Acute Effects of Short-Term Massage Procedures on Neuromechanical Contractile Properties of Rectus Femoris Muscle.

Background and Objectives: In many sports, maintaining muscle work at an optimal level despite fatigue is crucial. Therefore, it is essential to discover the most efficient way of recovery. This study aimed to evaluate and compare the acute effects of four different recovery methods on muscle neuromechanical properties. Materials and Methods: The research was conducted using a randomized, quasi-experimental, repeated-measures design. Fourteen healthy and active male students of the Faculty of Sport and Physical Education (age 25.1 ± 3.9 years) were included in this study. The tensiomyography was used to evaluate muscle responses after four different types of short-term recovery methods (passive rest, percussive mechanical, vibro-mechanical, and manual massage) on the rectus femoris muscle on four occasions: baseline, post fatigue, post recovery and prolonged recovery. Results: The ANOVA revealed that muscle fatigue decreased maximal vertical muscle displacement (Dm) and muscle contraction time (Tc) in post fatigue compared to the baseline. The most important finding shows that only the vibro-mechanical massage resulted in an increase in Tc in the prolonged recovery compared to the post fatigue (p = 0.028), whereas only manual massage showed no differences in Dm from the baseline in post-recovery (p = 0.148). Moreover, both manual and vibro-mechanical massages increased Dm and Tc in prolonged recovery, indicating no differences from the baseline (all p > 0.05), thus showing signs of muscle recovery. Percussion mechanical massage and passive rest did not show indices of muscle recovery. Conclusions: Manual massage could induce immediate positive changes in Dm by reducing muscle stiffness. In addition, vibro-mechanical and manual massage improved muscle tissue by rapidly returning Dm and Tc values to baseline at prolonged recovery measurement (5 min after the fatigue protocol). These findings can benefit sports practitioners, and physical therapists in developing the best recovery method after muscle fatigue.

Timing in Lower Limb Complex Movement Tests for DanceSport Athletes: Relation between FitLight Trainer and IMU Measurements.

We examine the relation between two devices used in measuring the timing in lower limb complex movement tests for DanceSport athletes, an inertial measurement unit (IMU) and a FitLight Trainer device, with the latter regarded as the gold standard method in the field. Four tests are selected to cover the lower limb movements. The research sample comprises 21 experienced dancers from different dance disciplines, performing the four tests with each of their lower limbs. Compared using concurrent validity, the two devices used show great agreement for estimating the total tests' run times, with interclass correlation coefficients between 0.967 and 0.994 for all tests. This agreement is additionally confirmed by Bland-Altman plots. As an alternative to other devices, the IMU sensor has proven to be a precise and suitable device for measuring timing and testing in sports. Its mobility, light weight, and size are advantages of this device in addition to measurement accuracy.

Mechanical and Contractile Properties of Knee Joint Muscles Measured by the Method of Tensiomyography in Differently Trained Men and Women.

ABSTRACT: Toskic, LD, Dopsaj, MJ, Markovic, MR, Toskic, DR, Ignjatovic, AM. Mechanical and contractile properties of knee joint muscles measured by the method of tensiomyography in differently trained men and women. J Strength Cond Res 36(6): 1532-1539, 2022-The aim of this study was to investigate the differences in mechanical and contractile properties of knee joint flexor and extensor muscles between differently trained men and women, using tensiomyography (TMG). The sample consisted of 159 subjects (84 men and 75 women), who were assigned to one of 5 groups according to the following levels and types of their physical activity: physically inactive, physically active nonathletes, strength and power athletes, endurance athletes, and team sports athletes. Measurements were performed on the following knee flexor and extensor muscles of the dominant leg: rectus femoris, vastus medialis, vastus lateralis, biceps femoris, and semitendinosus. The results showed significant differences in contraction time-Tc (F = 1.911, p = 0.010) and delay time-Td (F = 1.989, p = 0.007) parameters between differently trained men and women, whereas in other TMG parameters, there were no differences between groups. It is indicated that physical activities characteristic of strength and power sports (combat sports and sprint disciplines) could lead to an increased speed of twitch force generation and fast twitch muscle fibers, and that almost any regular, systematic, and planned physical activity leads to increased muscle responsiveness. Obtained results also indicated that TMG parameters do not have enough specific discriminatory power for detecting differences between differently trained young adults.

Use of IMU in Differential Analysis of the Reverse Punch Temporal Structure in Relation to the Achieved Maximal Hand Velocity.

To achieve good performance, athletes need to synchronize a series of movements in an optimal manner. One of the indicators used to monitor this is the order of occurrence of relevant events in the movement timeline. However, monitoring of this characteristic of rapid movement is practically limited to the laboratory settings, in which motion tracking systems can be used to acquire relevant data. Our motivation is to implement a simple-to-use and robust IMU-based solution suitable for everyday praxis. In this way, repetitive execution of technique can be constantly monitored. This provides augmented feedback to coaches and athletes and is relevant in the context of prevention of stabilization of errors, as well as monitoring for the effects of fatigue. In this research, acceleration and rotational speed signal acquired from a pair of IMUs (Inertial Measurement Unit) is used for detection of the time of occurrence of events. The research included 165 individual strikes performed by 14 elite and national-level karate competitors. All strikes were classified as slow, average, or fast based on the achieved maximal velocity of the hand. A Kruskal-Wallis test revealed significant general differences in the order of occurrence of hand acceleration start, maximal hand velocity, maximal body velocity, maximal hand acceleration, maximal body acceleration, and vertical movement onset between the groups. Partial differences were determined using a Mann-Whitney test. This paper determines the differences in the temporal structure of the reverse punch in relation to the achieved maximal velocity of the hand as a performance indicator. Detecting the time of occurrence of events using IMUs is a new method for measuring motion synchronization that provides a new insight into the coordination of articulated human movements. Such application of IMU can provide additional information about the studied structure of rapid discrete movements in various sporting activities that are otherwise imperceptible to human senses.

Validity of a Novel Specific Wrestling Fitness Test.

ABSTRACT: Markovic, M, Kukic, F, Dopsaj, M, Kasum, G, Toskic, L, and Zaric, I. Validity of a novel specific wrestling fitness test. J Strength Cond Res 35(12S): S51-S57, 2021-The specific wrestling fitness test (SWFT) is a novel test aiming to estimate the level of physical preparedness of wrestlers; therefore, it should posses an acceptable level of validity. The aim of this study was to investigate an internal, external, and construct validity of SWFT. The sample consisted of 15 national level male wrestlers (age = 22.6 ± 2.3 years, body mass [BM] = 83.3 ± 6.5 kg, and BM index [BMI] = 25.36 ± 1.2 kg·m-2). They performed the SWFT, specific judo fitness test (SJFT), and specific wrestling performance test (SWPT), each test on a separate day. For each test, performance was evaluated in absolute measure as total number of throws at the end of the test (TnThrows) and relative measure as TnThrows/BM and TnThrows/BMI. Heart rate at the end of the test (HR0min) and 1 minute into recovery (HR1min) was used as a measure of cardiovascular functionality, whereas specific judo fitness index (SJFIndex) was used as an indicator of cardiovascular functionality relative to given performance. A correlation and multiple linear regression analyses were used to investigate the internal, external, and construct validity of SWFT. The SWFT_TnThrows/BM had the highest internal validity relative to SJFT_TnThrows/BM (R2 = 0.722, p < 0.001) and the highest external validity relative to SWPT_TnThrows/BM (r = 0.846, p < 0.001). SWFT_TnThrows/BM predicted SWPT_TnThrows/BM with a large coefficient of determination (R2 = 0.818, p < 0.001). SWFT_TnThrows/BM is valid and easily attainable predictor of wrestlers' specific physical preparedness and as such is of high practical value.

Body composition and muscle strength predictors of jumping performance: differences between elite female volleyball competitors and nontrained individuals.

Studies of the role of various anthropometric, physiological, and biomechanical variables in performance of rapid movements have generally revealed inconsistent findings. Within this study, we tested the hypotheses that (a) both body composition and leg extensor strength variables would reveal significant relationship with jumping performance, whereas (b) the same relationships would be stronger in physically active nonathletes than in the elite athletes proficient in vertical jumping. Top-level female volleyball players (VP; N = 35) and physically active female nonathletes (PA; N = 21) were tested on maximum vertical jumps performed with and without arm swing, as well as on body composition (percent fat and muscle) and leg press strength (maximum force and the rate of force development). The results revealed significant relationships between the jumping performance and body composition variables that appeared to be higher in PA (r = 0.65-0.76; all p < 0.01) than in VP (r = 0.37-0.42; all p ≤ 0.05). The relationships between the jumping performance and the leg strength variables were mainly significant (r = 0.23-0.68) and similar in 2 groups. We conclude that not only the leg extensor strength but also the body composition variables could be valid predictors of jumping performance and, possibly, other rapid movements. Moreover, the body composition variables that have been mainly neglected in the literature could be particularly strong predictors of performance of jumping in nonathletes, as compared with relatively homogeneous populations of elite athletes.

Multiple regression analysis for competitive performance assessment of professional soccer players.

BACKGROUND: Being in peak physical condition and having specific motor abilities are necessity for every top-level soccer player in order to achieve success in competition. In order to correctly assess soccer players' performance, this research uses laboratory and field measurements, as well as results of competitive performance obtained by direct software measurements of players' movement during the actual soccer game. OBJECTIVE: The main goal of this research is to give insight into the key abilities that soccer players need to have in order to perform in competitive tournaments. Besides training adjustments, this research also gives insight into what variables need to be tracked in order to accurately assess the efficiency and functionality of the players. METHODS: The collected data need to be analyzed using descriptive statistics. Collected data is also used as input for multiple regression models that can predict certain key measurements: total distance covered, percent of effective movements and high index of effective performance movements. RESULTS: Most of the calculated regression models have high predictability level with statistically significant variables. CONCLUSION: Based on the results of regression analysis it can be deduced that motor abilities are important factor in measuring soccer player's competitive performance and team's success in the match.

Novel neurodigital interface reduces motion sickness in virtual reality.

Virtual reality (VR) is a computer-created 3D environment with a focus on realistic scenes and pictures created for entertainment, medical and/or educational and training purposes. One of the major side effects of VR immersion reported in the scientific literature, media and social media is Visually Induced Motion Sickness (VIMS), with clinical symptoms such as disorientation, nausea, and oculomotor discomfort. VIMS is mostly caused by the discrepancy between the visual and vestibular systems and can lead to dizziness, nausea, and disorientation. In this study, we present one potential novel solution to combat motion sickness in VR, showcasing a significant reduction of nausea in VR users employing the META Quest 2 headsets in conjunction with a whole-body controller. Using a neurodigital approach, we facilitate a more immersive and comfortable VR experience. Our findings indicate a marked reduction in VR-induced nausea, paving the way to promote VR technology for broader applications across various fields.

Characteristics of eating habits and physical activity in relation to body mass index among adolescents.

OBJECTIVE: To assess eating habits and the level of physical activity in adolescents and develop a predictive model for the body mass index (BMI) based on these variables. DESIGN: In this cross-sectional study, eating habits and the level of physical activity were assessed using a questionnaire validated in adolescents. Body mass and height collected during the last annual checkup were extracted from personal medical records. SUBJECTS: The sample included 330 boys and 377 girls (mean age 15.8 ± 0.2 years) who were first-year high school students in the city of Belgrade, Serbia. MEASURES: Responses to each of the 14 questions about eating habits and 6 questions about physical activity were scored from the least (0) to the most (3) desired behaviors. These ratings were then averaged to arrive to an aggregate score for each domain. The BMI was calculated according to the standard method. A series of regression analyses was performed to derive the best model for predicting BMI in boys and girls based on individual eating habits and physical activity items, first separately and then combined. RESULTS: In the sample, 24.5% of boys and 9.5% of girls were overweight or obese. Girls' eating habits were better than boys (mean aggregate score 2.3 ± 0.3 and 2.1 ± 0.3, respectively, p < 0.001), whereas the level of physical activity was greater in boys than girls (2.1 ± 0.6 vs 1.9 ± 0.6, p < 0.001). The differences between boys and girls in the BMI, eating habits, and physical activity remained significant after controlling for their knowledge about healthy eating and education level of their parents. Eating habits were a better predictor of BMI than physical activity, particularly in boys (R (2) = 0.13 vs R (2) = 0.02) compared to girls (R (2) = 0.04 vs R (2) = 0.01). Combining eating habits and physical activity in the multivariate model of BMI resulted in a better predictive accuracy in boys (R (2) = 0.17) but not girls (R (2) = 0.04). CONCLUSIONS: Eating habits and physical activity differ between adolescent boys and girls and can predict BMI, particularly in boys. The results suggest the need to develop gender-specific programs for promoting healthy lifestyle among adolescents in our country.

Acute responses of biomechanical parameters to different sizes of hand paddles in front-crawl stroke.

This study investigated the acute effects of different sizes of paddles on the force-time curve during tethered swimming and swimming velocity in front-crawl stroke. Fourteen male swimmers (20.0 ± 3.7 years; 100-m best time: 53.70 ± 0.87 s) performed two 10-s maximal efforts in tethered swimming to obtain peak force, average force, impulse, rate of force development, stroke duration and time to peak force. Swimming velocity, stroke rate and stroke length were obtained from two 25-m maximal swims. Both tests were repeated in five conditions: free swimming, wearing small (280 cm (2) ), medium (352 cm (2) ), large (462 cm (2) ) and extra-large (552 cm (2) ) hand paddles. Compared to free swimming, paddles provided significant increases of peak force (medium: 11.5%, large: 16.7%, extra-large: 21.7%), impulse (medium: 15.2%, large: 22.4%, extra-large: 30.9%), average force (medium: 5.1%, large: 7.5%), rate of force development (extra-large: 11.3%), stroke duration (medium: 9.3%, large: 11.8%, extra-large: 18.5%), time to peak force (medium: 11.1%, large: 15.9%, extra-large: 22.1%), swimming velocity (medium: 2.2%, large: 3.2%, extra-large: 3.7%) and stroke length (medium: 9.0%, large: 9.0%, extra-large: 14.8%), while stroke rate decreased (medium: -6.2%, large: -5.5%, extra-large: -9.5%). It is concluded that medium, large and extra-large paddles influence the force-time curve and change swimming velocity, suggesting these sizes may be useful for force development in water.

Hematological, oxidative stress, and immune status profiling in elite combat sport athletes.

The aim of this study was to profile hematological, oxidative stress, and immunological parameters in male athletes who practiced combat sports and to determine whether the type of combat sport influenced the measured parameters. Eighteen karate professionals, 15 wrestlers, and 14 kickboxers participated in the study. Hematological, iron-related, oxidative stress, and immunological parameters were measured at the beginning of a precompetitive period. The general linear model showed significant differences between the karate professionals, wrestlers, and kickboxers with respect to their hematological and iron status parameters (Wilks' Lambda = 0.270, F = 2.186, p < 0.05) and oxidative stress status (Wilks' Lambda = 0.529, F = 1.940, p < 0.05). The immature reticulocyte fraction was significantly higher in wrestlers (0.30 ± 0.03) compared with kickboxers (0.24 ± 0.04; p < 0.05) and karate professionals (0.26 ± 0.04; p < 0.05). Low hemoglobin density was significantly lower in wrestlers and kickboxers (p < 0.05) compared with karate professionals (karate: 3.51 ± 1.19, wrestlers: 1.95 ± 1.10, and kickboxers: 1.77 ± 0.76). Significant differences were observed between the karate professionals and wrestlers with respect to their pro-oxidant-antioxidant balance (437 ± 103 vs. 323 ± 148, p < 0.05) and superoxide-dismutase activity (SOD) (73 ± 37 vs. 103 ± 30, p < 0.05). All the measured parameters (with the exception of SOD activity) fell within their physiological ranges, indicating that the study participants represented a young and healthy male population. Hematological parameters differed between kickboxers and karate professionals. The low pro-oxidant-antioxidant balance and high SOD activity in wrestlers could be associated with the long-term impact of wrestling as a type of strenuous exercise.

Relations between lower body isometric muscle force characteristics and start performance in elite male sprint swimmers.

The aim of the present study was twofold. The first aim was to examine the influence of absolute and relative lower body muscle force on kinematic component which determine the start performance. The second aim was to create multiregressional model which could use as a tool for swimming coaches with the purpose to start performance control and improvement. Twenty seven high-level trained male competitive swimmers all members of the Serbian National Youth and Senior Swimming Team (Age = 21.1 ± 4.3 yrs., Height = 1. 89 ± 0.10 m, Weight = 81.6 ± 8.4 kg, 50m freestyle - long course = 24.36 ± 0.86 s) performed two trials of standing leg extensors isometric muscle force testing and three swimming start trials corresponding to 10m distance. The average start time significantly correlated with variables of leg extensors maximum voluntary force (Fmax, r = -0.559, p = 0.002), leg extensors relative muscle voluntary force (Frel, r = -0.727, p < 0.001), leg extensors specific rate of force development (RFD50%, r = -0.338, p = 0.047) and leg extensors relative value of specific rate of force development (RFD50%rel, r = -0.402, p = 0.040). Regression equation for t10m prediction was defined by following variables: maximum voluntary isometric force of leg extensors muscles at absolute and relative level (Fmax and Frel), as well as a specific rate of force development of the same muscle groups (RFD50% and RFD50%rel) at absolute and relative level too with 74.4% of explained variance. Contractile abilities indicators of the leg extensors muscles included consideration: Fmax, RFD50%, Frel and RFD50%rel showed significant correlation with swimming start times on 10m. Additionally, the results suggest that swimmers, who possess greater isometric maximum force and specific rate of force development at absolute and relative levels, tend to be able to swim faster on initial 10m swim start perforamnce. Key PointsIn high-level male swimmers:Leg extensors maximum voluntary force, leg exten-sors relative value of maximum muscle voluntary force, leg extensors specific rate of force develop-ment and leg extensors relative value of specific rate of force development positively associated with the start time measured on 10m-mark.Time at 10m-mark was not associated with legs ex-tensors basic level of rate of force development at absolute and relative level.Obtained multi-regressional model is defined by variables which measure the development of maxi-mum voluntary isometric leg extensor muscle force on the absolute and relative level, as well as vari-ables which measure the development of specific explosive force of the same muscle group on abso-lute and relative level, this could use as a tool for swimming coaches to control the direction and ex-tent of development of a given force characteristics for providing conditions for start improvement in highly trained elite male sprint swimmers.

Assessment of the Offensive Play in Elite Water Polo Using the Team Sport Assessment Procedure (TSAP) over an Entire Competitive Season.

In water polo, the team's technical and tactical performance is determined by the sum of the players' activities. This study aimed to investigate the playing offensive performance of an Italian First League team performed during all matches (n = 19) of the 2021/22 championship using the Team Sport Assessment Procedure (TSAP). For all subjects (n = 15), gaining possession of the ball (received balls (RB) and conquered balls (CB)) and disposing of the ball (neutral balls (NB); lost balls (LB); offensive ball (OB) and successful Shots (SS)) parameters, as well as volume of play (VP), efficiency index (EI) and performance score (PS) indexes, were analyzed in relation to the playing positions, season phase, match location and final score difference. Multiple linear regression showed a significant association between the playing position and VP and PS. Perimetral players showed the highest VP (65%) and PS (66%) values, and center defenders showed the highest values of CB (30%), while center forwards gained the highest amount of exclusion when handling the ball (48%). Although they were not significant, the other contextual factors showed that season phase and match location could affect the TSAP indexes. For water polo coaches, the TSAP represents an effective tool to assess how players interpret the match.

Effects of Playing Position and Contextual Factors on Internal Match Loads, Post-Match Recovery and Well-Being Responses of Elite Male Water Polo Players.

This study aimed to investigate the effects of playing position and contextual factors (match outcome, final score difference, match location, travel duration, number of scored and conceded goals) on the internal match load, players' perceived recovery and players' well-being. The session-RPE (s-RPE), Perceived Recovery Scale (PRS) and Hooper Index (HI) of 17 male elite water polo players were monitored during all matches (regular season and play-out) of the 2021/22 Italian Serie A1 championship. Three separate, mixed linear models for repeated measures showed significant main effects: drawn compared to won matches led to higher s-RPE values (mean ± SE = 277 ± 17.6 vs. 237.3 ± 20.6), while longer travel duration (estimate = -0.148) and goals scored (estimate = -3.598) led to lower s-RPE values; balanced compared to unbalanced matches led to higher PRS values (mean ± SE = 6.8 ± 0.3 vs. 5.1 ± 0.4), while playing time (estimate = -0.041) and goals scored (estimate = -0.180) led to lower PRS values; higher scores of the HI were registered for regular season compared to the play-out (mean ± SE = 15.6 ± 0.9 vs. 13.5 ± 0.8). This study marks the importance of ecological and non-invasive monitoring tools to assess internal match load, recovery and the well-being of elite water polo players.

The Effects of Massage Therapy on Sport and Exercise Performance: A Systematic Review.

BACKGROUND: A massage is a tool that is frequently used in sports and exercise in general for recovery and increased performance. In this review paper, we aimed to search and systemize current literature findings relating to massages' effects on sports and exercise performance concerning its effects on motor abilities and neurophysiological and psychological mechanisms. METHODS: The review has been written following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analysis) guidelines. One hundred and fourteen articles were included in this review. RESULTS: The data revealed that massages, in general, do not affect motor abilities, except flexibility. However, several studies demonstrated that positive muscle force and strength changed 48 h after the massage was given. Concerning neurophysiological parameters, the massage did not change blood lactate clearance, muscle blood flow, muscle temperature, or activation. However, many studies indicate pain reduction and delayed onset muscle soreness, which are probably correlated with the reduction of the level of creatine kinase enzyme and psychological mechanisms. In addition, the massage treatment led to a decrease in depression, stress, anxiety, and the perception of fatigue and an increase in mood, relaxation, and the perception of recovery. CONCLUSION: The direct usage of massages just for gaining results in sport and exercise performance seems questionable. However, it is indirectly connected to performance as an important tool when an athlete should stay focused and relaxed during competition or training and recover after them.

Effect of breakout phase on the stroke kinematics and coordinative swimming variables.

The first complete upper and lower limbswimming cycle after the underwater segment of start and turns represents the breakout phase in competitive swimming. The aim of the present research was to examine the effect of the breakout movements on the stroking variables and coordinative patterns of competitive swimmers. Thirty-three national-level male swimmers performed 4 x 25 m maximal efforts (one of each stroke in random order) from a push start and were recorded by two sequential cameras in the sagittal plane. The average velocity, stroke length, and stroke frequency; the relative duration (%) of the stroke phases; and the inter-limb discrete relative phases were calculated using direct linear transformation algorithms for the breakout and free-swimming phases. In general terms, swimming velocity during breakout was faster (δ 0.27 ± 0.04 m/s, p < 0.001, ES = 0.33) than free swimming (in all strokes but breaststroke), not because of a faster previous underwater kicking or a modified coordinative swimming pattern, but because of an increase in the stroke rate (δ 4.68 ± 0.79 cycles/min, p < 0.001, ES = 0.36). These results indicate how swimmers manage the changing constraints during breakout from underwater to surface swimming.

The effects of fatigue on linear and angular kinematics during bilateral squat.

This study was aimed to analyze in detail how the fatigue effects to kinematic parameters of body weight squat exercise (BSQ) by dividing a squat cycle into four different regions. Twenty-one male athletes participated in this study. Participants were divided into two groups according to their lower limb muscle ratio (LLMR). The BSQ was performed until participants were unable to continue the exercise due to the fatigue. Linear and angular kinematics were obtained by motion analysis software which has high validity and reliability. There was no significant but had large effect size interaction between fatigue conditions and LLMR groups in terms of knee ROM in the extension phase and hip angular velocity in braking phase of the flexion (0.08 > p >0.05, 0.18 > [Formula: see text] > 0.16). Fatigue condition did not have a significant effect on the duration in the acceleration and braking phases of BSQ (p > 0.05). There were many significant main effects on kinematics in the different regions due to the fatigue (0.01 < p <0.05, 0.44 > [Formula: see text] > 0.14). In the fatigue condition, there was a polynomial relationship between velocity of shoulder and hip joints (R2flex = 0.82, R2ext = 0.72) rather than linear (R2flex = 0.64, R2ext = 0.53) and coefficient correlations also decreased (rflex = 0.88 to 0.80, rext = 0.92 to 0.73). The sticking region was observed in the non-fatigue condition and disappeared when fatigue occurred. These results suggest that LLMR may be taken into consideration in the squat exercises, joint tracking may vary for velocity-based squat training and pre-test for sticking region observation may be apply with the BSQ.

How Supplementation with SOD-Rich Plant Extract, Combined with Gliadin, Can Affect Oxidative Stress Markers and Zonulin Levels in Exercise-Induced Oxidative Stress.

A randomized, double-blind, placebo-controlled study was conducted to investigate the influence of supplementation with a superoxide dismutase (SOD)-rich plant extract on markers of oxidative stress, zonulin levels and the performance of elite athletes. Participants were 30 international-level rowers, divided into an experimental group (n = 15) and a control group (n = 15). The rowers performed a maximal effort incremental test on a rowing ergometer at the beginning and at the end of the study. Markers of oxidative stress (total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI), superoxide dismutase (SOD), glutathione peroxidase (GPx), advanced oxidation protein products (AOPPs), malondialdehyde (MDA), sulfhydryl (SH) groups, bilirubin, uric acid, albumin and zonulin) were determined in serum. A lower TOS (p = 0.010) and OSI (p = 0.004), a lower MDA (p = 0.001) and a higher level of SH groups (p = 0.031) were observed in the experimental group after supplementation. Physical performance was evaluated through metabolic efficiency, taking lactate levels and power output on the ergometer into account. After 6 weeks of supplementation, the relative increase in metabolic efficiency at a 4 mmol/L lactate concentration and maximal effort was significantly higher in the experimental group (p = 0.004 and p = 0.015, respectively). These results suggest that supplementation with a SOD-rich extract promotes lower oxidative stress, better antioxidant protection and, consequently, the better work performance of athletes.

Can different variations of suspension exercises provide adequate loads and muscle activations for upper body training?

The purpose of this study was to assess the differences in muscle activation (EMG) and body weight distribution (%BW) between suspension (TRX™ push-up and TRX™ inverted row) and conventional exercises (bench press and lying barbell row) using different contraction types (isometric and isotonic) and position variations (feet on the ground [FG] and feet on suspension device [FD]). It was also used to determine the intensity of the force applied to the straps of the suspension device corresponding to one repetition maximum (1-RM). Twelve male athletes (ages-24.5±4.2 years (mean±standard deviation [SD]); Height-181.0±6.8 cm; body mass-83.08±6.81 kg) participated in this study. Two suspension devices were used, one for the FD variation and one for the FG variation pectoralis major (PM) and triceps brachii (TRI) activations were assessed during the TRX™ push-up and bench press exercises. Transversus trapezius (TRA) and biceps brachii (BB) activations were assessed during the TRX™ inverted row and lying barbell row exercises. The results showed significant differences between exercises (FG and FD variations of TRX™ push-up and bench press) in PM activities (isometric and isotonic) (p≤0.05). However, these differences were only observed during isometric TRI activation (p≤0.05). In the FG and FD variations of the TRX™ inverted row and lying barbell row exercises, there were only differences in the isometric contractions of the TRA and BB (p≤0.05). In the suspension device of push-ups and inverted row for the FD variations, 70.5% and 72.64% of 1-RM intensity were obtained, respectively. Similar responses to training intensities and muscle activations can be obtained in suspension exercises and conventional exercises. FD variations of suspension exercises can be more effective in terms of muscle activations than FG variations, and isotonic suspension exercises increase exercise intensity more than isometric suspension exercises.

Functional dimorphism and characteristics of maximal hand grip force in top level female athletes.

The aim of this work is to determine functional dimorphism (F(max)Nd/DoHG(iso)) and model characteristics at maximal isometric hand grip force (F(max)HG(iso)) in top level female athletes. 275 top level female athletes were tested from Taekwondo, Synchronised Swimming, Track and field, Table tennis, Volleyball, Karate, Skiing, Handball, well-trained students (students of the Academy for Criminalistic and Police studies - ACPS) and Control group. In order to assess the F(max)HG(iso), we used standardised equipment, i.e., a sliding device that measures isometric finger flexor force, with a tensiometric probe fixed inside the device. The average values of F(max)HG(iso) and relative force measured by allometric and classic method for dominant and non-dominant hand grip for the total sample were 381.87 +/- 60.28, 344.63 +/- 55.60 N; 24.06 +/- 3.50, 21.72 +/- 3.28 N/BM0.667; 0.62 +/- 0.10, 0.56 +/- 0.09 N/BM. The average value of F(max)Nd/DoHG(iso) was 0.9030 +/- 0.0797. General Significant difference was established between subsamples for the measurement characteristics at the level of Wilks' Lambda 0.476, F = 3.276, p = 0.000. Maximal average value F(max)HG(iso) for non-dominant and dominant hand is found in Karate (372.04 +/- 46.71, 407.04 +/- 71.31 N) and minimal in Table tennis (282.00 +/- 56.00, 304.00 +/- 58.51 N). The minimal index value of F(max)Nd/DoHG(iso) was found in Control group 0.8771 +/- 0.0877. Considering defined classification of F(max)Nd/ DoHG(iso), we classified the examinees from different sports in 4 groups: dominant symmetry of functional hand grip relations (Skiing > 0.9595); symmetry (Table tennis and Taekwondo 0.9288 to 0.9594); average (Karate, Volleyball, ACPS, Track and field 0.8980 to 0.9287); asymmetry (Control, Synchronised swimming and Handball 0.8674 to 0.8979). The results obtained can be used to determine criteria decisions from the aspect of diagnostic procedures, metric aspect, medical aspect.