bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acute Kinematic and Kinetic Adaptations to Wearable Resistance During Sprint Acceleration
Authors: Macadam Paul , Simperingham Kim D. , Cronin John B. 
Published: August 2016

Abstract
Macadam, P, Simperingham, KD, and Cronin, JB. Acute kinematic and kinetic adaptations to wearable resistance during sprint acceleration. J Strength Cond Res 31(5): 1297–1304, 2017—Wearable resistance (WR) in the form of weighted vests and shorts enables movement-specific sprint running to be performed under load. The purpose of this study was to determine the acute changes in kinematics and kinetics when an additional load equivalent to 3% body mass (BM) was attached to the anterior or posterior surface of the lower limbs during sprint running. Nineteen male rugby athletes (age: 19.7 ± 2.3 years; body mass: 96.1 ± 16.5 kg; height: 181 ± 6.5 cm) volunteered to participate in the study. Subjects performed six 20 m sprints in a randomized fashion wearing no resistance or 3%BM affixed to the anterior (quadriceps and tibialis anterior) or posterior (hamstring and gastrocnemius) surface of the lower limbs (2 sprints per condition). Optojump and radar were used to quantify sprint times, horizontal velocity, contact and flight times, and step length and frequency. A repeated measures analysis of variance with post hoc contrasts was used to determine differences (p ≤ 0.05) between conditions. No significant differences were found between the anterior and posterior WR conditions in any of the variables of interest. There was no significant change in sprint times over the initial 10 m, however, the 10–20 m split times were significantly slower (−2.2 to −2.9%) for the WR conditions compared with the unloaded sprints. A significant change in the relative force–velocity (F–v) slope (−10.5 to −10.9%) and theoretical maximum velocity (V
0) (−5.4 to −6.5%) was found, whereas a nonsignificant increase in theoretical maximum force (F
0) (4.9–5.2%) occurred. Wearable resistance of 3%BM may be a suitable training modality to enhance sprint acceleration performance by overloading the athlete without negatively affecting sprint running technique.
Relative Load Prediction by Velocity and the OMNI-RES 0–10 Scale in Parallel Squat
Authors: Naclerio Fernando , Larumbe-Zabala Eneko 
Published: August 2016

Abstract
Naclerio, F and Larumbe-Zabala, E. Relative load prediction by velocity and the OMNI-RES 0–10 scale in parallel squat. J Strength Cond Res 31(6): 1585–1591, 2017—This study analyzed the possibility of using movement velocity and the rate of perceived exertion as predictors of relative load in the parallel squat (PSQ) exercise. To determine the full load-velocity and load-rate of perceived exertion relationships, 290 young, resistance-trained athletes (209 males and 81 females) performed a progressive strength test up to the 1 repetition maximum. Longitudinal regression models were used to predict the relative load from the average velocity (AV) and the OMNI-RES 0–10 scale, considering sets as the time-related variable. Two adjusted predictive equations were developed from the association between the relative load and the AV or the rate of perceived exertion expressed after performing several sets of 1–3 repetitions during the progressive test. The resulting 2 models were capable of estimating the relative load with an accuracy of 79 and 86% for the AV (relative load [% 1 repetition maximum, RM] = 120.15–83.54 [AV]) and the exertion (relative load [% 1RM] = 5.07 + 9.63 [rate of perceived exertion]), respectively. The strong association between relative load with AV and the rate of perceived exertion supports the use of both predictive variables to estimate strength performance in PSQ.
The Effects of Caffeine on Arousal, Response Time, Accuracy, and Performance in Division I Collegiate Fencers
Authors: Doyle Taylor P. , Lutz Rafer S. , Pellegrino Joseph K. , Sanders David J. , Arent Shawn M. 
Published: August 2016

Abstract
Doyle, TP, Lutz, RS, Pellegrino, JK, Sanders, DJ, and Arent, SM. The effects of caffeine on arousal, response time, accuracy, and performance in Division I collegiate fencers. J Strength Cond Res 30(11): 3228–3235, 2016—Caffeine has displayed ergogenic effects on aerobic performance. However, sports requiring precision and quick reaction may also be impacted by central nervous system arousal because of caffeine consumption. The purpose of this study was to assess the effects of caffeine on arousal, response time (RT), and accuracy during a simulated fencing practice. Using a randomized, within-subjects, placebo-controlled, double-blind design, Division I male and female college fencers (N = 13; 69.1 ± 3.5 kg) were administered caffeine doses of 0, 1.5, 3.0, 4.5, 6.0, or 7.5 mg·kg−1 during separate testing days. Performance was assessed via RT and accuracy to a 4-choice reaction task. A total of 25 trials were performed each day using a random 2- to 8-s delay between trials. Arousal was assessed using the activation-deactivation adjective check list. Results of repeated-measures multivariate analysis of variance revealed a significant dose effect (p = 0.02) on performance. Follow-up analyses indicated this was due to a significant effect for RT (p = 0.03), with the dose-response curve exhibiting a quadratic relationship. Response time was significantly faster (p < 0.01) for the 1.5, 3.0, and 6.0 mg·kg−1 conditions than for the placebo condition. Results also indicated a significant dose effect for composite RT + accuracy performance (p < 0.01). The dose-response curve was again quadratic, with performance beginning to deteriorate at 7.5 mg·kg−1. Energetic arousal, tiredness, tension, and calmness all significantly changed as a function of caffeine dose (p ≤ 0.05). Based on these results, caffeine improves RT and overall performance in fencers, particularly as doses increase up to 4.5–6.0 mg·kg−1. Above this level, performance begins to deteriorate, consistent with an “inverted-U” model of arousal and performance.
Comparison of Strength Levels Between Players From Within the Same Club Who Were Selected vs. Not Selected to Play in the Grand Final of the National Rugby League Competition
Authors: Baker Daniel G. 
Published: August 2016

Abstract
Baker, DG. Comparison of strength levels between players from within the same club that were selected vs. not selected to play in the grand final of the National Rugby League competition. J Strength Cond Res 31(6): 1461–1467, 2017—A number of studies have established that higher levels of strength and power, tested at the end of the preseason, distinguish between playing level in professional rugby league. How this may impact the ability of players to get selected for final payoff games some 30 weeks later has not been fully investigated. The purpose of this study was to compare measures of upper- and lower-body strength between players from the same professional club, designated as those 17 players who attained selection and played in the team that won the Grand Final of the National Rugby League competition (GF) and those who did not attain selection (NSGF). Players were tested and compared for 1 repetition maximum bench press and full squat strength levels at the end of the preparation period, 30 weeks before the GF, using traditional significance analysis of variance and effect size (ES) statistics. Furthermore, the players were analyzed according to the 2 broad positional playing groups of forwards (FWD) and backs (BL). The results demonstrated that overall, the GF players were stronger than NSGF players by approximately 10 and 15%, respectively, for the upper and lower body. When analyzed according to positional groupings, there were significant differences and large ES for GF forwards, who were significantly stronger, heavier, and older than NSGF FWD players. For the BL groups, the differences between the groups were not significant. Because of the intense physical collisions inherent in rugby league, it would appear that higher levels of strength afford players greater performance benefits, resiliency against injury, and greater likelihood of being selected in the most important games at the end of the season.
Isometric Midthigh Pull Reliability and Relationship to Deadlift One Repetition Maximum
Authors: De Witt John K. , English Kirk L. , Crowell J. Brent , Kalogera Kent L. , Guilliams Mark E. , Nieschwitz Bruce E. , Hanson Andrea M. , Ploutz-Snyder Lori L. 
Published: August 2016

Abstract
De Witt, JK, English, KL, Crowell, JB, Kalogera, KL, Guilliams, ME, Nieschwitz, BE, Hanson, AM, and Ploutz-Snyder, LL. Isometric midthigh pull reliability and relationship to deadlift one repetition maximum. J Strength Cond Res 32(2): 528–533, 2018—The purpose of this investigation was to examine the reliability of the isometric midthigh pull (IMTP) and the relationship between IMTP peak force and deadlift 1 repetition maximum (1RM). Nine subjects (5 men and 4 women; 40.6 ± 8.0 years; 1.72 ± 0.10 m; 75.6 ± 13.4 kg) participated in this study. Isometric midthigh pull and deadlift 1RM were both performed during 2 testing sessions. For IMTP, peak force and peak rate of force development (RFD) were determined, in addition to RFD at 30 ms, 50 ms, 90 ms, 150 ms, 200 ms, and 250 ms after initiation of the pull. Intraclass correlation coefficients (ICCs) were calculated to evaluate the reliability of IMTP measures. Pearson product-moment correlations and linear regression were used to determine associations between IMTP and deadlift 1RM. Isometric midthigh pull peak force was reproducible both within (ICC = 0.98 and 0.97) and between sessions (ICC = 0.89) and significantly correlated with deadlift 1RM (r = 0.88, p ≤ 0.05), but intermediate force outputs and RFD were not. Lack of associations between RFD and deadlift 1RM indicate that the ability to create explosive force may be independent of the ability to create maximal force. The strong relationship between IMTP peak force and deadlift 1RM was present regardless of which IMTP repetition across the 2 sessions was examined. Peak force generated during IMTP is a reliable method to assess full body maximal strength. A single IMTP repetition, provided adequate familiarization and warm-up, correlates strongly with deadlift 1RM. Practitioners can use the IMTP test as a method to estimate maximal deadlift strength in a quick and potentially less provocative manner than traditional 1RM testing.
Validity of the Jump-and-Reach Test in Subelite Adolescent Handball Players
Authors: Muehlbauer Thomas , Pabst Jan , Granacher Urs , Büsch Dirk 
Published: August 2016

Abstract
Muehlbauer, T, Pabst, J, Granacher, U, and Büsch, D. Validity of the jump-and-reach test in subelite adolescent handball players. J Strength Cond Res 31(5): 1282–1289, 2017—The primary purpose of this study was to examine concurrent validity of the jump-and-reach (JaR) test using the Vertec system and a criterion device (i.e., Optojump system). In separate subanalyses, we investigated the influence of gym floor condition and athletes' sex on the validity of vertical jump height. Four hundred forty subelite adolescent female (n = 222, mean age: 14 ± 1 year, age range: 13–15 years) and male (n = 218, mean age: 15 ± 1 year, age range: 14–16 years) handball players performed the JaR test in gyms with region or point elastic floors. Maximal vertical jump height was simultaneously assessed using the Vertec and the Optojump systems. In general, significantly higher jump heights were obtained for the Vertec compared with the Optojump system (11.2 cm, Δ31%, Cohen's d = 2.58). The subanalyses revealed significantly larger jump heights for the Vertec compared with the Optojump system irrespective of gym floor condition and players' sex. The association between Optojump- and Vertec-derived vertical jump heights amounted to r
P = 0.84, with a coefficient of determination (R
2) of 0.71. The subanalyses indicated significantly larger correlations in males (r
P = 0.75, R
2 = 0.56) than in females (r
P = 0.63, R
2 = 0.40). Yet, correlations were not significantly different between region (r
P = 0.83, R
2 = 0.69) as opposed to point elastic floor (r
P = 0.87, R
2 = 0.76). Our findings indicate that the 2 apparatuses cannot be used interchangeably. Consequently, gym floor and sex-specific regression equations were provided to estimate true (Optojump system) vertical jump height from Vertec-derived data.
Nonlinear Analysis of an Unstable Bench Press Bar Path and Muscle Activation
Authors: Lawrence Michael A. , Leib Daniel J. , Ostrowski Stephanie J. , Carlson Lara A. 
Published: August 2016

Abstract
Lawrence, MA, Leib, DJ, Ostrowski, SJ, and Carlson, LA. Nonlinear analysis of an unstable bench press bar path and muscle activation. J Strength Cond Res 31(5): 1206–1211, 2017—Unstable resistance exercises are typically performed to improve the ability of stabilizing muscles to maintain joint integrity under a load. The purpose of this study was to examine the effects of an unstable load (as provided by a flexible barbell and a load suspended by elastic bands) on the bar path, the primary musculature, and stabilizing musculature while bench pressing using nonlinear analyses. Fifteen resistance-trained men (age 24.2 ± 2.7 years, mass 84.1 ± 12.0 kg, height 1.77 ± 0.05 m, 9.9 ± 3.4 years of lifting experience, and bench press 1 repetition maximum (RM) 107.5 ± 25.9 kg) volunteered for this study. Subjects pressed 2 sets of 5 repetitions in both stable (total load 75% 1RM) and unstable (total load 60% 1RM) conditions using a standard barbell and a flexible Earthquake bar, respectively. Surface electromyography was used to detect muscle activity of primary movers (pectoralis major, anterior deltoid, and triceps) and bar stabilizing musculature (latissimus dorsi, middle and posterior deltoid, biceps brachii, and upper trapezius). During the unstable condition, the bar moved in more ways and was less predictable in the mediolateral and anteroposterior directions. However, the muscle activation patterns of all muscles were more constrained with the unstable barbell. These findings suggest that the unstable condition was more challenging to control, but subjects controlled the instability by contracting their muscles in a more stable pattern or “staying tight” throughout the exercise.
The Effect of a Psychomotor Education Program on the Static Balance of Children With Intellectual Disability
Authors: Fotiadou Eleni G. , Neofotistou Konstantina H. , Giagazoglou Paraskevi F. , Tsimaras Vasilios K. 
Published: August 2016

Abstract
Fotiadou, EG, Neofotistou, KH, Giagazoglou, PF, and Tsimaras, VK. The effect of a psychomotor education program on the static balance of children with intellectual disability. J Strength Cond Res 31(6): 1702–1708, 2017—Children with intellectual disability (ID) demonstrate lower balance ability which results in substantial delays in motor growth and limits their function level. Psychomotor education comprises a holistic movement approach, with the aim to improve all aspects of each child personality. The aim of this study was to assess the effect of a psychomotor education program on static balance of school-aged children with ID. Twenty children with ID who were 8–12 years old participated in the study. They were assigned to 2 groups, 1 experiment and 1 control. The experiment group attended a 16-week psychomotor education program at a frequency of 2 lessons per week, for 45 minutes. All the children who participated in the above measurements had (a) recording of anthropometric characteristics, (b) assessment of motor developmental index, and (c) measurement of static balance. The static balance ability was measured by means of an electronic pressure platform. Each child was requested to keep a quiet stance posture under 4 different conditions: double-leg stance with eyes opened or closed while they observed a visual or visual-auditory target. Participants of the intervention group reduced the values of static balance variables for all the positions. In conclusion, findings of this study clearly indicate that psychomotor education program has an important contribution to make for the most benefit of children with ID in terms of static balance.
Hydration Status, Executive Function, and Response to Orthostatism After a 118-km Mountain Race: Are They Interrelated?
Authors: Martínez-Navarro Ignacio , Chiva-Bartoll Oscar , Hernando Barbara , Collado Eladio , Porcar Vicente , Hernando Carlos 
Published: August 2016

Abstract
Martínez-Navarro, I, Chiva-Bartoll, O, Hernando, B, Collado, E, Porcar, V, and Hernando, C. Hydration status, executive function and response to orthostatism after a 118-km mountain race: are they interrelated? J Strength Cond Res 32(2): 441–449, 2018—The present study aimed to explore whether blood pressure (BP) and heart rate (HR) variability (HRV) responsiveness to orthostatism, jointly with executive function (EF) performance, was diminished after an ultra-endurance mountain race. Besides, we wanted to assess whether hydration status was related to either performance or the abovementioned alterations. Fifty recreational ultra-endurance athletes participating in the Penyagolosa Trails CSP115 race (118 km and a total positive elevation of 5,439 m) were evaluated before and after the competition. The HRV and BP were measured in response to an orthostatic challenge. The EF was evaluated using the color-word interference task of the Stroop test. Body mass (BM) and urine specific gravity (USG) changes were used to assess hydration status. The HRV and BP responsiveness to orthostatism was diminished after the race. Besides, a significant BM loss of 3.51 ± 2.03% was recorded. Conversely, EF and USG showed no significant changes from prerace to postrace. Eventually, BM loss was inversely related to finishing time (r = −0.34) and postrace orthostatic HR and EF were positively associated (r = 0.60). The USG and BM loss appear to provide different insights into hydration status, and our results challenge the well-established criteria that BM losses >2% are detrimental to performance. Coaches are advised to consider athletes' performance level when interpreting their BM changes during an ultra-endurance competition. Similarly, coaches should be aware that increased vulnerability to orthostatism is a common phenomenon after ultra-endurance races, and diminished HR responsiveness to orthostatism could constitute a practical indicator of EF worsening.
Physiological Demands of Elite Cross-Country Skiing During a Real Competition
Authors: Gonzalez-Millan Cristina , Perez-Brunicardi Dario , Salinero Juan J. , Lara Beatriz , Abián-Vicen Javier , Areces Francisco , Ruiz-Vicente Diana , Soriano Lidon , Del Coso Juan 
Published: August 2016

AbstractGonzalez-Millan, C, Perez-Brunicardi, D, Salinero, JJ, Lara, B, Abián-Vicen, J, Areces, F, Ruiz-Vicente, D, Soriano, L, and Del Coso, J. Physiological demands of elite cross-country skiing during a real competition.J Strength Cond Res31(6): 1536–1543, 2017—The aim of this study was to assess different physiological variables before and after a 5-km (women) and 10-km (men) cross-country skiing competition to determine potential mechanisms of fatigue. Fourteen elite-level skiers competed in an official cross-country skiing competition using the classical style (9 men and 5 women). Instantaneous skiing velocity was measured during the race by means of 15-Hz global positioning system devices. Before and after the race, a sample of venous blood was obtained to assess changes in blood lactate and serum electrolyte and myoglobin concentrations. Prerace to postrace changes in blood oxygen saturation, forced vital capacity during a spirometry test, jump height during a countermovement jump, and handgrip force were also measured. Mean race speed was 15.8 ± 2.5 and 15.4 ± 1.5 km·h−1, whereas mean heart rate was 171 ± 6 and 177 ± 3 b·min−1for men and women, respectively. There were no significant prerace to postrace changes in jump height, handgrip force, and forced vital capacity in men and women. Blood oxygen saturation was reduced from prerace to postrace in men (95.9 ± 2.1% to 93.1 ± 2.3%,p= 0.02) and women (97.8 ± 1.1% to 92.4 ± 2.1%,p< 0.01), whereas blood lactate concentration increased at the end of the race in men (1.4 ± 0.5 to 4.9 ± 2.1 mmol·L−1,p< 0.01) and women (1.9 ± 0.1 to 6.9 ± 3.2 mmol·L−1,p< 0.01). After the race, blood markers of muscle damage were at low concentrations, whereas serum electrolytes remained unchanged. Fatigue in 5- and 10-km cross-country skiing competitions was related to a reduced blood oxygen carrying capacity and presumably increased muscle and blood acidosis, whereas the influence of exercise-induced muscle damage on fatigue was minor.
Estimating the Effective Population Size from Temporal Allele Frequency Changes in Experimental Evolution
Authors: Jónás Ágnes , Taus Thomas , Kosiol Carolin , Schlötterer Christian , Futschik Andreas 
Published: August 2016

Abstract
The effective population size (Ne) is a major factor determining allele frequency changes in natural and experimental populations. Temporal methods provide a powerful and simple approach to estimate short-term Ne. They use allele frequency shifts between temporal samples to calculate the standardized variance, which is directly related to Ne. Here we focus on experimental evolution studies that often rely on repeated sequencing of samples in pools (Pool-seq). Pool-seq is cost-effective and often outperforms individual-based sequencing in estimating allele frequencies, but it is associated with atypical sampling properties: Additional to sampling individuals, sequencing DNA in pools leads to a second round of sampling, which increases the variance of allele frequency estimates. We propose a new estimator of Ne, which relies on allele frequency changes in temporal data and corrects for the variance in both sampling steps. In simulations, we obtain accurate Ne estimates, as long as the drift variance is not too small compared to the sampling and sequencing variance. In addition to genome-wide Ne estimates, we extend our method using a recursive partitioning approach to estimate Ne locally along the chromosome. Since the type I error is controlled, our method permits the identification of genomic regions that differ significantly in their Ne estimates. We present an application to Pool-seq data from experimental evolution with Drosophila and provide recommendations for whole-genome data. The estimator is computationally efficient and available as an R package at https://github.com/ThomasTaus/Nest.