Than Unloaded Training in Midget Ice Hockey Players

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 191 - 200

Zusammenfassung

Abstract

A method of load variability is a common way of developing specific skills in various sports, however, not explored considering the use of different ice-hockey pucks. Therefore, the purpose of this study was to compare shooting speed, shooting accuracy, and handgrip strength changes after training with variable training loads (lighter 60g pucks and heavier 260g pucks) in the wrist shot and snapshot. Sixteen male ice hockey players (13.62±0.35y; 167.67±7.71cm; 53.87±7.55kg) were subjected to a 12 week experiment during which they trained six weeks with a light puck and six weeks with a heavy puck and were tested for shooting speed, shooting accuracy and handgrip strength. The variable load training increased shooting speed (the long hand snapshot by 7.4%, the shorthand snapshot by 8.5%, and the wrist shot by 13%), shooting accuracy (by 14%), and handgrip strength (by 8.7%) of the bottom hand; all at p<0.001. Training with heavy pucks was more effective (d=0.50-0.86) than training with lighter pucks (d=23-25) for increasing puck speed. Shooting accuracy was increased by variable load training with a similar effect of heavy and light puck training. The variable training load had a positive effect on shooting speed and accuracy and the use of a heavier load was more effective than using the unloaded puck. Variable load shooting training in youth ice-hockey players is more effective with heavier pucks than lighter ones, and the improvements are greater in players with better shooting skills.

Key words

  • variable load
  • motor learning
  • heavy-weight puck
  • light-weight puck
  • contrast training
Uneingeschränkter Zugang

Accuracy of Predicting One-Repetition Maximum from Submaximal Velocity in the Barbell Back Squat and Bench Press

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 201 - 212

Zusammenfassung

Abstract

This study examined the accuracy of predicting a free-weight back squat and a bench press one-repetition maximum (1RM) using both 2- and 4-point submaximal average concentric velocity (ACV) methods. Seventeen resistance trained men performed a warm-up and a 1RM test on the squat and bench press with ACV assessed on all repetitions. The ACVs during the warm-up closest to 1.0 and 0.5m.s-1 were used in the 2-point linear regression forecast of the 1RM and the ACVs established at loads closest to 20, 50, 70, and 80% of the 1RM were used in the 4-point 1RM prediction. Repeated measures ANOVA and Bland-Altman and Mountain plots were used to analyze agreement between predicted and actual 1RMs. ANOVA indicated significant differences between the predicted and the actual 1RM for both the 2- and 4-point equations in both exercises (p<0.001). The 2-point squat prediction overestimated the 1RM by 29.12±0.07kg and the 4-point squat prediction overestimated the 1RM by 38.53±5.01kg. The bench press 1RM was overestimated by 9.32±4.68kg with the 2-point method and by 7.15±6.66kg using the 4-point method. Bland-Altman and Mountain plots confirmed the ANOVA findings as data were not tightly conformed to the respective zero difference lines and Bland-Altman plots showed wide limits of agreement. These data demonstrate that both 2- and 4-point velocity methods predicted the bench press 1RM more accurately than the squat 1RM. However, a lack of agreement between the predicted and the actual 1RM was observed for both exercises when volitional velocity was used.

Key words

  • resistance training
  • movement
  • performance
  • biomechanics
  • strength testing

Section IV - Behavioural Sciences in Sport & Sport for the Disabled

Uneingeschränkter Zugang

Cognitive Factors in Elite Handball: Do Players’ Positions Determine their Cognitive Processes?

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 213 - 221

Zusammenfassung

Abstract

For an athlete to be successful at the professional level, he or she should be characterized by extraordinary preparation in four areas: physical, technical, cognitive (related to game strategy, perception, and decision-making), and emotional (coping, emotional control). This study aimed to determine the level of selected cognitive traits in handball players while considering their sports level and assigned position on the court. Fifty handball players participated in the study. Participants consisted of 35 national team players, six first-division players, and nine second-division players. There were no significant differences between players from the elite (national team) and the sub-elite (I and II divisions) group. The results identified major differences in selective attention and short-term memory between handball players assigned to different positions (goalkeepers, compared to players in other positions, had lower attention and short-term memory). Thus, it is possible to develop a more effective psychological training program. However, it must be remembered that the results showed great variability among handball players. With this in mind, individual differences should be taken into account when planning psychological interventions.

Key words

  • cognitive skills
  • attention and concentration
  • Vienna test system
  • handball
Uneingeschränkter Zugang

Movement Patterns of Polish National Paralympic Team Wheelchair Fencers with Regard to Muscle Activity and Co-Activation Time

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 223 - 232

Zusammenfassung

Abstract

The aim of this study was to determine muscle co-activation and muscle activity time using EMG in Paralympic wheelchair fencers categorized into two disability-level groups: A (n= 7) and B (n= 9). The study was carried out with the use of a 16-channel EMG system. The surface EMG electrodes were placed on the fencer’s body along nine channels: arm muscles - deltoideus middle head (DEL), triceps brachii (TRI) and biceps brachii (BC); forearm muscles - extensor carpi radialis longus (ECR), flexor carpi radialis (FCR); postural (abdominal and back) muscles - the right and the left external oblique abdominal (EOA RT and LT) and latissimus dorsi (LD RT and LT). To assess the relative level of co-activation (simultaneous contraction of both muscles) for the TRI-BC, ECR-FCR, LD RT-EDA RT and LD LT-EDA LT muscle pairs, the co-activation index (CI) was calculated. The collected data were processed using Jamovi. The study hypotheses were verified at the level of significance of p≤0.05 (Welch’s t-test). The normal distribution of analyzed statistical features was checked with the Shapiro-Wilk test. The analysis of muscle activation time, as a percent ratio of three attempts executed in a series, confirmed the study assumptions. Fencers from Group A had a shorter activation time in all tested muscles, with the exception of the ECR (58.24), than fencers from Group B. This confirms that the activation of antagonist muscles representing a centrally programmed anticipatory mechanism stabilizing technical actions was particularly intensified in Group A fencers. The study results indicate that the standard co-activation index (CI) of key muscles involved in wheelchair fencing ranges from 48 to 51%.

Key words

  • wheelchair fencing
  • EMG muscle co-activation
  • movement pattern
  • antagonist muscle group
  • muscle activation time
Uneingeschränkter Zugang

Handcycling Training in Men with Spinal Cord Injury Increases Tolerance to High Intensity Exercise

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 233 - 241

Zusammenfassung

Abstract

Individuals with spinal cord injury are characterised by reduced physical capacity as compared to able-bodied persons, and are at risk of developing cardiovascular disease. The study aimed to evaluate the differences in physiological responses to an exercise test in handcycling-trained vs. able-bodied-trained and non-trained men. Eight males with spinal cord injury who were trained in handcycling, eighteen able-bodied males who were trained in powerlifting, and fourteen physically active non-athletes performed a graded arm crank ergometer test. The following physiological indices were measured before and during the test: heart rate, oxygen uptake, and blood lactate concentrations. Aerobic capacity was significantly higher in athletes with spinal cord injury compared to able-bodied athletes (p<0.01) and the control group (p<0.01). The heart rate achieved by handcycling-trained athletes was significantly lower as compared to powerlifters (p<0.01), however, the oxygen pulse was significantly higher (p<0.05). Handcycling-trained athletes reached significantly higher peak power (Pmax) during the graded arm exercise in comparison with powerlifters, and significantly higher post exercise blood lactate concentration (p<0.05). The lactate threshold was observed at a significantly higher P in individuals with spinal cord injury compared to able-bodied-trained (p<0.05) and non-trained men (p<0.001). Athletes with spinal cord injury were found to have excellent aerobic capacity and better physiological adaptation to the maximal graded exercise test as compared to able-bodied-trained men. These findings emphasize the importance of regular physical exercise and its potential therapeutic role in the prevention of cardiovascular disease in patients with spinal cord injury.

Key words

  • aerobic capacity
  • disabilities
  • physique enhancement
  • paraplegic endurance athletes
Uneingeschränkter Zugang

Anaerobic Variables as Specific Determinants of Functional Classification in Wheelchair Basketball

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 243 - 252

Zusammenfassung

Abstract

Every parasport is currently encouraged to consider evidence-based classification to develop their respective classification system. Therefore, the aims of this study were to: (1) assess the relationship between trunk function and anaerobic power determining proficiency in wheelchair basketball, and (2) define “natural classes” in wheelchair basketball based on anaerobic power. Fifty-nine elite players (representing five national teams) were divided into four main functional classes: Group 1 (n=17), Group 2 (n=14), Group 3 (n=16), Group 4 (n=12). They performed the 6x10s Anaerobic Power Test using an arm crank ergometer. Average values of mean power, peak power, relative mean power, relative peak power, and power decrement were calculated for the 6x10s and 3x10s tests. The Spearman’s correlation matrix revealed significant correlations between classes and values recorded in the 6x10s test. This confirmation between anaerobic power and players’ classification endorses the division of players into different classes. Furthermore, cluster analysis (with fair quality) divided players into two “natural classes”. The first resulting class was mainly formed of participants from Group 1 (71%). An important complement to this research could be to consider wheelchair acceleration and the volume of trunk action in wheelchair basketball classification.

Key words

  • evidence-based classification
  • cluster
  • paralympics
Uneingeschränkter Zugang

Assessing the Sprint Force-Velocity Profile in International Football Players with Cerebral Palsy: Validity, Reliability and Sport Class’ Profiles

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 253 - 262

Zusammenfassung

Abstract

This study assessed and described the Sprint Force-velocity (SFv) profile, and its validity and reliability in international cerebral palsy (CP) football players. Twenty international male CP football players (age: 26.9±7.4) performed a 30-m sprint, a vertical jump (CMJ), a change of direction (MAT), a dribbling and an intermittent endurance (Yo-YoIR1) test. The SFv profile and physical performance variables were shown according to the players’ sport class with the estimation of the effect sizes between classes. The SFv showed high reliability (ICC=0.77 to 0.99; SEM=0.89 to 8.66%). Validity for the SFv was provided by its positive correlation with the players’ sport class (r=0.53 to 0.75; p=.02 to <.01) and the rest of the physical performance tests (r=0.45 to 0.99; p=.04 to <.01). The RFmax was the main SFv profile variable that explained players’ performance in the rest of the tests (β=0.77 to 1.0; p<.05; R2=0.59 to 0.99). The SFv profile seems to be an efficient test to assess international CP football players’ physical performance. This provides information about the players’ individual sprint mechanical characteristics and their sprint strengths and weaknesses, allowing coaches and conditioning trainers to individualize their training interventions to optimize sprint performance.

Key words

  • CP football
  • para-sports
  • physical performance
  • disability
Uneingeschränkter Zugang

The Importance of Posture And Body Composition for the Stability and Selected Motor Abilities of Professional Handball Players

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 264 - 273

Zusammenfassung

Abstract

The aim of the research was to analyze body composition, body posture and postural stability of professional male handball players and to determine the differences between players with correct and incorrect body posture, considering power of the lower limbs and agility, speed, and change of direction deficit. The study comprised 16 professional handball players. Body composition analysis was performed using the method of electrical bioimpedance. Body posture was examined using the Diers formetric III 4D optoelectronic method. Postural stability was tested via the Biodex Balance System. Players performed the following fitness tests assessing lower limb muscle power (LP, HS, CMJ), linear speed (SLS 20 m), and COD speed (Zig-Zag test, COD deficit). Only 31.25% of players demonstrated body posture with correct physiological curvatures, while 68.75% showed changes in body asymmetry. The group with correct body posture performed better in SLS 20m than the group with incorrect posture, yet in the Zig-Zag agility test, the difference in the results was not significant and this affected the COD deficit, which was higher. The vast majority of participants demonstrated postural defects and incorrect physiological curvatures of the spine. The occurrence of scoliotic posture was also observed. The body deflection angles indicated that athletes’ postural stability was good. However, it is worth noting that the majority demonstrated a tendency towards asymmetrical body deflections to the right or to the left, backwards direction. One-sided sports specialization leads to disturbances in the statics of the body, therefore, it becomes necessary to include postural re-education exercises in training.

Key words

  • body composition
  • body posture
  • postural stability
  • handball players
Uneingeschränkter Zugang

Hand Grip Strength vs. Locomotor Efficiency in Sitting Volleyball Players

Online veröffentlicht: 26 Apr 2022
Seitenbereich: 275 - 282

Zusammenfassung

Abstract

The objective of this paper was to determine the relationship between hand grip strength and movement time (locomotor efficiency in a seated position using the upper and lower extremities) in sitting volleyball players. In addition, a comparison was made between the velocity curves for forward and backward locomotion. Nine male members of the sitting volleyball team participated in the study. Hydraulic and spring manual dynamometers were used to measure hand grip strength. Movement times were registered for distances of 1, 2, 3, 4, 5, 6 and 10-m with the use of the Smart Speed System photocells. Significant relationships between hand grip strength of the left (rs=-0.78) and right (rs=-0.73) hands and the forward movement time over a distance of 1-m were found. Hand grip strength had no significant relationship with either forward movement times at other distances or backward movement times. Results suggest that hand strength is linked to locomotor efficiency of sitting volleyball players. High hand grip strength makes the start easier by pushing away from the ground with the upper limbs.

Key words

  • disabled athletes
  • locomotor efficiency
  • motor abilities
  • sitting volleyball

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