Physical Characteristics by Sex and Age for Custody Assistants From a Law Enforcement Agency
Lockie, RG, Orr, RM, Stierli, M, Cesario, KA, Moreno, MR, Bloodgood, AM, Dulla, JM, and Dawes, JJ. The physical characteristics by sex and age for custody assistants from a law enforcement agency. J Strength Cond Res 33(8): 2223–2232, 2019—Custody assistants (CAs) are a position within a law enforcement agency who are responsible for assisting officers with maintaining security in correctional facilities. Unlike other positions, CAs may not be required to complete physical testing before being hired. This lack of testing could influence the characteristics of CAs who attend academy training. Therefore, retrospe...
Source: Journal of Strength and Conditioning Research - July 26, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Body Image Among Elite Rugby Union Players
Gibson, C, Hindle, C, McLay-Cooke, R, Slater, J, Brown, R, Smith, B, Baker, D, Healey, P, and Black, K. Body image among elite rugby union players. J Strength Cond Res 33(8): 2217–2222, 2019—There is limited information on the risk of eating disorders (EDs) and body image of elite male athletes. However, research studies suggest that there are some athletes who have poor body image and they may be at increased risk of developing EDs. Therefore, the current study investigated risk of EDs, body image, and the relationship with age, in elite rugby union players during their preseason training period. This cross-se...
Source: Journal of Strength and Conditioning Research - July 26, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Team Dynamics, Running, and Skill-Related Performances of Brazilian U11 to Professional Soccer Players During Official Matches
Palucci Vieira, LH, Aquino, R, Moura, FA, Barros, RMLd, Arpini, VM, Oliveira, LdP, Bedo, BLdS, and Pereira Santiago, PR. Team dynamics, running, and skill-related performances of Brazilian U11 to professional soccer players during official matches. J Strength Cond Res 33(8): 2202–2216, 2019—Analyses of movements during soccer competition have been used previously to help develop conditioning programs. However, this has not been extensively studied in youth populations. Therefore, the purposes of this study were to examine (1) dynamics of collective tactical movements, (2) running, and (3) skill-related performa...
Source: Journal of Strength and Conditioning Research - July 26, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of Foam Rolling as a Recovery Tool in Professional Soccer Players
Rey, E, Padrón-Cabo, A, Costa, PB, and Barcala-Furelos, R. Effects of foam rolling as a recovery tool in professional soccer players. J Strength Cond Res 33(8): 2194–2201, 2019—Foam rolling (FR) is a common strategy used after training and competition by players. However, no previous studies have assessed the effectiveness of FR as a recovery tool in sports populations. The aim of this study was to examine the effectiveness of FR (20 minutes of FR exercises on quadriceps, hamstrings, adductors, gluteals, and gastrocnemius) and passive recovery (20 minutes sit on a bench) interventions performed immediate...
Source: Journal of Strength and Conditioning Research - July 26, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Impact of Weekly Swimming Training Distance on the Ergogenicity of Inspiratory Muscle Training in Well-Trained Youth Swimmers
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 IM...
Source: Journal of Strength and Conditioning Research - July 26, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Repeated Linear and Quadrangular Sprint as a Function of Anaerobic Power
Almansba, R, Boucher, VG, Parent, AA, and Comtois, AS. Repeated linear and quadrangular sprint as a function of anaerobic power. J Strength Cond Res 33(8): 2177–2184, 2019—This investigation aims to study in U17 soccer players the relationships among performance indices of linear or quadrangular (square shape) repeated-sprint bouts (RSBs) and leg muscular power measured with the Wingate test and the squat jump. Seventeen athletes were recruited. Participants were 16 ± 0.35 years old and had a body mass of 66.5 ± 8.69 kg and a height of 175 ± 0.05 cm. All participants performed linear or qua...
Source: Journal of Strength and Conditioning Research - July 26, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of Feedback Type and Personality on 2,000-m Ergometer Performance in Female Varsity Collegiate Rowers
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 &...
Source: Journal of Strength and Conditioning Research - July 26, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Seasonal Changes in Physiological Responses and Body Composition During a Competitive Season in Male and Female Elite Collegiate Ice Hockey Players
This study produced evidence that male and female collegiate hockey athletes' physiological responses and body composition profiles change over the season. Sport scientists working with collegiate hockey teams, may need to revise annual training programs to attenuate reductions in fitness and hopefully prevent injuries. (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - July 26, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Profiling Inflammatory Markers During the Competitive Season and Post Season in Collegiate Wrestlers
Roth, J, Szczygiel, T, Moore, M, O'Connor, P, Edwards, J, Sharma, N, Pettit-Mee, R, and Zuhl, M. Profiling inflammatory markers during the competitive season and post season in collegiate wrestlers. J Strength Cond Res 33(8): 2153–2161, 2019—The purpose of this study was to determine whether biological markers of muscle damage and inflammation coincide with subjective measures of muscle fatigue and sleep quality among Division I collegiate wrestlers. The goal was to provide practitioners with noninvasive techniques to evaluate a wrestler's inflammatory state. Subjects from the Central Michigan University Divisi...
Source: Journal of Strength and Conditioning Research - July 26, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Effect of Thigh-Compression Shorts on Muscle Activity and Soft-Tissue Vibration During Cycling
This study examined the effects of different levels of thigh compression (0, 2, 6, and 15 mm Hg) in shorts on both vibration and muscle activity of the thigh during cycling with superimposed vibrations. Twelve healthy males performed a 18-minute rectangular cycling test per shorts condition (randomized cross-over design) on a specifically designed vibrating cycloergometer. Each test was composed of 2 intensity levels (moderate then high) and 3 vibration frequencies of 18.3, 22.4, and 26.3 Hz, corresponding to cadences of 70, 85, and 100 rpm, respectively. Muscle vibrations were measured with 2 triaxial accelerometers locat...
Source: Journal of Strength and Conditioning Research - July 26, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Application of Change of Direction Deficit to Evaluate Cutting Ability
Cuthbert, M, Thomas, C, Dos'Santos, T, and Jones, PA. Application of change of direction deficit to evaluate cutting ability. J Strength Cond Res 33(8): 2138–2144, 2019—The purpose of this study was to examine the application of the change of direction deficit (CODD) to a 90° cut test to examine whether CODD provides a unique evaluation of an individual's cutting ability. Thirty-six male collegiate team–sport (23 Rugby/13 Soccer) athletes (age: 20 ± 1.4 years; height: 1.80 ± 0.08 m; mass: 83 ± 13.2 kg) participated in the study. Each athlete performed 3 trials of a 20-m sprint (wi...
Source: Journal of Strength and Conditioning Research - July 26, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

The Effect of Short- and Long-Term Aerobic Training Years on Systemic O2 Utilization, and Muscle and Prefrontal Cortex Tissue Oxygen Extraction in Young Women
This study aimed to determine if systemic O2 utilization (VO2) and tissue oxygen extraction (deoxyhemoglobin [HHb]) in the vastus lateralis (VL), gastrocnemius (GAST), and prefrontal cortex were different during exercise between short-term trained (STT, 6–24 months) and long-term trained (LTT,>5 years) young women while controlling for current training load. Thirteen STT and 13 LTT participants completed ramp incremental (RI) and square-wave constant load (SWCL) tests on a cycle ergometer. In LTT compared with STT: (a) VO2 was higher during the RI (p = 0.024) and SWCL (p = 0.001) tests; (b) HHb in the VL (p = 0.04...
Source: Journal of Strength and Conditioning Research - July 26, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Effect of a 16-Week Combined Strength and Plyometric Training Program Followed by a Detraining Period on Athletic Performance in Pubertal Volleyball Players
Fathi, A, Hammami, R, Moran, J, Borji, R, Sahli, S, and Rebai, H. Effect of a 16-week combined strength and plyometric training program followed by a detraining period on athletic performance in pubertal volleyball players. J Strength Cond Res 33(8): 2117–2127, 2019—The purpose of this study was to determine the effects of 16 weeks of combined strength and plyometric training or plyometric training alone and how a detraining program can modify adaptations in response to the training stimulus. Sixty male volleyball players (circa peak-height-velocity [PHV]: −1 to +1 year from PHV) were assigned to a combin...
Source: Journal of Strength and Conditioning Research - July 26, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Effect of Resistance Training Frequency on Neuromuscular Performance and Muscle Morphology After 8 Weeks in Trained Men
In conclusion, both G1 and G2 significantly enhance neuromuscular adaptations, with a similar change noted between experimental conditions. (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - July 26, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of Contrast Strength vs. Plyometric Training on Lower-Limb Explosive Performance, Ability to Change Direction and Neuromuscular Adaptation in Soccer Players
Hammami, M, Gaamouri, N, Shephard, RJ, and Chelly, MS. Effects of contrast strength vs. plyometric training on lower-limb explosive performance, ability to change direction and neuromuscular adaptation in soccer players. J Strength Cond Res 33(8): 2094–2103, 2019—The aim was to compare the effects of 2 differing 8-week in-season strength training programs (contrast strength training [CST] vs. plyometric training [PT]) on selected performance tests (5 and 40 m sprints, S 4 × 5 m change of direction test, squat jump [SJ] and countermovement jump [CMJ], leg peak power on a cycle-ergometer force-velocity test...
Source: Journal of Strength and Conditioning Research - July 26, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Individual and Combined Effect of Inter-repetition Rest and Elastic Bands on Jumping Potentiation in Resistance-Trained Men
Nickerson, BS, Williams, TD, Snarr, RL, and Park, K-S. Individual and combined effect of inter-repetition rest and elastic bands on jumping potentiation in resistance-trained men. J Strength Cond Res 33(8): 2087–2093, 2019—The purpose of this study was to determine the individual and combined effects of cluster sets (CS) and elastic bands for jumping potentiation in resistance-trained men. Twelve resistance-trained men (age: 22 ± 3 years) participated in this study. In a random order, participants completed 1 set of 3 repetitions at 85% 1-repetition maximum for the parallel back squat: (a) traditional se...
Source: Journal of Strength and Conditioning Research - July 26, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Transcranial Direct Current Stimulation of the Temporal Lobe Does Not Affect High-Intensity Work Capacity
Ciccone, AB, Deckert, JA, Schlabs, CR, Tilden, MJ, Herda, TJ, Gallagher, PM, and Weir, JP. Transcranial direct current stimulation of the temporal lobe does not affect high-intensity work capacity. J Strength Cond Res 33(8): 2074–2086, 2019—Stimulation of the left insular cortex may affect heart rate variability (HRV) and exercise effort perception. These studies investigated the effects transcranial direct current stimulation (tDCS) and electrode orientation on HRV and repeated maximal knee extensions. In study 1, after sham stimulation, anodal left temporal lobe stimulation, or anodal right temporal lobe stim...
Source: Journal of Strength and Conditioning Research - July 26, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Kinetic Contributions of The Upper Limbs During Counter-Movement Verical Jumps With and Without Arm Swing
This study examined the kinetic contributions of the upper extremities during countermovement vertical jumps (CMVJs) while using arm swing (AS) or no arm swing (NAS) conditions. Fourteen healthy men ( JOURNAL/jscr/04.02/00124278-201908000-00004/math_4MM1/v/2019-07-24T043809Z/r/image-tiff ± SD; age = 24.1 ± 3.9 years) volunteered for this investigation. Subjects performed in random order a total of 6 jumps consisting of 3 AS and 3 NAS CMVJs. A motion capture system was used to analyze the kinetic data. Paired samples t-tests were used to examine the subjects' mean differences in the AS and NAS CMVJ trials (p...
Source: Journal of Strength and Conditioning Research - July 26, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Effect of COL5A1, GDF5, and PPARA Genes on a Movement Screen and Neuromuscular Performance in Adolescent Team Sport Athletes
Stastny, P, Lehnert, M, De Ste Croix, M, Petr, M, Svoboda, Z, Maixnerova, E, Varekova, R, Botek, M, Petrek, M, Lenka, K, and Cięszczyk, P. Effect of COL5A1, GDF5, and PPARA genes on a movement screen and neuromuscular performance in adolescent team sport athletes. J Strength Cond Res 33(8): 2057–2065, 2019—The risk of injury increases with adolescents' chronological age and may be related to limited muscle function neuromuscular, genetic, and biomechanical factors. The purpose of this study was to determine whether COL5A1, PPARA, and GDF5 genes are associated with muscle functions and stretch-shortening cycle ...
Source: Journal of Strength and Conditioning Research - July 26, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Biomechanical Comparison of the Reverse Hyperextension Machine and the Hyperextension Exercise
Lawrence, MA, Chin, A, and Swanson, BT. Biomechanical comparison of the reverse hyperextension machine and the hyperextension exercise. J Strength Cond Res 33(8): 2053–2056, 2019—The purpose of this study was to compare activation of the erector spinae, gluteus maximus, and biceps femoris muscles, lower back extension moment, and lower extremity range of motion (ROM) between the reverse hyperextension (RHE) and hyperextension (HE) exercises. Motion and muscle activation of the trunk and lower extremity were measured while 20 recreationally active individuals performed 2 sets of 10 repetitions of each exercise. ...
Source: Journal of Strength and Conditioning Research - July 26, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Resistance Training for Older Adults: Position Statement From the National Strength and Conditioning Association
Fragala, MS, Cadore, EL, Dorgo, S, Izquierdo, M, Kraemer, WJ, Peterson, MD, and Ryan, ED. Resistance training for older adults: position statement from the national strength and conditioning association. J Strength Cond Res XX(X): 000–000, 2019—Aging, even in the absence of chronic disease, is associated with a variety of biological changes that can contribute to decreases in skeletal muscle mass, strength, and function. Such losses decrease physiologic resilience and increase vulnerability to catastrophic events. As such, strategies for both prevention and treatment are necessary for the health and well-being ...
Source: Journal of Strength and Conditioning Research - July 26, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Effect of Postactivation Potentiation on Explosive Vertical Jump: A Systematic Review and Meta-Analysis
This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Statement (PRISMA). Original research articles published by January 18, 2018, were located using an electronic search of 4 databases and yielded 759 original publications. Data were extracted and independently coded by 2 authors (W.C.D. and D.V.T.). The standardized mean effect size (ES) was calculated by subtracting the pre-treatment mean from the post-treatment mean and dividing by the pooled SD, adjusting for small sample bias. Multilevel random-effects model was used to aggregate a mean ES and 95% confidence int...
Source: Journal of Strength and Conditioning Research - June 28, 2019 Category: Sports Medicine Tags: Brief Review Source Type: research

A Meta-Analysis of Plyometric Training in Female Youth: Its Efficacy and Shortcomings in the Literature
Moran, J, Clark, CCT, Ramirez-Campillo, R, Davies, MJ, and Drury, B. A meta-analysis of plyometric training in female youth: its efficacy and shortcomings in the literature. J Strength Cond Res 33(7): 1996–2008, 2019—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 inte...
Source: Journal of Strength and Conditioning Research - June 28, 2019 Category: Sports Medicine Tags: Brief Review Source Type: research

Lower-Limb Stiffness and Maximal Sprint Speed in 11–16-Year-Old Boys
Meyers, RW, Moeskops, S, Oliver, JL, Hughes, MG, Cronin, JB, and Lloyd, RS. Lower-limb stiffness and maximal sprint speed in 11–16-year-old boys. J Strength Cond Res 33(7): 1987–1995, 2019—The purpose of the study was to examine the relationship between vertical stiffness, leg stiffness, and maximal sprint speed in a large cohort of 11–16-year-old boys. Three-hundred thirty-six boys undertook a 30-m sprint test using a floor-level optical measurement system, positioned in the final 15-m section. Measures of speed, step length, step frequency, contact time, and flight time were directly measured whil...
Source: Journal of Strength and Conditioning Research - June 28, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Physical Demands of Exergaming in Healthy Young Adults
This study aimed to: (a) compare the physical demands of WBE in healthy adults with traditional exercise; (b) determine whether the physical demands of WBE were reproducible. Twenty-five healthy adults (age: 22.9 ± 6.4 years; height: 1.7 ± 0.1 m; mass: 69.1 ± 12.2 kg) completed two 10-minute experimental conditions (WBE on the Xbox Kinect and treadmill walking) in a randomized cross-over design study. Whole-body exergaming produced a significant increase in the peak heart rate (138 ± 23 b·min–1), oxygen consumption (40 ± 13 ml·kg−1·min−1), metabolic ...
Source: Journal of Strength and Conditioning Research - June 28, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Exploring Game Dynamics in Padel: Implications for Assessment and Training
Courel-Ibáñez, J, Sánchez-Alcaraz Martinez, BJ, and Muñoz Marín, D. Exploring game dynamics in padel: implications for assessment and training. J Strength Cond Res 33(7): 1971–1977, 2019—A better understanding of in-game competition demands potentially improved coaching strategy and quality. However, there is very limited information about game patterns in padel, a very modern racket sport born in the 70s. The purpose of this study was therefore to quantify and classify game dynamics during the match in professional padel players through a multivariate decision tree approach i...
Source: Journal of Strength and Conditioning Research - June 28, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Morphological and Physical Fitness Profile of Young Female Sprint Kayakers
This study attempted to identify the differences in morphology and fitness level of 2 performance-based groups of young elite female paddlers. Eighty-six female kayakers, aged 13.62 ± 0.57 years (mean ± SD), were allocated in 2 groups (Top-10 and Rest) depending on their ranking in the 3 Olympic distances (200, 500, and 1,000 m). All subjects underwent a battery of anthropometrical (heights, mass, girths, and sum of skinfolds), physical fitness (overhead medicine ball throw, countermovement jump, sit-and-reach test, and 20-m multistage shuttle run test), and specific performance assessments (200, 500, and 1,0...
Source: Journal of Strength and Conditioning Research - June 28, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Relationship Between Percentages of Heart Rate Reserve and Oxygen Uptake Reserve During Cycling and Running: A Validation Study
This study investigated the relationship between percentages of heart rate reserve (%HRR) and oxygen uptake reserve (%VO2R) during a cardiopulmonary exercise test (CPET) and discrete bouts of isocaloric cycling and treadmill running. Thirty men visited the laboratory 3 times for anthropometrical and resting VO2 assessments, and perform cycling and running CPETs. Ten men visited the laboratory twice more to investigate the validity of the %HRR-%VO2R relationships during isocaloric bouts of cycling and running at 75% VO2R with energy expenditures of 400 kcals. The %HRR was significantly higher than the %VO2R during both CPET...
Source: Journal of Strength and Conditioning Research - June 28, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Practical Considerations for Assessing Pulmonary Gas Exchange and Ventilation During Flume Swimming Using the MetaSwim Metabolic Cart
Lomax, M, Mayger, B, Saynor, ZL, Vine, C, and Massey, HC. Practical considerations for assessing pulmonary gas exchange and ventilation during flume swimming using the MetaSwim metabolic cart. J Strength Cond Res 33(7): 1941–1953, 2019—The MetaSwim (MS) metabolic cart can assess pulmonary gas exchange and ventilation in aquatic environments. The aims of this study were: (a) to determine the agreement between minute ventilation (VE), pulmonary oxygen uptake (VO2), and carbon dioxide output (VCO2) using the MS and Douglas bag (DB) methods during flume swimming; and (b) to assess the repeatability of these and oth...
Source: Journal of Strength and Conditioning Research - June 28, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Sex Differences in the Health Status of Endurance Runners: Results From the NURMI Study (Step 2)
Boldt, P, Knechtle, B, Nikolaidis, P, Lechleitner, C, Wirnitzer, G, Leitzmann, C, and Wirnitzer, K. Sex differences in the health status of endurance runners: results from the NURMI study (step 2). J Strength Cond Res 33(7): 1929–1940, 2019—Optimized endurance performance is closely linked to a good health status (HS), which is crucially affected by sex. Therefore, the purpose of this study was to investigate sex differences in the HS of endurance runners of different distances. A total of 281 female and male recreational runners completed an online survey. Health status included body mass, smoking habits, felt...
Source: Journal of Strength and Conditioning Research - June 28, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Relationship Between Running Economy and Kinematic Parameters in Long-Distance Runners
Pizzuto, F, Fonseca de Oliveira, C, Amorim Soares, TS, Rago, V, Silva, G, and Oliveira, J. Relationship between running economy and kinematic parameters in long-distance runners. J Strength Cond Res 33(7): 1921–1928, 2019—The purpose of this study was to explore the relationship between running economy (RE) and sagittal, frontal, and transverse plane kinematic parameters in long-distance runners. A secondary purpose was to identify the kinematic predictors of RE during running at the lowest RE value, representing an individual's most efficient running intensity. Twenty recreational long-distance runners ran 3 s...
Source: Journal of Strength and Conditioning Research - June 28, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Between-Game Variation of Physical Soccer Performance Measures in Highly Trained Youth Soccer Players
Doncaster, G and Unnithan, V. Between-game variation of physical soccer performance measures in highly trained youth soccer players. J Strength Cond Res 33(7): 1912–1920, 2019—To assess the between-game variation in measures of physical performance during 11 vs. 11 soccer match play, over a short period, in highly trained youth soccer players. A single-cohort, observational, study design was used. Physical match performance data were collected from 17, male, highly trained, youth soccer players (age, 13.3 ± 0.4 years) over 3, 2 × 20 minutes, 11 vs. 11 matches. Using 10-Hz global positioning systems...
Source: Journal of Strength and Conditioning Research - June 28, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Somatotype and Body Composition in Young Soccer Players According to the Playing Position and Sport Success
Cárdenas-Fernández, V, Chinchilla-Minguet, JL, and Castillo-Rodríguez, A. Somatotype and body composition in young soccer players according to the playing position and sport success. J Strength Cond Res 33(7): 1904–1911, 2019—Soccer players undergo an evolution in their body composition throughout the growth and passage through the different base stages, that is, childhood, puberty, and adolescence. The aim of this study was to analyze the morphology and body composition of U14, U16, and U19 soccer players, taking into account in addition, their sport success endorsed through the regularity...
Source: Journal of Strength and Conditioning Research - June 28, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Comparison of 5vs5 Training Games and Match-Play Using Microsensor Technology in Elite Basketball
Svilar, L, Castellano, J, and Jukic, I. Comparison of 5vs5 training games and match-play using microsensor technology in elite basketball. J Strength Cond Res 33(7): 1897–1903, 2019—The aim of this study was to compare the data obtained using microsensor technology in 2 types of 5vs5 training games—the regular-stop game (RSG) and the no-stop game (NSG)—and in match-play (MP) in elite basketball. Sixteen top-level basketball players were monitored during pre- and in-season periods (10 weeks). The variables included: player load, accelerations (ACC), decelerations (DEC), changes of direction (CoD), an...
Source: Journal of Strength and Conditioning Research - June 28, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Relationships Among Circuit Training, Small-Sided and Mini Goal Games, and Competition in Professional Soccer Players: A Comparison of On-Field Integrated Training Routines
In conclusion, these drills may be useful for competition and impact microcycles (i.e., intermittent efforts with accelerations, decelerations, and walking actions) to achieve the specific adaptations of high-intensity efforts. (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - June 28, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Sleep Quality and Quantity of International Rugby Sevens Players During Pre-season
This study highlights the necessity to monitor and improve sleep among elite rugby sevens players, especially for the intense period of training. (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - June 28, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Relationship Between Body Mass, Peak Power, and Power-to-Body Mass Ratio on Sprint Velocity and Momentum in High-School Football Players
Jalilvand, F, Banoocy, NK, Rumpf, MC, and Lockie, RG. Relationship between body mass, peak power, and power-to-body mass ratio on sprint velocity and momentum in high-school football players. J Strength Cond Res 33(7): 1871–1877, 2019—The ability to rapidly shift one's body mass horizontally or vertically is common within American football irrespective of field position, and the capacity to generate power is a favorable physical quality. This requires analysis in high-school football players, especially considering the body mass disparities that exist in this population. Sixteen high-school players (7 backs and...
Source: Journal of Strength and Conditioning Research - June 28, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

U.S. Army Physical Demands Study: Differences in Physical Fitness and Occupational Task Performance Between Trainees and Active Duty Soldiers
Canino, MC, Foulis, SA, Zambraski, EJ, Cohen, BS, Redmond, JE, Hauret, KG, Frykman, PN, and Sharp, MA. U.S. Army Physical Demands Study: Differences in physical fitness and occupational task performance between trainees and active duty soldiers. J Strength Cond Res 33(7): 1864–1870, 2019—U.S. Army initial entry training (IET) is designed to prepare trainees for the military environment and subsequent training, including specific programs to increase physical fitness to perform job-specific tasks to the minimal acceptable performance standard (MAPS). The aim of this study was to compare physical fitness and occu...
Source: Journal of Strength and Conditioning Research - June 28, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

The Relationship Between a Jump-Landing Task and Functional Movement Screen Items : A Validation Study
Kraus, K, Schütz, E, and Doyscher, R. The relationship between a jump-landing task and functional movement screen items : a validation study. J Strength Cond Res 33(7): 1855–1863, 2019—Sports injuries and athletic performance are complex areas, which are characterized by manifold interdependencies. The landing error scoring system (LESS) is a valid screening tool to examine bilateral jump-landing mechanics, whereas the Functional Movement Screen (FMS) items are thought to operationalize flexibility and motor behavior during low-intense bodyweight patterns. The aim of the study was to explore possible inter...
Source: Journal of Strength and Conditioning Research - June 28, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Use of Functional Movement Screen Scores to Predict Dynamic Balance in Physically Active Men and Women
Scudamore, EM, Stevens, SL, Fuller, DK, Coons, JM, and Morgan, DW. Use of functional movement screen scores to predict dynamic balance in physically active men and women. J Strength Cond Res 33(7): 1848–1854, 2019—The primary focus of this study was to determine whether scores obtained from the Functional Movement Screen (FMS) can predict dynamic balance in young, healthy adults. Thirty-four physically active participants completed the FMS, and balance was assessed using measures of composite reach (CR) distance and overall stability indices (OSI) derived from Y Balance and Biodex Balance System testing, respec...
Source: Journal of Strength and Conditioning Research - June 28, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Optimizing Between-Session Reliability for Quadriceps Peak Torque and Rate of Torque Development Measures
Grindstaff, TL, Palimenio, MR, Franco, M, Anderson, D, Bagwell, JJ, and Katsavelis, D. Optimizing between-session reliability for quadriceps peak torque and rate of torque development measures. J Strength Cond Res 33(7): 1840–1847, 2019—Quadriceps peak torque and rate of torque development (RTD) have relevance for athletic performance and recovery after knee injury. The number of repetitions performed to determine RTD varies between studies, and the associated measurement error has not been established. The purpose of this study was to determine the number of repetitions necessary to optimize the between-sessio...
Source: Journal of Strength and Conditioning Research - June 28, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Changes in Body Composition and Neuromuscular Performance Through Preparation, 2 Competitions, and a Recovery Period in an Experienced Female Physique Athlete
Tinsley, GM, Trexler, ET, Smith-Ryan, AE, Paoli, A, Graybeal, AJ, Campbell, BI, and Schoenfeld, BJ. Changes in body composition and neuromuscular performance through preparation, two competitions, and a recovery period in an experienced female physique athlete. J Strength Cond Res 33(7): 1823–1839, 2019—This prospective case study evaluated an experienced female figure competitor during contest preparation, 2 competitions, and a recovery period. Twelve laboratory sessions were conducted over 8 months. At each visit, body composition was assessed by 4-compartment model, resting metabolic rate (RMR) by indirect c...
Source: Journal of Strength and Conditioning Research - June 28, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Oxidative Stress Parameters and Its Associations With Arterial Stiffness in Competitive Powerlifting Athletes After 12-Week Supervised Strength Training
Jürgenson, J, Serg, M, Kampus, P, Kals, J, Zagura, M, Viru, M, Zilmer, K, Zilmer, M, Eha, J, and Unt, E. Oxidative stress parameters and its associations with arterial stiffness in competitive powerlifting athletes after 12-week supervised strength training. J Strength Cond Res 33(7): 1816–1822, 2019—Available studies have not revealed a clear understanding of the impact of intensive strength training on arterial stiffness and oxidative stress (OxS) parameters, which may have a significant impact on further cardiovascular health of an athlete. The purpose of this study was to evaluate the effect of a 12-we...
Source: Journal of Strength and Conditioning Research - June 28, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of an 8-Week In-Season Elastic Band Training Program on Explosive Muscle Performance, Change of Direction, and Repeated Changes of Direction in the Lower Limbs of Junior Male Handball Players
Aloui, G, Hammami, M, Fathloun, M, Hermassi, S, Gaamouri, N, Shephard, RJ, and Chelly, MS. Effects of an 8-week in-season elastic band training program on explosive muscle performance, change of direction, and repeated changes of direction in the lower limbs of junior male handball players. J Strength Cond Res 33(7): 1804–1815, 2019—The aim of this study was to examine the effects of incorporating 8 weeks of biweekly lower-limb elastic band training (knee and hip extension) into the in-season regimen of junior handball players. Study participants (30 men, aged 18.7 ± 0.8 years, body mass 81.1 ± 15...
Source: Journal of Strength and Conditioning Research - June 28, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Combined Effects of Self-Myofascial Release and Dynamic Stretching on Range of Motion, Jump, Sprint, and Agility Performance
This study was designed to determine the effect of a 6-minute protocol of self massage known as self-myofascial release (SMR) using a foam rolling device in conjunction with a general warm-up and sport-specific dynamic stretching (DS) session on flexibility and explosive athletic performance in a sample of 14 female collegiate athletes. After familiarization, participants completed 2 testing sessions that began with 5 minutes of jogging at a self-selected pace, followed by either a 6-minute foam rolling session (SMR) or 6 minutes of light walking (LW) and a subsequent 6-minute period of sport-specific DS. Sit-and-reach (SR...
Source: Journal of Strength and Conditioning Research - June 28, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of Various Recovery Strategies on Repeated Bouts of Simulated Intermittent Activity
Crowther, FA, Sealey, RM, Crowe, MJ, Edwards, AM, and Halson, SL. Effects of various recovery strategies on repeated bouts of simulated intermittent activity. J Strength Cond Res 33(7): 1781–1794, 2019—A large variety of recovery strategies are used between and after bouts of exercise to maximize performance and perceptual recovery, with limited conclusive evidence regarding the effectiveness of these strategies. The aim of this study was to compare 5 postexercise recovery strategies (cold water immersion, contrast water therapy, active recovery, a combined cold water immersion and active recovery, and a contro...
Source: Journal of Strength and Conditioning Research - June 28, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Appetite Regulations After Sprint Exercise Under Hypoxic Condition in Female Athletes
Kojima, C, Kasai, N, Ishibashi, A, Murakami, Y, Ebi, K, and Goto, K. Appetite regulations after sprint exercise under hypoxic condition in female athletes. J Strength Cond Res 33(7): 1773–1780, 2019—The present study determined changes in appetite-regulating hormones and energy intake after high-intensity interval exercise (HIIT) under hypoxic conditions (HYP) in trained female athletes. Fifteen female athletes completed 3 trials on different days of either HIIT under HYP, HIIT under normoxic conditions (NOR), or rest in normoxia (CON). Exercise trials consisted of 2 successive sets of 8 repeated bouts of a 6-s...
Source: Journal of Strength and Conditioning Research - June 28, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Breakfast Omission Reduces Subsequent Resistance Exercise Performance
Bin Naharudin, MN, Yusof, A, Shaw, H, Stockton, M, Clayton, DJ, and James, LJ. Breakfast omission reduces subsequent resistance exercise performance. J Strength Cond Res 33(7): 1766–1772, 2019—Although much research has examined the influence of morning carbohydrate intake (i.e., breakfast) on endurance performance, little is known about its effects on performance in resistance-type exercise. Sixteen resistance-trained men (age 23 ± 4 years, body mass 77.56 ± 7.13 kg, and height 1.75 ± 0.04 m) who regularly (≥3 day/wk−1) consumed breakfast completed this study. After assessment of ...
Source: Journal of Strength and Conditioning Research - June 28, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Familiarization With Airflow-Restriction Mask During Resistance Exercise: Effect on Tolerance and Total Volume
This study investigated whether familiarization with the airflow-restriction mask (AIRfr) increases tolerance and avoids negative effects on performance of resistance exercise (RE). Ten resistance-trained male subjects performed a familiarization session (FAM), followed by 2 testing sessions, with the AIRfr and without airflow restriction (SHAM) in a counterbalanced and randomized cross-over design. The FAM was performed with the same number of sets, load, and level of airflow-restriction as the AIRfr experimental session. Each session consisted of 4 sets of the leg press exercise with 70% 1 repetition maximum until volunt...
Source: Journal of Strength and Conditioning Research - June 28, 2019 Category: Sports Medicine Tags: Short Research Source Type: research

Presence of Spotters Improves Bench Press Performance: A Deception Study
Sheridan, A, Marchant, DC, Williams, EL, Jones, HS, Hewitt, PA, and Sparks, SA. Presence of spotters improves bench press performance: a deception study. J Strength Cond Res 33(7): 1755–1761, 2019—Resistance exercise is a widely used method of physical training in both recreational exercise and athletic populations. The use of training partners and spotters during resistance exercise is widespread, but little is known about the effect of the presence of these individuals on exercise performance. The purpose of the current study was to investigate the effect of spotter presence on bench press performance. Twelve...
Source: Journal of Strength and Conditioning Research - June 28, 2019 Category: Sports Medicine Tags: Original Research Source Type: research