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EN
Resistance exercise is a popular form of conditioning for numerous sport disciplines, and recently different modes of strength training are being evaluated for health benefits. Resistance exercise differs significantly in nature, and several variables determine the direction and range of adaptive changes that occur in the muscular and skeletal system of the body. Some modes of resistance training can also be effective in stimulating the cardiovascular system. These variables include exercise selection (general, specific, single or multi joint, dynamic, explosive), type of resistance (free weights, variable resistance, isokinetics), order of exercise (upper and lower body or push and pull exercises), and most of all the training load which includes intensity expressed as % of 1RM, number of repetitions, number of sets and the rest interval between sets. Manipulating these variables allows for specific adaptive changes which may include gains in muscle mass, muscle strength or muscle endurance. It has been well established that during resistance exercise fatigue occurs, regardless of the volume and intensity of work applied. The peripheral mechanisms of fatigue have been studied and explained in more detail than those related to the CNS. This review is an attempt to bring together the latest knowledge regarding fatigue, both peripheral and central, during resistance exercise. The authors of this review concentrated on physiological and biochemical mechanisms underlying fatigue in exercises performed with maximal intensity, as well as those performed to exhaustion with numerous repetitions and submaximal load.
EN
Introduction: Resistance towing is perhaps the most specific form of developing strength and power in muscles involved directly during the start, acceleration and at maximum speed. Resisted sprint training may involve towing a sled which provides an overload through the friction between the sled and ground surface or a modern advanced training device which uses drag technology to provide fully controlled resistance during the movement, such as the 1080 Sprint. The main objective of the study was to evaluate the optimal loading for the development of power in the engine assisted drag technology system SPRINT 1080. Material and methods: We evaluated the changes in running velocity and the generated force and power during resisted sprints over 30m with a load of 1, 3, 6, 9, 12 and 15 kg. Seven male sprinters with national and international experience participated in the study. Their average age, body mass and body height were 22.2 ± 2.4 years, 77.43 ± 4.63 kg, and 178.6 ± 3.2 cm, respectively. All athletes performed six 30 m sprints with 5 min rest intervals in between. The first sprint was performed without additional resistance, while the remaining 5 were performed in an random order with additional resistance of 3, 6, 9, 12 and 15 kg. After receiving a verbal signal, the participant started at will from a semi crouched position. During the resisted sprint trials, the time [s] and the following variables were recorded in peak values: power output [W], generated force [N], and sprinting velocity [m/s]. Results: Our results show that loading with 6 kg decreased sprinting velocity by 9.37% while the generated horizontal power increased by 31,32%. The 6 kg loading on the Sprint 1080device corresponded to 8% body mass, yet as mentioned before the baseline results were not fully free sprinting as the tested athletes reached velocities 0.5-0.6 m/s greater without the harness. Conclusion: Taking into account this fact, our results seem to confirm previous findings, that external loads between 8 and 13% may be optimal for improving power and sprinting speed at the same time.
EN
The purpose of the study was to determine velocity changes in relation to the load lifted along with their muscular activity. Twenty athletes representing different sport disciplines, familiar with the flat bench press took part in the research project. The ANOVA analysis revealed a significantly higher effect on range of mean velocity (F = 128.34; η2 = 1.22 with p = 0.001) and maximal velocity (F = 7 3.31; η 2 = 0 .81 w ith p = 0 .001) t o m easured l oads ( 70÷100% 1-RM) i n a scending p hase. Tukey’s p ost-hoc t ests revealed a statistically significant difference between 70% and 100% 1-RM loads, in mean velocity with p = 0.001 and maximal velocity with p = 0.001. Similarly the results revealed a statistically significant difference between 80% and 100% 1-RM loads in mean velocity (p = 0,012) and maximal velocity (p = 0,021) during the ascending phase. Relationship between velocity and the muscles activity indicates that the anterior deltoid and latissimus dorsi muscles show synergy and a significant relationship for loads 90 and 100% 1-RM. The triceps brachii muscle shows a higher relationship with velocity of the barbell for loads 70% and 80%, then the relationship of the pectoralis major muscle with velocity only for 90% 1-RM.
EN
Introduction: The aim of the study was to examine relationships between power of the lower limb and agility, speed, and change of direction (COD) deficit in professional female soccer players. Material and methods: Thirty-three elite Polish Extraliga league soccer players (aged 22 ±5 years; body height 166 ± 4 cm; body weight 58 ± 8 kg) performed the following fitness tests: lower limb muscle power (Leg Press, Half Squat, Counter Movement Jump), straight linear speed (SLS 20 m), and COD speed ( Zig-Zag test, COD deficit). Using the median value as a reference, the players were subdivided into two groups (n=17; n=16) according to their LP, HS 60% 1RM, CMJ (High values below median = stronger group and Low = weaker group ). Results: The COD deficit was calculated as the difference between the 20m speed and the Zig-Zag test. The stronger group was better than the weaker group in SLS 20m (p<0.05; ES=1.23; 0.83; 0.93), but in the Zig-Zag agility test, the difference in the results was not statistically significant (p>0.05; ES=0.48; 0.34; 0.34) and this affected the COD deficit, which was higher (p<0.05; ES=0.9; 0.73; 0.72). The most important finding was that the stronger group had a higher COD deficit and its improvement (reduction) occurs only if the results of the agility test are improved (through agility training) [Ydeficit All groups=0.10+0.87* 20m - 0.83* Zig-Zag]. Increasing power (HS, LP) lead to the improvement in SLS p<0.05, not to COD abilities. Conclusion: This can be useful for coaches during agility training and to improve COD deficit in soccer players and women in general.
EN
Body response is a key element of the periodization of any training unit. The main control systems in the human body are the nervous and endocrine systems. The study aims to examine the effect of bench press at a specified movement tempo on post-exercise blood testosterone and cortisol levels. The study involved 16 men (experience in resistance training 5.5 ± 1.3 years, aged 24 ± 2 years, body weight 86.1 ± 7.2 kg, and 1RM 125 ± 17 kg). The first stage of the test focused on determining the maximum force based on a single bench press with the highest possible external load (1RM). The second stage included the main test, i.e. bench press. The participants were asked to perform 5 sets successively, with an external load of 70% of an individual 1RM and as many repetitions as possible. The tempo of the exercise was precisely specified. The metronome was used to set a bench press tempo. The movement tempo included time under tension (TUT) 2/0/2/0. TUT means the total time of muscle tension during one repetition. The tests showed significant changes in cortisol levels recorded 30 minutes after exercise, amounting to 13.75 (±4.60) at F=9.16 and p=0.006. and 60 minutes after exercise, amounting to 11.37 (±4.17) at F=19.46 and p=0.0002. No significant statistical values were found for testosterone levels. This study brings additional evidence of the importance of hormonal responses in muscle strength training.
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Time Series Approach To Athletes Motor Potential

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EN
Introduction. The aim of this study was to determine the dynamics of changes in selected motor abilities of javelin throwers and to determine predictors of javelin throw distances. Material and methods. Research material included the results obtained from a group of 60 competitors from the Silesia Region of Poland, aged 14 - 15 years. In order to answer the research question, the following statistical analysis were employed: Pearson's linear correlation coefficients, vectors R0 and R1, time series analysis, distributed lag analysis and Almon distributed lag analysis and coefficient of concordance φ2Results. The correlation analyzes allowed for a selection of two variables for further analyses: specific strength of arms and trunk (SSAT) and specific strength of shoulders girdle and trunk (SSGT). Calculated indexes revealed that the level of SSAT showed a constant upward tendency (+15%). The highest rise in SSAT level was recorded in the 4th and 5th quarter (+9%). The level of SSGT showed an upward tendency nearly (+6%). In this case, the highest rise was observed in the 7th and 8th quarter (+4.5%). Conclusions. The standardized regression analysis revealed that the variable of specific power of arms and trunk (SOBT) is the most important predictor for javelin throw distance with a full approach run.
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The aim of this study was to evaluate the effects of steroidal saponin supplementation on blood concentration of T, GH and IGF-1. The research involved 14 men between the age of 45 and 60 years. The duration of the experiment was 12 weeks. There were two series of laboratory tests. Independent tests were conducted at the beginning and after 12 weeks of the intervention. A two-way repeated measures ANOVA revealed a statistically significant effect of the intervention on the following variables: T-Ch (η2 = 0.542), HDL-Ch (η2 = 0.522), LDL-Ch (η2 = 0.587), T (η2 = 0.603), IGF-1 (η2 = 0.512) and GH (η2 = 0.621). Thus, FFM significantly increased while TBF and BM decreased in comparison to pre-intervention levels. The analyzed results indicate that treatment or supplementation of individual hormone deficiencies can be a successful form of counteracting the aging process. Nevertheless, the effects of TT supplementation on the concentration of T as well as GH and IGF-1, requires further studies, especially in middle-aged and older subjects, along with different exercise programs. The analyzed results indicate that treatment or supplementation of individual hormone deficiencies can be a major form of counteracting the aging process.
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