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Unlike in the previous decades, strength training is gaining more scientific attention owing to its numerous benefits on human health. It has major benefits on metabolic processes, cardiovascular system, musculoskeletal system, age-related processes, and mental health. In comparison with aerobic low-intensity exercises, chest press-based strength training cardiovascular adaptations have been ignored for many years. Yet, if properly prescribed and conducted, strength training has shown to be safe and effective in people with cardiovascular disease. This narrative review aims at summarizing the available evidence about the role of chest press-based strength training on the cardiovascular system.

World Taekwondo (WT) as an Olympic sport gained much more attention than before, and there is a growing need for precise and specific profiles of successful taekwondo competitors. Aim of this investigation was to determine body composition, somatotype, and selected anthropometric parameters/indexes of elite taekwondo champions and medal winners on the most demanding taekwondo tournaments in the World. The sample for this research consisted of n=16 (n=4 male ; n=12 female) elite taekwondo champions, n=8 juniors and n=8 seniors, who were European (n=13), and World (n=3) champions of European descent. Data was collected longitudinally for seven years since 2015. Obtained results revealed specific (absolute) phenotype of taekwondo champions, following: PI (11.50 female ; 11.85 male), HWR (43.96 female ; 44.47 male) and BMI (19.96 female ; 22.04 male). Further analysis shows that champions have greater values of body height, and have slightly greater ectomorphy and mesomorphy values in regard to other elite competitors. Presented research is the first publication of referent values for the general anthropometric dataset, and such results represent the anthropometric variability of European WT champions.

SUMMARY: The main purpose of this study was to determine the body composition and anthropometric reference values of male and female junior Croatian taekwondo competitors according to official weight category. Additional aim of the study was to identify possible differences in variables between the weight categories. The sample comprised 247 junior participants of the national taekwondo championships divided into male (N=121) and female (N=126). The variable sample was defined by a set of 8 measurements: Body height (cm), Body mass (kg), Body mass index, Body fat (%), Body fat (kg), Muscle mass (kg), Lean body mass (kg) and Total body water (%). Results confirm previous studies proving that younger taekwondo practitioners have higher levels of body fat than their more experienced peers (seniors). Significant differences were only found between lean and heavy categories. Male junior taekwondo athletes show total body water percentages from 57.4 to 74.8 %, with significantly lower percentages in higher weight categories, while female athletes in heigher categories demonstrate a worrying level of hydration status, therefore endangering their performance and overall health. As the first paper that investigates the reference values of junior taekwondo athletes but based on official weight categories it is especially important as each weight category warrant different body composition requirements, as seen from significant differences across different variables. Future studies should include motor abilities inspection throughout the weight categories and possible use of calculation of metabolic age.

The aim of this study was to assess the metabolic cost (Cr) with marathon shoes (Adidas Adizero 3 [AA]) vs. track spikes (Nike Zoom Matumbo 3 [NZM]) on track. For this, five experienced runners were randomly assessed (NZM/AA) on a running track at 73% and 85% of best performance speed on 1500-m race. At first, speed (4.39 +/- 0.53 m center dot s(-1)), Crs with AA and NZM resulted 3.63 +/- 0.29 and 3.64 +/- 0.43 J center dot kg(-1)center dot m(-1) (+0.3% with NZM, effect size [ES] small and p = 0.951), respectively. Besides, at second speed (5.20 +/- 0.18 m center dot s(-1)), Crs were 4.09 +/- 0.28 and 4.07 +/- 0.22 J center dot kg(-1)center dot m(-1) (-0.5% with NZM, ES small and p = 0.919) with AA and NZM, respectively. It resulted in an increased Cr (+12.2%) between s1 and s2 with both shoe conditions (ES large and p = 0.009 and 0.011 with AA and NZM, respectively). There is a pattern yet to be confirmed for track spikes to become more beneficial at higher speeds (when duty factor becomes lower and therefore grip on track is crucial).

De Giorgio, A, Iuliano, E, Turner, A, Millevolte, C, Cular, D, Ardigò, LP, and Padulo, J. Validity and reliability of a light-based electronic target for testing response time in fencers. J Strength Cond Res 35(9): 2636-2644, 2021-Response time (RT) is a fencing fundamental sensorimotor skill. Therefore, the aim of the current study was to examine the efficacy of a light-based electronic target in fencers, designed to measure and train this entity. Ninety-five fencers (M = 53; F = 42) were tested in regard to their RT, using a light-based electronic target, for 3 different attack types: simple attack, the lunge, and an attack after a 1.5-m thrust. All subjects were divided into elite vs. novice fencers. Elite fencers had national and international rankings, and were again divided with regard to used weapon: épéeists (n = 32; M = 19; F = 13) and foilists (n = 30; M = 13; F = 17). Measurement was evaluated for validity/reliability, sensitivity/specificity, and correlation. Reliability was high for all attack types (intraclass correlation coefficient 0.94-0.96). Lower RTs were found in males for 2 attack types with good sensitivity (81-93%)/specificity (50-91%) for all attack types. Elite fencers responded faster than novice fencers for all attack types (p0.001), whereas elite males were faster than females for 2 attack types (p0.01). Lower RTs in females correlated with level for one attack type (r = 0.797, p0.05). In conclusion, the light-based electronic target system was found to be highly reliable and therefore could be used by fencing athletes as a further measure of performance.

The paper provides an overview and review of the use, knowledge and importance of cannabidiol (CBD) on stakeholders in the sports system, on the example of members of the Sports Community of the City of Zadar. In particular, a review is given of the possible harmfulness of taking substances that contain prohibited amounts and ingredients for athletes, ie unfounded and unconfirmed independent research. The method and purpose of taking cannabidiol by the stakeholders of the sports system are presented, with special reference to athletes in the field of recreation. The survey, through a questionnaire, determined whether athletes and sports professionals are sufficiently aware of what are cannabidiols, and what is the impact on the health status of athletes when using cannabidiol and the possible harm to the health of athletes in uncontrolled cannabidiol intake. In conclusion, research has shown that athletes and sports professionals do not know enough about what are cannabidiols, and what is the impact of their use on athletes and recreational athletes. Therefore, the conclusion is that it is necessary to educate these stakeholders in sports and conduct future research.

Purpose: To determine the reliability and diagnostic accuracy of noninvasive urinary dehydration markers in field-based settings on a day-to-day basis in elite adolescent amateur boxers. Methods: Sixty-nine urine samples were collected daily from 23 athletes (17.3 ± 1.9 y) during their weight-stable phase and analyzed by field and laboratory measures of hydration status. Urine osmolality (UOSM), urine specific gravity (USG), total protein content (TPC), and body-mass stability were evaluated to determine fluid balance and hydration status. Overall macronutrient and water intake were determined using dietary records. According to their anthropometric characteristics, athletes were assigned into 2 groups: lightweight (LWB) and heavyweight (HWB) boxers. Results: Data presented on UOSM demonstrated a uniform increment by 11.2% ± 12.8% (LWB) and 19.9% ± 22.7% (HWB) (P −1 · d−1). The intraclass correlation coefficients (ICCs) ranged from .52 to .55 for USG and .38 to .52 for UOSM, further indicating inconsistency of the urinary dehydration markers. Poor correlations were found between USG and TPC metabolites (r = .27, P = .211). Conclusions: Urinary dehydration markers (both USG and UOSM) exhibit high variability and seem to be unreliable diagnostic tools to track actual body-weight loss in real-life settings. The ad libitum fluid intake was apparently inadequate to match acute fluid loss during and after intense preparation. The applicability of a single-time-point hydration-status assessment concept may preclude accurate assessment of actual body-weight deficits in youth boxers.

Objective(s). Main aim of this cross-sectional study was to analyse intra-positional, inter- positional differences in proportions of particular somatotype categories in youth volleyball players. Methods. Heath-Carter method was used to determine somatotype characteristics of 181 young female volleyball players (age 14.05±0.93, height 170.03±7.61 cm, mass 57.80±8.59 kg, body mass index 19.99±2.37 kg/m2, somatotype 4.33-2.79-3.73±1.02-1.02- 1.25). Dependent variables were playing position, player efficacy. Only 7 somatotype categories (of possible 13) were obtained. Results. By analysing intra-positional differences, a significantly higher frequency of somatotype categories dominated by the ectomorph component was established in a subsample of more successful players, and a significantly higher frequency of somatotype categories dominated by the endomorph component was found in a subsample of less efficient players. The most frequent somatotype category in all player positions in a sample of more efficient volleyball players is the balanced ectomorph. The smallest number of somatotype categories (only three) was obtained in the subsample of more efficient middle hitters. It indirectly indicates that the most stringent requirements for selection according to the body build are for that position. Similar small inter- positional differences were obtained in both subsamples. Ectomorph somatotype component was most pronounced in young middle-hitters, and endomorph in liberos. Small inter- positional differences in both subsamples are probably consequences of previous selection processes within the clubs. Conclusion. Results obtained in this study provide a clearer insight into inter- positional, intra- positional differences in somatotype categories of young female volleyball players.

The aim of the investigation was to verify the validity and reliability of a low-end 50-Hz Global Navigation Satellite System receiver (GNSSr) for different soccer-specific run distances and average speed assessments. Six soccer players were assessed on two different days while performing eight different running paths with changes of direction for a final total of 44 runs. During the runs, each participant was equipped with the GNSSr, while the time for each single run was recorded using a photocell gate. Reference vs. receiver assessment correspondences for distance and average speed were evaluated by calculating the standard error of the estimate (SEE), coefficient of variation (CV), and mean bias. Residual vs. predicted value comparison was performed by means of Bland-Altman plots. Finally, calculating the intra-class correlations coefficient (ICC) assessed the test-retest reliability of the measurement. Receiver distance assessment showed an SEE of 0.52 m (0.73%), and mean bias of 0.06 m. Receiver average speed assessment showed an SEE of 0.02 m.s(-1) (0.74%) and mean bias of 0.001 m.s(-1). The Bland-Altman plot showed a small difference between the two assessments with the 95% limits of agreement= +/- 1.08 m/0.046 m.s(-1). Receiver distance/speed assessment was found to be reliable, with ICC=0.999. In spite of its low cost, the new low- end GNSSr provides valid and reliable assessments of distance and average speed for young adults performing several standardized running actions of differing lengths within delimited setup spaces.

There is a strong need for a new, probably cheaper, smaller, and more portable isometric dynamometer. With this aim, we investigated the concurrent validity and reliability of a low-cost portable dynamometer to measure the isometric strength of the lower limb. Seventeen young participants (age 16.47 &plusmn, 0.51 years) were randomly assessed on three different days for knee flexion and extension isometric forces with two different devices: a commonly used isokinetic dynamometer (ISOC) and a portable isometric dynamometer prototype (ISOM). No significant differences were observed between the ISOC and the ISOM (all comparisons p &gt, 0.05). Test&ndash, retest comparison showed the ISOM to have high reliability (ICC 0.879&ndash, 0.990). This study showed that measurements with the ISOM could be performed without systematic bias and with high reliability. The ISOM is a device that is able to assess knee isometric strength with excellent concurrent validity and reliability.

Basketball is a team sport, where fundamental skills – fundamentals – are key determinants for success. Jump-shot (JS) is a basketball fundamental used frequently during game. It is interesting to spread light on the relationship between effort intensity and JS ability. Study aim was to investigate different heart rates (HRs) effect on JS accuracy (JS%) in 22 male youth (15.7 ± 0.9 years) players. Experimental sessions consisted of 10 JSs from five spots 5 m from basket at three different HRs: rest (0HR) and after warm-up (50% [50HR] and 80% maximal HR [80HR]). Analysis of variance showed differences in JS% over sessions (42.27 ± 14.78% at 0HR, 38.18 ± 10.53% at 50HR, and 30.00 ± 16.62% at 80HR ; P = 0.018). Least significant difference test did not show any significant difference between 50HR and 0HR JS% (P = 0.343), while 80HR elicited significantly lower values with respect to both 0HR (P = 0.006) and 50HR (P = 0.049). Study provided practical indications on maintaining high JS%: preliminary warm-up (even if injury-protecting) does not improve JS%, because between 50HR and 0HR difference was not significant ; and 80HR significantly decreases JS%. Therefore, to maximize JS scoring players have to rest as much as possible during game-play pauses, and coaches should manage timeouts and substitutions accordingly, especially during final minutes of close games.

The aim of this study was to identify characteristic pain prevalence in Croatian taekwondo athletes in order to indirectly decrease the number of injuries and organize a safer training process. The subject sample of 58 taekwondo athletes with international competitive experience was divided into four subsamples according to their body weight and competition category. Self-Estimated Functional Inability because of Pain questionnaire was used for data collection and neck, shoulders, elbows, upper arms, forearms, wrists, fingers, upper back, lower back, hips, thighs (front), thighs (back), knees, shins, calves, ankles/feet, and toes regions were analysed in accordance with the aim of the research. The most common pain reported by Croatian TKD athletes in total was in the knees (39.6%), lower back (31%), thighs/back (29.3%), ankles/feet (27.6%), and shoulders (20.7%) region. Early detection of lower intensity of pain can help in preventing the occurrence of injuries as well as improve professional guidance and appropriate safety requirements for taekwondo athletes.

The main aim of this study was to characterize the postural stability profile of elite Croatian male and female Taekwondo athletes. The second aim was to compare the postural stability in frontal and sagittal plane in Taekwondo athletes of different age groups. The sample was composed of three groups of Taekwondo athletes. First group included seniors (20.3±2.26), the second-juniors (16.6±0.63) and the third group was composed of cadets (14.625±0.73). The following stability parameters were used in the research: Range center of force X (RCX) ; Range center of force Y (RCY) ; Force (Force) ; Area of sway (ASWAY) ; Sway distance (SWAY) ; Speed of sway (SSWAY). Based on the discriminant analysis, all variables significantly contribute to the difference between the groups. We found that the seniors significantly differ from the cadets in all parameters, and the difference is in favour of seniors (p≤0.05). Seniors and juniors are not differ in any parameter, juniors and cadets are differ in all parameters. To conclude, postural stability parameters were higher in the senior compared junior and cadet group. The findings depend on trainee age (senior>cadets) and may be of important for the selection, training design and health care of Taekwondo athletes.

We propose several new repechage designs for knockout tournaments with 16 players, and then analyze the justness of medal distribution of such a tournament under random draw. The players are linearly ordered by strength, and a measure of justness of a tournament under a particular draw is introduced which depends on results of three (or four) best players. Then we take an average of such measure for every possible draw, and we obtain a measure of justness of a tournament design by which we compare tournaments with repechage designs proposed.

The purpose of this study was to compare the effects of programmed continuous endurance and relative strength training (CERS) with the basic military physical readiness training (BMPR) on the physical readiness. Croatian military recruits (21.3 ± 1.9 years) were divided in the CERS (N = 48) and BMPR (N = 76) groups. Training sessions were conducted three times a week for a total of 5 weeks. The t-test determined positive training effects for both training programs. Significant positive changes in BMPR group were measured in almost all measured variables. In CERS group, besides the 20 m dash run, statistically significant positive changes were not determined in standing horizontal jump, pull-ups and sit and reach test. The positive training effects in both training groups were achieved because of the low initial physical readiness level of the recruits and a short training period in which the statistically significant differences between programs could not be achieved.

The aim of this research is to determine the order and importance of impacts of particular anthropological characteristics and technical and tactical competence on success in taekwondo according to opinions of top taekwondo instructors (experts). Partial objectives include analysis of metric characteristics of the measuring instrument, and determining differences between two disciplines (sparring and technical discipline of patterns) and two competition systems (WTF and ITF). In accordance with the aims, the research was conducted on a sample of respondents which consisted of 730 taekwondo instructors from 6 continents and from 69 countries (from which we selected 242 instructors), who are at different success levels in both taekwondo competition systems (styles) and two taekwondo disciplines. The respondents were divided into 3 qualitative subsamples (OST-USP-VRH) using the dependant variable of accomplished results of the instructor. In 6 languages, they electronically evaluated the impact in percentage value (%) of motor and functional skills (MOTFS), morphological characteristics (MORF), psychological profile of an athlete (PSIH), athletic intelligence (INTE) and technical and tactical competence – (TE-TA) on success in taekwondo. The analysis of metric characteristics of the constructed instrument showed a satisfactory degree of agreement (IIr) which is proportional to the level of respondent quality, i.e. it grows along with the increase in instructor quality in all analysed disciplines of both systems. Top instructors assigned the highest portion of impact on success to the motor and functional skills (MOTFS) variable: WTF- -SPB=29.1, ITF-SPB=29.2, WTF-THN=35.0, ITF-THN=32.0). Statistically significant differences in opinions of instructors of different styles and disciplines were not recorded in any of the analysed variables. The only exception is the psychological profile of an athlete variable, which WTF instructors of sparring (AM=23.7%), on a significance level of p

The aim of this research was to determine the order and importance of particular fitness status variables impact on success in taekwondo according to opinions of top taekwondo instructors (experts). Partial objectives included analysis of metric characteristics of the measuring instrument, and determining differences between two disciplines (sparring and technical discipline of patterns) and two competition systems (WTF and ITF). In accordance with the aims, the research was conducted on a subject sample which consisted of 730 taekwondo instructors from 6 continents and from 69 coun- tries (from which we selected 242 instructors), who are at different success levels in both taekwondo competition systems (styles) and two taekwondo disciplines. The respondents were divided into 3 qualitative subsamples using a dependent variable of the instructor’s accomplished results. In 6 languages, they electronically evaluated, in percentage value (%), the impact of 8 motor and functional abilities: specific strength (STR), flexibility (FLX), specific endurance (END), speed (SPE), balance (BAL), coordination (COO), agility (AGI) and accuracy (ACC). The analysis of metric characteristics of the constructed instrument showed a satisfactory degree of agreement (IIr) which is proportional to the level of respon- dent quality, i.e. it grows along with the increase in instructor quality in all analyzed disciplines of both systems. Accord- ing to the obtained results, speed and specific endurance were ranked as the abilities which are most important for suc- cess in the sparring discipline in both competition systems (WTF and ITF), whose instructors also expressed a higher level of agreement in relation of speed and success in the technical disciplines.

Sex is one of major factors of individual variability. In kinesiology, we explore and record changes brought on by growth and development, so we will use a sample of 1020 subjects, at the age of powerful changes caused by sexual maturation, to investigate differences in morphological characteristics of children and to determine the significance of differences based on sex. The aim of this transversal research was to determine the sex differentiation of morphological characteristics in 5th and 8th grade students of elementary school as well as structural differences between the sexes. Differential sex differences in the structure of morphological parameters surely exist, and in their basis lies in a different temporal, or periodical onset of development phases, while multivariate analysis of variance for each age removes any doubt about these differences being more than obvious. Differences in the structure of discriminant function in children aged 11 are conditioned primarily by diverse structuring of transverse dimensions, in a way that boys are distinctly superior in knee diameter, and girls in bicristal diameter. As early as the age of 11, it can clearly be recognized that pre-puberty had already progressed in girls, which is then followed by puberty. At the age of 12 girls are already experiencing a puberty spurt, which is manifested in further development of bicristal diameter and longitudinal dimensionality of the skeleton, particularly of lower extremities. Thirteen year old boys are on the verge of a puberty spurt, which is manifested through the development of longitudinal dimensionality, and to a lesser extent, of transverse dimensionality of the skeleton. Secondary discriminant distinctiveness can be observed continuously across all variables assessing the dimension of deposition of fat reserves, and also, absolute values of measures of subcutaneous fat tissue are more prominent in female students. It is indicative that subcutaneous fat deposits are still secondary determinants in distinguishing groups of children according to sex, in a way that this dimension is continuously expressed more perceptibly in girls.

Purpose was To identify the differences in the profile of medal winners and other taekwondo competitors who participated in the Beijing 2008 Olympic Games. Athlete profiles were obtained from the “Official Olympic site” which included weight category, weight, height, age, points obtained, warnings, deduction point, defensive/offensive kicks, and punches. A total of 122 athletes competed (64 males and 64 females) in the Games. In males ANOVA found significant differences in both the subpatterns between the medal winners and other competitors in the: average number of points obtained per fight, average number of kicks received per fight, and average number of obtained defensive kicks to the trunk. Among females, a significant differences are evidenced in the average number of obtained offensive points to the trunk, average number of obtained offensive points to the head and average number of warnings per fight. In comparison to last two Olympics certain changes in the trend in obtaining points among the male and female competitors are evidenced. When compared with the 2000 and 2004 Olympics, in the Beijing, defensive kicks were dominant among the male competitors, whereas, in female athletes, greater homogeneity and changes in the style of fighting are observed.

The aim of the study was to determine whether a 15-hour kinesiology unicycling training might have a statistically significant impact on the development of static and/or dynamic balance of the 58 Physical Education University female (N=25) and male (N= 33) students. The subjects were divided in two groups, experimental and control. The experiment involved the measurements of morphological characteristics (body height ; body weight ; body mass index and body fat percentage) and balance by the Biodex Balance System SD in the control and the experimental group. The unicycling treatment for the experimental group lasted for 5 weeks and only the subjects without any prior motor knowledge of unicycling were included. In experimental group, the dependent sample t-test showed significant differences between the initial and the final measurement in dynamic balance with males (+12.8 % ; p

Dello Iacono, A, Martone, D, Cular, D, Milic, M, and Padulo, J. Game profile-based training in soccer: a new field approach. J Strength Cond Res 31(12): 3333-3342, 2017-The aim of the study was to profile and compare the time-motion, physiological, and neuromuscular responses of both National Youth League (NYL) and UEFA Youth League (UYL) matches with those of an experimental game profile-based training (GPBT) protocol. Time-motion traits and physiological, perceptual, and neuromuscular responses were investigated in 24 male soccer players across 14 matches and 6 GPBT training sessions, for a total of 420 samples. The GPBT had a greater influence on time-motion traits and perceptual responses than the NYL and UYL matches (all p < 0.001). No significant GPBT vs. match differences were found for mean heart rate or blood lactate (F = 1.228, p = 0.304, and F = 0.978, p = 0.385, respectively). Finally, the GPBT protocol led to greater impairment of the neuromuscular explosive performances when compared with those of the postmatch scores (squat jump: F = 19.991, p < 0.001; countermovement jump: F = 61.703, p < 0.001). Results identified the GPBT protocol as characterized by relatively greater high-intensity workloads than official NYL and UYL matches, requiring increased demanding efforts. In light of these outcomes, the GPBT protocol can be considered an advantageous training method for elite soccer players, capable of stimulating the physical effort and physiological capabilities required during a match. This approach is favorable when designing a training intervention according to the principle of sport specificity, as it is based on the specific metabolic demands.

Although government bodies, sport associations and funding organizations often need exact criterion for assessment of interests and trends for specific sports, there is no single definition of popularity determinants, as well as specific tool designed for reliable and valid measurement of particular sport’s popularity. Consequently, there is lack of scientific-based evidence about the public interests in particular sport. This paper introduces the Google Trends (GT) as a web- based tool to identify and compare public interests for 5 Olympic team sports (volleyball, handball, water polo, football, basketball) according to the worldwide public Google queries transformed into 1-100 Likert type scale. Observing last 5 years using GT, it can be concluded that football (mean = 30) is the most popular analyzed sport followed by basketball (mean = 8), volleyball (mean = 3), handball (mean =1) and water polo (mean ≤1). It can be concluded that, although limited, GT can provide valuable information about public interests for specific sport on the global, regional, or local level.