scholarly journals A Comparative Study on the Performance Profile of Under-17 and Under-19 Handball Players Trained in the Sports School System

2020 ◽  
Vol 17 (21) ◽  
pp. 7979
Author(s):  
Tomasz Gabrys ◽  
Arkadiusz Stanula ◽  
Subir Gupta ◽  
Urszula Szmatlan-Gabrys ◽  
Daniela Benešová ◽  
...  
Keyword(s):  
Power Output ◽  
Age Groups ◽  
Sprint Performance ◽  
Maximal Velocity ◽  
Relative Power ◽  
Jump Performance ◽  
Absolute Power ◽  
Counter Movement Jump ◽  
Significant Difference ◽  
Power Outputs

This study evaluates the anatomical profiles, jump, sprint, power outputs, endurance, and peak blood lactate levels ([LA]peak) of handball players of two age groups—U17 (n = 77) and U19 (n = 46)—and analyses the role of training in their physical abilities. Vertical jump performance was determined by counter movement jump (CMJ) and counter movement jump with free arms (CMJFA) tests. A running-based anaerobic sprint test (RAST) determined the relative power output (watts/kg body weight) and absolute power output (watts) of the players. Sprint performance over 5 m, 10 m, and 30 m distances was evaluated. An incremental shuttle run test (40 m) was designed to determine aerobic threshold (AeT), anaerobic threshold (AnT), and [LA]peak. All parameters were measured for pivots, wingers, backs, and goalkeepers of each group. The U19 players were significantly heavier than the U17 group, but both the groups were nearly equal in height. The U19 group jumped higher than the U17 members, although the only significant difference (p = 0.032) was observed between the wingers of the groups in CMJ. Sprint performance varied marginally between the groups and only U19 pivots were found to be significantly (for distances of 5, 10, and 30 m: p = 0.047, p = 0.018, and p = 0.021, respectively) faster than U17 pivots. No difference in relative power output between the groups was noted, although the U19 players recorded higher absolute power outputs. Maximal velocity and velocities at the AeT and AnT were almost similar in the groups. Distance covered by the groups at the intensities of AeT and AnT varied only little. Higher [LA]peak was observed in the U19 players. U19 players failed to convert their superior power into speed and jump. The training pattern of the handball players needs to be revised so that U19 players may develop faster and be more enduring than the U17 group.

Enhanced Performance With Elastic Resistance During the Eccentric Phase of a Countermovement Jump

2013 ◽  
Vol 8 (2) ◽  
pp. 181-187 ◽  
Author(s):  
Saied Jalal Aboodarda ◽  
Ashril Yusof ◽  
N.A. Abu Osman ◽  
Martin W. Thompson ◽  
A. Halim Mokhtar
Keyword(s):  
Power Output ◽  
High Speed ◽  
Tensile Force ◽  
Reaction Force ◽  
Jump Height ◽  
Vertical Ground Reaction Force ◽  
Jump Performance ◽  
Leg Stiffness ◽  
Significant Difference ◽  
Infrared Cameras

Purpose:To identify the effect of additional elastic force on the kinetic and kinematic characteristics, as well as the magnitude of leg stiffness, during the performance of accentuated countermovement jumps (CMJs).Methods:Fifteen trained male subjects performed 3 types of CMJ including free CMJ (FCMJ; ie, body weight), ACMJ-20, and ACMJ-30 (ie, accentuated eccentric CMJ with downward tensile force equivalent to 20% and 30% body mass, respectively). A force platform synchronized with 6 high-speed infrared cameras was used to measure vertical ground-reaction force (VGRF) and displacement.Results:Using downward tensile force during the lowering phase of a CMJ and releasing the bands at the start of the concentric phase increased maximal concentric VGRF (6.34%), power output (23.21%), net impulse (16.65%), and jump height (9.52%) in ACMJ-30 compared with FCMJ (all P < .05). However, no significant difference was observed in the magnitude of leg stiffness between the 3 modes of jump. The results indicate that using downward recoil force of the elastic material during the eccentric phase of a CMJ could be an effective method to enhance jump performance by applying a greater eccentric loading on the parallel and series elastic components coupled with the release of stored elastic energy.Conclusions:The importance of this finding is related to the proposition that power output, net impulse, takeoff velocity, and jump height are the key parameters for successful athletic performance, and any training method that improves impulse and power production may improve sports performance, particularly in jumping aspects of sport.

Anaerobic Capacity in Biathletes Depending on the Type of Autonomic Heart Rate Regulation

2020 ◽  
pp. 368-377
Author(s):  
Fedor B. Litvin ◽  
◽  
Tat’yana M. Bruk ◽  
Pavel A. Terekhov ◽  
Natal’ya V. Osipova
Keyword(s):  
Heart Rate ◽  
Power Output ◽  
Maximum Speed ◽  
Regulation Mechanism ◽  
Relative Power ◽  
Work Output ◽  
Total Work ◽  
Absolute Power ◽  
Rate Regulation ◽  
Heart Rate Regulation

Successful work of biathletes on the track and at the shooting range largely depends on the typological features of the autonomic regulation of heart rate. We examined 46 biathletes aged 18–25 years. The types of autonomic heart rate regulation were determined according to the generally accepted method using Varikard 2.51 equipment. Sport-specific performance was measured on the Ergomedic 894E Peak Bike ergometer (Monark Exercise, Sweden). Personified types of autonomic heart rate regulation were combined into two groups: with the dominance of the central regulation mechanism (CRM, 45 % of subjects) and of the autonomic regulation mechanism (ARM, 55 % of subjects). The 6-second test for assessing speed abilities revealed statistically significant (p < 0.05) differences: biathletes with CRM were faster, their peak power output was higher and their time to reach maximum speed was shorter compared to biathletes with ARM. As to the strength abilities, subjects with CRM were superior (p < 0.05) to their colleagues in terms of speed and relative power output; their power gradient was greater, and their time to reach maximum speed was shorter (p < 0.05). During the 15-second test, biathletes with ARM showed a statistically significant (p < 0.05) increase in total work output, absolute power output, and endurance coefficient compared to the subjects with CRM. When switching to the 45-second mode, biathletes with ARM retained their advantages (p < 0.05) in terms of total work output, absolute power output, and speed endurance. At the same time, their relative power output was lower compared to that of athletes with CRM. Thus, with the shortest possible anaerobic mode, the efficiency is higher in biathletes with dominant CRM, while at longer modes, in biathletes with ARM predominance.

Changes in Elbow Flexor Power with Intermittent Contractions and Various Loads

2008 ◽  
Vol 107 (2) ◽  
pp. 597-606
Author(s):  
Shunsuke Yamaji ◽  
Shinichi Demura ◽  
Hiroki Aoki ◽  
Kei Yamamoto
Keyword(s):  
Power Output ◽  
Peak Power ◽  
Muscle Power ◽  
Average Power ◽  
Elbow Flexion ◽  
Voluntary Contraction ◽  
Significant Difference ◽  
Average Power Output ◽  
Power Outputs ◽  
Intermittent Contractions

This study examined intermittent elbow flexion every 2 see. for 1 min. using various loads to study the properties of muscle power output and their relationship to peak power, defined as the maximum power output. 18 young men performed intermittent explosive elbow flexion (30 times × min.−1) using 30%, 40%, and 50% maximal voluntary contraction (MVC). The power outputs at 30% and 40% MVC slightly decreased (rate of decrease from peak power to average power output during the 26 to 30 contractions was about 5%). However, at 50% MVC, there was a marked decrease (33.6%). Power output for 8 contractions was significantly larger at 50% MVC than at 30% and 40% MVC, but after 9 contractions there was no significant difference between 40% and 50% MVC. In addition, after 27 contractions, 40% MVC was significantly larger than 30% and 50% MVC. That is, the tendency for power output to decrease differed among the various loads. The rate of decrease of power outputs showed no significant correlation with peak power for each load. Therefore, the rate of decrease or power output in intermittent contractions may help sustain the power output and cannot be evaluated as accurately as peak power.

Sex Differences of Intermittent Elbow Flexion Power Using Various Loads

2008 ◽  
Vol 107 (2) ◽  
pp. 629-642
Author(s):  
Shunsuke Yamaji ◽  
Shinichi Demura ◽  
Kei Yamamoto
Keyword(s):  
Sex Difference ◽  
Power Output ◽  
Peak Power ◽  
Muscle Power ◽  
Elbow Flexion ◽  
Young Males ◽  
Significant Difference ◽  
Power Outputs ◽  
Increasing Load ◽  
Load Mass

This study was designed to clarity a sex difference in muscle power output properties by intermittent elbow flexion using various loads. 10 young males and 10 young females performed intermittent elbow flexion power outputs at 30 times × min.−1 for 1 min. using 30%, 40%, and 50% MVC loads. For both sexes, the decreasing peak power showed a similar trend between trials at all loads, and the reliability of each power parameter was good. The power outputs decreased largely with increasing load mass, and the power output in 50% MVC for males markedly decreased to the same level as that during the final phase in 30% MVC. Although the absolute value of regression coefficients for males became significantly larger with increasing load mass, that for females showed a significant difference only between 30% and 50% MVC. In 50% MVC, a large decrease for males was observed. Maximal peak power outputs were significantly larger with increasing load mass for both sexes, but for males more than for females. In both sexes, there were no significant differences among final powers of each load mass, and between total powers of 40% and 50% MVC. For the sum of every 5 consecutive power outputs, males showed significant differences between 30% and 40% MVC in all periods after the 6th contraction, but females did not and also between 30% and 50%. MVC in periods after the 16th contraction. In conclusion, it is considered that power outputs in the latter phases in 50% MVC are affected largely by muscle fatigue, and an intermittent power output test with 50% MVC can measure sustained power (fatigue resistance) in the latter phases, but there is a sex difference in the tendency to decrease.

Absolute and Relative Power Output in Men and Women

1986 ◽  
Vol 63 (3) ◽  
pp. 1309-1310
Author(s):  
William S. Barnes ◽  
Scott M. Hasson ◽  
Walter L. Gadberry ◽  
Tim W. Henrich ◽  
Chin-Lung Fang
Keyword(s):  
Physical Activity ◽  
Power Output ◽  
Athletic Performance ◽  
Muscle Power ◽  
Weight Ratio ◽  
Power Weight ◽  
Relative Power ◽  
Men And Women ◽  
Absolute Power ◽  
Reliable Predictor

Measurements of 18 men and 19 women in physical activity courses show men generate more absolute muscle power than women and produce greater power per unit of time. If absolute power does not accurately reflect the power/weight ratio, it may not be a reliable predictor of certain athletic performance.

scholarly journals Korelasi Antara Lompat Vertikal Dengan Performa Sprint 60 Meter Pada Atlet Taekwondo dan Karate

2020 ◽  
Vol 10 (2) ◽  
pp. 63-68
Author(s):  
Tommy Apriantono ◽  
Syahruddin Syahruddin ◽  
Bagus Winata ◽  
Doddy Abdul Karim
Keyword(s):  
Martial Arts ◽  
Vertical Jump ◽  
Sprint Performance ◽  
Jump Performance ◽  
Warm Up ◽  
Jumping Performance ◽  
Significant Difference ◽  
First Session

Taekwondo dan Pencak silat merupaka dua contoh cabang olahraga seni bela diri yang saat ini sedang berkembang saat ini. Maka dari itu, tujuan daripada penelitian ini adalah untuk mengukur serta mengetahui korelasi antara performa lompat vertikal dengan sprint 60 meter pada atlet Taekwondo dan Pencak silat. Seluruh peserta, dibagi menjadi dua kelompok berdasarkan kecabangan mereka, yaitu kelompok Taekwondo (TKW), dan kelompok Pencak silat (PKS). Seluruh peserta diwajibkan untuk melakukan pemanasan secara statis dan dinamis selama minimal 15 menit. Setelah sesi pemanasan selesai, kelompok TKW memulai pertama untuk sesi pengukuran anthropometry, lompat vertikal, dan sprint. Kelompok PKS lebih unggul dalam melakukan performa loncatan, yaitu 57,33 (± 7,73) cm dibandingkan dengan kelompok TKW sebesar 55,78 (± 4,30) cm. Sedangkan untuk hasil sprint 60 meter, menunjukkan bahwa terdapat perbedaan yang signifikan antara sprint 60 meter antara kelompok TKW dan PKS (p = 0,007), dimana kelompok PKS (7,94 ± 0,15) detik lebih cepat dibandingkan dengan kelompok TKW (8,48 ± 0,49) detik. Hasil dalam penelitian ini, menunjukkan bahwa terdapat korelasi antara performa lompat vertikal dengan performa sprint 60 meter, pada atlet Takewondo dan Pencak silat.Taekwondo and Pencak silat are two examples of martial arts sports that are currently being developed. Therefore, the purpose of this study was to measure and determine the correlation between vertical jump performance and 60 meter sprints in Taekwondo and Pencak silat athletes. All participants were divided into two groups based on their branches, namely the Taekwondo group (TKW) and the Pencak silat group (PKS). All participants are required to warm up statically and dynamically for at least 15 minutes. After the warm-up session was over, the TKW group started the first session for anthropometry measurement, vertical jump, and sprint. The PKS group was superior in jumping performance, 57.33 (± 7.73) cm compared to the TKW group of 55.78 (± 4.30) cm. As for the results of the 60 meter sprint, it shows that there were a significant difference between the 60 meter sprint between the TKW and PKS groups (p = 0.007), where the PKS group (7.94 ± 0.15) seconds is faster than the TKW group (8, 48 ± 0.49) seconds. The results in this study indicate that there were a correlation between vertical jump performance and 60 meter sprint performance, for Takewondo and Pencak silat athletes.

scholarly journals Acceleration and Maximum Running Phases in 60-m Sprint and Vertical Jump Performance

Proceedings ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 21
Author(s):  
Ntoumas ◽  
Nounos ◽  
Ioannidis ◽  
Voutselas
Keyword(s):  
Pearson Correlation ◽  
Vertical Jump ◽  
Body Height ◽  
Sprint Performance ◽  
Maximal Velocity ◽  
Jump Height ◽  
Weak Correlation ◽  
Maximal Power ◽  
Acceleration Phase ◽  
Jump Performance

AIM: The purpose of the present study was to investigate the correlation between acceleration and maximum running phase in 60-m sprint and vertical jump performance. Furthermore, to investigate the factors that affect the acceleration phase, maximum running phase, and overall 60-m sprint performance. MATERIAL & METHOD: Participants were 25 young amateur athletes, aged 18 ± 1 years, with body mass 64.64 ± 13.39 kg and body height 1.71 ± 0.11 m. We examined the correlation between the acceleration phase (0–30 m) and maximum running phase (30–60 m) and 60-m sprint performance, measured with photocells (Optojump), and vertical jump performance (take-off velocity, jump height, maximal velocity, maximal power), measured with a force plate (Bertec). Pearson correlation was used to examine the correlation between the forementioned parameters (SPSS, v. 21). RESULTS: There was a correlation between jump height and 60-m sprint performance (r = −0.713, p < 0.001), maximum running phase (r = −0.512, p = 0.15), and a weak correlation with acceleration phase (r = −0.495, p = 0.19). There was a correlation between take-off velocity and 60-m sprint performance (r = −0.732, p < 0.001), maximum running phase (r = −0.553, p = 0.08), and a weak correlation with acceleration phase (r = −0.472, p = 0.27). There was a weak correlation between maximal velocity, acceleration phase (r = 0.439, p = 0.41), and 60-m sprint performance (r = 0.438, p = 0.42). There was a correlation between maximal power and 60-m sprint performance (r = −0.739, p < 0.001), acceleration phase (p = −0.635, p = 0.02), and a weak correlation with maximum running phase (r = −0.437, p = 0.042). There was a correlation between 60-m sprint performance and maximum running phase (r = 0.792, p < 0.001) and acceleration phase (r = 0.596, p = 0.03). Finally, there was a correlation between body height and 60-m sprint performance (r = −0.738, p = 0.02) and maximum running phase (r = −0.666, p = 0.07). CONCLUSIONS: According to our results, 60-m sprint performance was highly correlated with body height, maximum running phase and all the vertical jump parameters (explosive power), except for maximal power, which had a high correlation with the acceleration phase (sprint acceleration).

Liver Elastography in Healthy Children Using Three Different Systems – How Many Measurements Are Necessary?

2020 ◽  
Author(s):  
Anders Batman Mjelle ◽  
Anesa Mulabecirovic ◽  
Roald Flesland Havre ◽  
Edda Jonina Olafsdottir ◽  
Odd Helge Gilja ◽  
...  
Keyword(s):  
Shear Wave ◽  
Transient Elastography ◽  
Intraclass Correlation ◽  
Age Groups ◽  
Liver Stiffness ◽  
Shear Wave Elastography ◽  
Healthy Children ◽  
Significant Difference ◽  
Pediatric Liver Disease ◽  
Liver Elastography

Abstract Purpose Liver elastography is increasingly being applied in screening for and follow-up of pediatric liver disease, and has been shown to correlate well with fibrosis staging through liver biopsy. Because time is of the essence when examining children, we wanted to evaluate if a reliable result can be achieved with fewer acquisitions. Materials and Methods 243 healthy children aged 4–17 years were examined after three hours of fasting. Participants were divided into four age groups: 4–7 years; 8–11 years; 12–14 years and 15–17 years. Both two-dimensional shear wave elastography (2D-SWE; GE Logiq E9) and point shear wave elastography (pSWE; Samsung RS80A with Prestige) were performed in all participants, while transient elastography (TE, Fibroscan) was performed in a subset of 87 children aged 8–17 years. Median liver stiffness measurement (LSM) values of 3, 4, 5, 6, 7, and 8 acquisitions were compared with the median value of 10 acquisitions (reference standard). Comparison was performed for all participants together as well as within every specific age group. We investigated both the intraclass correlation coefficient (ICC) with absolute agreement and all outliers more than 10 %, 20 % or ≥ 0.5 or 1.0 kPa from the median of 10 acquisitions. Results For all three systems there was no significant difference between three and ten acquisitions, with ICCs ≥ 0.97. All systems needed 4 acquisitions to achieve no LSM deviating ≥ 1.0 kPa of a median of ten. To achieve no LSM deviating ≥ 20 % of a median of ten acquisitions, pSWE and TE needed 4 acquisitions, while 2D-SWE required 6 acquisitions. Conclusion Our results contradict recommendations of 10 acquisitions for pSWE and TE and only 3 for 2D-SWE.

The influence of osteopathic correction on the rate of various rhythms of the body

2019 ◽  
pp. 64-71 ◽  
Author(s):  
A. E. Chernikova ◽  
Yu. P. Potekhina
Keyword(s):  
Heart Rate ◽  
Respiratory Rate ◽  
Age Groups ◽  
Biomechanical Properties ◽  
Dispersion Analysis ◽  
The Body ◽  
Body Tissues ◽  
Age Related ◽  
Significant Difference ◽  
Before And After

Introduction. An osteopathic examination determines the rate, the amplitude and the strength of the main rhythms (cardiac, respiratory and cranial). However, there are relatively few studies in the available literature dedicated to the influence of osteopathic correction (OC) on the characteristics of these rhythms.Goal of research — to study the influence of OC on the rate characteristics of various rhythms of the human body.Materials and methods. 88 adult osteopathic patients aged from 18 to 81 years were examined, among them 30 men and 58 women. All patients received general osteopathic examination. The rate of the cranial rhythm (RCR), respiratory rate (RR) heart rate (HR), the mobility of the nervous processes (MNP) and the connective tissue mobility (CTM) were assessed before and after the OC session.Results. Since age varied greatly in the examined group, a correlation analysis of age-related changes of the assessed rhythms was carried out. Only the CTM correlated with age (r=–0,28; p<0,05) in a statistically significant way. The rank dispersion analysis of Kruskal–Wallis also showed statistically significant difference in this indicator in different age groups (p=0,043). With the increase of years, the CTM decreases gradually. After the OC, the CTM, increased in a statistically significant way (p<0,0001). The RCR varied from 5 to 12 cycles/min in the examined group, which corresponded to the norm. After the OC, the RCR has increased in a statistically significant way (p<0,0001), the MNP has also increased (p<0,0001). The initial heart rate in the subjects varied from 56 to 94 beats/min, and in 15 % it exceeded the norm. After the OC the heart rate corresponded to the norm in all patients. The heart rate and the respiratory rate significantly decreased after the OC (р<0,0001).Conclusion. The described biorhythm changes after the OC session may be indicative of the improvement of the nervous regulation, of the normalization of the autonomic balance, of the improvement of the biomechanical properties of body tissues and of the increase of their mobility. The assessed parameters can be measured quickly without any additional equipment and can be used in order to study the results of the OC.

The Influence of Age and Gender on Mandibular Indices among the Libyan Population

2019 ◽  
Vol 3 (2) ◽  
Keyword(s):  
Negative Correlation ◽  
Bone Mineralization ◽  
Age Groups ◽  
T Test ◽  
Chi Square ◽  
Age And Gender ◽  
Significant Difference ◽  
Chi Square Test ◽  
And Gender ◽  
Libyan Population

Radiographic Mandibular Indices serve as easy and relatively cheap tools for evaluating bone mineralization. Objectives: To examine the effect of age and gender on three mandibular indices: the panoramic mandibular index (PMI), the mandibular ratio (MR) and the mandibular cortical index (MCI), among Libyan population. Methods: The three indices were measured on 317 digital (OPGs) of adult humans (155 males, 162 females). The sample was divided into six age groups (from 18-25 years through 56-65 years). The measurements were analyzed for interactions with age and sex, using SPSS (Statistical Package for Social Studies) software version no. 22. The tests employed were two way ANOVA, the unpaired T-test and chi-square test. Results: The mean PMI fluctuated between 0.37 s.d. 0.012 and 0.38 s.d. 0.012. among the sixth age groups. One-way ANOVA statistical test revealed no significant of age on PMI. On the other hand gender variation has effect on PMI, since independent sample t-test disclosed that the difference between the male and female PMI means statistically significant. ANOVA test showed that the means of MR among age groups showed a negative correlation i.e. MR mean declined from 3.01 in 18-25 age groups to 2.7 in 55-65 age groups. In contrary, the gender showed no effect on MR according two sample t-test at p> 0.05. In regards with MCI, statistical analysis showed that it affected by age that is C1 was decreasing by age while C2 and C3 were increased by age. Using chi square test the result indicated that there is a significant difference among the different age group and the two genders in MCI readings. Conclusion: PMI was influenced significantly by age but minimally by the gender. MR is not affected by gender but has a negative correlation with age. MCI is affected by both age and gender

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