Effects of Sports Compression Socks on Performance, Physiological, and Hematological Alterations After Long-Haul Air Travel in Elite Female Volleyballers
This study suggests that compression socks are beneficial in combating the stressors imposed by long-haul travel in elite athletes, and may have merit for individuals frequenting long-haul travel or competing soon after flying. (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Influence of Environmental Conditions on Performance and Heart Rate Responses to the 30-15 Incremental Fitness Test in Rugby Union Athletes
Natera, AOW, Jennings, J, Oakley, AJ, and Jones, TW. Influence of environmental conditions on performance and heart rate responses to the 30-15 incremental fitness test in rugby union athletes. J Strength Cond Res 33(2): 486–491, 2019—The purpose of this study was to examine the differences in performance and heart rate (HR) responses between a high heat outdoor condition (34.0° C, 64.1% humidity) and a temperate indoor condition (22.0° C, 50.0% humidity) during the 30-15 intermittent fitness test (30-15IFT). Eight highly trained Rugby Union players (28.1 ± 1.5 years, 181.4 ± 8.8 cm, 88.4 ...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Neuromuscular Adaptations to Short-Term High-Intensity Interval Training in Female Ice-Hockey Players
Kinnunen, J-V, Piitulainen, H, and Piirainen, JM. Neuromuscular adaptations to short-term high-intensity interval training in female ice-hockey players. J Strength Cond Res 33(2): 479–485, 2019—High-intensity interval training (HIIT)-related neuromuscular adaptations, changes in force production, and on-ice performance were investigated in female ice-hockey players during preseason. Fourteen Finnish championship level ice-hockey players (average age 22 ± 3 years) participated in 2½-week HIIT. Both spinal (H-reflex) and supraspinal (V-wave) neuromuscular responses of the soleus muscle were recorded...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Comparing DXA and Air Displacement Plethysmography to Assess Body Composition of Male Collegiate Hockey Players
Delisle-Houde, P, Reid, RER, Insogna, JA, Prokop, NW, Buchan, TA, Fontaine, SL, and Andersen, RE. Comparing DXA and air-displacement-plethysmography to assess body composition of male collegiate hockey players. J Strength Cond Res 33(2): 474–478, 2019—Accurate assessment of body composition is an important consideration for athletes because it is a health/performance variable. However, little is known about the variability in values obtained across different assessment methods for specific athlete populations. The purpose of this study was to compare 2 common laboratory methods that assess body composition: air...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of Game Performance on Softball Pitchers and Catchers
Oliver, GD, Plummer, HA, Washington, JK, Weimar, WH, and Brambeck, A. Effects of game performance on softball pitchers and catchers. J Strength Cond Res 33(2): 466–473, 2019—The purpose of this study was to examine the effects of game exposure on pitchers and catchers' hip and glenohumeral range of motion (ROM), isometric strength, and vertical jump performance and power. Five college female softball pitchers (174.24 ± 7.53 cm; 82.10 ± 11.27 kg; 20 ± 1.82 years) and 4 catchers (165.10 ± 9.04 kg; 68.61 ± 3.87 cm; 20 ± 1.41 years) participated. Hip and glenohumeral rotati...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of Various Warm-Up Protocol on Special Judo Fitness Test Performance
Lum, D. Effects of various warm-up protocol on special judo fitness test performance. J Strength Cond Res 33(2): 459–465, 2019—The purposed of this study was to compare the effects of postactivation potentiation (PAP) on Special Judo Fitness Test (SJFT) performance using explosive exercises that activates upper and lower limbs muscles. Eleven male judo athletes (mean ± SD, age, 16–29 years; height, 170 ± 7 cm; body mass, 73 ± 16 kg) attended 4 separate sessions. The first session was used to familiarize the subjects to the experimental procedure, the SJFT, the high pull test (HPT), an...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Cross-Sectional and Retrospective Cohort Analysis of the Effects of Age on Flexibility, Strength Endurance, Lower-Body Power, and Aerobic Fitness in Law Enforcement Officers
Lockie, RG, Dawes, JJ, Kornhauser, CL, and Holmes, RJ. Cross-sectional and retrospective cohort analysis of the effects of age on flexibility, strength endurance, lower-body power, and aerobic fitness in law enforcement officers. J Strength Cond Res 33(2): 451–458, 2019—There can be a great age range in cohorts of law enforcement officers. As the tasks required of officers generally do not change with advancing age, it is important to understand how physical performance in tests that assess job-specific characteristics may be altered. Retrospective analysis of performance test data of 383 officers (362 men and ...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Prevalence and Predictors of Higher-Risk Supplement Use Among Collegiate Athletes
This study aimed to identify the prevalence and predictors associated with the use of higher-risk dietary supplements, defined as supplements containing herbal ingredients, caffeine, or those classified for weight loss, muscle-building, or as a preworkout supplement, among 557 National Collegiate Athletic Association Division I male and female collegiate athletes. Although 252 (45.2%) athletes reported the use of a dietary supplement on ≥2 days per week over the past year, 46 (8.3%) athletes met criteria for higher-risk supplement use. Twenty (3.6%) athletes reported the use of herbal, 1 (0.2%) caffeinated, 5 (0.9%) wei...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of Light-Emitting Diode Therapy on the Performance of Biceps Brachii Muscle of Young Healthy Males After 8 Weeks of Strength Training: A Randomized Controlled Clinical Trial
Vieira, KVSG, Ciol, MA, Azevedo, PH, Pinfildi, CE, Renno, ACM, Colantonio, E, and Tucci, HT. Effects of light-emitting diode therapy on the performance of biceps brachii muscle of young healthy males after 8 weeks of strength training: a randomized controlled clinical trial. J Strength Cond Res 33(2): 433–442, 2019—We assessed the effect of adding light-emitting diode therapy (LEDT) to an 8-week strength training of biceps brachii in healthy young males. Forty-five participants were randomized into training plus LEDT, training plus sham LEDT, and control groups (n = 15 each). Individuals in the LEDT groups part...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Perceived Exertion Is Affected by the Submaximal Set Configuration Used in Resistance Exercise
Mayo, X, Iglesias-Soler, E, and Kingsley, JD. Perceived exertion is affected by the submaximal set configuration used in resistance exercise. J Strength Cond Res 33(2): 426–432, 2019—Previously, perceived exertion in submaximal resistance exercise protocols was reported to be affected by the intensity of load followed by work-to-rest ratio. Nevertheless, the effect of set configuration, which entails the metabolic, hormonal, and neuromuscular implication of the session, is currently unknown, despite the fact that perceived exertion discriminates these differences. We aimed to analyze the effect of 3 submaximal ...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Possible Hormone Predictors of Physical Performance in Adolescent Team Sport Athletes
Martin, AC, Heazlewood, IT, Kitic, CM, Lys, I, and Johnson, L. Possible hormone predictors of physical performance in adolescent team sport athletes. J Strength Cond Res 33(2): 417–425, 2019—The research aim of this study was to determine possible hormone predictors of physical performance in adolescent team sport athletes. Saliva samples were collected immediately before performance testing sessions from 114 state squad athletes (77 males, 37 females) participating in either Australian football, basketball, hockey, or netball. Participants completed tests of aerobic and anaerobic capacity, agility, power, and ...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Acute Cardiopulmonary, Metabolic, and Neuromuscular Responses to Severe-Intensity Intermittent Exercises
Lisbôa, FD, Raimundo, JAG, Salvador, AF, Pereira, KL, Turnes, T, Diefenthaeler, F, Oliveira, MFMd, and Caputo, F. Acute cardiopulmonary, metabolic, and neuromuscular responses to severe-intensity intermittent exercises. J Strength Cond Res 33(2): 408–416, 2019—The purpose of this study was to compare cardiopulmonary, neuromuscular, and metabolic responses to severe-intensity intermittent exercises with variable or constant work rate (CWR). Eleven cyclists (28 ± 5 years; 74 ± 7 kg; 175 ± 5 cm; 63 ± 4 ml·kg−1·min−1) performed the following tests until ex...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Blood Pressure Response During Resistance Training of Different Work-to-Rest Ratio
Paulo, AC, Tricoli, V, Queiroz, ACC, Laurentino, G, and Forjaz, CLM. Blood pressure response during resistance training of different work-to-rest ratio. J Strength Cond Res 33(2): 399–407, 2019—Changes in the work-to-rest ratio (W:R) of resistance training protocols (RTPs) (i.e., decreasing work or increasing rest) reduce the marked elevation in blood pressure (BP) that occurs during RTP execution. However, whether changes in RTP structure without changing W:R can change BP responses to RTP is unknown. To investigate the effect of different structures of rest intervals and number of repetitions per set on BP re...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Estimation of Peak Muscle Power From a Countermovement Vertical Jump in Children and Adolescents
Gomez-Bruton, A, Gabel, L, Nettlefold, L, Macdonald, H, Race, D, and McKay, H. Estimation of peak muscle power from a countermovement vertical jump in children and adolescents. J Strength Cond Res 33(2): 390–398, 2019—Several equations to predict muscle power (MP) from vertical jump height (VJH) have been developed in adults. However, few have been derived in children. We therefore aimed to: (a) evaluate the validity of existing MP estimation equations from a vertical countermovement jump (CMJ) in children and adolescents and (b) develop and validate a new MP estimation equation for use in children and adolesce...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

A Warm-Up Routine That Incorporates a Plyometric Protocol Potentiates the Force-Generating Capacity of the Quadriceps Muscles
This study was designed to investigate whether a warm-up routine that incorporates drop jumps, induces post-activation potentiation (PAP), and if so, assess the magnitude and time course of the induced PAP. Participants performed a standard warm-up that incorporated either drop jumps (plyometric protocol) or a low-paced walk (control protocol). Post-activation potentiation was assessed by changes in electrically evoked isometric muscle twitches recorded throughout both protocols. The plyometric protocol increased peak twitch torque (PTT), rate of torque development (RTD), and impulse significantly (by 23, 39, and 46%, resp...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Unilateral Stiffness Interventions Augment Vertical Stiffness and Change of Direction Speed
Maloney, SJ, Richards, J, Jelly, L, and Fletcher, IM. Unilateral stiffness interventions augment vertical stiffness and change of direction speed. J Strength Cond Res 33(2): 372–379, 2019—It has previously been shown that preconditioning interventions can augment change of direction speed (CODS). However, the mechanistic nature of these augmentations has not been well considered. The current study sought to determine the effects of preconditioning interventions designed to augment vertical stiffness on CODS. Following familiarization, 10 healthy males (age: 22 ± 2 years; height: 1.78 ± 0.05 m; bod...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Assessing the Reliability of Using a Horizontal Leg Press Equipped With a Force Plate to Report on Measures of Positive and Negative Neuromuscular Characteristics
Ferley, DD and Vukovich, MD. Assessing the reliability of using a horizontal leg press equipped with a force plate to report on measures of positive and negative neuromuscular characteristics. J Strength Cond Res 33(2): 360–371, 2019—Individuals participating in sport or returning from a lower-extremity injury routinely perform assessments of lower-body anaerobic capacity and power to gauge fitness or readiness to return to competition. However, many commonly used assessments lack the specificity of movement and muscle contraction demonstrated in sprinting, jumping, and changing direction. Therefore, this inves...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of Load on Peak Power Output Fatigue During the Bench Throw
This study aimed to begin the process of establishing empirical upper-body power training guidelines for moderately strong athletes by determining how load (30, 45, and 60% 1 repetition maximum [1RM]) affects PPO (Watts) dropoff during 3 sets of 10 repetitions of the bench throw. Ten resistance-trained male volunteers ([mean ± SD]: age 20.58 ± 1.36 years, height 176.05 ± 9.09 cm, body mass 78.65 ± 9.93 kg, bench press 1RM 99.79 ± 18.52 kg) performed 3 sets of 10 repetitions of the bench throw with one of the 3 loads during 3 weekly sessions. A Humac 360 device collected concentric phase P...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Different Cluster Sets Result in Similar Metabolic, Endocrine, and Perceptual Responses in Trained Men
Tufano, JJ, Conlon, JA, Nimphius, S, Oliver, JM, Kreutzer, A, and Haff, GG. Different cluster sets result in similar metabolic, endocrine, and perceptual responses in trained men. J Strength Cond Res 33(2): 346–354, 2019—The purpose of this study was to compare the kinematic, metabolic, endocrine, and perceptual responses of 3 back squat protocols with equal loads, number of repetitions, and total rest duration. Eight strength-trained men performed 36 back squats using 75% 1 repetition maximum and 420 seconds of total rest during basic cluster sets of 4 (CS4), rest redistribution sets of 4 (RR4), and rest redis...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Efficacy of the Repetitions in Reserve-Based Rating of Perceived Exertion for the Bench Press in Experienced and Novice Benchers
Ormsbee, MJ, Carzoli, JP, Klemp, A, Allman, BR, Zourdos, MC, Kim, J-S, and Panton, LB. Efficacy of the repetitions in reserve-based rating of perceived exertion for the bench press in experienced and novice benchers. J Strength Cond Res 33(2): 337–345, 2019—Autoregulation (AR) is the practice of adjusting training variables in response to athlete feedback. One component of AR postulated to enhance resistance training adaptations involves implementing a resistance training–specific rating of perceived exertion (RPE) scale measuring repetitions in reserve (RIR). The purpose of this study was to examine the ...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Influence of the “Slingshot” Bench Press Training Aid on Bench Press Kinematics and Neuromuscular Activity in Competitive Powerlifters
This study examined the acute effects of the “Slingshot” (SS) on bench press performance, prime mover surface electromyographic (sEMG) amplitude, and barbell velocity during maximal and submaximal bench pressing in competitive male powerlifters. Fifteen male powerlifters (mean ± SD; age: 27.05 ± 5.94 years; mass: 94.15 ± 13.43 kg; 1 repetition maximum [1RM] bench press: 139.7 ± 16.79 kg) participated in the study. Bench press strength, average barbell velocity, and sEMG amplitude of the prime mover muscles (triceps brachii, pectoralis major, and anterior deltoid) were measured during...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Specificity and Transfer of Lower-Body Strength: Influence of Bilateral or Unilateral Lower-Body Resistance Training
Appleby, BB, Cormack, SJ, and Newton, RU. Specificity and transfer of lower-body strength: Influence of bilateral or unilateral lower-body resistance training. J Strength Cond Res 33(2): 318–326, 2019—To examine the development of lower-body strength using either bilateral or unilateral resistance training. Developmental rugby players (n = 33; mean training age = 5.4 ± 2.9 years; 1 repetition maximum [1RM] 90° squat = 178 ± 27 kg) completed an 18-week randomized controlled training design (bilateral group [BIL], n = 13; unilateral group [UNI], n = 10; comparison, n = 10). The 8-week training p...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Priming the Motor Cortex With Anodal Transcranial Direct Current Stimulation Affects the Acute Inhibitory Corticospinal Responses to Strength Training
We examined the priming effects of anodal tDCS of M1 on the acute corticospinal responses to ST. In a randomized double-blinded cross-over design, changes in isometric strength, corticospinal excitability, and inhibition (assessed as area under the recruitment curve [AURC] using transcranial magnetic stimulation) were analyzed in 13 adults exposed to 20 minutes of anodal tDCS and sham tDCS followed by a ST session of the right elbow flexors. We observed a significant decrease in isometric elbow-flexor strength immediately after training (11–12%; p (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Load-Velocity Relationships of the Back vs. Front Squat Exercises in Resistance-Trained Men
Spitz, RW, Gonzalez, AM, Ghigiarelli, JJ, Sell, KM, and Mangine, GT. Load-velocity relationships of the back vs. front squat exercises in resistance-trained men. J Strength Cond Res 33(2): 301–306, 2019—The purpose of this investigation was to describe and compare changes in barbell velocity in relation to relative load increases during the back squat (BS) and front squat (FS) exercises. Eleven National Collegiate Athletic Association Division I baseball position players (19.4 ± 1.0 years; 182.4 ± 6.5 cm; and 87.2 ± 7.4 kg) performed trials at maximum speed with loads of 30, 50, 70, and 90%...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Research Note Source Type: research

A Review of Field-Based Assessments of Neuromuscular Control and Their Utility in Male Youth Soccer Players
This article provides a review of the current literature pertaining to field-based screening tests and critically appraises their suitability for use with male youth soccer players. Currently, the only method that has been validated in male youth soccer players is the landing error scoring system. Asymmetrical anterior reach measured during the Y-Balance test may also be considered because of its strong predictive ability in male youth basketball players; however, further research is required to fully support its use with soccer players. (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - December 19, 2018 Category: Sports Medicine Tags: Brief Review Source Type: research

Ergogenic Effects of β-Alanine Supplementation on Different Sports Modalities: Strong Evidence or Only Incipient Findings?
Brisola, GMP and Zagatto, AM. Ergogenic effects of β-alanine supplementation on different sports modalities: strong evidence or only incipient findings? J Strength Cond Res 33(1): 253–282, 2019—β-Alanine supplementation is a popular nutritional ergogenic aid among the sports community. Due to its efficacy, already proven in the literature, to increase the intramuscular carnosine content (β-alanyl-L-histidine), whose main function is intramuscular buffering, β-alanine supplementation has become a nutritional strategy to improve performance, mainly in high-intensity efforts. However, although ...
Source: Journal of Strength and Conditioning Research - December 19, 2018 Category: Sports Medicine Tags: Brief Review Source Type: research

Effects of High-Intensity Interval Training on Olympic Combat Sports Athletes' Performance and Physiological Adaptation: A Systematic Review
Franchini, E, Cormack, S, and Takito, MY. Effects of high-intensity interval training on Olympic combat sports athletes' performance and physiological adaptation: A systematic review. J Strength Cond Res 33(1): 242–252, 2019—Combat sports represent around 25% of all Olympic medals disputed, and the success in these sports are determined by technical-tactical excellence and supported by physiological and psychological development. Although the training in combat sports is intermittent training by nature, some researchers have started to focus their attention on the effects of complementary high-intensity interva...
Source: Journal of Strength and Conditioning Research - December 19, 2018 Category: Sports Medicine Tags: Brief Review Source Type: research

Postexercise Hypotension Is Volume-Dependent in Hypertensives: Autonomic and Forearm Blood Responses
de Freitas Brito, A, Brasileiro Santos, MdS, Coutinho de Oliveira, CV, and da Cruz Santos, A. Postexercise hypotension is volume-dependent in hypertensives: autonomic and forearm blood responses. J Strength Cond Res 33(1): 234–241, 2019—The purpose of this study was to evaluate the effect of 2 sessions of resistance exercise (RE) with different volumes on postexercise hypotension (PEH), forearm blood flow (FBF), and cardiac autonomic balance (LF/HF) in hypertensive elderly woman. The study was conducted with 16 hypertensive elderly (25.7 ± 3 kg·m−², 55.5 ± 3 years) subjected to 3...
Source: Journal of Strength and Conditioning Research - December 19, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Changes in Unilateral Upper Limb Muscular Strength and Electromyographic Activity After a 16-Week Strength Training Intervention in Survivors of Breast Cancer
Hagstrom, AD, Shorter, KA, and Marshall, PWM. Changes in unilateral upper limb muscular strength and Electroymographic activity after a 16-week strength training intervention in survivors of breast cancer. J Strength Cond Res 33(1): 225–233, 2019—Upper limb strength deficits are frequently observed following breast cancer (BC) and its treatments. It is currently unknown whether these unilateral deficits can be corrected by a standard bilateral strength training intervention. Twenty-three survivors of BC were included in this analysis. Fourteen performed a 16-week resistance training (RT) intervention, 9 were as...
Source: Journal of Strength and Conditioning Research - December 19, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

The Effects of Multi-Day vs. Single Pre-exercise Nitrate Supplement Dosing on Simulated Cycling Time Trial Performance and Skeletal Muscle Oxygenation
Jo, E, Fischer, M, Auslander, AT, Beigarten, A, Daggy, B, Hansen, K, Kessler, L, Osmond, A, Wang, H, and Wes, R. The effects of multiday vs. single pre-exercise nitrate supplement dosing on simulated cycling time trial performance and skeletal muscle oxygenation. J Strength Cond Res 33(1): 217–224, 2019—A transient augmentation in the metabolic efficiency of skeletal muscle is the purported basis for dietary nitrate supplementation amongst competitive and recreational athletes alike. Previous studies support the ergogenic effects of nitrate supplementation, as findings indicated improved microvascular blood flo...
Source: Journal of Strength and Conditioning Research - December 19, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Physiological Factors Associated With Declining Repeated Sprint Performance in Hypoxia
This study aimed to investigate the influence of these factors on running performance during hypoxic and normoxic shuttle-run sprinting. Eight male amateur soccer players performed shuttle-run sprints in hypoxia (FiO2 ∼14.8%) and normoxia (random order). Each session comprized 3 sets of 5 × 10 seconds back and forth sprints (4.5 m), with recovery times between repetitions and sets of 20 seconds and 5 minutes, respectively. Sprinting distance, acceleration patterns, heart rate (HR) and breathing frequency were measured during each session (Zephyr-PSM Training System). Redox state and lactate concentration ([La]) w...
Source: Journal of Strength and Conditioning Research - December 19, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Intermittent but Not Continuous Static Stretching Improves Subsequent Vertical Jump Performance in Flexibility-Trained Athletes
This study examined changes in countermovement jump (CMJ) height after an intermittent or a continuous static stretching protocol of equal total duration. Sixteen male, elite-level gymnasts performed 90 seconds of intermittent (3 × 30 seconds with 30 seconds rest) or continuous stretching (90 seconds) of the quadriceps muscle. A single-leg stretching and jumping design was used, with the contralateral limb serving as a control. The same individuals performed both conditions with alternate legs in a randomized, counterbalanced order. One-leg CMJ height was measured for the stretched and the control leg after warm-up, ...
Source: Journal of Strength and Conditioning Research - December 19, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Cycling Power Profile Characteristics of National-Level Junior Triathletes
Stevens, CJ, Bennett, KJM, Novak, AR, Kittel, AB, and Dascombe, BJ. Cycling power profile characteristics of national-level junior triathletes. J Strength Cond Res 33(1): 197–202, 2019—With the draft-legal rule recently introduced to junior triathlon competition, it has become difficult to assess cycling performance through race results. Therefore, this study assessed the cycling power profile characteristics of national-level junior triathletes to assist with physical assessment and program design. Thirteen male (17.0 ± 1.0 years) and 11 female (17.2 ± 1.3 years) national-level junior triathletes...
Source: Journal of Strength and Conditioning Research - December 19, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of High-Intensity Interval Training vs. On-Court Tennis Training in Young Tennis Players
This study aimed to examine the effects of 6 weeks of high-intensity interval training (HIIT) vs. 6 weeks of on-court tennis training (OTT) on the psychophysiological responses, performance responses, and technical scores of young tennis players. Twenty-nine young male tennis players (aged 13.8 ± 0.4 years) were divided into HIIT (n = 14) and OTT groups (n = 15). Both groups trained for the same total training duration with passive rest in each session. Pre-test and post-test included maximum oxygen consumption ( JOURNAL/jscr/04.02/00124278-201901000-00022/math_22MM1/v/2018-12-18T073638Z/r/image-tiff max), sprinti...
Source: Journal of Strength and Conditioning Research - December 19, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

The Influence of Exercise-to-Rest Ratios on Physical and Physiological Performance During Hurling-Specific Small-Sided Games
Malone, S, Hughes, B, and Collins, K. The influence of exercise-to-rest ratios on physical and physiological performance during hurling-specific small-sided games. J Strength Cond Res 33(1): 180–187, 2019—The current study examined the impact of different exercise-to-rest ratios on hurling-specific small-sided games (SSG). Thirty-four (n = 34) hurling players were monitored during an in-season training period. Heart rate (Polar Electro Oy, Kempele, Finland) and global positioning system technology (4-Hz; VX Sport, Lower Hutt, New Zealand) were used to analyze the physical and physiological differences between e...
Source: Journal of Strength and Conditioning Research - December 19, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Influence of Night Soccer Matches on Sleep in Elite Players
This study examined the impact of night matches on the sleep/wake behavior of elite soccer players participating in the UEFA Champions League and French Ligue 1. A mixed method approach was used, combining objective sleep assessment with wrist activity monitors, and a survey to ascertain the sleep complaints after night matches (kick off after 18:00 hours). Most players (90%) indicated worse sleep in the nights after evening matches than after training days. Objective time in bed (−01:39 hours; effect size [ES] = 1.7; p (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - December 19, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

When Something Is at Stake: Differences in Soccer Performance in 11 vs. 11 During Official Matches and Training Games
Olthof, SBH, Frencken, WGP, and Lemmink, KAPM. When something is at stake: Differences in soccer performance in 11 vs. 11 during official matches and training games. J Strength Cond Res 33(1): 167–173, 2019—11 vs. 11 training games are used to mimic the official match, but differ in playing duration and a consequence of winning or losing. Anxiety levels, crowd pressure, and the intention to win are examples of constraints present in the match, but absent or less prevalent in training. The aim is, therefore, to compare soccer performance in official matches with 11 vs. 11 training games. Six elite youth soccer t...
Source: Journal of Strength and Conditioning Research - December 19, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Physical Determinants of Division 1 Collegiate Basketball, Women's National Basketball League, and Women's National Basketball Association Athletes: With Reference to Lower-Body Sidedness
Spiteri, T, Binetti, M, Scanlan, AT, Dalbo, VJ, Dolci, F, and Specos, C. Physical determinants of Division 1 Collegiate basketball, Women's National Basketball League, and Women's National Basketball Association athletes: with reference to lower-body sidedness. J Strength Cond Res 33(1): 159–166, 2019—In female basketball, the assumed components of success include power, agility, and the proficiency at executing movements using each limb. However, the importance of these attributes in discriminating between playing levels in female basketball has yet to be determined. The purpose of this study was to compare lo...
Source: Journal of Strength and Conditioning Research - December 19, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Effect of a High-Intensity Isometric Potentiating Warm-up on Bat Velocity
This study examined the acute effect of a high-intensity isometric potentiating warm-up on subsequent maximal horizontal bat velocity in experienced female softball players (n = 28). The isometric potentiating warm-up consisted of 3 sets of 5-second maximal voluntary contractions held in the early swing phase position, pulling against an immovable device. As one of the simplest methods to use the postactivation potentiation (PAP) stimulus, the warm-up was designed to acutely enhance muscle performance by inducing PAP. Because optimal recovery duration after a potentiating warm-up can be highly variable, swing trials were c...
Source: Journal of Strength and Conditioning Research - December 19, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Transient Fatigue is Not Influenced by Ball-In-Play Time During Elite Rugby League Matches
This study has reaffirmed the presence of transient fatigue during elite rugby league matches but questioned the influence of ball-in-play time as a confounding factor. These observations have implications for the design of appropriate training practices and informing tactical strategies used by coaches. Most importantly, any practitioner wishing to measure transient fatigue could follow a similar statistical approach taken herein and based on the current findings would not need to account for ball-in-play time as a confounding variable. (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - December 19, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

The Effect of Varying Plyometric Volume on Stretch-Shortening Cycle Capability in Collegiate Male Rugby Players
This study has demonstrated that it is possible to improve reactive strength capabilities through the use of a low volume plyometric program. The low volume program elicited the same performance improvement in RSI as a high volume program while undertaking a lower dose. This suggests that strength and conditioning coaches may be able to benefit from the ability to develop more time-efficient and effective plyometric programs. (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - December 19, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Inter- and Intra-rater Reliability of the Athletic Ability Assessment in Subelite Australian Rules Football Players
Rogers, DK, McKeown, I, Parfitt, G, Burgess, D, and Eston, RG. Inter- and intra-rater reliability of the athletic ability assessment in subelite Australian rules football players. J Strength Cond Res 33(1): 125–138, 2019—The aim of this study was to determine the inter- and intra-rater rater reliability of the Athletic Ability Assessment (AAA) in subelite Australian Rules football (ARF) players. Eighteen male ARF players completed the AAA movement assessment (overhead squat, double lunge [left and right], single-leg Romanian deadlift [left and right], chin-up and push-up), on 2 occasions separated by 1 week. Du...
Source: Journal of Strength and Conditioning Research - December 19, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Perceived Wellness Associated With Practice and Competition in National Collegiate Athletic Association Division I Football Players
This study assessed the influence of movement demands resulting from weekly practice sessions and games, on perceived wellness measurements taken postgame (Sunday) and 48 hours pregame (Thursday) throughout the in-season period in National Collegiate Athletic Association (NCAA) Division I football players. Thirty players were monitored using global positioning system receivers (OptimEye S5; Catapult Innovations) during 12 games and 24 in-season practices. Movement variables included low-intensity distance, medium-intensity distance, high-intensity distance, sprint distance, total distance, player load, and acceleration and...
Source: Journal of Strength and Conditioning Research - December 19, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

National Scouting Combine Scores as Performance Predictors in the National Football League
Vincent, LM, Blissmer, BJ, and Hatfield, DL. National Scouting Combine scores as performance predictors in the National Football League. J Strength Cond Res 33(1): 104–111, 2019—The National Football League (NFL) hosts an annual scouting combine to evaluate the approximately 300 elite college football players who are most likely to be selected in the upcoming NFL draft. Given the public interest, player obligations, coaching staff commitments, and business aspects of the combine, several questions have arose in recent years concerning the applicability of combine scores to eventual draft NFL performance. The pr...
Source: Journal of Strength and Conditioning Research - December 19, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Effect of an 11-Week In-Water Training Program With Increased Resistance on the Swimming Performance and the Basic Kinematic Characteristics of the Front Crawl Stroke
Gourgoulis, V, Valkoumas, I, Boli, A, Aggeloussis, N, and Antoniou, P. Effect of an 11-week in-water training program with increased resistance on the swimming performance and the basic kinematic characteristics of the front crawl stroke. J Strength Cond Res 33(1): 95–103, 2019—The purpose of the study was to assess the effect of an 11-week in-water training program with increased resistance on the swimming performance and the basic kinematic characteristics of the front crawl stroke in young female swimmers. Twelve swimmers were matched in pairs according to their best performance in 50-m front crawl swimming ...
Source: Journal of Strength and Conditioning Research - December 19, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Bilateral Quadriceps Strength Asymmetry Is Associated With Previous Knee Injury in Military Special Tactics Operators
Eagle, SR, Keenan, KA, Connaboy, C, Wohleber, M, Simonson, A, and Nindl, BC. Bilateral quadriceps strength asymmetry is associated with previous knee injury in military special tactics operators. J Strength Cond Res 33(1): 89–94, 2019—Bilateral strength asymmetries have been related to lower-limb injury in athletes. Given that military populations often participate in recreational sport, in addition to a physically demanding workload, bilateral strength asymmetries may be related to injury in military populations. The purpose of this study was to determine whether isokinetic strength differs between Operators w...
Source: Journal of Strength and Conditioning Research - December 19, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Effect of ACTN3 Polymorphism on Self-reported Running Times
Kreutzer, A, Martinez, CA, Kreutzer, M, Stone, JD, Mitchell, JB, and Oliver, JM. Effect of ACTN3 polymorphism on self-reported running times. J Strength Cond Res 33(1): 80–88, 2019—This investigation examined the effect of ACTN3 genotype on self-reported distance running personal records (PRs). Of 94 (n = 94) recreationally active men and women, 82 (f = 42, m = 40; age: 22.6 ± 4.5 years; body mass index [BMI]: 23.5 ± 3.4 kg·m−2) reported 1-mile running PRs, whereas 57 (f = 33, m = 24; age: 23.4 ± 5.3 years; BMI: 22.9 ± 9.3 kg·m−2) reported 5K running PRs. Su...
Source: Journal of Strength and Conditioning Research - December 19, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of Combined Strength and Sprint Training on Lean Mass, Strength, Power, and Sprint Performance in Masters Road Cyclists
This study was undertaken to examine whether muscle and performance characteristics could be improved in endurance-trained masters cyclist by adding strength and sprint-training stimuli into their training regimen. Twenty-five masters road cyclists were assigned to a combined strength and sprint-training group (CT; n = 9, 53.5 ± 9.3 years), a sprint-training group (ST, n = 7, 49.4 ± 4.8 years) or a control group (CG, n = 9, 56.9 ± 8.6 years). Before and after the 12 weeks intervention, whole body lean mass, total lower limb lean mass (LLLM), countermovement jump height, peak isometric torque of quadric...
Source: Journal of Strength and Conditioning Research - December 19, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

The Effects of a Cycling Warm-up Including High-Intensity Heavy-Resistance Conditioning Contractions on Subsequent 4-km Time Trial Performance
Chorley, A and Lamb, KL. The effects of a cycling warm-up including high-intensity heavy-resistance conditioning contractions on subsequent 4-km time trial performance. J Strength Cond Res 33(1): 57–65, 2019—Previous exercise has been shown to improve subsequent performance through different mechanisms. Sport-specific conditioning contractions can be used to exploit the “post-activation potentiation” (PAP) phenomenon to enhance performance although this has rarely been investigated in short endurance events. The aim of this study was to compare a cycling warm-up with PAP-inducing conditioning contra...
Source: Journal of Strength and Conditioning Research - December 19, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of 6 Weeks of Different High-Intensity Interval and Moderate Continuous Training on Aerobic and Anaerobic Performance
Cavar, M, Marsic, T, Corluka, M, Culjak, Z, Cerkez Zovko, I, Müller, A, Tschakert, G, and Hofmann, P. Effects of 6 weeks of different high-intensity interval and moderate continuous training on aerobic and anaerobic performance. J Strength Cond Res 33(1): 44–56, 2019—To provide practical data, we compared the training effects of 3 different programs, using a shuttle run stimulus, on aerobic and anaerobic performance, measured using the 20-m maximal shuttle run (Beep) test and 300-yd shuttle run, respectively. Forty-five physically trained men, with a mean age of 21.1 ± 1.8 years, participated. The 6...
Source: Journal of Strength and Conditioning Research - December 19, 2018 Category: Sports Medicine Tags: Original Research Source Type: research