Comparison of Incremental Intermittent and Time Trial Testing in Age-Group Swimmers
Zacca, R, Azevedo, R, Peterson Silveira, R, Vilas-Boas, JP, Pyne, DB, Castro, FAdS, and Fernandes, RJ. Comparison of incremental intermittent and time trial testing in age-group swimmers. J Strength Cond Res 33(3): 801–810, 2019—The aim of this study was to compare physiological and biomechanical characteristics between an incremental intermittent test and a time trial protocol in age-group swimmers. Eleven national level age-group swimmers (6 men and 5 women) performed a 7 × 200-m incremental intermittent protocol (until exhaustion; 30-second rest) and a 400-m test (T400) in front crawl on separate days....
Source: Journal of Strength and Conditioning Research - February 21, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Changes in Sprint-Related Outcomes During a Period of Systematic Training in a Girls' Soccer Academy
Wright, MD and Atkinson, G. Changes in sprint-related outcomes during a period of systematic training in a girls' soccer academy. J Strength Cond Res 33(3): 793–800, 2019—The longitudinal tracking of performance indicators is lacking during the training of young female soccer players. Therefore, changes in 5-m acceleration, 20-m speed, change-of-direction (COD) speed, and repeated-sprint ability (RSA) were quantified during a 3-year period in an English Football Association Center of Excellence. Fourteen players (mean age = 12.1 years, SD = ±0.9) were recruited, and their best performance scores from pre...
Source: Journal of Strength and Conditioning Research - February 21, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of Different Fatigue Levels on Physiological Responses and Pacing in Judo Matches
The objective of this study was to compare athletes' pacing during judo match simulation between different fatigue states. Twelve judo athletes (30.2 ± 3.2 years old, 85.6 ± 10.8 kg, 181.0 ± 5.7 cm, 19 ± 7 years of judo experience) completed three 4-minute matches against the same opponents, at 15-minute intervals in 3 different conditions: after warm-up (Control; C); after a regular training session (totaling 90 minutes); after a high-intensity interval exercise (2 blocks of 10 sets of 20-second all-out uchi-komi, with 10-second interval between sets and 5-minute interval between blocks). All m...
Source: Journal of Strength and Conditioning Research - February 21, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Effect of Low-Volume High-Intensity Interval Exercise and Continuous Exercise on Delayed-Onset Muscle Soreness in Untrained Healthy Males
In conclusion, a single session of low-volume HIIE and CE elicited a similar mild DOMS 24 hours after exercise in untrained healthy males. (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - February 21, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Using Load-Velocity Relationships to Quantify Training-Induced Fatigue
Hughes, LJ, Banyard, HG, Dempsey, AR, Peiffer, JJ, and Scott, BR. Using load-velocity relationships to quantify training-induced fatigue. J Strength Cond Res 33(3): 762–773, 2019—The purpose of this study was to investigate using load-velocity relationships to quantify fluctuations in maximal strength (1 repetition maximum [1RM]), which occur as a result of training-induced fatigue. The 19 well-trained men (age: 24.3 ± 2.9 years, height: 180.1 ± 5.9 cm, body mass: 84.2 ± 10.5 kg, and squat 1RM: 151.1 ± 25.7 kg) who were recruited for this study attended 5 sessions. After baseline str...
Source: Journal of Strength and Conditioning Research - February 21, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Understanding Anthropometric Characteristics Associated With Performance in Manual Lifting Tasks
Beck, B, Middleton, KJ, Billing, DC, Caldwell, JN, and Carstairs, GL. Understanding anthropometric characteristics associated with performance in manual lifting tasks. J Strength Cond Res 33(3): 755–761, 2019—Manual lifting is an essential military job task and is commonly linked to occupational injury. Methods to reduce injury risk focus on ensuring that employees have the requisite physical capacity to safely conduct critical job tasks. The aim of this study was to investigate which anthropometric characteristics are associated with lifting performance to inform targeted training programs for job-critical lif...
Source: Journal of Strength and Conditioning Research - February 21, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Ideal Cardiovascular Health, Handgrip Strength, and Muscle Mass Among College Students: The FUPRECOL Adults Study
Garcia-Hermoso, A, Correa-Bautista, JE, Izquierdo, M, Tordecilla-Sanders, A, Prieto-Benavides, D, Sandoval-Cuellar, C, González-Ruíz, K, and Ramírez-Vélez, R. Ideal cardiovascular health, handgrip strength, and muscle mass among college students: the FUPRECOL Adults study. J Strength Cond Res 33(3): 747–754, 2019—The American Heart Association established the 2020 Strategic Impact Goals to define the concept of ideal cardiovascular health (CVH) and the metrics needed to monitor it across populations. The purpose of this study was to investigate the relationship between handgrip stren...
Source: Journal of Strength and Conditioning Research - February 21, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Endurance Running Training Individually Guided by HRV in Untrained Women
da Silva, DF, Ferraro, ZM, Adamo, KB, and Machado, FA. Endurance running training individually guided by HRV in untrained women. J Strength Cond Res 33(3): 736–746, 2019—The aim of this study was to analyze the effects of heart rate variability (HRV)-guided training compared with a standardized prescription on (a) time to complete 5-km running performance (t5km), (b) peak treadmill running speed (Vpeak) and its time limit (tlim at Vpeak), and (c) autonomic cardiac modulation (i.e., parasympathetic activity and recovery) in untrained women. Additionally, we correlated changes in t5km with changes in Vpeak, tlim ...
Source: Journal of Strength and Conditioning Research - February 21, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Heat Exposure and Hypohydration Exacerbate Physiological Strain During Load Carrying
This study compared separate and combined effects of heat exposure and hypohydration on physiological strain, mood state, and visual vigilance during loaded exercise. Twelve men (mean ± SD; age, 20 ± 2 years; body mass, 74.0 ± 8.2 kg; maximal oxygen uptake, 57.0 ± 6.0 ml·kg−1·min−1) completed 4 trials under the following conditions: euhydrated temperate (EUT), hypohydrated temperate (HYT), euhydrated hot (EUH), and hypohydrated hot (HYH). Exercise was 90 minutes of treadmill walking (∼50% V[Combining Dot Above]O2max, 5% grade) while carrying a 45-lb rucksack. Profil...
Source: Journal of Strength and Conditioning Research - February 21, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Duration-Dependent Effects of Passive Static Stretching on Musculotendinous Stiffness and Maximal and Rapid Torque and Surface Electromyography Characteristics of the Hamstrings
This study aimed to examine the effects of stretching duration on passive musculotendinous stiffness and maximal and rapid torque and surface electromyography (EMG) characteristics of the hamstrings. Thirteen young females (age = 21 ± 2 years) underwent 2 passive straight-leg raise (SLR) assessments and 2 isometric maximal voluntary contractions (MVCs) of the hamstrings before and after 4 randomized conditions that included a control treatment and 3 experimental treatments of passive static stretching for 30-, 60-, and 120-second durations. Passive stiffness was calculated during each SLR as the slope of the final 1...
Source: Journal of Strength and Conditioning Research - February 21, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Variations in Verbal Encouragement Modify Isokinetic Performance
This study examined the effects of 4 variations in verbal encouragement during isokinetic knee flexion and extension exercises. Twenty-three healthy participants (aged 19–34 years) completed 4 isokinetic testing sessions on a Biodex isokinetic dynamometer. Each session consisted of 5, 10, and 15 repetitions at 1.05 rad·s−1 (60°·s−1), 3.14 rad·s−1 (180°·s−1), and 5.24 rad·s−1 (300°·s−1), respectively, separated by 5-minute passive recoveries. The variations in verbal encouragement randomized during each testing session used the f...
Source: Journal of Strength and Conditioning Research - February 21, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Adaptive Changes on the Dominant Shoulder of Collegiate Handball Players—A Comparative Study
Vogler, T, Schorn, D, Gosheger, G, Kurpiers, N, Schneider, K, Rickert, C, Andreou, D, and Liem, D. Adaptive changes on the dominant shoulder of collegiate handball players—A comparative study. J Strength Cond Res 33(3): 701–707, 2019—Handball players are susceptible to adaptive bony and soft-tissue changes of the dominant shoulder. Our goal was to compare the glenohumeral range of motion and posterior capsule thickness between the dominant and nondominant arm of throwing athletes and between the dominant arm of nonthrowers and throwing athletes. Twenty-three collegiate handball players and 23 nonthrowing ...
Source: Journal of Strength and Conditioning Research - February 21, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

The A-allele of the FTO Gene rs9939609 Polymorphism Is Associated With Decreased Proportion of Slow Oxidative Muscle Fibers and Over-represented in Heavier Athletes
In conclusion, the A/A genotype of the FTO T> A polymorphism is under-represented in athletes more reliant on a lean phenotype and associated with decreased proportion of slow-twitch muscle fibers, while is over-represented in strength and heavier athletes. (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - February 21, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of Flywheel Strength Training on the Running Economy of Recreational Endurance Runners
Festa, L, Tarperi, C, Skroce, K, Boccia, G, Lippi, G, La Torre, A, and Schena, F. Effects of flywheel strength training on the running economy of recreational endurance runners. J Strength Cond Res 33(3): 684–690, 2019—Running economy (RE) has been defined as the most important determining factor in endurance performance in both elite and recreational runners. The purpose of this study was to evaluate the effect of flywheel strength training (FST) and high-intensity training (HIT) protocols on RE and strength parameters in a group of recreational runners. Twenty-nine recreational runners were recruited to take ...
Source: Journal of Strength and Conditioning Research - February 21, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Repeatability and Specificity of Eccentric Force Output and the Implications for Eccentric Training Load Prescription
Harden, M, Wolf, A, Haff, GG, Hicks, KM, and Howatson, G. Repeatability and specificity of eccentric force output and the implications for eccentric training load prescription. J Strength Cond Res 33(3): 676–683, 2019—Prescribing supramaximal eccentric (ECC) loads based on repetition maximum, isometric (ISO), or concentric-only (CON) strength overlooks the possibility that individuals have a different tolerance for ECC exercise. To inform the prescription of ECC training regimes, this study implemented a test battery that included maximal accentuated-eccentric (ECC+), traditional coupled eccentric-concentric (T...
Source: Journal of Strength and Conditioning Research - February 21, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of Combined Plyometric and Short Sprint With Change-of-Direction Training on Athletic Performance of Male U15 Handball Players
This study examined the effects of combined plyometric and change-of-direction training (CPT) on selected measures of performance (repeated-sprint T-test [RSTT], sprint performance [5, 10, 20, and 30 m], change-of-direction tests [modified Illinois test and T-half test], squat jump, countermovement jump, countermovement jump with aimed arms 5-jump test, Y-balance test, Stork balance test, and 20-m shuttle run) in male U15 handball players. Players were randomly divided between experimental (n = 14; age: 14.5 ± 0.3 years) and control (n = 14; age: 14.6 ± 0.2 years) groups. All trial participants trained and pl...
Source: Journal of Strength and Conditioning Research - February 21, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of 8-Week Functional vs. Traditional Training on Athletic Performance and Functional Movement on Prepubertal Tennis Players
This study included 28 young tennis players (mean age: 9.6 ± 0.7, height: 134.1 ± 6.8, body mass: 31.3 ± 4.1, and fitness age: 3.1 ± 1.1) who have an 80% or more dominant side based on the lateralization test and a functional movement screen (FMS) score below 75%. Ten subjects were included in each of the FT group (FTG) and the traditional training group (TTG), 8 subjects were included in the control group (CG). The training program was implemented on 3 nonconsecutive days in a week for 8 weeks. All subjects performed CG exercises; FTG performed additional exercises based on the FT model, and TT...
Source: Journal of Strength and Conditioning Research - February 21, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Short-Term Effects of Resistance Training Modalities on Performance Measures in Male Adolescents
This study compared the effects of 7 weeks of bodyweight, mobility, and resistance training programs on strength, power, and sprint times. Thirty-nine male adolescents (aged 14–15 years) were randomly assigned to 1 of 2 groups: bodyweight and mobility training (BMT) (n = 25) or combined bodyweight, mobility, and free-weights training (CBT) (n = 14). A physical education class (n = 23) of similar age constituted a control group (CON). Both training groups performed 2 BMT sessions per week, and the CBT group performed 2 additional free-weight resistance exercise training sessions. Pretesting and posttesting consisted o...
Source: Journal of Strength and Conditioning Research - February 21, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Comparison Between Unilateral and Bilateral Plyometric Training on Single- and Double-Leg Jumping Performance and Strength
This study compared the effects of unilateral and bilateral plyometric training on single- and double-leg jumping performance, maximal strength, and rate of force development (RFD). Fifteen moderately trained subjects were randomly assigned to either a unilateral (U, n = 7) or bilateral group (B, n = 8). Both groups performed maximal effort plyometric leg exercises 2 times per week for 6 weeks. The B group performed all exercises with both legs, whereas the U group performed half the repetitions with each leg, so that total exercise volume was the same. Jumping performance was assessed by countermovement jumps (CMJs) and d...
Source: Journal of Strength and Conditioning Research - February 21, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Effect of Attentional Focus Strategies on the Biomechanical Performance of the Drop Jump
Comyns, TM, Brady, CJ, and Molloy, J. Effect of attentional focus strategies on the biomechanical performance of the drop jump. J Strength Cond Res 33(3): 626–632, 2019—Motor performance can be influenced by focusing an athlete's attention through the use of verbal instructions. There is limited research on the effect of internal, neutral, and external attentional focus strategies on drop jump (DJ) performance aimed at maximizing height jumped (HJ) and minimizing ground contact time (CT). The purpose of this study was to assess the effect of attentional focus strategies on biomechanical variables related to eff...
Source: Journal of Strength and Conditioning Research - February 21, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Muscular and Neural Contributions to Postactivation Potentiation
This study's purpose was to explain the relationship between muscle factors (twitch potentiation [TP]) and neural factors (reflex potentiation) contributing to total postactivation potentiation (PAP) that couples these. The tibial nerve of 15 participants were stimulated intermittently for 20 minutes at supramaximal (Mmax) and submaximal (Hmax) intensities on separate days under 2 conditions: (a) rest (Control) and (b) after a 10-second plantarflexion maximum voluntary isometric contraction (MVIC). Isometric twitch torque and rate of force development (RFD) as well as soleus and gastrocnemius electromyographic values were ...
Source: Journal of Strength and Conditioning Research - February 21, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Heel-Raised Foot Posture Does Not Affect Trunk and Lower Extremity Biomechanics During a Barbell Back Squat in Recreational Weight lifters
Lee, S-P, Gillis, CB, Ibarra, JJ, Oldroyd, DF, and Zane, RS. Heel-raised foot posture does not affect trunk and lower extremity biomechanics during a barbell back squat in recreational weight lifters. J Strength Cond Res 33(3): 606–614, 2019—It is claimed that weightlifting shoes with a raised heel may lead to a more upright trunk posture, and thus reduce the risk of back injuries during a barbell back squat. These proclaimed biomechanical effects have not been thoroughly investigated. The purpose of this study was to compare trunk and lower extremity biomechanics during barbell back squats in three foot postur...
Source: Journal of Strength and Conditioning Research - February 21, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Factors Related to Average Concentric Velocity of Four Barbell Exercises at Various Loads
Fahs, CA, Blumkaitis, JC, and Rossow, LM. Factors related to average concentric velocity of four barbell exercises at various loads. J Strength Cond Res 33(3): 597–605, 2019—The resistance exercise load is the primarily determinant of the average concentric velocity (ACV) during a repetition. It is unknown whether individual factors such as training experience or anthropometrics also influence the ACV. Previous research has shown the ACV during the 1 repetition maximum (1RM) varies between exercises, but it is not clear whether ACV is different between exercises at various percentages of the 1RM. This informati...
Source: Journal of Strength and Conditioning Research - February 21, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Abstracts
No abstract available (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Abstracts Source Type: research

Effects of Reactiv “Maximum HMB” on Body Mass and Performance in Elite Male Rugby Players
No abstract available (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Manuscript Clarification Source Type: research

Methodological Approaches and Related Challenges Associated With the Determination of Critical Power and Curvature Constant
Muniz-Pumares, D, Karsten, B, Triska, C, and Glaister, M. Methodological approaches and related challenges associated with the determination of critical power and W′. J Strength Cond Res 33(2): 584–596, 2019—The relationship between exercise intensity and time to task failure (P-T relationship) is hyperbolic, and characterized by its asymptote (critical power [CP]) and curvature constant (W′). The determination of these parameters is of interest for researchers and practitioners, but the testing protocol for CP and W′ determination has not yet been standardized. Conventionally, a series of con...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Brief Review Source Type: research

Effects of Blood Flow Restriction Training on Aerobic Capacity and Performance: A Systematic Review
Bennett, H and Slattery, F. Effects of blood flow restriction training on aerobic capacity and performance: A systematic review. J Strength Cond Res 33(2): 572–583, 2019—Blood flow restriction (BFR) is a novel training method that can elicit training adaptations at low training intensities. Recent research has aimed to determine the effect of aerobic exercise with BFR on aerobic fitness and performance, with conflicting results. This review aimed to systematically identify and assess studies that have combined BFR with aerobic exercise in humans, establishing its effect on aerobic fitness and performance. Five ...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Brief Review Source Type: research

Reliability of Zephyr Bioharness and Fitbit Charge Measures of Heart Rate and Activity at Rest, During the Modified Canadian Aerobic Fitness Test, and Recovery
Nazari, G, MacDermid, JC, Sinden, KE, Richardson, J, and Tang, A. Reliability of Zephyr Bioharness and Fitbit Charge measures of heart rate and activity at rest, during the modified Canadian Aerobic Fitness Test, and recovery. J Strength Cond Res 33(2): 559–571, 2019—The purpose of this study was to determine the intrasession and intersession reliability of Zephyr Bioharness (ZB) and Fitbit Charge variables in both healthy men and women at rest, during the Modified Canadian Aerobic Fitness Test (mCAFT), and throughout recovery. Stratified convenience and snowball sampling were used to recruit 60 participants (3...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Improving Active Gaming's Energy Expenditure in Healthy Adults Using Structured Playing Instructions for the Nintendo Wii and Xbox Kinect
Naugle, KE, Carey, C, Ohlman, T, Godza, M, Mikesky, A, and Naugle, KM. Improving active gaming's energy expenditure in healthy adults using structured playing instructions for the Nintendo Wii and Xbox Kinect. J Strength Cond Res 33(2): 549–558, 2019—Professionals work constantly to increase energy expenditure and improve cardiovascular outcomes. A newer form of physical activity used to improve cardiovascular outcomes and increase energy expenditure while also providing entertainment is active gaming. The purpose was to determine energy expenditure and enjoyment levels during participation in different games p...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

The Impact of Dry-Land Sprint Start Training on the Short Track Speed Skating Start
Haug, WB, Drinkwater, EJ, Cicero, NJ, Barthell, JA, and Chapman, DW. The impact of dry-land sprint start training on the short track speed skating start. J Strength Cond Res 33(2): 544–548, 2019—This investigation sought to determine the effects of dry-land sprint start training on short track speed skating (STSS) start performance. Nine highly trained short track athletes completed a control period of normal STSS training followed by a 4-week training intervention. Before and after the control and intervention periods, athletes performed 3 electronically timed dry-land and on-ice 14.43 m maximal sprint start e...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Power Profiles of Competitive and Noncompetitive Mountain Bikers
Novak, AR, Bennett, KJM, Pluss, MA, Fransen, J, Watsford, ML, and Dascombe, BJ. Power profiles of competitive and noncompetitive mountain bikers. J Strength Cond Res 33(2): 538–543, 2019—The performance of Olympic distance cross-country mountain bikers (XCO-MTB) is affected by constraints such as erosion of track surfaces and mass start congestion which can affect race results. Standardized laboratory assessments quantify interseasonal and intraseasonal cycling potential through the assessment of multiple physiological capacities. Therefore, this study examined whether the power profile assessment (PPA) could d...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of Intracyclic Velocity Variations on the Drag Exerted by Different Swimming Parachutes
This study aimed to assess the drag provided by 2 swimming parachutes of different shape, also characterized by different volumes and cross-sectional areas, under conditions of velocity variations in the range of those occurring in swimming. A flat square-shaped parachute (FLAT, cross-sectional area and volume: 400 cm2; 0.12 L) and a truncated cone-shaped parachute (CONE, 380 cm2; 7.15 L) were passively towed: (a) at constant velocities ranging from 1.0 to 2.2 m·s−1, and (b) with velocity fluctuations from 10 to 40% around a mean of 1.6 m·s−1. At constant velocities, FLAT showed 0.1 N (at 1.0 m&mi...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

A Match-Derived Relative Pitch Area Facilitates the Tactical Representativeness of Small-Sided Games for the Official Soccer Match
Olthof, SBH, Frencken, WGP, and Lemmink, KAPM. A match-derived relative pitch area facilitates the tactical representativeness of small-sided games for the official soccer match. J Strength Cond Res 33(2): 523–530, 2019—Small-sided games (SSGs) are a promising training format in soccer to replicate (situations of) the official match across all age groups. Typically, SSGs are played on a smaller relative pitch area (RPA; i.e., (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

Predictors of Linear and Multidirectional Acceleration in Elite Soccer Players
Jonathan, N, Russell, M, Shearer, D, Cook, CJ, and Kilduff, LP. Predictors of linear and multidirectional acceleration in elite soccer players. J Strength Cond Res 33(2): 514–522, 2019—Linear and multidirectional acceleration underpins success in professional soccer match play. However, the physical qualities that determine these performance indicators are poorly understood in elite players. English Premier League players (n = 26) performed isometric midthigh pulls (IMTPs), bilateral and unilateral drop jumps (from 40 and 20 cm, respectively), bilateral and unilateral countermovement jumps (CMJs), and assessmen...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

Effect of Cold Water Immersion Performed on Successive Days on Physical Performance, Muscle Damage, and Inflammatory, Hormonal, and Oxidative Stress Markers in Volleyball Players
de Freitas, VH, Ramos, SP, Bara-Filho, MG, Freitas, DGS, Coimbra, DR, Cecchini, R, Guarnier, FA, and Nakamura, FY. Effect of cold water immersion performed on successive days on physical performance, muscle damage, and inflammatory, hormonal, and oxidative stress markers in volleyball players. J Strength Cond Res 33(2): 502–513, 2019—The aim of this study was to investigate the effects of daily cold water immersion (CWI) on physical performance, muscle damage, and inflammatory, hormonal, and oxidative stress markers in volleyball. Six players were submitted to CWI and six players to a placebo, during 5 training...
Source: Journal of Strength and Conditioning Research - January 29, 2019 Category: Sports Medicine Tags: Original Research Source Type: research

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