Power-Force-Velocity Profiling of Sprinting Athletes: Methodological and Practical Considerations When Using Timing Gates
In conclusion, the present findings showed that the entire acceleration phase should be covered by timing gates to ensure acceptably valid and reliable sprint mechanical outputs. However, only 3 timing checkpoints (i.e., 10, 20, and 30 m) are required to ensure valid and reliable outputs for team sport athletes. (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Technical Report Source Type: research

Match-Play Temporal and Position-Specific Physical and Physiological Demands of Senior Hurlers
Young, D, Beato, M, Mourot, L, and Coratella, G. Match-play temporal and position-specific physical and physiological demands of senior hurlers. J Strength Cond Res 34(6): 1759–1768, 2020—The aims of the current study were to examine the temporal differences in match-running performances and heart rate (HR) in elite senior hurling players between halves of play and field positions. Global positioning systems (10 Hz) and HR monitors were used to collect data from 48 players over 18 games. Running performances (total distance [TD], relative distance, high-speed running [HSR], sprint efforts [SE], mean length of s...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Acceleration Profile of Elite Gaelic Football With Special Reference to Position of Play
Ryan, M, Malone, S, Donnellan, A, and Collins, K. Acceleration profile of elite Gaelic football with special reference to position of play. J Strength Cond Res 34(6): 1750–1758, 2020—The current study aimed to characterize the positional match-play demands of elite Gaelic football players with special reference to acceleration using predetermined 5-minute periods (epochs). Thirty-five male Gaelic players (mean ± SD, age: 24 ± 6 years; height: 180 ± 7 cm; mass: 81 ± 7 kg) across 5 playing positions (full-back, half-back, midfield, half-forward, and full-forward) were monitored during ...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Match-Play Running Performance and Exercise Intensity in Elite International Women's Rugby Sevens
Malone, S, Earls, M, Shovlin, A, Eddy, A, and Winkelman, N. Match-play running performance and exercise intensity in elite international women's rugby sevens. J Strength Cond Res 34(6): 1741–1749, 2020—The aim of the current investigation was to describe the running and physiological performance demands of elite women's rugby sevens match-play. Twenty-seven (n = 27) rugby seven's players (24.4 ± 2.1 years; 168 ± 7.1 cm; 67.9 ± 4.3 kg) were recruited for the current investigation. Across the observational period, 36 games were analyzed; during these games, players wore global positioning sys...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of Two Different Tapering Protocols on Fitness and Physical Match Performance in Elite Junior Soccer Players
Krespi, M, Sporiš, G, and Trajković, N. Effects of two different tapering protocols on fitness and physical match performance in elite junior soccer players. J Strength Cond Res 34(6): 1731–1740, 2020—The purpose of this study was to determine the effects of 2 different tapering protocols on fitness and physical match performance in elite junior soccer players. One-hundred fifty-eight elite junior soccer players (mean age: 17.1 ± 0.79 years; mean height: 177.9 ± 6.64 cm; mean body mass: 71.3 ± 7.96 kg; and mean body mass index: 22.5 ± 1.66 kg·m−2) were randomly a...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Reliability and Validity of Integrated External and Internal Load Ratios as Measures of Fitness in Academy Rugby Union Players
This study aimed to assess the relationships between integrated ratios of external and internal load measures and aerobic fitness in 3 different training exercise protocols. Twelve academy rugby union players (aged; 17.6 ± 0.44 years, height; 179.4 ± 6.3 cm, body mass 83.3 ± 9.7 kg) performed a lactate threshold/V[Combining Dot Above]O2max test (LT/V[Combining Dot Above]O2max) followed by 3 exercise protocols; 760 m continuous shuttle running (20 m shuttle run at 9 km·h−1), sprint interval training (SIT: 6 × 6 seconds sprint with 54 seconds recovery), and a small-sided game (SSG: 6 v...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Wingate Anaerobic Test Reliability on the Velotron With Ice Hockey Players
This study evaluated the test-retest reliability of the Wingate Anaerobic Test (WAnT) performed on a Velotron electromagnetically braked cycle ergometer for power-trained athletes and assessed whether a familiarization trial was necessary to achieve high test-retest reliability. Twenty-one male ice hockey players (age 23.5 ± 4.7 years, mass 86.3 ± 16.6 kg, height 180.9 ± 7.4 cm) from a collegiate club team (Club = 10) and a recreational league (Rec = 11) performed three 30-second WAnTs within 2 weeks and with at least 24 hours between visits. Mean power (MP), anaerobic capacity, peak power (PP), anaero...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Dynamic Balance Evaluation: Reliability and Validity of a Computerized Wobble Board
Fusco, A, Giancotti, GF, Fuchs, PX, Wagner, H, Varalda, C, Capranica, L, and Cortis, C. Dynamic balance evaluation: reliability and validity of a computerized wobble board. J Strength Cond Res 34(6): 1709–1715, 2020—Computerized wobble boards (WBs) are inexpensive, transportable, and user-friendly devices to objectively quantify the dynamic balance performances out of laboratory settings, although it has not been established if they are reliable and valid tools. Therefore, the purpose of this study was to determine the reliability and validity of a computerized WB. Thirty-nine (18 females and 21 males) young ad...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Agreement Between Bioelectrical Impedance and Dual-Energy X-Ray Absorptiometry to Track Changes in Fat-Free Mass After Resistance Training in Older Women
Nascimento, MA, Silva, DRP, Ribeiro, AS, Pina, FLC, Gerage, AM, Gobbo, LA, Mayhew, JL, and Cyrino, ES. Agreement between bioelectrical impedance and dual-energy x-ray absorptiometry to track changes in fat-free mass after resistance training in older women. J Strength Cond Res 34(6): 1700–1708, 2020—The aim of our study was to compare the agreement between bioelectrical impedance (BIA) and dual-energy X-ray absorptiometry (DXA) to track changes on fat-free mass (FFM) after a resistance training (RT) program in older women. Forty-three older women (65.2 ± 4.6 years, 59.5 ± 9.2 kg, 156.4 ± 6....
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Association of Compartmental Leg Lean Mass Measured by Dual X-Ray Absorptiometry With Force Production
Raymond-Pope, CJ, Dengel, DR, Fitzgerald, JS, and Bosch, TA. Association of compartmental leg lean mass measured by dual X-ray absorptiometry with force production. J Strength Cond Res 34(6): 1690–1699, 2020—We recently reported a novel method for measuring upper leg anterior/posterior compartmental composition. The purpose of this study was to determine the association of this method with measures of muscle-specific and explosive strength and to compare this method with traditional dual energy X-ray absorptiometry (DXA) measurements of total and upper leg masses. We hypothesize this method will be related to m...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Body Composition Assessment in Male and Female Bodybuilders: A 4-Compartment Model Comparison of Dual-Energy X-Ray Absorptiometry and Impedance-Based Devices
Graybeal, AJ, Moore, ML, Cruz, MR, and Tinsley, GM. Body composition assessment in male and female bodybuilders: a 4-compartment model comparison of dual-energy x-ray absorptiometry and impedance-based devices. J Strength Cond Res 34(6): 1676–1689, 2020—The purpose of this study was to examine the group and individual accuracy of body composition estimates obtained from multicompartment models, dual-energy x-ray absorptiometry (DXA), and several impedance-based devices in male and female bodybuilders. Twenty-seven male (n = 17; 4-compartment [4C] model fat-free mass index [FFMI]: 25.1 ± 1.8 kg·m&m...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Waist Circumference and Waist-to-Hip Ratio in Law Enforcement Agency Recruits: Relationship to Performance in Physical Fitness Tests
This study examined relationships between waist circumference (WC) and waist-to-hip ratio (WHR), practical measures of fat distribution, and fitness test performance. Retrospective analysis of 267 LEA recruits (age: ∼28 years; height: ∼1.73 m; and body mass: ∼80 kg; 219 males and 48 females) was conducted. The tests included: WC and WHR; grip strength; push-ups, sit-ups, and arm ergometer revolutions in 60 seconds; vertical jump (VJ); medicine ball throw; 75-yd pursuit run (75PR); and multistage fitness test (MSFT) shuttles. Partial correlations, controlling for sex, calculated relationships between WC, WHR, an...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Muscle Power Predicts Bone Strength in Division II Athletes
Yingling, VR, Webb, SL, Inouye, C, O, J, and Sherwood, JJ. Muscle power predicts bone strength in Division II athletes. J Strength Cond Res 34(6): 1657–1665, 2020—The relationship between muscle fitness measures and tibial bone strength in collegiate level athletes was investigated. Eighty-six Division II collegiate athletes (mean ± SD: age: [18–29 years], height: 1.71 m [0.09], mass: 66.7 kg [10.5], 56 female: 30 male) participated in this cross-sectional study. Maximum grip strength (GS), 1 repetition maximum leg press, and vertical jump peak power (PP) tests were measured. Cortical area, cortica...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Cardiac-Autonomic Responses to In-Season Training Among Division-1 College Football Players
Flatt, AA, Esco, MR, Allen, JR, Robinson, JB, Bragg, A, Keith, CM, Fedewa, MV, and Earley, RL. Cardiac-autonomic responses to in-season training among Division-1 college football players. J Strength Cond Res 34(6): 1649–1656, 2020—Despite having to endure a rigorous in-season training schedule, research evaluating daily physiological recovery status markers among American football players is limited. The purpose of this study was to determine whether recovery of cardiac-autonomic activity to resting values occurs between consecutive-day, in-season training sessions among college football players. Subjects (n = ...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Caffeine's Effects on an Upper-Body Resistance Exercise Workout
Salatto, RW, Arevalo, JA, Brown, LE, Wiersma, LD, and Coburn, JW. Caffeine's effects on an upper-body resistance exercise workout. J Strength Cond Res 34(6): 1643–1648, 2020—The purpose of this study was to examine the effects of caffeine on an upper-body resistance exercise workout. Fifteen men (mean ± SD: age, 23.1 ± 1.9 years; body mass, 89.1 ± 13.9 kg; height, 175 ± 6.1 cm) volunteered to come to the laboratory 3 times. During visit 1, 1-repetition maximum (RM) values were determined for the barbell bench press, incline barbell bench press, and dumbbell bench press exercises. For...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Footwear and Sex Differences in Performance and Joint Kinetics During Maximal Vertical Jumping
Smith, RE, Paquette, MR, Harry, JR, Powell, DW, and Weiss, LW. Footwear and sex differences in performance and joint kinetics during maximal vertical jumping. J Strength Cond Res 34(6): 1634–1642, 2020—This investigation examined the effects of footwear and sex on vertical jump displacement and joint power contributions. Twenty-three young adults with basketball experience performed 3 maximal countermovement vertical jumps in minimal and standard footwear. Ground reaction force and 3D kinematic data were collected during jumping. Footwear by sex analysis of variance for all dependent variables and effect sizes ...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Cardiopulmonary Demand of 16-kg Kettlebell Snatches in Simulated Girevoy Sport
Chan, M, MacInnis, MJ, Koch, S, MacLeod, KE, Lohse, KR, Gallo, ME, Sheel, AW, and Koehle, MS. Cardiopulmonary demand of 16-kg kettlebell snatches in simulated Girevoy Sport. J Strength Cond Res 34(6): 1625–1633, 2020—Kettlebell lifting has become popular both as a strength and conditioning training tool and as a sport in and of itself: Girevoy Sport (GS). Although several kettlebell multimovement protocols have been analyzed, little research has attempted to quantify the aerobic stimulus of the individual events in GS, which could better inform kettlebell-related exercise prescription. The purpose of this study...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Comparison of the Force-, Velocity-, and Power-Time Curves Between the Concentric-Only and Eccentric-Concentric Bench Press Exercises
Pérez-Castilla, A, Comfort, P, McMahon, JJ, Pestaña-Melero, FL, and García-Ramos, A. Comparison of the force-, velocity-, and power-time curves between the concentric-only and eccentric-concentric bench press exercises. J Strength Cond Res 34(6): 1618–1624, 2020—The aim of this study was to compare the temporal and mechanical variables between the concentric-only and eccentric-concentric bench press (BP) variants. Twenty-one men (age: 22.0 ± 4.2 years, body mass: 73.4 ± 7.7 kg, height: 177.2 ± 8.0 cm; 1 repetition maximum [1RM]: 1.12 ± 0.12 kg·kg−1) ...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of Different Plyometric Training Frequencies on Measures of Athletic Performance in Prepuberal Male Soccer Players
This study aimed to compare the effects of 1 vs. 2 sessions of equal-weekly volume plyometric training (PT) across 8 weeks on measures of athletic performance (i.e., sprint time, change of direction [CoD], jumping ability, and muscle strength) in prepuberal male soccer players. Thirty participants were randomly assigned either to 1 session PT group (1SPT [n = 15]) or 2 sessions PT group (2SPT [n = 15]). Plyometric training was integrated into their regular soccer training routine. Pretraining and posttraining tests for the assessment of sprint time (e.g., 5, 10, 20, and 30-m), CoD (e.g., T-test and modified Illinois change...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Post Activation Potentiation and Concentric Contraction Performance: Effects on Rate of Torque Development, Neuromuscular Efficiency, and Tensile Properties
This study investigated how a 6-second maximal voluntary isometric contraction (MVIC) conditioning affected plantar flexor twitch rate of torque development (RTDTW), as well as peak torque (PTCC) and rate of torque development (RTDCC) of maximal voluntary concentric contractions (MVCC) performed at 60°·s−1. RTDCC and normalized triceps surae electromyography signals (EMGTS) were measured during different phases of contraction. In addition, muscle tendon unit passive stiffness index (SI) calculated from the torque-angle relation was measured after each MVCC. Enhancements were found in the RTDTW immediately ...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Acute Hormone Responses Subsequent to Agonist-Antagonist Paired Set vs. Traditional Straight Set Resistance Training
In conclusion, from an acute standpoint, the TS approach showed a tendency to cause greater disruption in hormone levels, despite the lack of significant differences vs. the PS approach at all time points. However, both strategies may promote similar acute hormone responses. (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Mechanical, Metabolic, and Perceptual Acute Responses to Different Set Configurations in Full Squat
This study aimed to compare mechanical, metabolic, and perceptual responses between 2 traditional (TR) and 4 cluster (CL) set configurations. In a counterbalanced randomized order, 11 men were tested with the following protocols in separate sessions (sets × repetitions [interrepetition rest]): TR1: 3 × 10 [0 seconds]; TR2: 6 × 5 [0 seconds]; CL1: 3 × 10 [10 seconds]; CL2: 3 × 10 [15 seconds]; CL3: 3 × 10 [30 seconds]; CL4: 1 × 30 [15 seconds]. The exercise (full squat), number of repetitions (30), interset rest (5 minutes), and resistance applied (10 repetition maximum) was the sam...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Epigenetic Responses to Acute Resistance Exercise in Trained vs. Sedentary Men
Bagley, JR, Burghardt, KJ, McManus, R, Howlett, B, Costa, PB, Coburn, JW, Arevalo, JA, Malek, MH, and Galpin, AJ. Epigenetic responses to acute resistance exercise in trained vs. sedentary men. J Strength Cond Res 34(6): 1574–1580, 2020—Acute resistance exercise (RE) alters DNA methylation, an epigenetic process that influences gene expression and regulates skeletal muscle adaptation. This aspect of cellular remodeling is poorly understood, especially in resistance-trained (RT) individuals. The study purpose was to examine DNA methylation in response to acute RE in RT and sedentary (SED) young men, specifically...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

The Running and Technical Performance of U13 to U18 Elite Japanese Soccer Players During Match Play
Goto, H and Saward, C. The running and technical performance of U13 to U18 elite Japanese soccer players during match play. J Strength Cond Res 34(6): 1564–1573, 2020—The aims of the current study were (a) to examine age-related differences in match running performance with 2 different approaches (speed vs. metabolic power) in U13–U18 Japanese elite soccer players and (b) to examine age-related differences in technical match performance in U13–U18 Japanese elite soccer players. Participants were 110 outfield players from academies of 2 professional soccer clubs in Japan. Forty-eight 11-a-side offici...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Physiological Performance Characteristics of Danish National Team Handball Players 1990–2016: Implications on Position-Specific Strength and Conditioning Training
Bøgild, P, Jensen, K, and Kvorning, T. Physiological performance characteristics of Danish National Team Handball players 1990–2016: implications on position-specific strength and conditioning training. J Strength Cond Res 34(6): 1555–1563, 2020—The aims of this study were: (a) to examine the anthropometric and physiological performance characteristics in male and female national team handball (TH) players before and after 2000; and (b) to compare anthropometry and physiological performance characteristics between court playing positions in male and female national TH players. Using a federal datab...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Dietary Intake and Energy Expenditure During Two Different Phases of Athletic Training in Female Collegiate Lacrosse Players
This study aims to investigate the state of nutrient intake and energy expenditure (EE) among various phases of periodization in female collegiate lacrosse players. A total of 17 Japanese female collegiate lacrosse players (age: 20.0 ± 0.9 years) were enrolled in this study. Physical activity (PA) and dietary intake were assessed over each 1-week period during the training preparatory phase (P-phase) and transition phase (T-phase). The exercise training-related EE (EEE) and EE associated with other daily living activities (i.e., nonexercise activity thermogenesis [NEAT]), were measured using accelerometers and heart...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Quantitative Analysis of the Acetic Acid Content in Substances Used by Athletes for the Possible Prevention and Alleviation of Exercise-Associated Muscle Cramps
Marosek, SEH, Antharam, V, and Dowlatshahi, K. Quantitative analysis of the acetic acid content in substances used by athletes for the possible prevention and alleviation of exercise-associated muscle cramps. J Strength Cond Res 34(6): 1539–1546, 2020—Athletes regularly consume commercially available food and sports shot products, carbohydrate beverages, and water to improve their physical exertion and to possibly prevent or relieve exercise-associated muscle cramps (EAMCs)—often experienced during practice, training, or competition. Acetic acid, a component of interest within these products, has been rec...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

The Effect of Overreaching on Neuromuscular Performance and Wellness Responses in Australian Rules Football Athletes
This study seeks to evaluate the effect of periodized fluctuations in training load on wellness and psychological questionnaires, perceived exertion, performance, and neuromuscular measures in team-sport athletes. Thirteen amateur Australian rules football athletes completed 6 weeks of periodized training, consisting of 2-week normal training (NT), intensified training (IT), and taper training (TT). Training sessions were quantified using global positioning system devices, heart-rate, and session rating of perceived exertion (sRPE), with wellness (general soreness, sleep quality/quantity, readiness to train, fatigue, stres...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Voluntary Muscle Relaxation Can Mitigate Fatigue and Improve Countermovement Jump Performance
Pinto, BL and McGill, SM. Voluntary muscle relaxation can mitigate fatigue and improve countermovement jump performance. J Strength Cond Res 34(6): 1525–1529, 2020—When muscles contract, they create force and stiffness. Thus, muscle activation and relaxation must be strategically sequenced to coordinate and control movement, to enhance athletic variables such as speed and strength. However, research has favored investigation of muscle activation over relaxation. Athletes such as runners, swimmers, and boxers often shake their limbs to allow the muscle to oscillate freely, immediately before a bout. The purpose ...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Criterion Validity, and Interunit and Between-Day Reliability of the FLEX for Measuring Barbell Velocity During Commonly Used Resistance Training Exercises
Weakley, J, Chalkley, D, Johnston, R, García-Ramos, A, Townshend, A, Dorrell, H, Pearson, M, Morrison, M, and Cole, M. Criterion validity, and interunit and between-day reliability of the FLEX for measuring barbell velocity during commonly used resistance training exercises. J Strength Cond Res 34(6): 1519–1524, 2020—The aim of this study was to assess the criterion validity, interunit reliability (accounting for technological and biological variance), and between-day reliability of a novel optic laser device (FLEX) for quantifying mean concentric velocity. To assess the validity against a three-dimensio...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Training Prescription Guided by Heart Rate Variability Vs. Block Periodization in Well-Trained Cyclists
Javaloyes, A, Sarabia, JM, Lamberts, RP, Plews, D, and Moya-Ramon, M. Training prescription guided by heart rate variability vs. block periodization in well-trained cyclists. J Strength Cond Res 34(6): 1511–1518, 2020—Predefined training programs are common place when prescribing training. Within predefined training, block periodization (BP) has emerged as a popular methodology because of its benefits. Heart rate variability (HRV) has been proposed as an effective tool for prescribing training. The aim of this study is to examine the effect of HRV-guided training against BP in road cycling. Twenty well-trained ...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Comparison of Plyometric Training With Two Different Jumping Techniques on Achilles Tendon Properties and Jump Performances
This study compared the influence of 10 weeks of plyometric training with 2 different jumping techniques on Achilles tendon properties and the height achieved in drop jumps (from 20, 40, and 60 cm) and countermovement jumps (CMJ). Subjects were allocated to 2 training groups (n = 11 in each group) and 1 control group (CON, n = 10). One training group kept the knees extended (KE) during ground contact, whereas the other training group flexed the knees to ∼80–90° (KF). Achilles tendon stiffness was assessed with ultrasonography, and jump performance was derived from force platform recording. Training increased ...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Modulation of Countermovement Jump–Derived Markers of Neuromuscular Function With Concurrent vs. Single-Mode Resistance Training
This study assessed changes in countermovement jump (CMJ)-derived markers of neuromuscular function with concurrent training vs. resistance training (RT) alone and determined associations between changes in CMJ parameters and other neuromuscular adaptations (e.g., maximal strength gain). Twenty-three recreationally active men performed 8 weeks of RT alone (RT group, n = 8) or combined with either high-intensity interval training cycling (HIIT + RT group, n = 8) or moderate-intensity continuous cycling (MICT + RT group, n = 7). Maximal strength and CMJ performance were assessed before (PRE), after 4 weeks of training (MID),...
Source: Journal of Strength and Conditioning Research - May 27, 2020 Category: Sports Medicine Tags: Research Note Source Type: research

Effects of Citrulline Supplementation on Exercise Performance in Humans: A Review of the Current Literature
Gonzalez, AM and Trexler, ET. Effects of citrulline supplementation on exercise performance in humans: A review of the current literature. J Strength Cond Res 34(5): 1480–1495, 2020—L-citrulline, a nonessential amino acid found primarily in watermelon, has recently garnered much attention for its potential to augment L-arginine bioavailability, nitric oxide production, and exercise performance. Over the past decade, L-citrulline has received considerable scientific attention examining potentially ergogenic properties for both aerobic and anaerobic exercise performance. Thus, the purpose of this article is to su...
Source: Journal of Strength and Conditioning Research - April 24, 2020 Category: Sports Medicine Tags: Brief Review Source Type: research

Complex and Contrast Training: Does Strength and Power Training Sequence Affect Performance-Based Adaptations in Team Sports? A Systematic Review and Meta-analysis
In conclusion, both training interventions may lead to positive performance-based adaptations in team-sports with CPX interventions potentially leading to slightly greater effects. (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - April 24, 2020 Category: Sports Medicine Tags: Brief Review Source Type: research

Sex Differences in Resistance Training: A Systematic Review and Meta-Analysis
Roberts, BM, Nuckols, G, and Krieger, JW. Sex differences in resistance training: A systematic review and meta-analysis. J Strength Cond Res 34(5): 1448–1460, 2020—The purpose of this study was to determine whether there are different responses to resistance training for strength or hypertrophy in young to middle-aged males and females using the same resistance training protocol. The protocol was pre-registered with PROSPERO (CRD42018094276). Meta-analyses were performed using robust variance random effects modeling for multilevel data structures, with adjustments for small samples using package robumeta in R. ...
Source: Journal of Strength and Conditioning Research - April 24, 2020 Category: Sports Medicine Tags: Brief Review Source Type: research

Sensitivity of the Footeval Test to Different Training Modes
This study also compares those sensibility with classic test, Vameval. A total of 36 young elite players' performance were split in 3 groups to perform 2 times a week a specific complements training: generic (GENERIC), small-sided game (SSG), and technical (TECH). After 4 weeks with training intervention, all players improved their performance to Footeval and Vameval tests. Regarding improvement, we noted that each training complement obtained different magnitude of modification. For all groups, Footeval increase was more important than Vameval. Small-sided game obtained highest improvement to Footeval (15 ± 1.8%) b...
Source: Journal of Strength and Conditioning Research - April 24, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Seasonal Repeated Sprint Ability With Change of Direction Variations in U17 and U20 Elite Brazilian Soccer Players: A Comparative Study
This study aimed to describe seasonal variations of repeated sprint with change-of-direction ability in young elite Brazilian soccer players. The Bangsbo sprint test (BST) was performed by 21 under-17 (U17) (176.9 cm; 68.2 kg) and 22 under-20 (U20) athletes (178.7 cm, 74.4 kg) at the start, middle, and end of the season. The fatigue index (FI) was calculated in seconds and in percentage of decrease (%D) for comparisons. Both age categories showed higher BST performance in the middle and end compared with the start of the season (p ≤ 0.05). The U20 players performed better at the start than the U17 players. The U17 socce...
Source: Journal of Strength and Conditioning Research - April 24, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Positional Demands and Physical Activity Profiles of Netball
van Gogh, MJ, Wallace, LK, and Coutts, AJ. Positional demands and physical activity profiles of netball. J Strength Cond Res 34(5): 1422–1430, 2020—The aim of this study was to examine the activity profiles and physiological demands of netball. Eleven representative youth netball players participated in this study. Global positioning system, heart rate, and accelerometer data were collected during 8 competitive matches. Sport-specific skills were analyzed using notational methods. The main findings were that players traveled less distance during a match than previously reported. The center covered significantly...
Source: Journal of Strength and Conditioning Research - April 24, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Sex Differences in Y-Balance Performance in Elite Figure Skaters
Slater, LV, Vriner, M, Schuyten, K, Zapalo, P, and Hart, JM. Sex differences in Y-balance performance in elite figure skaters. J Strength Cond Res 34(5): 1416–1421, 2020—Asymmetrical dynamic balance compared with normative populations have been associated with increased risk of injury in athletes; however, it is unclear if the current data are similar to balance performance in figure skaters. Therefore, the purpose of this study was to compare performance on the Y-balance test between sexes and disciplines in elite figure skaters. Thirty-two senior level figure skaters from 3 different disciplines (singles, dan...
Source: Journal of Strength and Conditioning Research - April 24, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Performance in 100-km Ultramarathoners—At Which Age, It Reaches Its Peak?
In conclusion, the age of peak performance was younger in women than in men, which might reflect the overall younger age of women participants than men. Compared with previous studies, we observed the peak performance at an age older by ∼10 years, which could be attributed to an increase of finishers' age across calendar years. Because the knowledge of the age of peak performance is unique for each sport, coaches and fitness trainers might benefit from the findings of this study in the long-term training of their athletes. (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - April 24, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Polygenic Profile and Exercise-Induced Muscle Damage by a Competitive Half-Ironman
Del Coso, J, Salinero, JJ, Lara, B, Gallo-Salazar, C, Areces, F, Herrero, D, and Puente, C. Polygenic profile and exercise-induced muscle damage by a competitive half-ironman. J Strength Cond Res 34(5): 1400–1408, 2020—To date, it is still unknown why some individuals develop higher levels of muscle damage than other individuals, despite participating in exercise with comparable levels of physical intensity. The aim of this investigation was to analyze 7 single-nucleotide polymorphisms (SNPs) that are candidates to explain individual variations in the level of muscle damage attained during a half-ironman compet...
Source: Journal of Strength and Conditioning Research - April 24, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Strength and Conditioning Habits of Competitive Distance Runners
This study aimed to explore S&C practices of competitive middle- and long-distance runners and examined whether reported frequency of injuries was influenced by training behaviors. One thousand eight hundred eighty-three distance runners (≥15 years old) completed an online survey. All runners who raced competitively were included in data analysis (n = 667). Distance runners mainly engaged with S&C activities to lower risk of injury (63.1%) and improve performance (53.8%). The most common activities used were stretching (86.2%) and core stability exercises (70.2%). Resistance training (RT) and plyometric training...
Source: Journal of Strength and Conditioning Research - April 24, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Examination of Coach and Player Perceptions of Recovery and Exertion
This study compared coach and athlete perceptions of effort and recovery, and it evaluated the efficacy of perceptually based TL monitoring. Participants included 56 athletes (Women's volleyball, soccer, and basketball and Men's basketball) and their coaches (n = 4). Perceived recovery was estimated via the Perceived Recovery Status scale. Scores of TL were calculated using the Edward's heart rate (HR) method and by multiplying SRPE by duration. Coaches provided an intended SRPE (SRPE-CI) before practice. Also, SRPE was independently estimated by coaches (SRPE-CO) and athletes (SRPE-A) ∼15–20 minutes after practi...
Source: Journal of Strength and Conditioning Research - April 24, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Reliability and Validity of the 6-Minute Step Test for Clinical Assessment of Cardiorespiratory Fitness in People at Risk of Cardiovascular Disease
Giacomantonio, N, Morrison, P, Rasmussen, R, and MacKay-Lyons, MJ. Reliability and validity of the 6-minute step test for clinical assessment of cardiorespiratory fitness in people at risk of cardiovascular disease. J Strength Cond Res 34(5): 1376–1382, 2020—The purpose of this study was to determine the test-retest reliability and validity of the 6-minute step test (6MST) as a potential assessment of cardiorespiratory fitness (CRF) of people at risk of cardiovascular disease (CVD). A prospective, cross-sectional, correlational study design was used. A single cohort of 30 adults with 2 or more risk factors for ...
Source: Journal of Strength and Conditioning Research - April 24, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Sodium Bicarbonate Supplementation Delays Neuromuscular Fatigue Without Changes in Performance Outcomes During a Basketball Match Simulation Protocol
Ansdell, P and Dekerle, J. Sodium bicarbonate supplementation delays neuromuscular fatigue without changes in performance outcomes during a basketball match simulation protocol. J Strength Cond Res 34(5): 1369–1375, 2020—To investigate the development of neuromuscular fatigue during a basketball game simulation and to ascertain whether sodium bicarbonate (NaHCO3) supplementation attenuates any neuromuscular fatigue that persists. Ten participants ingested 0.2 g·kg−1 of NaHCO3 (or an equimolar placebo dosage of sodium chloride [NaCl]) 90 and 60 minutes before commencing a basketball game simulation ...
Source: Journal of Strength and Conditioning Research - April 24, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Comparing the Immediate Effects of a Total Motion Release Warm-up and a Dynamic Warm-up Protocol on the Dominant Shoulder in Baseball Athletes
Gamma, SC, Baker, R, May, J, Seegmiller, JG, Nasypany, A, and Iorio, SM. Comparing the immediate effects of a total motion release warm-up and a dynamic warm-up protocol on the dominant shoulder in baseball athletes. J Strength Cond Res 34(5): 1362–1368, 2020—A decrease in total range of motion (ROM) of the dominant shoulder may predispose baseball athletes to increased shoulder injury risk; the most effective technique for improving ROM is unknown. The purpose of this study was to compare the immediate effects of Total Motion Release (TMR) to a generic dynamic warm-up program in baseball athletes. Baseball ath...
Source: Journal of Strength and Conditioning Research - April 24, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Adding Whole-Body Vibration to Preconditioning Squat Exercise Increases Cycling Sprint Performance
In conclusion, it is plausible to suggest that body-loaded half-squats with WBV acutely induce higher power output levels. The practical application of the current study is that body-loaded squats with WBV can be incorporated into preparations for specific sprint training to improve the quality of the sprint training and also to improve sprint performance in relevant competitions. (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - April 24, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Comparison of Linear and Reverse Linear Periodized Programs With Equated Volume and Intensity for Endurance Running Performance
Bradbury, DG, Landers, GJ, Benjanuvatra, N, and Goods, PS. Comparison of linear and reverse linear periodized programs with equated volume and intensity for endurance running performance. J Strength Cond Res 34(5): 1345–1353, 2020—This investigation examined the effectiveness of 2 periodization methods on endurance running performance. Thirty recreational runners (25.2 ± 7.4 years; 175.4 ± 8.1 cm; 69.0 ± 9.8 kg) were assigned to 3 groups based on preintervention test results: linear periodization group (LPG, n = 10), reverse linear periodization group (RPG, n = 10), and control group (CG, n...
Source: Journal of Strength and Conditioning Research - April 24, 2020 Category: Sports Medicine Tags: Original Research Source Type: research

Ratings of Perceived Exertion During Walking Predicts Endurance Independent of Physiological Effort in Older Women
This study aimed to determine whether ratings of perceived exertion (RPE) and physiological effort at different exercise intensities relate to exercise endurance. Ninety-eight sedentary women (older than 60 years) completed 3 submaximal locomotion tasks: (a) stair climbing, (b) flat walking at 2 mph, and (c) grade walking at 2 mph. Maximal treadmill endurance was measured at least 3 days before the submaximal tests. Oxygen uptake was measured during all tests, and RPE were collected for the submaximal tasks. Ratings of perceived exertion during moderate-intensity exercise (walking on the flat at 43% V[Combining Dot Above]O...
Source: Journal of Strength and Conditioning Research - April 24, 2020 Category: Sports Medicine Tags: Original Research Source Type: research