bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Relationship Between Multidirectional Jumping and Performance in Change of Direction Tasks
Authors: Bourgeois Frank A. , Gamble Paul , Gill Nic D. , McGuigan Mike R. 
Published: November 2017

Abstract
Bourgeois, FA II, Gamble, P, Gill, ND, and McGuigan, MR. The relationship between multidirectional jumping and performance in change of direction tasks. J Strength Cond Res 32(3): 690–699, 2018—This study investigated the test-retest reliability of 2 change of direction (COD; 180 and 45° COD) sprints and 3 multidirectional jump (MDJ) tests. Variables examined were approach time (sprint before plant-step), exit time (sprint after plant-step), total time (time to completion) and MDJ approach time, and distance, respectively. Second, the ability of MDJ tests to predict performance in COD tests was examined. Twenty men (age: 27.5 ± 5.9 years; height: 1.79 ± 0.1 m; and body mass: 79.1 ± 12.0 kg) performed 5 trials for each assessment, executing left plant-leg (LT) and right plant-leg (RT) steps, on 2 testing occasions separated by 7 days. Between-session and within-session intraclass correlation coefficients (ICCs) and coefficients of variation (CVs) for all measurements were calculated. Usefulness of COD and MDJ tests was assessed using typical error and smallest worthwhile change (SWC) comparison. Results showed only one MDJ measurement generated unstable between-session reliability. Within-session reliability of approach and exit COD times, and MDJ approach times possessed confidence limits (90% CL) that extended below 0.75 ICC. All COD total times and MDJ distances presented high reliability (ICC = 0.87–0.99) with low CV (0.9–4.1%). Right-leg MDJ distances were predictors of RT COD performances (r = 0.50–0.68, p = 0.001–0.024), whereas LT MDJ distances were predictors of LT180 COD performance (r = 0.67–0.71, p = 0.001). All measurements were useful in detecting SWC in performance. These findings suggest the COD tests and MDJ distances are reliable for assessing and monitoring COD performance in similar cohorts.
Independent and Combined Effects of Weight Status and Maturation on Aerobic Fitness in Adolescent School-Aged Males
Authors: Batista Mariana B. , Valente-dos-Santos João , Duarte João P. , Sousa-e-Silva Paulo , Coelho-e-Silva Manuel J. , Werneck André O. , Ohara David , Cyrino Edilson S. , Ronque Enio R.V. 
Published: November 2017

Abstract
Batista, MB, Valente-dos-Santos, J, Duarte, JP, Sousa-e-Silva, P, Coelho-e-Silva, MJ, Werneck, AO, Ohara, D, Cyrino, ES, and Ronque, ERV. Independent and combined effects of weight status and maturation on aerobic fitness in adolescent school-aged males. J Strength Cond Res 34(9): 2663–2671, 2020—This study aimed to examine the independent and combined effects of pubertal and weight status on concurrent measurements of peak oxygen (V̇o
2peak) in school-aged adolescent males. The final sample included 49 boys (12.3 ± 0.8 years). V̇o
2peak was derived from an incremental progressive maximal protocol using a motorized treadmill. In addition, maximal oxygen uptake was estimated from a 20-m shuttle run test. Static allometric models were obtained as an alternative to performance output per unit of size descriptors. Weight status had a significant effect on V̇o
2peak using simple ratio standards per unit of body mass (BM) with adolescents classified as overweight and obese (OWOB) attaining lower values of V̇o
2peak. A similar trend was noted for the allometric models adopting body mass (ml·kgBM
−0.542·min−1), stature (L·m−2.602·min), and fat-free mass (FFM; ml·kgFFM
−0.907·min−1). Findings also suggest the influence and interaction of pubertal and weight status on absolute values of V̇o
2peak. Considering the data obtained, linear equations to estimate V̇o
2peak from the 20-m shuttle run test should not be applied to boys who are OWOB because it will produce inaccurate assessments of cardiorespiratory fitness and penalize those who are heavier. Equations for V̇o
2peak prediction need to be specific for pubertal status and preferably consider FFM as a body size descriptor.
Energy Cost of Continuous Shuttle Running: Comparison of 4 Measurement Methods
Authors: Ciprandi Daniela , Lovecchio Nicola , Piacenza Marco , Limonta Eloisa , Esposito Fabio , Sforza Chiarella , Zago Matteo 
Published: November 2017

Abstract
Ciprandi, D, Lovecchio, N, Piacenza, M, Limonta, E, Esposito, F, Sforza, C, Zago, M. Energy cost of continuous shuttle running: Comparison of 4 measurement methods. J Strength Cond Res 32(8): 2265–2272, 2018—Assessing runs with frequent turns (shuttle run) is a viable option to evaluate the energy cost associated with sport-specific high-intensity intermittent activities. To date, no study investigated the extent to which the computation of energy cost of exercise is affected by the following factors: procedure and duration of oxygen uptake measurement during exercise, oxygen uptake measurement during recovery, estimation of the anaerobic alactic contribution, consideration of respiratory exchange ratio (RER) in the computation, and exercise intensity. Therefore, the aim of the current study was to determine whether these factors may lead to different estimations of the energy cost of locomotion. Twenty-six healthy young men participated in two 5-m shuttle-run trials at an average speed of 50 and 75% of their maximal aerobic velocity, respectively. Oxygen uptake and lactate concentration were measured before, during, and after the trials. Results revealed that different methods of computing the energy cost of 5-m shuttle run returned significantly different results, in particular at high intensity levels. The largest significant difference found between methods was lower than 10%. This suggests that for the most accurate computation of the workload, the contribution of the anaerobic alactic mechanisms and the influence of the RER cannot be neglected. These findings might help sport scientists and conditioning trainers in identifying the exercise conditions in which including all the metabolic components are required for an accurate computation of athletes' energy expenditure. In turn, exercise conditions would be defined where the computation could be conveniently simplified without worsening results reliability.
Importance of Speed and Power in Elite Youth Soccer Depends on Maturation Status
Authors: Murtagh Conall F. , Brownlee Thomas E. , O'Boyle Andrew , Morgans Ryland , Drust Barry , Erskine Robert M. 
Published: November 2017

Abstract
Murtagh, CF, Brownlee, TE, O'Boyle, A, Morgans, R, Drust, B, and Erskine, RM. Importance of speed and power in elite youth soccer depends on maturation status. J Strength Cond Res 32(2): 297–303, 2018—Maturation status is a confounding factor when identifying talent in elite youth soccer players (ESP). By comparing performance of ESP and control participants (CON) matched for maturation status, the aims of our study were to establish the importance of acceleration, sprint, horizontal-forward jump, and vertical jump capabilities for determining elite soccer playing status at different stages of maturation. Elite youth soccer players (n = 213; age, 14.0 ± 3.5 years) and CON (n = 113; age, 15.0 ± 4.4 years) were grouped using years from/to predicted peak height velocity (PHV) to determine maturation status (ESP: pre-PHV, n = 100; mid-PHV, n = 25; post-PHV, n = 88; CON: pre-PHV, n = 44; mid-PHV, n = 15; post-PHV, n = 54). Participants performed 3 reps of 10- and 20-m sprint, bilateral vertical countermovement jump (BV CMJ), and bilateral horizontal-forward CMJ (BH CMJ). Elite youth soccer players demonstrated faster 10-m (p < 0.001) and 20-m sprint (p < 0.001) performance than CON at all stages of maturation. Mid-PHV and post-PHV ESP achieved greater BV CMJ height (p < 0.001) and BH CMJ distance (ESP vs. CON; mid-PHV: 164.32 ± 12.75 vs. 136.53 ± 21.96 cm; post-PHV: 197.57 ± 17.05 vs. 168.06 ± 18.50 cm; p < 0.001) compared with CON, but there was no difference in BV or BH CMJ between pre-PHV ESP and CON. Although 10 and 20 m and sprint performance may be determinants of elite soccer playing status at all stages of maturation, horizontal-forward and vertical jumping capabilities only discriminate ESP from CON participants at mid- and post-PHV. Our data therefore suggest that soccer talent identification protocols should include sprint, but not jump assessments in pre-PHV players.
Validity and Reliability of the Load-Velocity Relationship to Predict the One-Repetition Maximum in Deadlift
Authors: Ruf Ludwig , Chéry Clément , Taylor Kristie-Lee 
Published: November 2017

Abstract
Ruf, L, Chéry, C, Taylor, KL. Validity and reliability of the load-velocity relationship to predict the 1RM in deadlift. J Strength Cond Res 32(3): 681–689, 2018—The aim of this study was to verify the reliability and validity of using submaximal loads from the load-velocity relationship to predict the actual 1 repetition maximum (1RM) in the deadlift. Data from 11 resistance-trained athletes were analyzed performing three 1RM assessments separated by at least 3 days. Reliability was assessed by comparing predicted 1RMs of sessions 2 and 3, whereas for validity purposes, predicted 1RMs of session 3 were compared with actual 1RMs of session 2. Mean concentric velocity at 1RM (v at 1RM) was entered in individualized linear regression equations, derived from the load-velocity relationship for 3 (20–60%, 40–80%, and 60–90% of 1RM), 4 (20–80% and 40–90% of 1RM), and 5 (20–90% of 1RM) incremental loads to predict 1RMs. There were trivial changes for all predicted 1RMs between sessions with 20–90% of 1RM being the most reliable model. Similarly, the actual 1RM was very stable (effect size [ES] = 0.04, 90% confidence limit [CL] [−0.03 to 0.12], typical error of measurement [TE] = 3.4 kg [2.5–5.4], intraclass coefficient [ICC] = 0.99 [0.96–0.996], and coefficient of variation [CV] = 1.9% [1.4–3.0]), whereas the v at 1RM was unreliable between trials (ES = −0.30, 90% CL [−0.78 to 0.17], TE = 0.029 m·s−1 [0.022–0.047], ICC = 0.63 [0.19–0.86], and CV = 15.7% [11.7–26.1]). However, predicted 1RMs computed from all submaximal load ranges substantially overestimated the actual 1RM with considerable differences between athletes. Although 1RM predictions showed high reliability, they all overestimated the actual 1RM, which was stable between sessions. Therefore, it is not recommended to apply the prediction models used in this study to compute daily 1RMs.
Effects of Plyometric and Directional Training on Speed and Jump Performance in Elite Youth Soccer Players
Authors: Beato Marco , Bianchi Mattia , Coratella Giuseppe , Merlini Michele , Drust Barry 
Published: November 2017

Abstract
Beato, M, Bianchi, M, Coratella, G, Merlini, M, and Drust, B. Effects of plyometric and directional training on speed and jump performance in elite youth soccer players. J Strength Cond Res 32(2): 289–296, 2018—Soccer players perform approximately 1,350 activities (every 4–6 seconds), such as accelerations/decelerations and changes of direction (CODs) during matches. It is well established that COD and plyometric training have a positive impact on fitness parameters in football players. This study analyzed the effect of a complex COD and plyometric protocol (CODJ-G) compared with an isolated COD protocol (COD-G) training on elite football players. A randomized pre-post parallel group trial was used in this study. Twenty-one youth players were enrolled in this study (mean ± SD; age 17 ± 0.8 years, mass 70.1 ± 6.4 kg, and height 177.4 ± 6.2 cm). Players were randomized into 2 different groups: CODJ-G (n = 11) and COD-G (n = 10), training frequency of 2 times a week more than 6 weeks. Sprint 10, 30, and 40 m, long jump, triple hop jump, and 505 COD test were considered. Exercise-induced within-group changes in performance for both CODJ-G and COD-G: long jump (effect size [ES] = 0.32 and ES = 0.26, respectively) and sprint 10 m (ES = −0.51 and ES = −0.22, respectively), after 6 weeks of training. Moreover, CODJ-G reported substantially better results (between-group changes) in long jump test (ES = 0.32). In conclusion, this study showed that short-term protocols (CODJ-G and COD-G) are important and able to give meaningful improvements on power and speed parameters in a specific soccer population. CODJ-G showed a larger effect in sprint and jump parameters compared with COD-G after the training protocol. This study offers important implications for designing COD and jumps training in elite soccer.
Impact of Weekly Swimming Training Distance on the Ergogenicity of Inspiratory Muscle Training in Well-Trained Youth Swimmers
Authors: Lomax Mitch , Kapus Jernej , Brown Peter I. , Faghy Mark 
Published: November 2017

Abstract
Lomax, M, Kapus, J, Brown, PI, and Faghy, M. Impact of weekly swimming training distance on the ergogenicity of inspiratory muscle training in well-trained youth swimmers. J Strength Cond Res 33(8): 2185–2193, 2019—The aim of this study was to examine the impact of weekly swimming training distance on the ergogenicity of inspiratory muscle training (IMT). Thirty-three youth swimmers were recruited and separated into a LOW and HIGH group based on weekly training distance (≤31 km·wk−1 and >41 km·wk−1, respectively). The LOW and HIGH groups were further subdivided into control and IMT groups for a 6-week IMT intervention giving a total of 4 groups: LOWcon, LOWIMT, HIGHcon, and HIGHIMT. Before and after the intervention period, swimmers completed maximal effort 100- and 200-m front crawl swims, with maximal inspiratory and expiratory mouth pressures (PImax and PEmax, respectively) assessed before and after each swim. Inspiratory muscle training increased PImax (but not PEmax) by 36% in LOWIMT and HIGHIMT groups (p ≤ 0.05), but 100- and 200-m swims were faster only in the LOWIMT group (3 and 7% respectively, p ≤ 0.05). Performance benefits only occurred in those training up to 31 km·wk−1 and indicate that the ergogenicity of IMT is affected by weekly training distance. Consequently, training distances are important considerations, among others, when deciding whether or not to supplement swimming training with IMT.
Effects of Feedback Type and Personality on 2,000-m Ergometer Performance in Female Varsity Collegiate Rowers
Authors: Stine Kaitlyn A. , Moxey Jacqueline R. , Gilbertson Nicole M. , Malin Steven K. , Weltman Arthur L. 
Published: November 2017

Abstract
Stine, KA, Moxey, JR, Gilbertson, NM, Malin, SK, and Weltman, AL. Effects of feedback type and personality on 2,000-m ergometer performance in female varsity collegiate rowers. J Strength Cond Res 33(8): 2170–2176, 2019—Rowing performance is routinely tested on ergometers, involving visual cues and verbal encouragement, whereas on-water rowing lacks the visual cues. Personality is also hypothesized to influence rowing performance. The purpose was to examine the effects of visual and verbal feedback and to determine the impact of personality on performance. Thirty-eight female collegiate rowers (body mass 75.0 ± 5.7 kg and height 176.6 ± 5.0 cm) were recruited. Participants were asked to complete a progressive continuous graded exercise test, body composition analysis, personality questionnaire (Neo five-factor inventory, version 3), and 2 randomly ordered 2000-m ergometer tests: routine verbal and visual vs. verbal only. Differences between the 2,000-m tests were analyzed with a paired t-test. The relationships among Vo
2max, body composition, and 2,000-m performance were analyzed with Pearson's Correlations. A 2 × 2 analysis of variance analyzed neuroticism, openness, agreeableness, and conscientiousness to investigate how personality impacted 2,000-m performance. Statistical significance was set to p ≤ 0.05. The combination of visual plus verbal feedback trended toward improving performance compared with the verbal feedback alone (430.3 ± 8.6, 431.6 ± 8.9 seconds, respectively). High neuroticism negatively impacted 2,000-m performance (p ≤ 0.05). Conscientiousness and agreeableness trended toward improved performance: as conscientiousness and agreeableness increase, time decreases. We conclude that the combination of verbal plus visual feedback tends to yield better 2,000-m performance and that highly conscientious, highly agreeable, and low neurotic athletes outperform their respective counterparts. Using visual plus verbal encouragement while simultaneously targeting personality factors may be a novel strategy to optimize rowers' training.
Frontal Eye Field Inactivation Diminishes Superior Colliculus Activity, But Delayed Saccadic Accumulation Governs Reaction Time Increases
Authors: Peel Tyler R. , Dash Suryadeep , Lomber Stephen G. , Corneil Brian D. 
Published: November 2017

Stochastic accumulator models provide a comprehensive framework for how neural activity could produce behavior. Neural activity within the frontal eye fields (FEFs) and intermediate layers of the superior colliculus (iSC) support such models for saccade initiation by relating variations in saccade reaction time (SRT) to variations in such parameters as baseline, rate of accumulation of activity, and threshold. Here, by recording iSC activity during reversible cryogenic inactivation of the FEF in four male nonhuman primates, we causally tested which parameter(s) best explains concomitant increases in SRT. While FEF inactivation decreased all aspects of ipsilesional iSC activity, decreases in accumulation rate and threshold poorly predicted accompanying increases in SRT. Instead, SRT increases best correlated with delays in the onset of saccade-related accumulation. We conclude that FEF signals govern the onset of saccade-related accumulation within the iSC, and that the onset of accumulation is a relevant parameter for stochastic accumulation models of saccade initiation.SIGNIFICANCE STATEMENTThe superior colliculus (SC) and frontal eye fields (FEFs) are two of the best-studied areas in the primate brain. Surprisingly, little is known about what happens in the SC when the FEF is temporarily inactivated. Here, we show that temporary FEF inactivation decreases all aspects of functionally related activity in the SC. This combination of techniques also enabled us to relate changes in SC activity to concomitant increases in saccadic reaction time (SRT). Although stochastic accumulator models relate SRT increases to reduced rates of accumulation or increases in threshold, such changes were not observed in the SC. Instead, FEF inactivation delayed the onset of saccade-related accumulation, emphasizing the importance of this parameter in biologically plausible models of saccade initiation.
Evaluation of alternative drive systems based on driving patterns comparing Germany, China and Malaysia
Authors: Schüller M. , Tewiele S. , Bruckmann T. , Schramm D. 
Published: November 2017

Requirements to mobility are changing worldwide due to a focus on environment and resource protection and a simultaneous increase of mobility needs. Accordingly, the focus in automotive development shifts to the use of alternative energies for vehicle propulsions in order to reduce emissions. The amount of emission reduction by using alternative drive systems depends on marginal conditions, such as the energy mix structure, climate conditions and the vehicle’s usage profile. The individual usage profile contains characteristic values such as the number of trips, trip duration and length, as well as the velocity distribution. These characteristic data are individual for each user and differ from the values derived through test cycles such as e.g. the NEDC or the JC08. Accordingly, for the current market analysis and future trends prediction, different user profiles have to be considered and analysed. Within this paper, real world driving data recorded within the German project RuhrautoE will be analysed. The focus lies on evaluation criteria that differentiate between countries due to local framework conditions. In this context, the costs and emissions of different propulsion systems are compared between Germany and China. Afterwards an outlook on Malaysia is given for these criteria. Hitherto, such an approach is rarely considered for Malaysia. Conventional and alternative fuel vehicles as well as electrified vehicles (EV) are compared within this paper. All car models considered are based on real vehicle series to ensure a valid common basis. As expected, the consumptions of all analysed propulsion systems are higher for real driving data than for the NEDC. Then the consumption costs of the electric vehicle are the lowest in Germany and China, but not in Malaysia, where a gas driven vehicle (LPG) achieves the best results. Though, while electric cars can reduce well-to-wheel emissions by 82 % in Germany, there is no reduction possible in China as long as the fossil proportion during the generation of electricity is not reduced. However, EV can reduce the local emission in high traffic areas. According to our estimation, EV are not profitable in all considered countries due to the Total Cost of Ownership.
Dynamics properties of a Go-kart chassis structure and its prediction improvement using model updating approach
Authors: Abdullah N. A. Z. , Sani M. S. M. , Husain N. A. , Rahman M. M. , Zaman I. 
Published: November 2017

Model updating is concerned about the correction of finite element models by processing the record of dynamic response from test structures in order to have an accurate model for any simulated analysis. Finite element model updating had emerged years ago as an important subject in structural dynamics. It has been used frequently and has been successfully applied to many fields especially in detecting the dynamic stiffness of a structure. The purpose of this study is to perform model updating of a go-kart chassis structure in order to reduce the percentage of error between the experimental modal analysis (EMA) and finite element analysis (FEA). Modal properties (natural frequency, mode shapes, and damping ratio) of the go-kart chassis structure were determined using both EMA and FEA. Correlation of the modal parameters gathered in FEA and EMA was carried out before optimizing the data from finite element. By adjusting the selective parameters, incongruities between those two analyses are generally reduced. The sensitivity of selected parameters is also obtained. The significant reduction in percentage of error before and after model updating procedure was carried out in this study clearly shows that model updating technique is a reliable method in reducing the discrepancies between EMA and FEA. Therefore, in cases of high discrepancies between analytical and actual test data, model updating can be considered as an option in order to obtain better correlation between those two sets of data.