Linear and nonlinear programming: effects on the physical abilities of young basketball players

BackgroundThe aim of the investigation was to compare the occurrence of post-activation performance enhancement (PAPE) after drop jumps, or heavy sled towing, and the subsequent effect on repeated sprint ability (RSA).MethodsTen young basketball players (17 ± 1 yrs) performed, in randomized order, RSA test with changes of direction after a standardized warm up followed by drop jumps, heavy sled towing, or no exercise (control condition). Neuromuscular assessments composed of two maximal voluntary contractions of the knee extensors, peripheral nerve stimulation, and surface electromyography (EMG), responses were recorded before and immediately after the RSA. The EMG signal of leg muscles during sprinting were also recorded as well as the blood lactate concentration.ResultsThe drop jumps improved the RSA mean time (P = 0.033), total time (P = 0.031), and slowest time (P = 0.029) compared to control condition, while heavy sled towing did not change RSA outcomes (P > 0.05). All conditions exhibited a decrease of doublet high frequency stimulation force (pre-post measurement) (P = 0.023) and voluntary activation (P = 0.041), evidencing the occurrence from peripheral and central components of fatigue after RSA, respectively, but no difference was evident between-conditions. There was a significantly greater EMG activity during sprints for the biceps femoris after drop jumps, only when compared to control condition (P = 0.013).ConclusionRepeated drop jumps were effective to induce PAPE in the form of RSA, while heavy sled towing had no effect on RSA performance in young basketball players. Furthermore, both conditioning activities exhibited similar levels of fatigue following the RSA protocol. Thus, drop jumps may be used as an alternative to induce PAPE and thus improve performance during sprints in young male basketball players.

Background and Study Aim. Team sports, basketball and handball, as well as their competitions, are very popular throughout the world. The aim of this research was evaluation and comparative analysis of the results of a vertical jump between young basketball and handball players. Material and Methods. A group of 37 participants took part in the research: 21 basketball players from the basketball club OKK ''Novi Pazar'' (age: 15.5 ± 0.5) from Novi Pazar formed the first subgroup and 16 handball players from the handball club RK ''Železničar 1949'' (age: 25.4 ± 5.8; body height = 193.5 ± 7.5 cm; body weight = 94.0 ± 7.4 kg; body mass index = 25.03 ± 2.38 kg/m2) from Niš formed the second subgroup. Explosive power of the vertical jumps was assessed by the following tests: countermovement jump, countermovement jump/arm swing, squat jump. Participants had at least 5 years of training experience and held similar acute training histories prior to study commencement, completing 4 weeks of baseline conditioning during the general preparatory phase. Participants were free of injury, illness and disease as determined by a team physician prior to study participation. Results. The results of the independent samples t-test show that there were no significant differences (p > 0.05) between basketball and handball players in all vertical jump tests. Conclusions. This article contains new information about vertical jumps of young male basketball and elite male handball players that could be extremely useful for coaches. Also, these findings suggest that basketball coaches may benefit from talents’ identification in young basketball players.

Previous article Next article Extensions of Lagrange Multipliers in Nonlinear ProgrammingF. J. GouldF. J. Gouldhttps://doi.org/10.1137/0117120PDFBibTexSections ToolsAdd to favoritesExport CitationTrack CitationsEmail SectionsAbout[1] K. J. Arrow, , Leonid Hurwicz and , Hirofumi Uzawa, Studies in linear and non-linear programming, With contributions by H. B. Chenery, S. M. Johnson, S. Karlin, T. Marschak, R. M. Solow. Stanford Mathematical Studies in the Social Sciences, vol. II, Stanford University Press, Stanford, Calif., 1958vii+229, Chap. 3 MR0108399 (21:7115) 0091.16002 Google Scholar[2] R. Brooks and , A. Geoffrion, Finding Everett's Lagrange multipliers by linear programming, Operations Res., 14 (1966), 1149–1153 MR0210449 (35:1342) CrossrefISIGoogle Scholar[3] G. Eppen and , F. J. 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A lot of sport and vigorous games (football, handball, basketball and others) are connected by similar movement actions that are based on the same or similar physical properties and demand similar models of movement, which are performed in different conditions; therefore, physiological requirements differ according to the time and intensity of their performance (Meckel, Gottlieb, Eliakim, 2009). They are influenced by different factors (the surface and size of the field, number of players); however, these sports are similar in terms of aerobic and anaerobic capacity demands for the fitness of players. Despite that aerobic activity prevails in team sports, the main actions are accomplished in anaerobic conditions in competitions (Abdelkrim et al., 2007; Sporis, Vuleta, Vuleta, Milanovic, 2010). The aim of the current research is to explore the results of the indicators of physical development, general and special physical fitness of young football, handball and basketball players, as well as to accomplish their comparative analysis. 22 basketball players, 22 football players and 22 handball players aged 13-14 took part in the research. Their physical development (height, weight) and physical fitness (30 m run, standing long jump, and 10×5 meter shuttle run) were determined. The analysis of research results was carried out using SPSS 19.0 for Windows. The research results on physical development revealed that the tallest were handball players, as well as their scores were the highest. The smallest weight and height were determined among footballers. The results of 30 meter run, standing long jump and 10×5 meter shuttle run of handball players were considerably better in comparison to football and basketball players. The results of basketball players in 30 meter run, standing long jump and shuttle run were lower than the ones of handball and football players. Statistically significant differences were determined in the test of 30 m run and standing long jump between basketball and handball players, and between basketball and football players (p < 0,05), as well as a statistically significant difference was identified in the results of shuttle run between basketball and football players (p < 0,05). The analysis of the physical development and anaerobic capacity results of 13-14 year old football, basketball and handball players revealed the greatest height and weight of handball players, as well as disclosed statistically significantly better results in 30 m run and standing long jump. The weight and height of footballers was the lowest; yet their results in shuttle run were considerably better. It is possible to assume that basketball, football and handball players have similar anaerobic physical capacities. Therefore, the obtained data can be beneficial for coaches in evaluating anaerobic sport activity, the selection process of gifted athletes, as well as adjusting training programmes for young handball, basketball and football players. Keywords: physical fitness, special physical development, physical capacities. DOI: http://dx.doi.org/10.15823/sm.2016.28

The Basketball School program was launched to track and support young talented basketball players in Russia under the aegis of the Russian Basketball Federation and the SIBUR gas processing company. Physical and technical conditions of players and their anthropometric indicators are monitored each year. The program covers a three-year period and is held annually in several stages. The stages include testing the physical and motor conditions of young players, field sessions with the coaches of the Russian professional basketball team, training camps for talented players and seminars for coaches of youth basketball teams. A study was conducted based on the results obtained during the testing. It was aimed to determine the periods of increase in physical qualities and motor abilities among young basketball players. The relationship between height and other anthropometric indicators was indicated, they can serve as a selection criteria for basketball teams. The results obtained can be used in the formation of training methodology for young basketball players.

Jumping ability in basketball is usually assessed using standardized vertical jump tests. However, they lack specificity and do not consider the player’s basketball skills. Several studies have suggested performing specific jump tests, which are tailored to the movement patterns and requirements of a basketball game. The pivot step jump test (PSJT) is a novel test designed to evaluate the specific jumping abilities of basketball players by combining a pivot step on one leg with a maximum bilateral vertical jump. This study had two aims: to determine the reliability and validity of the PSJT using typical jump tests as the criterion measure and to demonstrate the PSJT as a practical test to evaluate specific jumping ability in young male and female basketball players. Twenty female (EGA; 14.0 ± 0.7 years, 59.3 ± 7.9 kg, 162.1 ± 5.5 cm) and fifteen male (EGB; 14.0 ± 0.7 years, 58.1 ± 7.7 kg, 170.3 ± 6.4 cm) basketball players participated in the study. The test–retest reliability of the PSJT within sessions (intrasession reliability) and across sessions (intersession reliability) was assessed within EGA. For the evaluation of validity, EGB performed the PSJT and a series of criterion jumping tests. For EGA, no changes (p > 0.05) were found in PSJT performance between test sessions and excellent intra- and intersession reliability was observed (ICCs > 0.75). Correlation coefficients indicated high factorial validity between the jumping tests and PSJT (r = 0.71–0.91, p < 0.001). The PSJT appears to offer a valid assessment of jumping ability in basketball and is a practical test for assessing sport-specific jumping skills in young basketball players.

Improving Anaerobic Fitness in Young Basketball Players: Plyometric vs. Specific Sprint Training Basketball is a game that is typically performed in an intermittent manner, and includes numerous bursts of explosive activity. Thus, implementation of training methods that best develop anaerobic fitness is of significant importance to basketball coaches and players. The aim of the present study was to compare the effect of plyometric and specific sprint training, matched for total volume, on the anaerobic fitness of young basketball players. Nineteen young (16.3 ± 0.5 years) male basketball players were randomly assigned to either a plyometric training group or a specific sprint training group, and completed two similar fitness tests prior to and following six weeks of training. The two training programs consisted of plyometric jump training (4 sets of 4-6 series with 6 jumps each) and specific sprint training (4 sets of 4-6 × 20 m repetitions). Prior to training there were no baseline differences between the groups in 20 m sprint time (speed test), bounding distance and vertical jump height (power tests), 2×5 m run time (agility test) or suicide run time (basketball-specific anaerobic endurance test). Plyometric training led to a significant improvement only in the suicide test time (1.6 ± 1.6%, p<0.05). Specific sprint training led to a significant improvement in the 20 m sprint time (2.6 ± 1.7%), bounding distance (3.9 ± 3.8%), and suicide test time (1.2 ± 1.1%, p<0.05 for all). However, there was no significant between-group differences in the training effects on any of the anaerobic variables measured. Neither training program had a significant effect on jump height or the 2×5 m run. The study showed that plyometric training and specific sprint training do not differ statistically in enhancing anaerobic fitness of young basketball players. Thus, coaches may have the possibility of alternating between these methods during the busy basketball season.

The main purpose of this research was to determine relationship of the target-based orientation and the Competitive anxiety with the young Basketball players’ performance in Erzurum province championship tournaments. So the whole young Basketball players’ of Erzurum Province participating in the championship tournaments in 2014 were selected as the statistical technique. The questionnaire of the target-based orientation at sport and the questionnaire of the competitive anxiety and the study of the Basketball players’' results were applied in order to gather the related data. This study was an applied and a descriptive-correlation type. The results showed there is a significant relationship between the target-based orientation and sport performance of Basketball players’ participated in Erzurum championship tournaments. There is also significant relationship between the task-based element and sport performance of the young Basketball players’. There is no observed a significant relationship between the target-based orientation and sport performance of the Basketball players’. There is a significant relationship between the competitive anxiety and the sport performance of the young Basketball players’ in the championship tournaments of Erzurum.

The aim of this study was to examine the effects of maximal aerobic power (V(.-)O2max peak) level on the ability to repeat sprints (calculated as performance decrement and total sprinting time) in young basketball players. Subjects were 18 junior, well-trained basketball players (age, 16.8 +/- 1.2 years; height, 181.3 +/- 5.7 cm; body mass, 73 +/- 10 kg; V(.-)O2max peak, 59.6 +/- 6.9 ml x kg(-1) x min(-1)). Match analysis and time-motion analysis of competitive basketball games was used to devise a basketball-specific repeated-sprint ability protocol consisting of ten 15-m shuttle run sprints with 30 s of passive recovery. Pre, post, and post plus 3-minute blood lactate concentrations were 2.5 +/- 0.7, 13.6 +/- 3.1, and 14.2 +/- 3.5 mmol x L(-1), respectively. The mean fatigue index (FI) value was 3.4 +/- 2.3% (range, 1.1-9.1%). No significant correlations were found between V(.-)O2max peak and either FI or total sprint time. A negative correlation (r = -0.75, p = 0.01) was found between first-sprint time and FI. The results of this study showed that V(.-)O2max peak is not a predictor of repeated-sprint ability in young basketball players. The high blood lactate concentrations found at the end of the repeated-sprint ability protocol suggest its use for building lactate tolerance in conditioned basketball players.

Engineering Optimization Theory and Practice

Basketball is a major sport worldwide among different age groups that leads to a high frequency of injuries at multiple body sites. Upper and lower extremities and lower back are common pain sites in basketball players; however, there is little information about the relationship between upper or lower extremity pain and lower back pain. This study elucidated the associations between upper extremity (shoulder and elbow) pain and lower back pain (LBP) among young basketball players. We conducted a cross-sectional study using self-reported questionnaires mailed to 25,669 young athletes; the final study population comprised 590 basketball players, and their median age was 13 years (range: 6-15 years). The point prevalence rates of lower back, shoulder, elbow, and upper extremity pain among young basketball players were 12.9% (76/590), 4.6% (27/590), 2.7% (16/590), and 7.1% (42/590), respectively. Multivariate logistic regression analyses revealed that upper extremity pain was significantly associated with LBP (adjusted odds ratio [OR]: 7.86; 95% confidential interval [CI], 3.93-15.72). Shoulder pain was significantly associated with training per week (> 4 days) (adjusted OR: 4.15; 95% CI: 1.29-13.40) and LBP (adjusted OR: 13.77; 95% CI: 5.70-33.24). This study indicates that upper extremity and shoulder pain is associated with LBP among young basketball players. Assessing for lower back pain, as well as elbow and/or shoulder pain, may help prevent severe injuries in young basketball players. In conclusion, parents and coaches should be properly re-educated to help improve lower back, upper extremity, and shoulder pain among young basketball players.

Comparison of linear, nonlinear, and network flow programming techniques in fuel scheduling

The aim of this study was to evaluate young football and basketball players in terms of different agility tests. The eleven young basketball and twelve young football players joined to this study voluntarily. The Ilinois test, T-test and 505 tests were performed for determination agility performances of players. The test durations were recorded by photocell system and pre-test and post-test heart rate values were determined by heart rate monitors. The intergroups differences of all agility test values were examined by independent samples T-test. According to analyze results, T-test agility values didn’t differentiate among groups significiantly as statistical while it was seen significiant difference between young football and basketball players in regard to Ilinois and 505 test values (p < 0.05). It was determined that young football players had better values than young basketball players in regard to Ilinois and 505 test values. The young football players had better test values than young basketball players in terms of Ilinois and 505 test values and this situation revealed that agility performance differentiated among football and basketball events. It could be said that football players had better agility values because of the fact that football game needed to activities requiring agility further in comparison to basketball game.

Background and Study Aim. Coordination skills are an important indicator of success for young athletes in team sports. Therefore, the methods used to monitor these skills should include reliable and valid tests of coordination. The purpose of this study is to identify ways to improve the monitoring of coordination abilities in young basketball players aged 13–14 years. Material and Methods. Basketball players aged 13–14 years participated in the study (n=35, training experience – 3–5 years). Twelve tests were used to assess the level of technical and tactical preparedness of the athletes. The reliability of these tests was evaluated by determining the correlation coefficients between the results of the first test and subsequent tests. The criteria for the informativeness of the tests were based on the experts' rank assessments of the coordination and technical preparedness of young basketball players. A 10-point scale was used for the expert assessment of players' technical skills, with each indicator evaluated from 1 to 10 points. Results. The data obtained indicate that all selected tests demonstrated reliability with correlation coefficients above r = 0.5. Tests assessing muscle effort, adjusting motor activity, sense of rhythm, spatial orientation, and reaction speed showed reliability coefficients sufficient for both individual and group assessments (r &gt; 0.70). Slightly lower reliability coefficients were observed in the time taken to perform individual motor tasks. The validity of the tests was evaluated based on ratings of coordination and technical readiness, as well as overall test battery ratings. In most cases, the validity was not lower than r = 0.3, with some tests exceeding r = 0.5. The correlation coefficient between grades and the total rank score based on the coordination test battery ranged from r = 0.5 to 0.7. The coefficient of concordance showed a high level of agreement among experts regarding the effectiveness of the technical and tactical actions of young basketball players. Conclusions. The conducted study demonstrated the importance of developing and monitoring the coordination abilities of young basketball players during adolescence. The use of several homogeneous tests to assess each individual coordination ability allows for a more reliable evaluation. The need to identify specific types of coordination skills that play a key role in competitive basketball activities has been emphasized. Additionally, the use of a latent indicator in evaluating the coordination abilities of young basketball players will contribute to optimizing a differentiated approach in the training process.

A team shared belief in its capability to organize and execute some actions required to achieve given performance level is referred as collective efficacy. Collective efficacy in sports appears to be dependent on the interactions and organized dynamics between the players within the team, their competences, including physical competence, organization, structure and strategies. It is directly related to team performance potential. In the present study we examined the changes of perceived collective efficacy among young basketball players and 10 to 17 years across a 4-month competitive season, accounting for variation by age group since youth sports are generally organized by competitive age groups. Based on the repeated measures across 4 months in the range of age observed, we explored the trends of perceived collective efficacy among this sample players. Sixty-five adolescent male basketball players aged 13,7 (9,5 to 17,3) years at baseline were considered. Collective Efficacy Questionnaire for Sports (CEQS) was used to assess players´ perception of collective efficacy. The adolescent basketball players had high CEQS scores. Except for persistence, all CEQS factors did not vary by age group. However, no distinct trend of differences between age group was present. The CEQS factors remained high after 4-months competitive season exposure, except for ability where there was a systematic decrease for players scores at end-season. A negative trend of change was apparent for persistence, preparation and unity as players were closer to late adolescence years. The results in this study highlight the importance for coaches and practitioners to consider environment and context influence on young basketball players´ collective efficacy perception. A team shared belief in its capability to organize and execute some actions required to achieve given performance level is referred as collective efficacy. Collective efficacy in sports appears to be dependent on the interactions and organized dynamics between the players within the team, their competences, including physical competence, organization, structure and strategies. It is directly related to team performance potential. In the present study we examined the changes of perceived collective efficacy among young basketball players and 10 to 17 years across a 4-month competitive season, accounting for variation by age group since youth sports are generally organized by competitive age groups. Based on the repeated measures across 4 months in the range of age observed, we explored the trends of perceived collective efficacy among this sample players. Sixty-five adolescent male basketball players aged 13,7 (9,5 to 17,3) years at baseline were considered. Collective Efficacy Questionnaire for Sports (CEQS) was used to assess players´ perception of collective efficacy. The adolescent basketball players had high CEQS scores. Except for persistence, all CEQS factors did not vary by age group. However, no distinct trend of differences between age group was present. The CEQS factors remained high after 4-months competitive season exposure, except for ability where there was a systematic decrease for players scores at end-season. A negative trend of change was apparent for persistence, preparation and unity as players were closer to late adolescence years. The results in this study highlight the importance for coaches and practitioners to consider environment and context influence on young basketball players´ collective efficacy perception.