Hemodynamic and Cardiorespiratory Predictors of Sport Rock Climbing Performance
Fryer, SM, Giles, D, Garrido Palomino, I, de la O Puerta, A, and España-Romero, V. Hemodynamic and cardiorespiratory predictors of sport rock climbing performance. J Strength Cond Res 32(12): 3543–3550, 2018—Rock climbing performance has been suggested to involve a notable contribution from aerobic metabolism. Previously, it has been shown that forearm oxygenation kinetics can be used to distinguish ability groups and predict red-point sport climbing performance. Currently, it is not known if forearm oxygenation kinetics or a sport-specific assessment of cardiorespiratory fitness best predicts sport rock...
Source: Journal of Strength and Conditioning Research - November 27, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Basketball Players' Dynamic Performance Across Competition Levels
Bullock, GS, Arnold, TW, Plisky, PJ, and Butler, RJ. Basketball players' dynamic performance across competition levels. J Strength Cond Res 32(12): 3537–3542, 2018—Dynamic balance is an integral component in screening lower extremity injury risk. Previous research has identified the need to create sport- and competition level–specific dynamic balance injury cut points. The purpose of this study was to determine if dynamic balance differences exist, using the Lower Quarter Y Balance Test (YBT-LQ), across varying competition levels (middle school, high school, college, and professional), in basketball playe...
Source: Journal of Strength and Conditioning Research - November 27, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Benefits of Compression Garments Worn During Handball-Specific Circuit on Short-Term Fatigue in Professional Players
Ravier, G, Bouzigon, R, Beliard, S, Tordi, N, and Grappe, F. Benefits of compression garments worn during handball-specific circuit on short-term fatigue in professional players. J Strength Cond Res 32(12): 3528–3536, 2018—The purpose of this study was to investigate the benefits of full-leg length compression garments (CGs) worn during a handball-specific circuit exercises on athletic performance and acute fatigue-induced changes in strength and muscle soreness in professional handball players. Eighteen men (mean ± SD: age 23.22 ± 4.97 years; body mass: 82.06 ± 9.69 kg; height: 184.61 &plu...
Source: Journal of Strength and Conditioning Research - November 27, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Quantification of a Professional Football Team's External Load Using a Microcycle Structure
Martín-García, A, Gómez Díaz, A, Bradley, PS, Morera, F, and Casamichana, D. Quantification of a professional football team's external load using a microcycle structure. J Strength Cond Res 32(12): 3520–3527, 2018—The aims of this study were to (a) determine the external load of a football team across playing position and relative to competition for a structured microcycle and (b) examine the loading and variation the day after competition for players with or without game time. Training and match data were obtained from 24 professional football players who belonging to the reserve sq...
Source: Journal of Strength and Conditioning Research - November 27, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Individualizing Acceleration in English Premier League Academy Soccer Players
Abbott, W, Brickley, G, Smeeton, NJ, and Mills, S. Individualizing acceleration in English Premier League academy soccer players. J Strength Cond Res 32(12): 3512–3519, 2018—Global thresholds are typically used to band acceleration dependent on intensity. However, global thresholds do not account for variation in individual capacities, failing to quantify true intensity of acceleration. Previous research has investigated discrepancies in high-speed distance produced using global and individual speed thresholds, not yet investigated for acceleration. The current aim was to investigate discrepancies between globa...
Source: Journal of Strength and Conditioning Research - November 27, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Grip Strength in Youth Ice Hockey Players: Normative Values and Predictors of Performance
This study describes normative grip strength values in youth ice hockey players according to age, sex, body mass, and playing level. These athlete-specific norms may be used to help evaluate and monitor changes in grip strength over time in youth ice hockey players. (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - November 27, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Importance, Reliability, and Usefulness of Acceleration Measures in Team Sports
This study assessed movement data from one professional rugby league team throughout 2 full seasons and 1 preseason period. Using both 5 and 10 Hz global positioning systems (GPS) units, a range of acceleration-based variables were evaluated for their interunit reliability, ability to discriminate between positions, and associations with perceived muscle soreness. The reliability of 5 Hz global positioning systems for measuring acceleration and deceleration ranged from good to poor (CV = 3.7–27.1%), with the exception of high-intensity deceleration efforts (CV = 11.1–11.8%), the 10 Hz units exhibited moderate-t...
Source: Journal of Strength and Conditioning Research - November 27, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Self-reported Measures of Strength and Sport-Specific Skills Distinguish Ranking in an International Online Fitness Competition
Serafini, PR, Feito, Y, and Mangine, GT. Self-reported measures of strength and sport-specific skills distinguish ranking in an international online fitness competition. J Strength Cond Res 32(12): 3483–3493, 2018—To determine if self-reported performance measures could distinguish ranking during the 2016 CrossFit Open, data from 3,000 male (n = 1,500; 27.2 ± 8.4 years; 85.2 ± 7.9 kg; 177.0 ± 6.5 cm) and women (n = 1500, 28.7 ± 4.9 years; 63.7 ± 5.8 kg; 163.7 ± 6.6 cm) competitors was used for this study. Competitors were split by gender and grouped into quintiles (Q1&n...
Source: Journal of Strength and Conditioning Research - November 27, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

The Seasonal Variations in Anthropometric and Performance Characteristics of Elite Intercounty Gaelic Football Players
Kelly, RA, and Collins, K. The seasonal variations in anthropometric and performance characteristics of elite inter county gaelic football players. J Strength Cond Res 32(12): 3475–3482, 2018—There is limited research assessing the anthropometric and performance variations in elite Gaelic football. The aim of this study was to assess the anthropometric and performance characteristics of an elite intercounty squad within a season. After ethical approval and informed consent, 26 participants were assessed at the start of preseason (November), after early in-season (January), and midseason (March). Measurements in...
Source: Journal of Strength and Conditioning Research - November 27, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Movement Patterns and Muscle Damage During Simulated Rugby Sevens Matches in National Team Players
Pereira, LA, Nakamura, FY, Moraes, JE, Kitamura, K, Ramos, SP, and Loturco, I. Movement patterns and muscle damage during simulated rugby sevens matches in national team players. J Strength Cond Res 32(12): 3465–3474, 2018—The aim of this study was to analyze the match performance (i.e., distance covered in different intensities), signs of muscle damage (assessed by means of creatine kinase [CK] activity and rate of force development [RFD]), and neuromuscular fatigue (using linear sprint and vertical jump performances) after 3 single-day simulated matches performed by rugby sevens players from the Brazilian Nat...
Source: Journal of Strength and Conditioning Research - November 27, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Energetic Demands of Interchange and Full-Match Rugby League Players
Cummins, CJ, Gray, AJ, Shorter, KA, Halaki, M, and Orr, R. Energetic demands of interchange and full-match rugby league players. J Strength Cond Res 32(12): 3456–3464, 2018—The purpose of this study was to describe and compare the metabolic demands of rugby league for interchange and full-match players in relation to positional groups. Eighteen elite rugby league players were recruited. A time-motion model was used to estimate the energy expenditure and metabolic demands of rugby league match-play using Global Positioning System (GPS) technology. This approach uses players' GPS velocity-time curves to examine r...
Source: Journal of Strength and Conditioning Research - November 27, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

The Activity Profile of Elite Male Amateur Boxing After the 2013 Rule Changes
Davis, P, Connorton, AJ, Driver, S, Anderson, S, and Waldock, R. The activity profile of elite male amateur boxing after the 2013 rule changes. J Strength Cond Res 32(12): 3450–3455, 2018—An activity profile of competitive elite amateur boxing after the rule changes in 2013 was created from video footage to allow identification of the technical and tactical demands as well as differences between winners and losers. The study analyzed 50 World Championship bouts involving 60 male boxers (mean ± SD) of age: 23.5 ± 2.8 years, height: 176.2 ± 12.2 cm, and body mass: 71.7 ± 16.2 kg. The r...
Source: Journal of Strength and Conditioning Research - November 27, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Response Time and Effectiveness in Elite Greco-Roman Wrestlers Under Simulated Fight Conditions
Gierczuk, D, Bujak, Z, Cieśliński, I, Lyakh, V, and Sadowski, J. Response time and effectiveness in elite Greco-Roman wrestlers under simulated fight conditions. J Strength Cond Res 32(12): 3442–3449, 2018—The purpose of the study was to determine changes in response time and its correlations with tactical and technical actions performed by Greco-Roman wrestlers in a fight. Twenty wrestlers aged 19–25 (21.4 JOURNAL/jscr/04.02/00124278-201812000-00017/math_17MM1/v/2018-11-25T214713Z/r/image-tiff 1.8) years were divided into 2 groups, i.e., finalists of Polish Senior Championships (winners of 1st and 2...
Source: Journal of Strength and Conditioning Research - November 27, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Relationships and Reliability Between a Drive Block Test and Traditional Football Performance Tests in High School Offensive Line Players
This study investigated the reliability of the average and peak velocity (avgV, peakV) and momentum (avgM, peakM) of a drive block test (DBT) in 15 high school OL and relationships to performance tests. A linear position transducer attached to the OL waist measured the DBT from a 3-point stance into a blocking pad. Linear speed was measured by a 36.58-m sprint. Change-of-direction (COD) ability was measured by the pro-agility shuttle (first COD, second COD, and total time) and COD deficit from the first (COD deficit 1) and second COD (COD deficit 2) of the pro-agility shuttle. Vertical jump, standing broad jump (SBJ), and ...
Source: Journal of Strength and Conditioning Research - November 27, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Changes in Vertical and Joint Stiffness in Runners With Advancing Age
Powell, DW and Williams, DSB. Changes in vertical and joint stiffness in runners with advancing age. J Strength Cond Res 32(12): 3425–3431, 2018—Age-related changes in the neuromuscular system underlie reduced performance and injury but may be mitigated through regular physical activity. It was hypothesized that older (OLD) compared with young (YOUNG) adults would exhibit greater vertical and joint stiffness when running at 3.35 m·s−1. Nine YOUNG and 10 OLD runners performed over ground running trials while three-dimensional biomechanics were recorded. Ankle and knee joint angles, moments and stiff...
Source: Journal of Strength and Conditioning Research - November 27, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Impact of Mild Hypohydration on Muscle Endurance, Power, and Strength in Healthy, Active Older Men
In this study, we examined this question, believing it may identify a factor exacerbating dynapenia. One-hour after having been passively exposed to heat where either a body mass loss of 1% was induced or euhydration maintained with fluid ingestion, 8 healthy, active older men (age: 68 ± 5 years) completed an exercise testing session where indices of muscle strength (30-second chair stand, grip strength, maximal isometric seated leg-press extension), endurance (seated leg-curl flexion + seated leg-press extension to exhaustion at 60% of 1 repetition maximum), and power (30-second Wingate test) were assessed. Gastroi...
Source: Journal of Strength and Conditioning Research - November 27, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Impact of Direction of Unloading Influence on Template Rate of Perceived Exertion
This study examined how altering workload intensity during a positive-pressure treadmill task may impact Rating of Perceived Exertion (RPE). In a counterbalanced design, 15 collegiate cross-country runners (7 men and 8 women) performed 2 25-minute runs at a constant velocity, while body mass (BM) was either increased from 60 to 100% (low-to-high progression trial [INC]) or decreased from 100 to 60% (high-to-low progression trial) in 5-minutes increments. Oxygen consumption (V[Combining Dot Above]O2), heart rate (HR), and respiratory exchange ratio (RER) were collected. RPE was recorded at the end of each stage, and energy ...
Source: Journal of Strength and Conditioning Research - November 27, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of High-Intensity Interval Training With Different Interval Durations on Physical Performance in Handball Players
Viaño-Santasmarinas, J, Rey, E, Carballeira, S, and Padrón-Cabo, A. Effects of high-intensity interval training with different interval durations on physical performance in handball players. J Strength Cond Res 32(12): 3398–3406, 2018—The purpose of this study was to compare the effects of 2 high-intensity interval training (HIIT) protocols with different interval durations (short [SI] vs. long [LI]) based on peak running velocity in 30–15 Intermittent Fitness Test (VIFT) in handball players. Eighteen highly-trained players (age: 22.7 ± 3.9 years; height: 181.5 ± 6.6 cm; body m...
Source: Journal of Strength and Conditioning Research - November 27, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Ammonia Inhalation Does Not Increase Deadlift 1-Repetition Maximum in College-Aged Male and Female Weight Lifters
Vigil, JN, Sabatini, PL, Hill, LC, Swain, DP, and Branch, JD. Ammonia inhalation does not increase deadlift 1-repetition maximum in college-aged male and female weight lifters. J Strength Cond Res 32(12): 3392–3397, 2018—Ammonia inhalant use by powerlifters and weight lifters is a prevalent practice with little research support for improved performance. The purpose of this study was to investigate the effects of ammonia as a stimulant on athletic performance during a deadlift 1-repetition maximum (1RM) absolute strength test. Subjects (men: n = 10, mean ± SD age = 21 ± 1 year, mass = 72.5 ±...
Source: Journal of Strength and Conditioning Research - November 27, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

A Low-Carbohydrate Ketogenic Diet Reduces Body Mass Without Compromising Performance in Powerlifting and Olympic Weightlifting Athletes
Greene, DA, Varley, BJ, Hartwig, TB, Chapman, P, and Rigney, M. A low-carbohydrate ketogenic diet reduces body mass without compromising performance in powerlifting and Olympic weightlifting athletes. J Strength Cond Res 32(12): 3382–3391, 2018—Weight class athletes use weight-making strategies to compete in specific weight categories with an optimum power-to-weight ratio. There is evidence that low carbohydrate diets might offer specific advantages for weight reduction without the negative impact on strength and power previously hypothesized to accompany carbohydrate restriction. Therefore, the purpose of this...
Source: Journal of Strength and Conditioning Research - November 27, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Between-Session Reliability of Isometric Midthigh Pull Kinetics and Maximal Power Clean Performance in Male Youth Soccer Players
Dos'Santos, T, Thomas, C, Comfort, P, McMahon, JJ, Jones, PA, Oakley, NP, and Young, AL. Between-session reliability of isometric midthigh pull kinetics and maximal power clean performance in male youth soccer players. J Strength Cond Res 32(12): 3373–3381, 2018—The aim of the study was to determine the between-session reliability of isometric midthigh pull (IMTP) kinetics and maximal weight lifted during the power clean (PC) in male youth soccer players, and to identify the smallest detectable differences between sessions. Thirteen male youth soccer players (age: 16.7 ± 0.5 years, height: 1.80 ± ...
Source: Journal of Strength and Conditioning Research - November 27, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Differences in the Electromyographic Activity of the Hamstring, Gluteus Maximus, and Erector Spinae Muscles in a Variety of Kinetic Changes
This study aimed to clarify the differences in the electromyographic (EMG) activity of the semitendinosus (ST), semimembranosus (SM), biceps femoris long head (BFl), gluteus maximus (GM), and erector spinae (ES) muscles during leg curl and bridge exercises across different knee angles and isometric contraction outputs. Sixteen male volunteers participated in this study. The EMG of all targeted muscles was measured at 20 and 40% of the maximal voluntary isometric contraction (MVIC) in the leg curl and during bilateral and unilateral bridge exercises. The knee flexion angle was randomly set at 30, 60, 90, and 120° during...
Source: Journal of Strength and Conditioning Research - November 27, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

The Effects of 10-week Integrated Neuromuscular Training on Fundamental Movement Skills and Physical Self-efficacy in 6–7-Year-Old Children
This study examined the effect of INT on process and product fundamental movement skill measures and physical self-efficacy in 6–7-year-old children. Ninety-four children from 2 primary schools were randomized into either a 10-week INT program or a control group (CON) (n = 41). Results indicated significantly greater increases in process fundamental movement skill (FMS) scores in INT vs. CON (p = 0.001). For product measures of FMS, 10-m sprint time, counter movement jump, seated medicine ball throw and standing long jump (all p = 0.001), all significantly increased to a greater extent in the INT group vs. CON. A sig...
Source: Journal of Strength and Conditioning Research - November 27, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Repetition Performance and Blood Lactate Responses Adopting Different Recovery Periods Between Training Sessions in Trained Men
Miranda, H, Maia, MF, Paz, GA, de Souza, JAAA, Simão, R, Farias, DA, and Willardson, JM. Repetition performance and blood lactate responses adopting different recovery periods between training sessions in trained men. J Strength Cond Res 32(12): 3340–3347, 2018—The purpose of this study was to examine the effect of different recovery periods (24, 48, and 72 hours) between repeated resistance training (RT) sessions for the upper-body muscles on repetition performance and blood lactate responses in trained men. Sixteen recreationally trained men (age: 26.1 ± 3.1 years; height: 179 ± 4.5 cm; b...
Source: Journal of Strength and Conditioning Research - November 27, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

The Effects of Ballistic and Nonballistic Bench Press on Mechanical Variables
Moir, GL, Munford, SN, Moroski, LL, Davis, SE. The effects of ballistic and nonballistic bench press on mechanical variables. J Strength Cond Res 32(12): 3333–3339, 2018—The purpose of this study was to investigate the effects of ballistic and nonballistic bench press performed with loads equivalent to 30 and 90% 1 repetition maximum (1RM) on mechanical variables. Eleven resistance-trained men (age: 23.0 ± 1.4 years; mass: 98.4 ± 14.4 kg) attended 4 testing sessions where they performed one of the following sessions: (a) 3 sets of 5 nonballistic repetitions performed with a load equivalent to 30% ...
Source: Journal of Strength and Conditioning Research - November 27, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Maximal Strength Training Improves Strength Performance in Grapplers
Øvretveit, K and Tøien, T. Maximal strength training improves strength performance in grapplers. J Strength Cond Res 32(12): 3326–3332, 2018—The aim of this study was to assess the short-term effects of maximal strength training (MST) as an accessory to grappling training on strength performance in competitive Brazilian Jiu-Jitsu (BJJ) athletes. Fourteen male BJJ athletes underwent measurements of 1 repetition maximum (1RM) in the squat and bench press, rate of force development (RFD) and peak force (PF) in the squat jump, countermovement jump (CMJ) height, and muscular endurance in pull-ups, sit-...
Source: Journal of Strength and Conditioning Research - November 27, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Metabolic Responses to a Battling Rope Protocol Performed in the Seated or Stance Positions
Brewer, W, Kovacs, R, Hogan, K, Felder, D, and Mitchell, H. Metabolic responses to a battling rope protocol performed in the seated or stance positions. J Strength Cond Res 32(12): 3319–3325, 2018—The purpose of this study is to compare the levels of oxygen consumption and heart rate responses elicited by a treadmill or cycle V[Combining Dot Above]O2max test with a standing or sitting battling rope protocol (BRP) (treadmill vs. standing BRP) (cycle vs. seated BRP). Forty healthy subjects performed either a ramped V[Combining Dot Above]O2max treadmill or cycle test. At least 3 days later, the subjects who perfor...
Source: Journal of Strength and Conditioning Research - November 27, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Acute Physiological Responses to an Intensity-And Time-Under-Tension-Equated Single- vs. Multiple-Set Resistance Training Bout in Trained Men
Cintineo, HP, Freidenreich, DJ, Blaine, CM, Cardaci, TD, Pellegrino, JK, and Arent, SM. Acute physiological responses to an intensity-and time under-under-tension-equated single- vs. multiple-set resistance training bout in trained men. J Strength Cond Res 32(12): 3310–3318, 2018—Regardless of the setting, proper manipulation of resistance training program design variables is pivotal in eliciting the desired physiological adaptations. Furthermore, how these variables, especially volume and intensity, work together to affect training outcomes is a major topic of investigation. The purpose of this study was to co...
Source: Journal of Strength and Conditioning Research - November 27, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Kinetic Analysis of Isometric Back Squats and Isometric Belt Squats
This study compared lower extremity and low-back kinetics during isometric back squats and isometric belt squats. Sixteen men (age: 22.6 ± 3.4 years; height: 1.74 ± 0.11 m; mass: 82.0 ± 5.6 kg) and 10 women (age: 21.5 ± 2.5 years; height: 1.64 ± 0.10 m; mass: 68.9 ± 7.1 kg) performed isometric back squats and belt squats at 4 squat depths. Joint resultant moments were calculated from kinematic and ground reaction force data. Linear interpolation was used to estimate peak vertical forces and joint moments at a 45° thigh segment angle. Subjects increased peak forces, ankle moment...
Source: Journal of Strength and Conditioning Research - November 27, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of Variable Resistance Training on Maximal Strength: A Meta-Analysis Retraction
No abstract available (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - November 1, 2018 Category: Sports Medicine Tags: Retraction Source Type: research

Effects of Variable Resistance Training on Maximal Strength: A Meta-analysis
No abstract available (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - November 1, 2018 Category: Sports Medicine Tags: Manuscript Clarification Source Type: research

Sex-Related Differences in the Accuracy of Estimating Target Force Using Percentages of Maximal Voluntary Isometric Contractions vs. Ratings of Perceived Exertion During Isometric Muscle Actions
Keller, JL, Housh, TJ, Smith, CM, Hill, EC, Schmidt, RJ, and Johnson, GO. Sex-related differences in the accuracy of estimating target force using percentages of maximal voluntary isometric contractions vs. ratings of perceived exertion during isometric muscle actions. J Strength Cond Res 32(11): 3294–3300, 2018—The purpose of this study was to examine sex-related differences in the accuracy of estimating actual target force and to compare the accuracy of estimating actual target force using percentages of maximal voluntary isometric contraction (MVIC) or ratings of perceived exertion (RPE) values during isomet...
Source: Journal of Strength and Conditioning Research - November 1, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Time Response of Photobiomodulation Therapy on Muscular Fatigue in Humans
Rossato, M, Dellagrana, RA, Sakugawa, RL, Lazzari, CD, Baroni, BM, and Diefenthaeler, F. Time response of photobiomodulation therapy on muscular fatigue in humans. J Strength Cond Res 32(11): 3285–3293, 2018—The aim of this study was to identify the effects of 2 different time responses on fatigue of knee extensor. Sixteen male volunteers (26 ± 6.0 years, 81 ± 12 kg, and 181 ± 7.4 cm) participated in the study. Participants performed the same protocol in 5 sessions {control, placebo (placebo applied both 6 hours before and immediately before the test), 6 hours before + immediately before (p...
Source: Journal of Strength and Conditioning Research - November 1, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Differential Effects of Different Warm-up Protocols on Repeated Sprints-Induced Muscle Damage
Chen, CH, Ye, X, Wang, YT, Chen, YS, and Tseng, WC. Differential effects of different warm-up protocols on repeated sprints-induced muscle damage. J Strength Cond Res 32(11): 3276–3284, 2018—The purpose of this investigation was to examine whether adding a set of hamstring resistance exercise or dynamic stretching to a regular running-based warm-up before a bout of repeated sprints provides protective effects against the sprinting-induced muscle damage. Twelve elite tennis players participated in this study. After the familiarization, subjects completed 3 separate randomly sequenced experimental visits, during ...
Source: Journal of Strength and Conditioning Research - November 1, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Self-Preferred Initial Position Could Be a Viable Alternative to the Standard Squat Jump Testing Procedure
Petronijevic, MS, Garcia Ramos, A, Mirkov, DM, Jaric, S, Valdevit, Z, and Knezevic, OM. Self-preferred initial position could be a viable alternative to the standard squat jump testing procedure. J Strength Cond Res 32(11): 3267–3275, 2018—The purpose of this study was to compare both the magnitude and reliability of different variables (knee angle, squat depth, jump height [Hmax], maximum force [Fmax], and maximum power [Pmax]) between the standardized squat jump (SJ) and the SJ performed from the self-preferred position. Eleven team handball players (age: 19.5 ± 1.1 years; height: 1.88 ± 0.06 m;...
Source: Journal of Strength and Conditioning Research - November 1, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Very-Short-Duration, Low-Intensity Half-Time Re–warm up Increases Subsequent Intermittent Sprint Performance
This study investigated the effect of very-short-duration, low-intensity half-time re–warm up (RW) on subsequent intermittent sprint performance. Using a randomized cross-over design, 11 healthy men performed 3 trials. In the experimental trials, participants performed the first 40-minute intermittent exercise followed by a 15-minute half-time. The interventions at half-time were 15 minutes of seated rest (control), 3 minutes of moderate-intensity RW (cycling at 60% of maximal oxygen uptake [V[Combining Dot Above]O2max]; [60% RW]), and 3 minutes of low-intensity RW (cycling at 30% of V[Combining Dot Above]O2max; [30%...
Source: Journal of Strength and Conditioning Research - November 1, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of Different Footwear Properties and Surface Instability on Neuromuscular Activity and Kinematics During Jumping
Lesinski, M, Prieske, O, Borde, R, Beurskens, R, and Granacher, U. Effects of different footwear properties and surface instability on neuromuscular activity and kinematics during jumping. J Strength Cond Res 32(11): 3246–3257, 2018—The purpose of this study was to examine sex-specific effects of different footwear properties vs. barefoot condition during the performance of drop jumps (DJs) on stable and unstable surfaces on measures of jump performance, electromyographic (EMG) activity, and knee joint kinematics. Drop jump performance, EMG activity of lower-extremity muscles, as well as sagittal and frontal kn...
Source: Journal of Strength and Conditioning Research - November 1, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Understanding the Relationship Between Coach and Athlete Perceptions of Training Intensity in Youth Sport
Scantlebury, S, Till, K, Sawczuk, T, Weakley, J, and Jones, B. Understanding the relationship between coach and athlete perceptions of training intensity in youth sport. J Strength Cond Res 32(11): 3239–3245, 2018—To alleviate issues arising from the over-/under-prescription of training load, coaches must ensure that desired athlete responses to training are being achieved. The present study aimed to assess the level of agreement between the coach-intended (presession) and observed (postsession) rating of perceived exertion (RPE), with athlete RPE during different training intensities (easy, moderate, hard). Co...
Source: Journal of Strength and Conditioning Research - November 1, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

A Reliable Testing Battery for Assessing Physical Qualities of Elite Academy Rugby League Players
This study assessed the interday reliability of a testing battery for the assessment of physical qualities of rugby league players. Fifty players (age 17.1 ± 1.1 years; stature 181.3 ± 6.3 cm; and body mass 89.0 ± 11.6 kg) from 3 Super League academies participated in this study. Tests of countermovement jump performance, 10- and 20-m sprint performance, change of direction, medicine ball throw, and a modified Yo-Yo Intermittent Recovery Test Level 1 (prone Yo-Yo IR1) were completed on 3 separate occasions. Between-day intraclass correlation coefficient, typical error (TE), coefficient of variation, an...
Source: Journal of Strength and Conditioning Research - November 1, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Positional Differences in GPS Outputs and Perceived Exertion During Soccer Training Games and Competition
Abbott, W, Brickley, G, and Smeeton, NJ. Positional differences in GPS outputs and perceived exertion during soccer training games and competition. J Strength Cond Res 32(11): 3222–3231, 2018—Soccer training games are popular training modalities, allowing technical, tactical, and physical aspects to be trained simultaneously. Small (SSGs), medium (MSGs), and large training games (LSGs) elicit differing physical demands. To date, no research has investigated physical and perceived demands of training games on soccer playing positions relative to competitive demands. In addition, previous research has referenced ...
Source: Journal of Strength and Conditioning Research - November 1, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Sex Differences in Aerobic Fitness in Top-Class Soccer Referees
Castagna, C, Bizzini, M, D'Ottavio, S, and Araújo Póvoas, SC. Sex differences in aerobic fitness in top-class soccer referees. J Strength Cond Res 32(11): 3216–3221, 2018—The aim of this study was to assess the aerobic-fitness differences between male and female top-class soccer field referees (FRs). This with the purpose to provide cutoff values useful for training prescription in female FRs. Forty female top-class FRs (age 34.18 ± 3.50 years and 5 ± 3.9 years international refereeing experience) and 52 male FRs (age 38.4 ± 3.3 years and 5 ± 3.5 years international ref...
Source: Journal of Strength and Conditioning Research - November 1, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Glomerular Filtration Rate Is Unchanged by Ultramarathon
In this study, we calculated eGFR and also measured creatinine clearance after every 25 km of a 100-km run. Twenty healthy, amateur runners (males, mean age 40.75 ± 7.15 years, mean body mass 76.87 ± 8.39 kg) took part in a 100-km run on a track. Blood and urine were collected before the run, after every 25 km, and 12 hours after the run. Seventeen runners completed the study. There was increase in creatinine, urea, and uric acid observed after 100 km (p (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - November 1, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Physical Fitness and Blood Glucose Influence Performance in IndyCar Racing
Ferguson, DP and Myers, ND. Physical fitness and blood glucose influence performance in IndyCar racing. J Strength Cond Res 32(11): 3193–3206, 2018—Charlie Kimball (CK) is an elite-level IndyCar driver who has type 1 diabetes. Since CK became a full-time competitor, there has been exponential growth in the number of racing drivers competing with type 1 diabetes. Therefore, the purpose of this article is to present a case report of data collected on CK over 6 years, to better inform strength and conditioning coaches on how to prepare racing drivers with type 1 diabetes for competition. We hypothesized that the p...
Source: Journal of Strength and Conditioning Research - November 1, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Maximal Upper-Body Strength and Oxygen Uptake Are Associated With Performance in High-Level 200-m Sprint Kayakers
Pickett, CW, Nosaka, K, Zois, J, Hopkins, WG, and Blazevich, AJ. Maximal upper-body strength and oxygen uptake are associated with performance in high-level 200-m sprint kayakers. J Strength Cond Res 32(11): 3186–3192, 2018—Current training and monitoring methods in sprint kayaking are based on the premise that upper-body muscular strength and aerobic power are both important for performance, but limited evidence exists to support this premise in high-level athletes. Relationships between measures of strength, maximal oxygen uptake (V[Combining Dot Above]O2max), and 200-m race times in kayakers competing at nat...
Source: Journal of Strength and Conditioning Research - November 1, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Influence of Different Methods to Determine Maximum Heart Rate on Training Load Outcomes in Basketball Players
Berkelmans, DM, Dalbo, VJ, Fox, JL, Stanton, R, Kean, CO, Giamarelos, KE, Teramoto, M, and Scanlan, AT. Influence of different methods to determine maximum heart rate on training load outcomes in basketball players. J Strength Cond Res 32(11): 3177–3185, 2018—The summated-heart-rate-zones (SHRZ) approach uses heart rate (HR) responses relative to maximum HR (HRmax) to calculate the internal training load (TL). Age-predicted, test-derived, and session-based approaches have all been used to determine HRmax in team sports. The purpose of this study was to determine the effects of using age-predicted, test-derived,...
Source: Journal of Strength and Conditioning Research - November 1, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Physical, Anthropometric, and Athletic Movement Qualities Discriminate Development Level in a Rugby League Talent Pathway
This study compared the physical, anthropometric, and athletic movement qualities of talent-identified rugby league (RL) players within a development pathway. From a total of 174 players, 3 developmental levels were defined: under 18 (U18; n = 52), under 20 (U20; n = 53), and state league (SL; n = 69). All players performed a test battery that consisted of 5 physical assessments, 2 anthropometric measurements, and an athletic movement assessment. A multivariate analysis of variance modeled the main effect of developmental level (3 levels: U18, U20, and SL) on test criterion variables. Receiver-operating characteristic (ROC...
Source: Journal of Strength and Conditioning Research - November 1, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Comparison of Physical Fitness Parameters for Starters vs. Nonstarters in an NCAA Division I Men's Lacrosse Team
Sell, KM, Prendergast, JM, Ghigiarelli, JJ, Gonzalez, AM, Biscardi, LM, Jajtner, AR, and Rothstein, AS. Comparison of physical fitness parameters for starters vs. nonstarters in an NCAA Division I men's lacrosse team. J Strength Cond Res 32(11): 3160–3168, 2018—The purpose of this study was to present a fitness profile of Division I male lacrosse players and compare the fitness attributes across different positions and starting status. Forty-one Division I men's lacrosse players (19.6 ± 1.6 years, 82.5 ± 9.5 kg, 182.0 ± 5.4 cm) volunteered to participate in the study. Fitness attributes ass...
Source: Journal of Strength and Conditioning Research - November 1, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Body Composition Variables by Sport and Sport-Position in Elite Collegiate Athletes
Fields, JB, Merrigan, JJ, White, JB, and Jones, MT. Body composition variables by sport and sport-position in elite collegiate athletes. J Strength Cond Res 32(11): 3153–3159, 2018—To assess body composition measures by sport and sport-position. Elite collegiate athletes participated (n = 475): men's and women's soccer (MSOC, n = 67; WSOC, n = 110); men's and women's swimming (MSWIM, n = 26; WSWIM, n = 22); men's and women's track and field (MTF, n = 29; WTF, n = 24); women's lacrosse and volleyball (WLAX, n = 84; WVB, n = 73); and baseball (BASE, n = 40). One-way analysis of variances assessed differences acro...
Source: Journal of Strength and Conditioning Research - November 1, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Seasonal Changes in Functional Fitness and Neurocognitive Assessments in Youth Ice-Hockey Players
This study evaluated changes in functional fitness and concussion status over the course of a competitive season in youth ice-hockey players, and examined the relationship between these variables and injury occurrence. Thirty-six participants (8.9 ± 1.1 years) completed preseason and postseason assessments including anthropometric measurements, the functional movement screen (FMS), Lower Quarter Y-Balance Test (YBT-LQ), and a computerized neurocognitive assessment (ImPACT). Paired-samples t-tests were used to compare preseason and postseason data. Independent samples t-tests were used to compare FMS, YBT-LQ, and ImP...
Source: Journal of Strength and Conditioning Research - November 1, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Importance of Body Composition in the National Hockey League Combine Physiological Assessments
Chiarlitti, NA, Delisle-Houde, P, Reid, RER, Kennedy, C, and Andersen, RE. Importance of body composition in the national hockey league combine physiological assessments. J Strength Cond Res 32(11): 3135–3142, 2018—The National Hockey League (NHL) combine was designed to assess draft-eligible players based on body composition, speed, power, and strength. The importance of body composition in the battery of combine physical tests was investigated, and differences in results based on position were explored. Thirty-seven elite male Canadian university hockey players (age = 22.86 ± 1.55 years, mass = 87.21 &...
Source: Journal of Strength and Conditioning Research - November 1, 2018 Category: Sports Medicine Tags: Original Research Source Type: research