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This study aimed to compare the effects of 8-week combined vertical-oriented vs. horizontal-oriented training interventions in basketball athletes. Eighteen highly trained U-16 basketball players participated in this study and were randomly assigned to either a combined vertical-oriented training group (CVG, n = 9) or a combined horizontal-oriented training group (CHG, n = 9). Bilateral and unilateral vertical jump height, unilateral horizontal jump distance, 5-m, 10-m, and 20-m sprint times, change- of-direction sprint times, and a limb symmetry index were among the measured performance variables. Combined strength training was performed twice a week for 8 weeks. CVG was compounded by the squat exercise (3 sets of 6-8 R at 30-45% 1 repetition maximum [1RM]), jump squats (2 sets of 6 R, at 5-12.5% body mass [BM]), and vertical jumps (3-4 sets × 6 R). CHG included the hip thrust exercise (3 sets of 6-8 R at 30-45% 1RM), sled towing sprints (2-3 R, at 5-12.5% BM), and sprints (3-4 R of 20-m). Within-group differences showed significant (p < 0.05 and statistical power >80%) improvements in unilateral vertical jumping with the right leg after both training interventions. By contrast, only CHG improved 5-m, 10-m, and 20-m sprint times (p < 0.05 and statistical power >80%). Significant effects were observed for CHG compared with CVG in 5-m, 10-m, and 20-m sprint times (p < 0.05 and statistical power >80%). This study reinforces the importance of oriented-combined training based on force-vector specificity target, mainly in horizontal-oriented actions. [ABSTRACT FROM AUTHOR]

Brink, NJ, Constantinou, D, and Torres, G. Postactivation performance enhancement in healthy adults using a bodyweight conditioning activity: a systematic review and meta-analysis. J Strength Cond Res 37(4): 930–937, 2023—A systematic review and meta-analysis were conducted to review the available evidence on whether a bodyweight conditioning activity can acutely improve the performance outcome of a subsequent task through postactivation performance enhancement. Data sources included PubMed (National Library of Medicine), Web of Science (Clarivate Analytics), Google Scholar, SPORTDiscuss (EBSCO), Embase (Elsevier), and Thesis Global. Subjects were healthy, active adults who performed either a vertical jump or a linear sprint outcome measurement. All studies were randomized controlled trials where the effects of a bodyweight conditioning activity were compared with a control condition. The control group followed the same course as the experimental group excluding the intervention, with the intervention and outcome measurement carried out in the same session. The intervention was completed before the initiation of the outcome measure testing. Nineteen studies fulfilled the eligibility criteria and were included. There was a small overall effect of 0.30 (95% confidence interval 0.14–0.46, p = 0.0003) in favor of using a bodyweight conditioning activity to improve the outcome of a subsequent vertical jump or linear sprint. Secondary analysis indicated that there was no difference between the vertical jump and sprint subgroup, <5 minutes or 5 minutes and greater between the intervention and outcome measurement subgroup, or whether an intervention with the same movements or different movements was used before the outcome task subgroup. Using bodyweight conditioning activities before performing a maximal vertical jump or sprint may provide a small benefit in performance outcome. [ABSTRACT FROM AUTHOR]

The aim of this brief narrative review is to summarize the present evidence, provide recommendations for data analysis, and provide appropriate training methods to reduce strength and power asymmetries within athlete populations. Present evidence shows that a strong interest in the assessment of asymmetry exists. Despite the perceived associated relationship between asymmetry and injury and performance, a clear link is still missing. Practitioners need to be aware of this when they decide to assess asymmetries and later design training interventions. Several bilateral and unilateral tests could be used to assess asymmetries, such as isokinetic dynamometry, the isometric mid-thigh pull, squat, and Nordic hamstring exercise. Based on the current evidence, future investigations require further standardization of methodology and analysis to optimize interpretation (e.g., within session and between session), adoption, and implementation of interlimb asymmetry testing and appropriate interventions. In this review, 3 training interventions have been proposed to reduce existing lower limb asymmetries in sport populations: traditional resistance training, flywheel resistance training, and combined training interventions, with some evidence suggesting that such interventions can reduce lower limb asymmetries. Nonetheless, the number and quality of articles currently available are too limited to draw firm conclusions; therefore, further research is needed to verify whether training interventions can achieve these aims. To develop an understanding and application of interventions addressing interlimb asymmetries within the sport, greater methodological rigor should be applied toward study design, data analysis, and interpretation of future investigations and when appraising the current literature. [ABSTRACT FROM AUTHOR]

Madruga-Parera, M, Bishop, C, Fort-Vanmeerhaeghe, A, Beato, M, Gonzalo-Skok, O, and Romero-Rodríguez, D. Effects of 8-weeks of Isoinertial vs. Cable-resistance Training on Motor Skills Performance and Interlimb Asymmetries. J Strength Cond Res 36(5): 1200–1208, 2022—The aim of this study was to compare the effects of 8 weeks of isoinertial vs. cable-resistance training on motor skills performance and interlimb asymmetries in handball players. Thirty-four young male handball players (mean ± SD : age: 15.96 ± 1.39 years; height: 1.74 ± 0.73 m; body mass: 70.5 ± 13.3 kg) participated in a randomized trial. The players performed an isoinertial program using a portable flywheel device or a cable-resistance device. Performance variations and interlimb asymmetries in dominant (D) and nondominant (ND) limb means of the unilateral countermovement jump (UCMJ), the unilateral lateral jump (ULJ), the unilateral broad jump (UBJ), handball throwing (HT), change of direction speed (COD180), the linear sprint (S20), the V-CUT test, and the repeated change of direction (RCOD) were recorded. Significant interactions were shown in RCODD (p = 0.003, η p = 0.25), HT (p = 0.015, η p = 0.17) and UCMJASY (p = 0.037, η p = 0.13). Post-hoc testing revealed higher effect sizes in the isoinertial group (p < 0.05) for the performance improvements in RCODD (−1.35 large vs. −0.22, small) and HT (0.88, moderate vs. 0.00, trivial), in addition to interlimb asymmetry reductions in UCMJASY (−0.70 moderate vs. −0.32, small). Significant main effects of time in COD180, RCOD, UCMJ, and UBJ for both limbs (p < 0.05, from moderate to large effect size), and in ULJND (p < 0.001, large), UCMJASY (p < 0.001, moderate), V-CUT (p = 0.014, small), and HT (p = 0.015, large) were found. The effect sizes revealed greater magnitudes in the isoinertial group. In conclusion, although both resistance training programs improve players' to physical performance and reduce interlimb asymmetries, greater improvements were recorded with the isoinertial resistance training than with the cable-resistance methodology. [ABSTRACT FROM AUTHOR]

Galiano, C, Pareja-Blanco, F, Hidalgo de Mora, J, and Sáez de Villarreal, E. Low-velocity loss induces similar strength gains to moderate-velocity loss during resistance training. J Strength Cond Res 36(2): 340–345, 2022—This study aimed to analyze the effects of 2 velocity-based resistance training (VBT) programs that used the same relative loading but differed in the velocity loss (VL) throughout the set: 5% (VL5) vs. 20% (VL20). Twenty-eight physically active men (age: 23.0 ± 3.2 years; height: 175.8 ± 4.7 cm; body mass: 73.8 ± 10.8 kg) were randomly assigned to 2 groups: VL5 (n = 15) or VL20 (n = 13). Subjects followed a 7-week (14 sessions) VBT program using the squat exercise while repetition velocity was monitored. The following variables were assessed at pretest and posttest: estimated 1-repetition maximum (1RM); average velocity attained for all absolute loads common to pretest and posttest (AV); average velocity for those loads that were moved faster than 1 m·s−1 (AV > 1); average velocity for those loads that were moved slower than 1 m·s−1 (AV < 1); countermovement jump (CMJ); and 20-m running sprint time (T20). T20 and CMJ height were assessed before each training session to analyze their evolution during the training program. The VL5 group executed only 32.6% of the total repetitions performed by the VL20 group (156.9 ± 25.0 vs. 480.5 ± 162.0 rep). Both groups improved significantly (p < 0.01) in all variables analyzed (1RM, AV, AV > 1, AV < 1, CMJ, and T20) from pretest to posttest, with no significant differences between them. Therefore, a low VL (5%) induced similar gains in strength, jump, and sprint performance to a moderate VL of 20%, despite VL5 performing only 32.6% of the repetitions achieved by the VL20 group. [ABSTRACT FROM AUTHOR]

Peng, H-T, Zhan, D-W, Song, C-Y, Chen, Z-R, Gu, C-Y, Wang, I-L, and Wang, L-I. Acute effects of squats using elastic bands on postactivation potentiation. J Strength Cond Res 35(12): 3334-3340, 2021-The study aimed to investigate the acute effects of squats using elastic bands at different resistance and recovery time points on postactivation potentiation (PAP). Fifteen male collegiate physical education students volunteered to participate in the study. Subjects were assigned to 6 experimental visits, which consisted of repeated factors that were 2 resistance squats (3 repetition maximum [RM] and 5RM) with elastic bands as intervention and 3 performance tests (countermovement jumps [CMJs], 20-m sprints, and change of direction [COD]). The performance test was measured before the resistance squat (pre-test) and at 15 seconds, 4 minutes, and 8 minutes after the resistance squat (post-tests) on each visit. An AMTI force plate and a set of Optojump sensors were used to obtain ground reaction force data during the CMJs and during the 20-m sprints and COD test, respectively. Repeated-measures two-way analyses of variance were performed for the resistance squats and recovery time points for each dependent variable. The 20-m sprint and COD test times at the 4-minute recovery time point after 3RM and 5RM resistance squatting were shorter than the pre-test values (p < 0.05). The rates of force development at the 4- and 8-minute recovery time points after 5RM resistance squatting were higher than the corresponding pre-test values (p < 0.05). All test performance variables significantly decreased at the 15-second recovery time point (p < 0.05). The use of elastic bands in 3RM and 5RM resistance squatting as a warm-up activity may positively affect PAP to improve sprinting, COD ability, and jump explosiveness at the 4-minute recovery time point. [ABSTRACT FROM AUTHOR]

Football is characterized by short-term high-intensity triaxial activities that require optimized neuromuscular capacity. Thus, training routines must consider the direction of force application, particularly when strength exercises are performed. This study aimed to explore the effects of adding vertical or horizontal force-vector exercises to a 20-week in-season general strength training program on jumping and sprinting performance of youth football players. Twenty-four well-trained male under-17 players participated in this study and were randomly assigned to a control, vertical, or horizontal training group. Control group performed a general strength training program (free weights, eccentric-overload, and body mass exercises) once a week during 20 weeks. Vertical and horizontal groups additionally performed back-half-squat or barbell hip-thrust, respectively. Vertical group improved vertical jump (VJ) (squat jump, likely 4.5; ± 4.4% and counter movement jump, likely 4.9; ± 4.1%), horizontal jump (HJ) (most likely 7.5; ± 2.7%), and sprint (10 m, likely 21.6; ± 2.0% and 20 m, very likely 23.3; ± 1.6%). The horizontal group showed unclear results in VJ; however, large improvements were observed in HJ (most likely, 13.0; ± 4.8%), 10 m and 20 m (very likely 23.0; ± 1.8% and most likely 23.8; ± 1.0%, respectively). Back-squat and hip-thrust showed an important transference effect to both jumping and sprinting performance. If considering the effects of back-squat on VJ, hip-thrust improved HJ and sprint to a greater extent. This study reinforces the importance of performing both vertical and horizontal force-vector exercises to enhance physical performance during football in-season, even when performed only once a week. [ABSTRACT FROM AUTHOR]

This study aimed to compare 2 squat training programs repeated until momentary failure with different eccentric phase duration (2 seconds vs. 4 seconds) on the changes in muscle cross-sectional area, squat 1 repetition maximum (1RM), squat jump (SJ), and countermovement jump (CMJ) height, agility (T-test), and Yo-Yo intermittent recovery test (YY-IR2). Male university soccer players (19.9 ± 0.9 years, 172.2 ± 3.8 cm, 66.1 ± 6.6 kg) were randomly assigned to one of the 2 groups; CON for 2 seconds and ECC for 4 seconds (C2/E4, n = 11) or CON for 2 seconds and ECC for 2 seconds (C2/E2, n = 11). They performed parallel backsquat exercises twice a week for ± weeks using 75% 1RM weight to momentary failure in each set for 3 sets with each protocol. Outcome measurements were taken before (Pre) and after 3 (Mid; 1RM, SJ, and CMJ only), and at 6 weeks (Post). One repetition maximum increased more (p, 0.05) for C2/E2 (Pre: 95.9 ± 12.2 kg, Mid: 108.2 ± 15.4 kg, Post: 113.6 ± 14.8 kg) than C2/E4 (95.5 ± 12.9 kg, 102.7 ± 15.6 kg, 105.5 ± 14.9 kg, respectively). Cross-sectional area (50% of the thigh length: 3.5 ± 2.8%), SJ (6.7 ± 8.9%) and CMJ height (6.3 ± 8.6%) increased similarly between C2/E2 and C2/E4, but no significant changes in T-test or YY-IR2 were evident in either group. These results suggest that increasing the ECC phase duration during squat exercises does not produce greater training effects when compared with a shorter ECC phase-duration program with momentary failure. [ABSTRACT FROM AUTHOR]

The aim of this study was to verify the effects of different aerobic intensities combined with the same resistance training on strength and aerobic performances. Thirty-nine men were randomly assigned to a low-intensity group (LIG), moderate-intensity group (MIG), high-intensity group (HIG), and a control group. The training program consisted of full squat, jumps, sprints, and running at 80% (LIG), 90% (MIG), or 100% (HIG) of the maximal aerobic speed for 16-20 minutes. The training period lasted for 8 weeks, followed by 4 weeks of detraining. Evaluations included 20-m sprints (0-10 m: T10; 0-20 m: T20), shuttle run, countermovement jump (CMJ), and strength (1RMest) in full squat. There were significant improvements from pre-training to post-training in T10 (LIG: 4%; MIG: 5%; HIG: 2%), T20 (3%; 4%; 2%), CMJ (9%; 10%; 7%), 1RMest (13%; 7%; 8%), and oxygen uptake (...O2max; 10%; 11%; 10%). Comparing the changes between the experimental groups, 1RMest gains were significantly higher in the LIG than HIG (5%) or MIG (6%). Furthermore, there was a tendency for higher gains in LIG and MIG compared with HIG, with "possibly" or "likely" positive effects in T10, T20, and CMJ. Detraining resulted in performance decrements, but minimal losses were found for ...O2max in LIG (-1%). Concurrent training seems to be beneficial for strength and aerobic development regardless of the aerobic training intensity. However, choosing lower intensities can lead to increased strength and is recommended when the cardiorespiratory gains should be maintained for longer. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare physical performance in amateur handball players of 2 different competitive levels. Thirty-four senior handball players were divided into 2 groups according to their competitive level (regional category: REG or national category: NAC). Although no significant differences were found between groups in any of the horizontal jump (HJ) or vertical jump (VJ) variables (p> 0.05), NAC players obtained a better performance in the repeated sprint ability (RSA) test (RSABest [the best attempt] and RSATT [the total time in the total of sprints] in 15 m and 30 m), in change of direction ability (CODA) and in the Yo-Yo Intermittent Recovery Test Level 1 (YYIR1) test (p< 0.01, effect size = 21.32 to 1.75, large). A significant association was observed between the body mass index (BMI) and the HJ or VJ capacity (r = -0.35 to -0.55, p< 0.01), the RSA15mBest and RSA30mBest (r = 0.41 to 0.59, p< 0.01), and YYIR1 distance (r = -0.54, p≤ 0.05), and a also between the performance in the HJ or the VJ and the RSA15mBest and RSA30mBest, the CODA and the YYIR1, and between the RSA30m Best and the YYIR1 (r = -0.54, p ≤ 0.05). Specific strength and conditioning programs should aim toward improving RSA, CODA, and YYIR1, as these abilities may be needed at higher levels of competition. The programs also should aim toward improved HJ and VJ abilities, given their association with RSA, CODA, and YYIR1 performance. Moreover, maintaining an adequate BMI may aid players to sustain greater physical performance levels. [ABSTRACT FROM AUTHOR]

This investigation examined the effects of footwear and sex on vertical jump displacement and joint power contributions. Twenty-three young adults with basketball experience performed 3 maximal countermovement vertical jumps in minimal and standard footwear. Ground reaction force and 3D kinematic data were collected during jumping. Footwear by sex analysis of variance for all dependent variables and effect sizes (d) was computed. An interaction effect showed that men produced greater lower-limb–positive work than women in standard footwear. Men jumped higher than women (d = 2.53) and produced greater peak ankle, knee and hip joint moments (d > 0.99), positive joint powers (d > 1.07) and, positive knee and hip joint work (d > 1.04) with no sex differences for negative joint powers and work (p > 0.05). Minimal footwear produced less peak-positive knee power (d = 0.27) and less positive ankle (d = 0.34) and knee (d = 0.21) joint work than standard footwear. Because negative joint power and work were similar between sexes, men may be better able to use the stretch-shortening cycle compared with women. Higher joint mechanical demands may provide a better vertical jumping training stimulus in standard compared with minimal footwear. Future studies should investigate footwear training effects on performance and joint mechanics during jumping. [ABSTRACT FROM AUTHOR]

The pole vault is a complex track and field discipline requiring speed, strength, and efficient technique. Strength is a fundamental physical requirement, which facilitates general sprinting ability; this in turn represents the exploitable potential during the approach, where kinetic energy for the subsequent vault is generated. This study investigated the relationships between pole vault height, approach speed, sprint-speed potential, and indicators of both explosive and reactive strength in 20 international female pole vaulters. Furthermore, changes in step characteristics between flying sprints and approach runs were analyzed. Data were collected during and after an international pole vault competition. The correlations between approach speed and vault height, between sprint speed and approach speed, and between explosive strength indicators and sprint speed were large or very large. However, the correlation between reactive strength and sprint speed was small. Differences in speed during the vault approach compared with the flying sprint are mainly due to reduced step length rather than lower step frequency. With the help of a flow chart and regression equations, sound decisions can be made regarding the prioritization of various training components of pole vaulters. With this tool, coaches and athletes can easily evaluate whether or not a facilitator ability is sufficient for improving a more specific performance measure on the way to the central criterion: pole vault height. Furthermore, the results of this study suggest that maintaining step length should be emphasized during approach drills to best exploit sprint-speed potential during the pole vault approach. [ABSTRACT FROM AUTHOR]

This meta-analysis characterized female youths' adaptability to plyometric training (PT). A second objective was to highlight the limitations of the body of literature with a view to informing future research. Fourteen studies were included in the final analysis. The effect size (ES = Hedges' g) for the main effect of vertical jump performance was "small" (ES = 0.57, 95% confidence interval: 0.21-0.93). Effect sizes were larger in younger (<15 years; ES = 0.78 [0.25-1.30] vs. 0.31 [-0.18 to 0.80]), shorter (<163 cm; ES = 1.03 [0.38-1.68] vs. 0.25 [-0.20 to 0.70]), and lighter (<54 kg; ES = 1.14 [0.39-1.89] vs. 0.26 [-0.15 to 0.67]) participants. Programming variables seemed to influence adaptive responses with larger effects in interventions which were longer (8 weeks; ES = 1.04 [0.35-1.72] vs. 0.24 [-0.11 to 0.59]), had greater weekly training frequency (>2; ES = 1.22 [0.18-2.25] vs. 0.37 [0.02-0.71]), and whose sessions were of longer duration (≥30 minutes ES = 1.16 [0.14-2.17] vs. 0.33 [0.03-0.63]). More than 16 sessions per program (0.85 [0.18-1.51]) was more effective than exactly 16 sessions (0.46 [0.08-0.84]) which, in turn, was more effective than less than 16 (0.37 [-0.44 to 1.17]). These findings can inform the prescription of PT in female youth. [ABSTRACT FROM AUTHOR]

Plyometric exercises are frequently performed as part of a strength and conditioning program. Most studies assessed the kinetics of plyometric exercises primarily performed in the vertical plane. The purpose of this study was to evaluate the multiplanar kinetic characteristics of a variety of plyometric exercises, which have a significant horizontal component. This study also sought to assess sex differences in the intensity progression of these exercises. Ten men and 10 women served as subjects. The subjects performed a variety of plyometric exercises including the double-leg hop, standing long jump, single-leg standing long jump, bounding, skipping, power skipping, cone hops, and 45.72-cm hurdle hops. Subjects also performed the countermovement jump for comparison. All plyometric exercises were evaluated using a force platform. Dependent variables included the landing rate of force development and landing ground reaction forces for each exercise in the vertical, frontal, and sagittal planes. A 2-way mixed analysis of variance with repeated-measures for plyometric exercise type demonstrated main effects for exercise type for all dependent variables (p ≤ 0.001). There was no significant interaction between plyometric exercise type and sex for any of the variable as- sessed. Bonferroni-adjusted pairwise comparisons identified a number of differences between the plyometric exercises for the dependent variables assessed (p ≤ 0.05). These findings should be used to guide practitioners in the progression of plyometric exercise intensity, and thus program design, for those who require significant horizontal power in their sport. [ABSTRACT FROM AUTHOR]

The article discusses a study of the impact of static stretching on explosive performance which indicates that static stretching can impair explosive performance for at least 24 hours. Topics include dynamic stretching, sprint ability, long-jump performances, stretching protocols, and the testing of soccer players.

The article discusses a study which was aimed to investigate the impact of wearing shoes inducing moderate dorsiflexion on neuromuscular fatigue induced by volleyball exercises involving multiple stretch-shortening cycles. The study concluded that acute moderate dorsiflexion had no effect on jumping performance and neuromuscular fatigue in unfamiliarized trained subjects.

The article discusses a study of the benefits of plyometric training methods in cricket players, focusing on changes in performance in intermittent shuttle running in simulated cricket innings and the mechanical properties of the Achilles tendon. Subjects were evaluated for sprint times and countermovement and squat jumping before and after an 8 week plyometric training regimen, as well as monitoring of the strength and elasticity of the Achilles tendon using dynamometry and ultrasonography.

The article describes a study of the correlation between jumping event performance and running performance at various race distances by college track and field athletes. Subjects were evaluated in a triple long jump and sprint, middle-distance, or long-distance running. The results indicate that high jump performance correlated strongest with sprint running and suggest that improvements in lower body muscle power from jump training produced faster race times.

The article reports on research which was conducted to examine the anthropometric, vertical jump, and strength quality changes over two years in a group of national team volleyball players. Researchers evaluated 14 players. After evaluating the players for two years researchers concluded that elite male volleyball players can improve leanness and power, which contribute to improvements in vertical jump.

The article discusses the changes in performance indicators related to strength and the development of speed-strength in the transitioning of volleyball players from junior to senior national team. An overview of the study conducted to professional players who played at the world championships, World Cup, and senior continental championships is provided. It explores aspects of the training for counter movement vertical jumps (CMVJ) and spike jump (SPJ).

The article presents a study which determined the relationship between functional movement screen and athletic performance capabilities of golfers. The researchers investigated the sport-specific performance of the golfers from the National Collegiate Athletic Association (NCAA) with focus on sprint time, agility, and club head velocity. The study found that repetition maximum squat strength appeared to be a good indicator of athletic performance.

The article presents the results of a study which investigated the impact of weight training on basketball player performance. An overview of related previous research is provided, along with details of the experimental protocol, which involved half squats in a Smith machine. It was found that strength training produced improved running and jumping ability.

The article reports on research conducted to examine the fatigue pattern of elite female soccer players after competitive games. Researchers evaluated 23 players from the Danish women Premier League. They found that the type of fatigue that occurs after a female soccer game caused marked impairment in intense intermittent exercise and repeated sprint performance but did not affect vertical jump performance.

The article focuses on research conducted to examine the strength, power, and anthropometric contributors to vertical jump performances that are considered specific to volleyball success by examining changes across 12 months of training in elite volleyball players. Researchers evaluated 20 male elite volleyball players. They found that stretch-shortening cycle performance and the ability to tolerate high stretch loads are critical to improving jumping performance.

The article reports on research conducted to investigate the physiologic demands, physiologic characteristics, and jumping ability of different playing positions in elite male volleyball players. Researchers evaluated 142 players. They found that larger jumping and landing demands were placed on taller and heavier players in the middle position.

The article presents a study on the impact of training on the power-, force- and velocity-time curves of the countermovement jump (CMJ). Results revealed significant differences in peak performance variables, such as peak power, force and velocity, between jumpers and nonjumpers. Jumpers and nonjumpers were also observed to have differences throughout the power-, force-, velocity- and displacement-time curves of the CMJ.

The article reports on the power performance of elite Australian Rules Football (ARF) among football players. This study measured variables showing the significance of performance in peak power output. The effects of training and informing adjustments among twelve members of the ARF team were studied and recorded.

The article presents a study which examined the impact of anaerobic fitness on basketball players. It also aims to analyze the effect of game rule changes implemented in 2000 on the physiological factors of success in basketball. It involved eight elite male players and eight average-level players, who conducted seven tests, including vertical jump, sprint and isokinetic testing of the knee extensors. Results have shown that elite players achieve better performances than average players.

The article discusses a study to examine the potential strength, power and anthropometric contributors to vertical jump performances that are specific to the success of volleyball players. A correlation and regression analysis was performed to assess the relationship among strength, power and anthropometric variables. The results of the study demonstrate that stretch shortening cycle performance and the ability to tolerate high stretch loads.

The aim of this study was to establish the anthropometric and physiological profiles of young nonelite soccer players according to their playing position, and to determine their relevance for the selection process. Two hundred forty-one male soccer players who were members of the Getxo Arenas Club (Bizkaia) participated in this study. Players, age 17.31 (± 2.64) years, range 14-21 years, were classified into the following groups: forwards (n = 56), midfielders (n = 79), defenders (n = 77), and goalkeepers (n = 29). Anthropometric variables of participants (height, weight, body mass index, 6 skinfolds, 4 diameters, and 3 perimeters) were measured. Also, their somatotype and body composition (weights and percentages of fat, bone, and muscle) were calculated. Participants performed the Astrand test to estimate their absolute and relative O2max, an endurance test, sprint tests (30 meters flat and 30 meters with 10 cones) and 3 jump tests (squat jump, counter movement jump and drop jump). Forwards were the leanest, presenting the highest percentage of muscle. They were the best performers in all the physiological tests, including endurance, velocity, agility, and power. In contrast, goalkeepers were found to be the tallest and the heaviest players. They also had the largest fat skinfolds and the highest fat percentage, but their aerobic capacity was the lowest. In the selection process, agility and the jump tests were the most discriminating for forwards. In contrast, agility, height, and endurance were the key factors for midfielders. The defenders group was characterized by a lower quantity of fat. Thus, we may conclude that anthropometric and physiological differences exist among soccer players who play in different positions. These differences fit with their different workload in a game. Therefore, training programs should include specific sessions for each positional role. [ABSTRACT FROM AUTHOR]

On the basis of the principles of geometric scaling, maximum vertical-jump height should decrease in an approximately linear fashion with increasing mass. To test this prediction, a group of 10 male subjects performed maximum vertical jumps with masses up to 22.7 kg strapped to their trunks. The results from these jumps indicated that jump height did scale on an individual basis in a linear fashion. A computer simulation model of jumping was developed that permitted the examination of a greater range of masses than was possible experimentally. The simulations also support the trend of linear scaling, but do replicate the decrement expected based on geometric scaling principles. Experimental and simulation model results provide evidence for a linear decrement in subject maximum vertical-jump height with increasing mass, which is relevant information for athletes aiming to increase their body mass or performing jump training while carrying additional mass. [ABSTRACT FROM AUTHOR]