Vertical Versus Horizontal Training for Improving the Change of Direction Speed in Adult Basketball Players: A Systematic Review and Meta-analysis.

ABSTRACT: Barrera-Domínguez, FJ, Martínez-García, D, Jerez-Mayorga, D, Chirosa-Ríos, LJ, Almagro, BJ, and Molina-López, J. Vertical versus horizontal training for improving the change of direction speed in adult basketball players: a systematic review and meta-analysis. J Strength Cond Res XX(X): 000-000, 2023-The ability to perform changes of direction (COD) is a complex skill that involves the application of multiple force-orientations, and its execution at maximum speed is crucial in basketball players. The present study aimed to synthesize findings from previous interventions classified according to force-orientation (vertical, horizontal, or mixed) and determine their magnitude of the effect on COD performance in basketball players. A systematic review of the literature was performed in several databases (Web of Science, Scopus, SPORTDiscus, and PubMed) following the PRISMA statement and reviewed the quality of the included papers according to the Cochrane Collaboration Guidelines Assessment. Sixteen articles with a total of 21 reports were included to analyze the role of force-orientations in COD performance. For the meta-analysis, the standardized mean differences with 95% confidence intervals (CIs) were calculated to determine the chronic changes induced by training and performed an effect size (ES) analysis with a random-effects model. The results showed that all force-orientations generated improvements in COD performance (ES = -0.47 [95% CI -0.57, -0.36], Z = 8.74 [p < 0.01]). It was a mixed force-orientation that produced the greatest changes (ES = -0.91 [95% CI -1.27, -0.55], Z = 4.96 [p < 0.01]), followed by vertical training (ES = -0.45 [95% CI -0.70, -0.20], Z = 3.51 [p < 0.01]). Horizontal training was the least studied and showed the smallest change (ES = -0.10 [95% CI -0.14, -0.07], Z = 5,71 [p < 0.01]). This meta-analysis demonstrates that mixed vertical and horizontally oriented training may be the most optimal because it offers a greater variety of multidirectional stimuli that better prepares the athlete to deal with complex COD in real-game situations.

The role of motivation and emotions in physical education: understanding academic achievement and the intention to be physically active.

Introduction: This study aims to understand how emotions and motivation influence the academic achievement of physical education (PE) students and their future intention to practice physical activity (PA). Despite the influence on student's behaviors and the reciprocal associations between motivation and emotion, the number of studies addressing both constructs at the same level is very limited. Methods: A structural equation model was used with 799 students aged 11-17 years (M = 13.16; SD = 1.17). Results and discussion: The results showed that the teacher support of the basic psychological needs (BPN) predicted students' BPN satisfaction, which in turn predicted their autonomous motivation and positive emotions, and negatively predicted their negative emotions. Finally, autonomous motivation predicted students' intention to be physically active, whereas academic achievement was predicted by both autonomous motivation and emotions. We conclude that to better understand the consequences of PE classes, it is necessary to consider both constructs.

Effect of individualised strength and plyometric training on the physical performance of basketball players.

The aims of this study were to examine the effects of eight weeks of individualised force-velocity imbalance (F-Vimb) training on physical performance in basketball players and to analyse the differences in physical performance between two periods of time (four to eight weeks) with this training. Thirty male players (age, 22.8 ± 5.68 years; height, 1.87 ± 0.07 m; body mass, 86.3 ± 11.1 kg) were divided into an intervention group (INT, n = 15), who performed an individualised training based on individual F-Vimb; and a control group (CON, n = 15), who underwent a non-individualised training programme; both groups performed two days/week of intervention and the same pre-season basketball training. At baseline, at four weeks, and at eight weeks of intervention, an assessment was performed including countermovement-jumps, unilateral drop jumps, triple hop test, force-velocity profile, sprint and change of direction (COD). At four weeks, the INT showed improvements in sprint and vertical jumping actions (≥3.76%, ES ≥0.44, p ≤ 0.02). At eight weeks, the INT continued to improve vertical jumping actions (p < 0.05) and showed improvements in horizontal jumping (6.80%, ES = 0.45, p < 0.01) and COD (≥2.99%, ES ≥0.96, p < 0.01). A significant reduction in F-Vimb was observed for INT (ES = 0.77, p = 0.01). In contrast, none of these changes were observed in CON. Thus, an individualised F-Vimb training intervention improved physical performance after eight weeks, with changes in sprint and vertical jump after first four weeks. Basketball coaches should optimise the force-velocity profile and improve the performance in sport-related actions as jumping and changing direction.

An individualised F-Vimb training programme improved sport-specific actions after eight weeks in basketball athletes.Improvements were specific to the orientation worked on, with vertical jumping and sprint actions being the most sensitive to change after just four weeks of individualised F-Vimb intervention.In complex actions such as COD, it would be recommended to optimise the F-V profile, emphasising a vertical force-orientation for at least 8 weeks.

Late embryo mortality in Holstein cows inseminated with Holstein or Limousine frozen semen.

The objective of this study was to compare the late embryo mortality (LEM) rate (losses approximately between 32 and 53 days of gestation) and Pregnancy Specific Protein B (PSPB) and progesterone (P4) concentrations on day 32 post AI in Holstein cows bred with either Holstein or Limousine semen. A sample size of 1082 cows per group diagnosed pregnant between 28- and 35-days post breeding was calculated. The study consisted of evaluating LEM (%) in a cohort of Holstein cows bred with Holstein semen (HO × HO) or Limousine semen (HO × LM), to compare pregnancy loss from 28 to 35 days post breeding to 50-57 days post breeding. A logistic regression model to compare embryo losses was developed considering as main explanatory variable the cohort (HO × HO embryo vs. HO × LM embryo), correcting by lactation number, breeding season, days to breeding and AI technician. HO × HO embryos had greater LEM (15.16%) than HO × LM embryos (9.79%). Cows bred in summertime had higher LEM (15.23%) than cows bred in no-summertime (9.88%). There were no differences among AI technicians. Within summertime there was no difference in LEM (%) between groups within each lactation number; yet, within no-summertime, LEM (%) was higher in HO × HO than HO × LM within each lactation number. Pregnancy SPB optical densities were significantly greater in the HO × HO than in the HO × LM (p = .023) group; yet, the concentration of P4 was not different between groups (p > .05).

Predicting Perceived Sport Performance via Self-Determination Theory.

Sport performance depends in part on psychological factors. Self-determination theory emphasizes that the satisfisfaction of basic psychological needs and autonomous motivation may be linked to positive behavioral results and positive perceptions of performance. Our main objective in this study was to analyze the predictive power of such variables as perceived autonomy support, the satisfaction of psychological needs, and autonomous motivation on perceived sport performance. We recruited 447 young Portuguese athletes/participants (340 males, 107 females; Mage = 15.72 years, SD = 1.8). We had participants complete Portuguese sport versions of the Perceived Autonomy Support Exercise Climate Questionnaire, the Basic Psychological Needs in Exercise Scale, the Behavior Regulation Sport Questionnaire and the Perceived Performance in Sport Questionnaire. A gender invariant structural equation model showed that the coach's autonomy support significantly predicted the satisfaction of psychological needs for autonomy, competence, and relatedness. The satisfaction of these three psychological needs predicted autonomous motivation. Satisfying the need for competence positively predicted perceived sport performance, but autonomous motivation was not significantly related to perceived performance.

Analysis of the Different Scenarios of Coach's Anger on the Performance of Youth Basketball Teams.

In spite of the negative effects of anger, coaches are often seen becoming angry during games. This is especially worrying in U18 categories. Thus, the objective of this study was to identify the influence that the coach's anger has on the performance of a basketball team in competition. For this, an ad hoc observation tool was designed, in which 587 moments of anger from the coaching staff (64 coaches) were recorded in the 24 semi-final and final matches of the Spanish Autonomous Region Team Championships in 2019 and 2020 in the infantil (M = 14 years old) and cadete (M = 16 years old) categories. The results show that, in response to most incidents of coach anger, the performance of the team did not change. Significant differences were identified in some scenarios, with low- or medium-intensity anger targeted at the defence, where the team performance improved. However, anger towards the referee in the last quarter with scores level had a negative influence on the team's performance.

Complementarity between microhistological analysis and PCR-capillary electrophoresis in diet analysis of goats and cattle using faecal samples.

An evaluation is made of the complementarity between two non-invasive techniques, cuticle microhistological analysis (CMA) and PCR-capillary electrophoresis (PCR-CE) DNA-based analysis, for the determination of herbivore diet composition from faecal samples. Cuticle microhistological analysis is based on the different microanatomical characteristics of the epidermal fragments remaining in the faeces. The PCR-CE technique combines PCR amplification of a trnL(UAA) genomic DNA region with amplicon length determination by CE, with this length being characteristic for each species or taxon. A total of 37 fresh stool samples were analyzed, including 16 from feral goats (Capra hircus) from the Tramuntana mountain range (Mallorca, Baleares) and 11 from Bruna dels Pirineus cattle breed (Bos taurus) from the surrounding Montserrat mountain range (Barcelona, Spain). All the animals were in a free grazing Mediterranean pine habitat, dominated by Aleppo pine (Pinus halepensis). The results showed that both techniques detected a similar number of plant components in the faeces of goats and cows. In the case of goats, a positive correlation was obtained between the percentage of samples in which a particular taxon is detected by CMA and the percentage of samples in which that taxon is detected by PCR-CE. This correlation was not observed in the case of cows. It is concluded that PCR-CE is a fast and reliable method to detect the different plant components in the faeces of herbivores. However, it cannot be considered as an alternative to CMA, but as a complementary method, since both techniques can detect some taxa that are not detected by the other technique. In addition, CMA detected the presence of the different taxa in a greater number of samples, and at the same time, it enables quantitative data to be obtained for plant diet composition. The species of herbivore also seems to influence the results obtained by PCR-CE, so more studies are required to address this aspect.

The association of prepartum urine pH, plasma total calcium concentration at calving and postpartum diseases in Holstein dairy cattle.

The use of anionic salts to prevent milk fever in dairy cattle has been an effective nutritional strategy; however, the degree of acidification that determines the most acceptable productive responses and well-being of the cow is still a controversial topic. The objective of this study was to assess urine pH in prepartum Holstein cows fed anionic diets and determine its association with plasma total Ca, Mg, P, ß-hydroxyl-butyrate (BHB) concentrations at parturition and the occurrence of peripartum disorders. This investigation consisted of 2 studies. Study 1 was conducted on a grazing dairy. Between February and May 2019, 60 prepartum multiparous cows were tested for urine pH and plasma metabolite concentration at parturition. Total Ca, P, Mg and BHB at day 1 in milk (DIM) were assessed and statistically analyzed by ANOVA (models for polynomial regression). Study 2 was conducted on a drylot dairy farm. Between July 2018 and January 2019, 203 cows were evaluated for urine pH and followed-up for 30 DIM to obtain the incidence of dystocia, stillbirths, milk fever, retained fetal membranes, metritis, clinical mastitis and ketosis. Cows were categorized based on their last urine pH as group 1: pH > 7.0 (n = 135); group 2: pH between 6.0 and 7.0 (n = 46) and group 3: pH < 6.0 (n = 22). A logistic regression model for each health event was conducted considering urine pH group as the main effect. Urine sample was collected at 2.71 ±â€¯2.84 days before parturition. In study 1, there was a quadratic effect of urine pH on total Ca. Total Ca concentration was higher between urine pH 6.0 and 7.0, while decreasing below pH 6.0 and above pH 7.0. There was a trend (P = 0.11) for a quadratic effect of urine pH on the concentration of plasma BHB at parturition. ß-Hydroxyl-butyrate was lower approximately between urine pH 6.5 and 7.5. In study 2, the odds for a stillborn in cows with urine pH < 6.0 was 2.39 (95% CI = 1.06-5.40) times the odds for a stillborn in cows with urine pH ≥ 7.0. There was no association between urine pH and the other diseases. In conclusion, cows with prepartum urine pH < 6.0 and >7.0 had lower concentration of plasma total Ca and tended to have a higher concentration of BHB. Cows with urine pH < 6.0 had a higher incidence of stillbirths than cows with urine pH > 7.0.

Perceived Performance, Intrinsic Motivation and Adherence in Athletes.

Sports performance depends on a complex interaction of variables, such as psychological, physical, technical and tactical abilities. The purpose of the three studies described in this article was to validate an instrument to measure perceived performance in athletes (studies 1 and 2), and to analyze the predictive power of perceived performance, basic psychological needs and intrinsic motivation on the intention to be physically active (which was used as a predictor of adherence to sport) (study 3). In study 1, the Perceived Performance in Sports Questionnaire was validated in the Spanish sports context, analyzing its factorial structure, reliability, and temporal stability with 146 soccer players. The objective of study 2 was to check the factorial structure of the questionnaire with an objective performance measure (points scored and time played). The sample was 180 young basketball players. The objective of study 3 was to analyze the predictive power of basic psychological needs in exercise, intrinsic motivation, and perceived performance on the intention to be physically active in 339 athletes of fifteen different sports. The results show the reliability and validity of the questionnaire, and positive correlations with the points scored. Finally, the analysis of the structural equation model showed that the satisfaction of the need for competence predicted perceived performance and intrinsic motivation predicted perceived performance and intention to remain physically active.

Efficacy of estradiol or GnRH in combination with progesterone intravaginal devices to control the follicular wave dynamics and resulting fertility in lactating dairy cows.

This study was conducted to compare efficacy of treatments with EB or GnRH and different quantities of exogenous progesterone (P4) for synchronization of time of ovulation on follicular growth and pregnancy in lactating dairy cows. In Experiment 1, 40 cows were treated with EB or GnRH and 1.9 or 3.0 g of P4 via progesterone-containing intravaginal devices (IVPD; D0), two doses of PGF2α on D7, GnRH on D9, and TAI on D10. In Experiment 2, 1,440 cows were treated with EB or GnRH and 1 g IVPD on D0, cloprostenol, eCG and EB on D7. Cows in estrus by 48 h were AIDE, and non-estrous cows were administered GnRH and TAI 60 h after IVPD removal. Non-estrous cows were AIDE 72 h after IVPD removal. In Experiment 1, P4 was greater on D7 for cows treated with GnRH than those treated with EB. The dominant follicle was larger for cows treated with GnRH than those treated with EB. In Experiment 2, for estrous cows, pregnancy per AI was greater in cows AI at 48 h compared to 60 h after IVPD removal for cows treated with GnRH, and greater with AI at 60 h after IVPD removal compared to 48 h in EB-treated cows. In non-estrous cows, there was no effect on pregnancy. In conclusion, treatment with GnRH compared with EB resulted in increased P4 regardless of amount of exogenous P4, and there were differential proportions of estrous cows pregnant depending on time of AI after IVPD removal.

Decisive Factors for a Greater Performance in the Change of Direction and Its Angulation in Male Basketball Players.

A study was made to initially evaluate whether the age category directly could influence anthropometric measurements, functional movement tests, linear sprint (30 m) and strength. Moreover, and as the main purpose, this study aimed to examine the relationship between the time execution and angles in different changes of direction (COD) test with the analyzed sport performance variables. A total sample of 23 basketball players (age: 17.5 ± 2.42 years; height: 184.6 ± 6.68 cm; body weight: 78.09 ± 11.9 kg). Between-groups' comparison explored the differences between basketball categories (Junior, n = 12; Senior, n = 11). The COD variables were divided by the time execution into low responders (LR) and high responders (HR) to establish comparisons between groups related to COD time execution. Pearson's correlation coefficient was used to establish correlations between different CODs and sport performance variables. The results showed a greater influence of age category upon COD performance, especially when the cutting angle was sharper (7.05% [Confidence limits (CL) 90%: 2.33; 11.99]; Quantitative chances (QC) 0/2/98), in which athletes need greater application of strength. Moreover, the sharper the angle or the larger the number of cuts made, the greater the relationship with the vertical force-velocity profile (-42.39 [CL 90%: -57.37; -22.16]; QC 100/0/0%). Thus, the usefulness of the f-v profile to implement training programs that optimize the f-v imbalance and the improvement of the COD performance in basketball players is suggested.

Validation of the Achievement Emotions Questionnaire for Physical Education (AEQ-PE).

The fundamental role of emotions in education has been revealed in recent years. The control-value theory of achievement emotions has been postulated as one of the most used theories in this field. Thanks to the Achievement Emotions Questionnaire (AEQ), achievement emotions have been measured in different subjects and countries. The purpose of this research was to adapt and validate this questionnaire to assess achievement emotions in physical education. The sample of participants consisted of 902 (Mage = 13.15, SD = 1.17) secondary education students from various secondary schools in Spain. The psychometric properties of the Achievement Emotions Questionnaire for Physical Education (AEQ-PE) indicate that the scales are reliable and valid, as demonstrated by exploratory and confirmatory factor analysis, temporal stability, internal consistency and regression analysis. Considering the results achieved in the present study, the AEQ-PE opens a range of possibilities for both teachers and researchers. This instrument will help to understand the role of emotions in student learning and their motivation towards physical education.

Complementing the Self-Determination Theory With the Need for Novelty: Motivation and Intention to Be Physically Active in Physical Education Students.

The theoretical framework of the self-determination theory establishes that the satisfaction of basic psychological needs and more self-determined motivational forms are related to positive behavioral consequences and, therefore, may increase the intention to be physically active in Physical Education students. In this sense, the need for novelty has been proposed as a psychological need by recent scientific evidence, so it is necessary to prove its possible contribution to the prediction of young people's behavior. Therefore, the main objective of the study was to test a model that analyzed the power of prediction of the satisfaction of the needs for autonomy, competence, relatedness, and novelty as well as the motivation experienced in Physical Education on the intention to be physically active. A questionnaire was administered to 1665 Physical Education students with an average age of 12.43 years (SD = 1.87), of which 835 were boys and 830 were girls. An adaptation of the Spanish educational context of the Basic Psychological Needs in Exercise Scale (BPNES) that includes the need for novelty, the Perceived Locus of Causality Scale (PLOC), and the Intention to be Physically Active Scale (IPAS) was used. Path analysis results showed that the satisfaction of the psychological needs for autonomy, competence, relatedness, and novelty predicted autonomous motivation. On the other hand, the need for autonomy positively predicted controlled motivation, while the satisfaction of relatedness did so negatively. The need for competence and autonomous motivation positively predicted the intention to be physically active in Physical Education students, obtaining an explained variance of 33%. However, controlled motivation was not related in a statistically significant way to the intention to be physically active. In conclusion, the results of the hypothesized model highlight the importance of satisfying all the basic psychological needs (including novelty) and give special emphasis to the need for competence, since it predicts autonomous motivation and the intention to be physically active outside of the educational context.

Effects of Cooperative-Learning Interventions on Physical Education Students' Intrinsic Motivation: A Systematic Review and Meta-Analysis.

The aim was to review the effects of cooperative learning interventions on intrinsic motivation in physical education students, as well as to conduct a meta-analysis to determinate the overall effect size of these interventions. The PRISMA guidelines were followed to conduct this systematic review and meta-analysis. The PEDro Scale was used to assess the risk of bias and the GRADE approach was used to evaluate the quality of the evidence. A total of five studies fulfilled the inclusion criteria and they were included in the meta-analysis. Effect size for intrinsic motivation of each study was calculated using the means and standard deviations of the Perceived Locus of Causality Scale (PLOC) before and after the intervention. The overall effect size for intrinsic motivation was 0.38 (95% CI from 0.17 to 0.60) while the heterogeneity was large. Although four of the five studies reported significant within-group improvements in intrinsic motivation, only three studies showed significant between-group differences in favor of the experimental group. The findings showed that program duration and participant age may be relevant factors that must be considered by educators and researchers to conduct future effective interventions. Cooperative learning interventions could be a useful teaching strategy to improve physical education students' intrinsic motivation. However, given the large heterogeneity and the low quality of the evidence, these findings must be taken with caution.

Perceived Novelty Support and Psychological Needs Satisfaction in Physical Education.

In recent years, novelty has been proposed as a potential fourth basic psychological need. In the present study, the behavior of novelty resulting from support from the Physical Education teacher was evaluated in 723 students with an average age of 13.30 years old. The first objective was to validate the Support for Basic Psychological Needs-4 (SBPN-4) in Physical Education questionnaire, which included support for the novelty factor. The second objective was to test the mediation model in order to confirm the effect of support for novelty in relation to basic psychological needs and intrinsic motivation. The results obtained show that the Support for Basic Psychological Needs-4 (SBPN-4) questionnaire is a valid and reliable tool. On the other hand, support for novelty predicts satisfaction of basic psychological needs, particularly novelty satisfaction, which in turn predicts intrinsic motivation. These results show how the students are capable of perceiving the teacher's support for novelty and how this positively influences their intrinsic motivation. Further investigations are required to continue developing our knowledge of the role of novelty as a basic psychological need.

Absence of Quantum-Confined Stark Effect in GaN Quantum Disks Embedded in (Al,Ga)N Nanowires Grown by Molecular Beam Epitaxy.

Several of the key issues of planar (Al,Ga)N-based deep-ultraviolet light-emitting diodes could potentially be overcome by utilizing nanowire heterostructures, exhibiting high structural perfection, and improved light extraction. Here, we study the spontaneous emission of GaN/(Al,Ga)N nanowire ensembles grown on Si(111) by plasma-assisted molecular beam epitaxy. The nanowires contain single GaN quantum disks embedded in long (Al,Ga)N nanowire segments essential for efficient light extraction. These quantum disks are found to exhibit intense light emission at unexpectedly high energies, namely, significantly above the GaN bandgap, and almost independent of the disk thickness. An in-depth investigation of the actual structure and composition of the nanowires reveals a spontaneously formed Al gradient both along and across the nanowire, resulting in a complex core/shell structure with an Al-deficient core and an Al-rich shell with continuously varying Al content along the entire length of the (Al,Ga)N segment. This compositional change along the nanowire growth axis induces a polarization doping of the shell that results in a degenerate electron gas in the disk, thus screening the built-in electric fields. The high carrier density not only results in the unexpectedly high transition energies but also in radiative lifetimes depending only weakly on temperature, leading to a comparatively high internal quantum efficiency of the GaN quantum disks up to room temperature.