Introduction. The rapid development of the World's Olympic Taekwondo began with the introduction of this discipline to the programme of the Olympic Games. In its Olympic form, taekwondo fight is based on the rivalry of two players in a direct challenge, mainly to strike a specific blow at an opponent. All over the world the most popular Taekwondo dyscipline is Kyourugi -sports fight. The main objective of undertaken studies was to determine the effect of changes in sports regulations of taekwondo on the range of technical activities used by female athletes.Material and methods. In the study it was analyzed a total of 48 fights (84 players) in two Olympic taekwondo tournaments: Beijing -2008 and London -2012. There were observed 6 fights in each weight category (-49 kg, -57 kg, -67kg, over 67kg), 24 fights in each tournament. It was used the method of secondary direct analysis.Results. It was observed an increase in number of technical activities taken in upper zone -olgul (attack on an opponent's head) and a decrease in number of technical activities in lower zone -montong (attack on an opponent's trunk).Conclusions. The changes in the sports regulations have changed the range of technical acctivities used by female athletes in attack and counterattack. The players more often realized actions in the counterattack. In both analyzed tournaments it was found that a greater number of technical activities were taken towards a trunk (zone montong) than towards a head (zone olgul). However, it should be noted the significant statistical increase of technical activities towards olgul between the tournament in Beijing and the tournament in London (p <0.05).

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Open Access License:This is an open access article distributed under the terms of the Creative Commons Attribution-Non-commercial 4.0 International (http://creativecommons.org/licenses/by-nc/4.0/), which permits use, distribution, and reproduction in any medium, provided the original work is properly cited, the use is non-commercial and is otherwise in compliance with the license. abstract BackgroundThe aim of the study was to investigate the effectiveness of kettlebell exercises in the aspect of shaping the special efficiency characteristics required by American football players. Material/MethodsThekettlebellstraininggroup(n=12)andtheAmericanfootballgroup(n=12),whoused trainingtypicaloftheirdiscipline,weresubjectedtoafitnesstestinUSfootball,consisting ofa40-yardrunspeedtest,anagilitytestintwoshuttleruns,ajumpingtestinCounter MovementJump(CMJ),andapowerandstrengthendurancetests. ResultsIntestsofspeed,agility,jumpingandpower,therewerenosignificantdifferencesbetween footballers and kettlebell exercisers, while strength endurance testing (benchpress with 100kg)andonespecialagilitytest(twoshuttleruns)showedthattrainingwithkettlebells develops these qualities of physical fitness significantly worse than standard football practice(p<0.05). ConclusionsKettlebelltrainingcanbebeneficialforshapingmostcharacteristicsofthespecialefficiency neededinAmericanfootballbutitisnotabletocompletelyreplacethetraditionalfootball strengthtrainingprogram,basedonexerciseswithbarbells.

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SummaryStudy aim: To find out whether a 6-week creatine supplementation would significantly augment body mass and muscle circumferences in male bodybuilders. Material and methods: A group of 14 male bodybuilders aged 16 -29 years were randomly divided into two groups: experimental (E) and control (C), 7 subjects each. Group E received creatine monohydrate, Group C -placebo, 10 g daily for 6 weeks without saturation phase. The experimental design was a double-blind one. All subjects were on strictly controlled diet, the daily intakes amounting to 2.3 -2.8 g of protein, 1.0 -1.2 g of fat and 5 -6 g/kg body mass of carbohydrate, and 3200 -4000 kcal. All subjects trained 3 days a week, each session lasting 120 min, in the 'Power, Rep-Range, Shock' mode. Chest, waist, arm, forearm, thigh and calf girths were measured in the relaxed and contracted states, together with body mass, before and after the study. Results: Significant, training-induced changes were noted in almost all body circumferences studied in both groups and muscle states, those in the chest, biceps and thigh girths being the most pronounced ones and significantly (p<0.05) greater in the experimental than in control group in the contracted muscle state. In the relaxed state the between-group differences were significant for the chest and thigh girths. The increments in body mass were significantly (p<0.01) higher in the experimental than in control group (4.3 ± 1.3 and 2.1 ± 0.7 kg, respectively). Conclusions:The observed changes may have been brought about by creatine administration.

The problem addressed in this study is the appropriateness of using different pre-training supplementation strategies and their ability to improve training performance and psychological measures. The aim of the study is the evaluation of the effectiveness of a multi-ingredient pre-workout supplement (MIPS) containing beta-alanine, L-citrulline malate, arginine alpha-ketoglutarate, L-taurine, L-tyrosine and caffeine compared to an exact dosage of anhydrous caffeine in bench press strength endurance, feeling scale (FS), felt arousal scale (FAS) and session rating of perceived exertion (sRPE). A group of fifteen resistance-trained males, weighing 83.92 ± 8.95 kg and having an average of 5.6 ± 3.38 years of training experience, tested their bench press 10 repetition maximum (79.01 ± 12.13). In a cross-over manner, they participated in two sessions where they were blinded to the order of supplementation they were given: either a MIPS including caffeine or caffeine alone. They completed the bench press strength endurance test with pre- and post-training psychological assessments containing FS, FAS and sRPE. Bench press repetition volume was greater after anhydrous caffeine than MIPS supplementation with no difference in psychological measures. These results indicate that MIPS supplementation is less ergogenic and cost effective than caffeine alone.

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Polymorphism (rs1805086), c.458A>G, p.Lys(K)153Arg(R), (K153R) of the myostatin gene (MSTN) has been associated with a skeletal muscle phenotype (hypertrophic response in muscles due to strength training). However, there are not enough reliable data to demonstrate whether MSTN rs1805086 K and R allelic variants are valid genetic factors that can affect the strength phenotype of athletes’ skeletal muscles. The aim is to conduct a systematic review and meta-analysis of the association of MSTN rs1805086 polymorphism with the strength phenotype of athletes. This study analyzed 71 research articles on MSTN and performed a meta-analysis of MSTN K153R rs1805086 polymorphism in strength-oriented athletes and a control (non-athletes) group. It was found that athletes in the strength-oriented athlete group had a higher frequency of the R minor variant than that in the control group (OR = 2.02, P = 0.05). Thus, the obtained results convincingly demonstrate that there is an association between the studied polymorphism and strength phenotype of athletes; therefore, further studies on this association are scientifically warranted.