Interlimb Asymmetries: The Need for an Individual Approach to Data Analysis
Bishop, C, Lake, J, Loturco, I, Papadopoulos, K, Turner, A, and Read, P. Interlimb asymmetries: the need for an individual approach to data analysis. J Strength Cond Res 35(3): 695–701, 2021—It has been shown that the magnitude of interlimb asymmetries varies depending on the test selected; however, literature relating to whether asymmetries always favor the same limb is scarce. The aim of this study was to determine whether interlimb asymmetries always favored the same side for common metrics across unilateral strength and jumping-based tests. Twenty-eight recreational sport athletes performed unilateral isome...
Source: Journal of Strength and Conditioning Research - February 26, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Preliminary Investigation Into the Effect of ACTN3 and ACE Polymorphisms on Muscle and Performance Characteristics
This study may serve as a framework to generate hypotheses regarding the effect of genetics on performance. (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - February 26, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Comparison of Acute Energy Expenditure and Rating of Perceived Exertion in Equivalent Bouts of Circuit Training and Treadmill Running
Brewer, CB, Booher, BM, and Lawton, N. Comparison of acute energy expenditure and rating of perceived exertion in equivalent bouts of circuit training and treadmill running. J Strength Cond Res 35(3): 680–687, 2021—Circuit weight training (CT) maximizes exercise density, which may lead to an inaccurate perception of energy expenditure (EE). The purpose of this study was to compare acute EE indices and rating of perceived exertion (RPE) between CT and an equivalent bout of treadmill running (TR). College-aged men (n = 9) who regularly engaged in running and resistance training performed CT first. Circuit weight ...
Source: Journal of Strength and Conditioning Research - February 26, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Peak Power Output and Onset of Muscle Activation During High Pull Exercise
Barnes, MJ, Petterson, A, and Cochrane, DJ. Peak power output and onset of muscle activation during high pull exercise. J Strength Cond Res 35(3): 675–679, 2021—The aim of this study was to determine the percentage of 1 repetition maximum (1RM) at which peak power output occurred during the high pull (HP) exercise. In addition, the onset time of the biceps femoris (BF) and gluteus maximus (GM), across a range of loads, was investigated. Twelve resistance-trained men performed 1RM testing for the HP followed by lifts at 10% increments from 30 to 80% 1RM. During each load of power, output was measured using a lin...
Source: Journal of Strength and Conditioning Research - February 26, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of Prolonging Eccentric Phase Duration in Parallel Back-Squat Training to Momentary Failure on Muscle Cross-Sectional Area, Squat One Repetition Maximum, and Performance Tests in University Soccer Players
This study aimed to compare 2 squat training programs repeated until momentary failure with different eccentric phase duration (2 seconds vs. 4 seconds) on the changes in muscle cross-sectional area, squat 1 repetition maximum (1RM), squat jump (SJ), and countermovement jump (CMJ) height, agility (T-test), and Yo-Yo intermittent recovery test (YY-IR2). Male university soccer players (19.9 ± 0.9 years, 172.2 ± 3.8 cm, 66.1 ± 6.6 kg) were randomly assigned to one of the 2 groups; CON for 2 seconds and ECC for 4 seconds (C2/E4, n = 11) or CON for 2 seconds and ECC for 2 seconds (C2/E2, n = 11). They perfo...
Source: Journal of Strength and Conditioning Research - February 26, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Barbell Hip-Thrust Exercise: Test-Retest Reliability and Correlation With Isokinetic Performance
Dello Iacono, A, Padulo, J, Bešlija, T, and Halperin, I. Barbell hip-thrust exercise: Test-retest reliability and correlation with isokinetic performance. J Strength Cond Res 35(3): 659–667, 2021—The barbell hip-thrust (BHT) exercise is growing in popularity as evident by the large increase in research outputs investigating its utility as a training intervention and a testing tool. The aim of this study was to examine the test-retest reliability of the BHT and its correlation with isokinetic performance. Test-retest reliability was established by correlating the peak force and power outcomes measured wit...
Source: Journal of Strength and Conditioning Research - February 26, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Comparison of Isolated Lumbar Extension Strength in Competitive and Noncompetitive Powerlifters, and Recreationally Trained Men
In conclusion, this study suggests that powerlifting training likely has little impact on conditioning of the lumbar extensors. (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - February 26, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Relative Age Effects as Evidence of Selection Bias in Major League Baseball Draftees (2013–2018)
This study comprised 7,078 men drafted in the MLB first-year player draft from 2013 to 2018. Data collected for each draftee included birth date, year drafted, academic-level classification, position, round drafted, batting side, and throwing arm. Draftee's birth dates were categorized into quarters based on the calendar year for baseball in the United States (Q1: August–October; Q2: November–January; Q3: February–April; Q4: May–July). Player birth-date distributions were compared with average expected birth-date distributions and evaluated with the χ2 goodness of fit statistic. Significant &chi...
Source: Journal of Strength and Conditioning Research - February 26, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Bone Mineral Density Differences Across Female Olympic Lifters, Power Lifters, and Soccer Players
Jeon, W, Harrison, JM, Stanforth, PR, and Griffin, L. Bone mineral density differences across female Olympic lifters, power lifters, and soccer players. J Strength Cond Res 35(3): 638–643, 2021—Athletic training improves bone mineral density (BMD) through repeated mechanical loading. The location, intensity, and direction of applied mechanical pressure play an important role in determining BMD, making some sports more advantageous at improving BMD at specific regions. Thirty-seven (10 power lifters [PL], 8 Olympic lifters [OL], 8 soccer players [SP], and 11 recreationally active [RA]) women participated in a cr...
Source: Journal of Strength and Conditioning Research - February 26, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

A Comparison of Methods Used to Determine Percent Body Fat, Minimum Wrestling Weight, and Lowest Allowable Weight Class
Cutrufello, PT, Landram, MJ, Venezia, AC, and Dixon, CB. A comparison of methods used to determine percent body fat, minimum wrestling weight, and lowest allowable weight class. J Strength Cond Res 35(3): 633–637, 2021—The National Collegiate Athletic Association's weight management program allows for the use of skinfold measurements (SF), air displacement plethysmography (ADP), and hydrostatic weighing in the assessment of percent body fat (%BF) and determination of a wrestler's minimum wrestling weight (MWW). Dual energy x-ray absorptiometry (DXA) and ultrasound (US) may offer alternative assessment methods. ...
Source: Journal of Strength and Conditioning Research - February 26, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Recovery of Inflammation, Cardiac, and Muscle Damage Biomarkers After Running a Marathon
Bernat-Adell, MD, Collado-Boira, EJ, Moles-Julio, P, Panizo-González, N, Martínez-Navarro, I, Hernando-Fuster, B, and Hernando-Domingo, C. Recovery of inflammation, cardiac and muscle damage biomarkers after running a marathon. J Strength Cond Res 35(3): 626–632, 2021—Physical endurance sports conditions the increase of blood biomarkers responsible for the acute inflammatory response. The purpose of this study was to observe the impact of intense physical exercise on these biomarkers and detect their recovery pattern. This is an experimental study of repeated measures (pre-post marathon). The biom...
Source: Journal of Strength and Conditioning Research - February 26, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Potential Predictors of Vertical Jump Performance: Lower Extremity Dimensions and Alignment, Relative Body Fat, and Kinetic Variables
Daugherty, HJ, Weiss, LW, Paquette, MR, Powell, DW, and Allison, LE. Potential predictors of vertical jump performance: Lower extremity dimensions and alignment, relative body fat, and kinetic variables. J Strength Cond Res 35(3): 616–625, 2021—The association of structural and kinetic variables with restricted vertical jump (RVJ) displacement without and with added mass was examined in 60 men and women. Added mass (weighted vest) simulated a 5% increase in body fat (BF%). Independent variables included BF%, thigh length, and static Q-angle (Q-angles), and while performing RVJ, different expressions of frontal-...
Source: Journal of Strength and Conditioning Research - February 26, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

The Effect of Low-Volume Preseason Plyometric Training on Force-Velocity Profiles in Semiprofessional Rugby Union Players
Watkins, CM, Gill, ND, Maunder, E, Downes, P, Young, JD, McGuigan, MR, and Storey, AG. The effect of low-volume preseason plyometric training on force-velocity profiles in semiprofessional rugby union players. J Strength Cond Res 35(3): 604–615, 2021—Rugby union is a physically demanding and complex team sport requiring athletes across all positions to express speed and acceleration. Plyometrics can effectively improve speed profiles by enhancing both force- and velocity-(FV) characteristics; however, the optimal dose and exercise direction for trained athletes is still relatively unknown. Therefore, the aim of...
Source: Journal of Strength and Conditioning Research - February 26, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of Four Different Velocity-Based Training Programming Models on Strength Gains and Physical Performance
Riscart-López, J, Rendeiro-Pinho, G, Mil-Homens, P, Costa, RS-d, Loturco, I, Pareja-Blanco, F, and León-Prados, JA. Effects of Four different velocity-based training programming models on strength gains and physical performance. J Strength Cond Res 35(3): 596–603, 2021—The aim of this study was to compare the effects of 4 velocity-based training (VBT) programming models (linear programming [LP], undulating programming [UP], reverse programming [RP], and constant programming [CP]) on the physical performance of moderately strength-trained men. Forty-three young (age: 22.9 ± 4.8 years; body m...
Source: Journal of Strength and Conditioning Research - February 26, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Efficacy of Rest Redistribution During Squats: Considerations for Strength and Sex
This study examined the kinematic, perceptual, and heart rate responses to rest redistribution (RR) and traditional sets (TS) during the barbell back squat for men and women possessing a wide range of strength levels. Forty-five resistance-trained subjects (30 men and 15 women) performed 40 repetitions of the barbell squat with 65% 1RM load with TS (4 × 10 repetitions, 3-minute rest) or RR (10 × 4 repetitions, 1-minute rest), in a randomized order on days separated by ≥72 hours. The significance was set at p ≤ 0.05 for all statistical analyses. The mean velocity (MV) maintenance was significantly higher f...
Source: Journal of Strength and Conditioning Research - February 26, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

JSCR-08-13218 and JSCR-08-15296 Retraction
No abstract available (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - February 26, 2021 Category: Sports Medicine Tags: Retraction Source Type: research

Muscle Strength Does Not Adapt From a Second to Third Bout of Eccentric Contractions: A Systematic Review and Meta-Analysis of the Repeated Bout Effect
Lindsay, A, Abbott, G, Ingalls, CP, and Baumann, CW. Muscle strength does not adapt from a second to third bout of eccentric contractions: A systematic review and meta-analysis of the repeated bout effect. J Strength Cond Res 35(2): 576–584, 2021—The greatest muscle strength adaptations to repeated bouts of eccentric contractions (ECC) occur after the initial injury, with little to no change in subsequent bouts. However, because of the disparity in injury models, it is unknown whether three or more bouts provide further adaptation. Therefore, we performed a systematic review of the literature to evaluate whethe...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Brief Review Source Type: research

Determining the Intracortical Responses After a Single Session of Aerobic Exercise in Young Healthy Individuals: A Systematic Review and Best Evidence Synthesis
Alibazi, RJ, Pearce, AJ, Rostami, M, Frazer, AK, Brownstein, C, and Kidgell, DJ. Determining the intracortical responses after a single session of aerobic exercise in young healthy individuals: a systematic review and best evidence synthesis. J Strength Cond Res 35(2): 562–575, 2021—A single bout of aerobic exercise (AE) may induce changes in the excitability of the intracortical circuits of the primary motor cortex (M1). Similar to noninvasive brain stimulation techniques, such as transcranial direct current stimulation, AE could be used as a priming technique to facilitate motor learning. This review examined...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Brief Review Source Type: research

Exercise-Induced Muscle Damage During the Menstrual Cycle: A Systematic Review and Meta-Analysis
Romero-Parra, N, Cupeiro, R, Alfaro-Magallanes, VM, Rael, B, Rubio-Arias, JA, Peinado, AB, and Benito, PJ, IronFEMME Study Group. Exercise-induced muscle damage during the menstrual cycle: A systematic review and meta-analysis. J Strength Cond Res 35(2): 549–561, 2021—A strenuous bout of exercise could trigger damage of muscle tissue, and it is not clear how sex hormone fluctuations occurring during the menstrual cycle (MC) affect this response. The aims of this study were to systematically search and assess studies that have evaluated exercise-induced muscle damage (EIMD) in eumenorrheic women over the MC and ...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Brief Review Source Type: research

Characterization of Heart Rate Responses, Duration, and Distances Traveled in Youth Participating in Recreational Skateboarding at Community Skateparks
Furr, HN, Nessler, JA, and Newcomer, SC. Characterization of heart rate responses, duration, and distances traveled in youth participating in recreational skateboarding at community skateparks. J Strength Cond Res 35(2): 542–548, 2021—Recreational skateboarding continues to gain popularity in youth within the United States and abroad. Surprisingly, there is a paucity of research regarding the cardiovascular responses of youth participating in recreational skateboarding. Therefore, the purpose of this study was to test the hypothesis that skateboarding would elicit heart rates and durations consistent with the A...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Insight Into the Development and Competitiveness of Male UK-Based Stand-up Paddleboard Flatwater Distance Racing From 2013 to 2017
Dyer, B. Insight into the development and competitiveness of male UK-based stand-up paddleboard flatwater distance racing from 2013 to 2017. J Strength Cond Res 35(2): 535–541, 2021—An analysis of 2 stand-up paddleboard “distance” events was undertaken to investigate any change in their participation, racing behavior, and whether such events should be approached differently by practitioners. The completion time paddler-to-paddler gap was investigated as a means of assessing the performances in 2 flatwater distance events from 2013 to 2017. The level of participation at these events had not noticeabl...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Reliability, Sensitivity, and Minimal Detectable Change of a New Specific Climbing Test for Assessing Asymmetry in Reach Technique
Čular, D, Dhahbi, W, Kolak, I, Iacono, AD, Bešlija, T, Laffaye, G, and Padulo, J. Reliability, sensitivity, and minimal detectable change of a new specific climbing test for assessing asymmetry in reach technique. J Strength Cond Res 35(2): 527–534, 2021—The aims of this study were to establish intertrial and intersession reliability, sensitivity, and minimal detectable change of a new climbing test specifically for assessing asymmetry in reach technique (TEST). Twenty-four young climbers (16 males and 8 females) participated in this study. The protocol consisted of performing, in counterbalanced random...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Influence of Sex on Current Methods of Adjusting Saddle Height in Indoor Cycling
Encarnación-Martínez, A, Ferrer-Roca, V, and García-López, J. Influence of sex on current methods of adjusting saddle height in indoor cycling. J Strength Cond Res 35(2): 519–526, 2021—The popularity of indoor cycling has increased in fitness centers, and therefore, proper bike fitting is important to avoid biomechanical-related injuries. However, no previous studies have compared the biomechanical kinematics of various existing protocols of saddle-height adjustment in indoor cycling. Furthermore, it was not clear if these protocols were appropriate for both men and women, as these e...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Running Demands and Activity Profile of the New Four-Quarter Match Format in Men's Field Hockey
This study determined the running demands of men's field hockey with regards to the revised four-quarter match format. Twenty-eight male field hockey players were equipped with global positioning system units while competing in 14 competitive international games over a 1-year period. All matches allowed for unlimited substitutions, and consisted of four 15-minute quarters (i.e., Q1—Q4). A progressive decline in total distance (TD) was observed in Q2 (2,072 ± 141 m) to Q4 (2,055 ± 212 m) compared with Q1 (2,171 ± 195 m, p (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Identifying Contextual Influences on Training Load: An Example in Professional Rugby Union
Dalton-Barron, NE, McLaren, SJ, Black, CJ, Gray, M, Jones, B, and Roe, G. Identifying contextual influences on training load: an example in professional rugby union. J Strength Cond Res 35(2): 503–511, 2021—We aimed to investigate the contextual factors influencing training load (TL), as determined by session rating of perceived exertion (sRPE-TL), accumulated within a match-to-match microcycle in rugby union players. Session rating of perceived exertion-TL data were collected daily from 35 professional rugby union players from the same team in the English Championship over the course of an in-season period. Pl...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Strength Training in Long-Distance Triathletes: Barriers and Characteristics
Luckin, KM, Badenhorst, CE, Cripps, AJ, Landers, GJ, Merrells, RJ, Bulsara, MK, and Hoyne, GF. Strength training in long-distance triathletes: Barriers and characteristics. J Strength Cond Res 35(2): 495–502, 2021—The purpose of this investigation was to identify perceived and physical barriers toward the completion of concurrent strength training and endurance training in long-distance triathletes. Three hundred ninety long-distance triathletes (224 women, 166 men; age [y]: 39 ± 10) completed a 68-question self-administered, semiquantitative survey that assessed endurance and strength training character...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Physiological Responses to Swimming Repetitive “Ice Miles”
Knechtle, B, Stjepanovic, M, Knechtle, C, Rosemann, T, Sousa, CV, and Nikolaidis, PT. Physiological responses to swimming repetitive “Ice Miles.” J Strength Cond Res 35(2): 487–494, 2021—“Ice Mile” swimming (i.e., 1,608 m in water of below 5° C) is becoming increasingly popular. Since the foundation of the International Ice Swimming Association (IISA) in 2009, official races are held as World Cup Races and World Championships. Ice swimming was a demonstration sport at the 2014 Winter Olympics in Sochi, Russia. This case study aimed to identify core body temperature and selected hemat...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Shorter Ground Contact Time and Better Running Economy: Evidence From Female Kenyan Runners
This study is the first to report the RE and gait characteristics of East African female athletes measured under everyday training settings. We provided the evidence that GCT is associated with the superior RE of the female Kenyan runners. (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Are There Differences in Elite Youth Soccer Player Work Rate Profiles in Congested vs. Regular Match Schedules?
In this study, accelerations, decelerations, mean metabolic power (MP), and technical performance (offensive and defensive variables) were compared across very congested match (VCM; 10 international matches played over 3 successive days, including 2 days with 2 consecutive matches separated by a 4- to 5-hour interval) and 10 regular (noncongested match [NCM]) match periods in elite male Under 15 (U15, n = 11) and Under 17 (U17, n = 13) soccer players. Players wore a 15-Hz Global Positioning System unit with a 100-Hz triaxial accelerometer. The session rating of perceived exertion (RPE) were assessed 30 minutes after match....
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Relationships Between Eccentric and Concentric Knee Strength Capacities and Maximal Linear Deceleration Ability in Male Academy Soccer Players
Harper, DJ, Jordan, AR, and Kiely, J. Relationships between eccentric and concentric knee strength capacities and maximal linear deceleration ability in male academy soccer players. J Strength Cond Res 35(2): 465–472, 2021—The purpose of this study was to investigate the relationships between maximal linear deceleration ability, and knee flexor (KF) and knee extensor (KE) strength. Fourteen male academy soccer players completed a 30-m linear sprint, a maximal linear deceleration test, and eccentric and concentric KF and KE contractions in both dominant leg (DL) and nondominant leg (NDL) at slower (60°&middo...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Physical Performance Measures of Flexibility, Hip Strength, Lower Limb Power, and Trunk Endurance in Healthy Navy Cadets: Normative Data and Differences Between Sex and Limb Dominance
The objectives were to provide normative data on commonly used physical performance tests that may be associated with musculoskeletal injuries in Navy cadets and assess for sex and limb dominance differences. A large cohort of Navy cadets were assessed for physical performance tests of flexibility (ankle dorsiflexion range of motion and sit and reach), isometric hip strength, lower limb power (single-leg hop), and trunk endurance (plank and side plank tests). Besides providing normative data tables, sex and limb dominance differences were assessed by a 2-way mixed analysis of variance. A total of 545 Brazilian Navy cadets ...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Hormonal Contraceptive Use Does Not Affect Strength, Endurance, or Body Composition Adaptations to Combined Strength and Endurance Training in Women
This study examined the effects of a 10-week period of high-intensity combined strength and endurance training on strength, endurance, body composition, and serum hormone concentrations in physically active women using hormonal contraceptives (HCs, n = 9) compared with those who had never used hormonal contraceptives (NHCs, n = 9). Training consisted of 2 strength training sessions and 2 high-intensity running interval sessions per week. Maximal bilateral isometric leg press (Isom), maximal bilateral dynamic leg press (one repetition maximum [1RM]), countermovement jump (CMJ), a 3,000-m running test (3,000 m), body composi...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Using Sprint Velocity Decrement to Enhance Acute Sprint Performance
Cochrane, DJ and Monaghan, D. Using sprint velocity decrement to enhance acute sprint performance. J Strength Cond Res 35(2): 442–448, 2021—Acute sled towing has the capability to elicit a potentiation. Currently, sled loading is determined from body mass (BM) percent. However, it may be more relevant to use a percentage of maximal sprint reduction to determine an individual's load. The purpose of this study was to determine if individualizing sled loads at 35 and 55% reduction in velocity would improve 20-m sprint performance. In addition, electromyography (EMG) was assessed to determine if any sprint-related ...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Responses of Angiogenic Regulators to Resistance Exercise Under Systemic Hypoxia
Kon, M, Ikeda, T, Homma, T, and Suzuki, Y. Responses of angiogenic regulators to resistance exercise under systemic hypoxia. J Strength Cond Res 35(2): 436–441, 2021—Resistance exercise and hypoxia powerfully affect the secretions of angiogenic regulators. However, the effects of resistance exercise under acute systemic hypoxia on circulating levels of angiogenic regulators are unknown. Therefore, we investigated the effects of resistance exercise under systemic hypoxia on angiogenic regulator responses. Twelve healthy male subjects completed 2 experimental trials: (a) resistance exercise under normoxia (NRE), ...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Abdominal Muscle Activation During Common Modifications of the Trunk Curl-up Exercise
Crommert, ME, Bjerkefors, A, Tarassova, O, and Ekblom, MM. Abdominal muscle activation during common modifications of the trunk curl-up exercise. J Strength Cond Res 35(2): 428–435, 2021—The purpose of this study was to investigate effects of common modifications of trunk curl-up exercise on the involvement of the abdominal muscles, particularly the deepest muscle layer, transversus abdominis (TrA). Ten healthy females performed 5 different variations of the trunk curl-up at a standardized speed, varying the exercise by assuming 3 different arm positions and applying left and right twist. Indwelling fine-wire e...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Accentuated Eccentric Loading and Cluster Set Configurations in the Back Squat: A Kinetic and Kinematic Analysis
This study examined the kinetic and kinematic differences between accentuated eccentric loading (AEL) and cluster sets in trained male subjects (age = 26.1 ± 4.1 years, height = 183.5 ± 4.3 cm, body mass = 92.5 ± 10.5 kg, and back squat to body mass ratio = 1.8 ± 0.3). Four load condition sessions consisted of traditionally loaded (TL) “straight sets,” TL cluster (TLC) sets, AEL cluster (AEC) sets, and AEL “straight sets” where only the first repetition had eccentric overload (AEL1). An interrepetition rest interval of 30 seconds was prescribed for both TLC and AEC. Conce...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Whole Egg Vs. Egg White Ingestion During 12 weeks of Resistance Training in Trained Young Males: A Randomized Controlled Trial
Bagheri, R, Moghadam, BH, Ashtary-Larky, D, Forbes, SC, Candow, DG, Galpin, AJ, Eskandari, M, Kreider, RB, and Wong, A. Whole egg vs. egg white ingestion during 12 weeks of resistance training in trained young males: a randomized controlled trial. J Strength Cond Res 35(2): 411–419, 2021—The primary purpose was to compare the effects of whole egg ingestion and egg white ingestion during 12 weeks of resistance training (RT) on muscle cross-sectional area, body composition, muscular strength, and anaerobic power in resistance-trained young males. A secondary purpose was to examine systemic hormonal responses. Thi...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Dietary Supplement Use According to Sex and Triad Risk Factors in Collegiate Endurance Runners
Barrack, MT, Fredericson, M, Dizon, F, Tenforde, AS, Kim, BY, Kraus, E, Kussman, A, Singh, S, and Nattiv, A. Dietary supplement use according to sex and Triad risk factors in collegiate endurance runners. J Strength Cond Res 35(2): 404–410, 2021—This cross-sectional study evaluated the prevalence in the use of dietary supplements among elite collegiate runners among 2 NCAA Division I cross-country teams. At the start of each season from 2015 to 2017, male and female endurance runners were recruited to complete baseline study measures; the final sample included 135 (male n = 65, female n = 70) runners. Runners c...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Ergogenic and Physiological Outcomes Derived From a Novel Skin Cooling Device
Gray, WD, Jett, DM, Cocco, AR, Vanhoover, AC, Colborn, CE, Pantalos, GM, Stumbo, J, Quesada, PM, and Caruso, JF. Ergogenic and physiological outcomes derived from a novel skin cooling device. J Strength Cond Res 35(2): 391–403, 2021—Our study's purpose assessed a cooling headband's ergogenic and physiological impacts. Subjects (15 women and 13 men) completed six visits; the final 3 entailed rowing workouts with the following treatment conditions: no head cooling (NoHC), intermittent head cooling during exercise (HCex), and intermittent head cooling during exercise and post-exercise recovery (HCex&post). Dat...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of Hydration Educational Intervention in High School Football Players
Atkins, WC, McDermott, BP, Kanemura, K, Adams, JD, and Kavouras, S. Effects of Hydration Educational Intervention in High School Football Players. J Strength Cond Res 35(2): 385–390, 2021—The purpose of this study was to assess the effects of a one-time educational intervention (EI) on hydration behaviors, status, and knowledge. In a pre-test, post-test quasi-experimental design, 41 in-season American high school football players (16 ± 1 years) voluntarily participated. Teams were assigned to EI or no intervention (NI) groups. Educational intervention included a 5-minute presentation on hydration importa...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Urine Specific Gravity Effect on Total and Segmental Body Composition Validity of Multifrequency Bioelectrical Impedance Analysis Compared With Dual Energy X-Ray Absorptiometry
Fleck, SJ, Hayes, A, Stadler, G, Goesch, T, Goldammer, M, and Braun, S. Urine specific gravity effect on total and segmental body composition validity of multifrequency bioelectrical impedance analysis compared with dual energy x-ray absorptiometry. J Strength Cond Res 35(2): 373–384, 2021—The purposes were to compare body composition measures between a specific multifrequency bioelectrical impedance analyzer (InBody770) and dual-energy x-ray absorptiometry (DXA) and determine if hydration status within a specified range affected these measures. Methods included determining urine specific gravity before testing...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Exercise Recovery Practices of Wheelchair Court Sports Athletes
This study investigated if and why athletes in wheelchair court sports (basketball, rugby, and tennis) use recovery strategies, what type of strategies are used, and whether the period of the season influences the prevalence of use. A cross-sectional questionnaire was developed to acquire data pertaining to individual characteristics, recovery habits, reasons for use/nonuse, the use of specific recovery strategies, and lifestyle habits. One hundred forty-four athletes (92 = international and 52 = national/club) completed the questionnaire online. In total, 85% (n = 122) of athletes reported using at least one type of recov...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Urinary N-Terminal Fragment of Titin Reflects Muscle Damage After a Soccer Match in Male Collegiate Soccer Players
Tanabe, Y, Shimizu, K, Kondo, E, Yasumatsu, M, Nakamura, D, Sagayama, H, and Takahashi, H. Urinary N-terminal fragment of titin reflects muscle damage after a soccer match in male collegiate soccer players. J Strength Cond Res 35(2): 360–365, 2021—Previous studies have demonstrated that noninvasive urinary N-terminal fragment of titin (U-titin) concentration highly correlates with serum creatine kinase (CK) activity, a classic invasive muscle damage marker. This finding indicates that U-titin could be used to estimate muscle damage. However, these results were achieved using a laboratory-based eccentric exercis...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

The Effect of the Oral Contraceptive Cycle Phase on Exercise-Induced Muscle Damage After Eccentric Exercise in Resistance-Trained Women
Romero-Parra, N, Rael, B, Alfaro-Magallanes, VM, Janse de Jonge, X, Cupeiro, R, and Peinado, AB; On Behalf of the IronFEMME Study Group. The effect of the oral contraceptive cycle phase on exercise-induced muscle damage after eccentric exercise in resistance-trained women. J Strength Cond Res 35(2): 353–359, 2021—To evaluate the influence of the active pill phase versus withdrawal phase of a monophasic oral contraceptive (OC) cycle on exercise-induced muscle damage and inflammation after eccentric resistance exercise. Eighteen resistance-trained female OC users (age: 25.6 ± 4.2 years, height: 162.4 &plus...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of Transspinal Direct Current Stimulation on Cycling Perception of Effort and Time to Exhaustion
This study used noninvasive thoracic spine tsDCS to determine if cycling performance and perception of effort could be modulated by tsDCS. In 3 different stimulation conditions, anodal, cathodal, and sham, subjects cycled at 80% of their maximal aerobic capacity until exhaustion and reported their rating of perceived exertion (RPE) every minute. From this period, we compared the RPE responses over the first 3 minutes and time to exhaustion. There was no significant difference in time to exhaustion between anodal (408 ± 121 seconds), cathodal (413 ± 168 seconds), and sham (440 ± 189 seconds) conditions ...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Validity and Reliability of Using Load-Velocity Relationship Profiles to Establish Back Squat 1 m·s‐1 Load
This study examined test-retest reliability of the load-velocity relationship during the back squat to predict loads corresponding to a mean velocity of 1 m·s−1 (V1Load), test-retest reliability of mean concentric velocity at V1Load, and criterion validity of mean concentric velocity at V1Load. Twenty-seven resistance-trained male rugby league players completed 2 testing sessions on separate days to establish individualized back squat load-velocity relationship profiles (30, 40, 60, and 80% estimated 1 repetition maximum). Velocity during the back squat was assessed at each load and V1Load derived using indivi...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

The Influence of Countermovement Strategy and External Load on Amortization Forces During Jump Squats
Barker, L, Siedlik, J, and Mercer, J. The influence of countermovement strategy and external load on amortization forces during jump squats. J Strength Cond Res 35(2): 332–339, 2021—The purpose of this study was to investigate the influence of countermovement strategy on amortization forces when performing jump squats. To gather a range of deceleration demands, jump squats were performed across a range of external loads (0, 15, 30, 45, and 60% of repetition maximum [1RM]) and verbally cued countermovement depths (preferred: PREF; quarter: QTR; and full: FULL). Dual force platform ground reaction force data were...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Lower-Limb Biomechanics Differ Between Sexes During Maximal Loaded Countermovement Jumps
Fain, AC, Semore, KD, Lobb, NJ, and Brown, TN. Lower-limb biomechanics differ between sexes during maximal loaded countermovement jumps. J Strength Cond Res 35(2): 325–331, 2021—To improve military personnel's operational performance, this study determined the impact of heavy, military body–borne load on vertical jump performance. Twenty men and 17 women had lower-limb work and power quantified during a series of countermovement jumps with 4 body-borne loads (20, 25, 30, and 35 kg). For each jump, subjects stood in athletic position with feet shoulder-width apart, then squatted down and immediately perfor...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Acute Performance Enhancement Following Squats Combined With Elastic Bands on Short Sprint and Vertical Jump Height in Female Athletes
Krčmár, M, Krčmárová, B, Bakaľár, I, and Šimonek, J. Acute performance enhancement after squats combined with elastic bands on short sprint and vertical jump height in female athletes. J Strength Cond Res 35(2): 318–324, 2021—The main purpose of this study was to compare back squats with and without elastic bands on sprint and vertical jump height. Fourteen female athletes (21.9 ± 2.3 years; 177.5 ± 6.36 cm; 66.2 ± 6.2 kg; 1 repetition maximum [1RM]/ body mass: 1.96 ± 0.14) agreed to participate. On 4 separate days, athletes walked freely for 5 m...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of Cluster Set Configuration on Mechanical Performance and Neuromuscular Activity
Ortega-Becerra, M, Sánchez-Moreno, M, and Pareja-Blanco, F. Effects of cluster set configuration on mechanical performance and neuromuscular activity. J Strength Cond Res 35(2): 310–317, 2021—The aim of this study was to compare the effects of different cluster set (CS) configurations on mechanical performance and electromyography (EMG) activity during the bench press (BP) exercise. Fourteen strength-trained men (age 23.0 ± 2.4 years; height 1.76 ± 0.08 m; body mass 78.3 ± 12.2 kg) performed 3 different protocols in the BP exercise consisting of 3 sets of 12 repetitions at 60% of 1 r...
Source: Journal of Strength and Conditioning Research - January 30, 2021 Category: Sports Medicine Tags: Original Research Source Type: research