Longitudinal Changes in Body Composition Throughout Successive Seasonal Phases Among Canadian University Football Players
Kim, J, Delisle-Houde, P, Reid, RER, and Andersen, RE. Longitudinal changes in body composition throughout successive seasonal phases among Canadian university football players. J Strength Cond Res 32(8): 2284–2293, 2018—The purpose of this study was to assess changes in body composition during seasonal phases of the training year among Canadian Inter-University Sport (CIS) football players. Forty university football players were assessed for anthropometry, total body composition, regional body composition, and central adiposity over a 7-month period including the summer off-season and the in-season. Baseline t...
Source: Journal of Strength and Conditioning Research - July 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Evaluation of Skating Top Speed, Acceleration, and Multiple Repeated Sprint Speed Ice Hockey Performance Tests
Bond, CW, Bennett, TW, and Noonan, BC. Evaluation of skating top speed, acceleration, and multiple repeated sprint speed ice hockey performance tests. J Strength Cond Res 32(8): 2273–2283, 2018—Skating speed, acceleration (ACC), and economy are important attributes related to ice hockey success and should ideally be tested on the ice in a reliable and time efficient manner that is accessible to coaches at all levels of the sport. The purpose of this study was to determine the reliability of certain on-ice tests and further, to use these results to evaluate changes in performance across a season. It was hypothes...
Source: Journal of Strength and Conditioning Research - July 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Energy Cost of Continuous Shuttle Running: Comparison of 4 Measurement Methods
Ciprandi, D, Lovecchio, N, Piacenza, M, Limonta, E, Esposito, F, Sforza, C, Zago, M. Energy cost of continuous shuttle running: Comparison of 4 measurement methods. J Strength Cond Res 32(8): 2265–2272, 2018—Assessing runs with frequent turns (shuttle run) is a viable option to evaluate the energy cost associated with sport-specific high-intensity intermittent activities. To date, no study investigated the extent to which the computation of energy cost of exercise is affected by the following factors: procedure and duration of oxygen uptake measurement during exercise, oxygen uptake measurement during recovery,...
Source: Journal of Strength and Conditioning Research - July 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

An Assessment of Running Power as a Training Metric for Elite and Recreational Runners
This study sought to investigate a novel training tool, the Stryd Running Power Meter, and the applicability of running power (and its individually calculated run mechanics) to be a useful surrogate of metabolic demand (V[Combining Dot Above]O2), across different running surfaces, within different caliber runners. Recreational (n = 13) and elite (n = 11) runners completed a test assessing V[Combining Dot Above]O2 at 3 different paces, while wearing a Stryd Power Meter on both an indoor treadmill and an outdoor track, to investigate relationships between estimated running power and metabolic demand. A weak but significant r...
Source: Journal of Strength and Conditioning Research - July 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Deception of Ambient Temperature Does Not Elicit Performance Benefits During a 5 km Run in Hot, Humid Conditions
Hanson, NJ, Carriveau, DM, Morgan, HE, Smith, AR, Michael, TJ, and Miller, MG. Deception of ambient temperature does not elicit performance benefits during a 5 km run in hot, humid conditions. J Strength Cond Res 32(8): 2250–2257, 2018—The purpose of this study was to investigate the effect of deception of ambient temperature on 5 km performance in recreational runners. Eleven participants (6 men, 5 women) each performed three 5 km runs in a random order consisting of a control trial (CON) in temperate conditions (21° C, 43% RH), a hot humid trial (HOT; 31° C, 65% RH) and a deception trial (DEC; 31°...
Source: Journal of Strength and Conditioning Research - July 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Repeated High-Intensity Cycling Performance Is Unaffected by Timing of Carbohydrate Ingestion
Shei, R-J, Paris, HL, Beck, CP, Chapman, RF, and Mickleborough, TD. Repeated high-intensity cycling performance is unaffected by timing of carbohydrate ingestion. J Strength Cond Res 32(8): 2243–2249, 2018—To determine whether carbohydrate (CHO) feeding taken immediately before, early, or late in a series of high-intensity cycling exercises affected cycling performance. A total of 16 trained, male cyclists (>6 hours postprandial) performed 3-, 4-km cycling time trials (TT1, TT2, and TT3) separated by 15 minutes of active recovery on 4 separate occasions. Carbohydrate feeding (80 g) was given either before TT...
Source: Journal of Strength and Conditioning Research - July 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

The Effects of Beef, Chicken, or Whey Protein After Workout on Body Composition and Muscle Performance
Sharp, MH, Lowery, RP, Shields, KA, Lane, JR, Gray, JL, Partl, JM, Hayes, DW, Wilson, GJ, Hollmer, CA, Minivich, JR, and Wilson, JM. The effects of beef, chicken, or whey protein after workout on body composition and muscle performance. J Strength Cond Res 32(8): 2233–2242, 2018—The purpose of this study was to determine the effects of postworkout consumption of beef protein isolate (Beef), hydrolyzed chicken protein (Chx), or whey protein concentrate (WPC), compared with a control on body composition and muscle performance during 8 weeks of resistance training. Forty-one men and women were randomized into 4 gr...
Source: Journal of Strength and Conditioning Research - July 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Acute Capsaicin Supplementation Improves Resistance Training Performance in Trained Men
Conrado de Freitas, M, Cholewa, JM, Freire, RV, Carmo, BA, Bottan, J, Bratfich, M, Della Bandeira, MP, Gonçalves, DC, Caperuto, EC, Lira, FS, and Rossi, FE. Acute capsaicin supplementation improves resistance training performance in trained men. J Strength Cond Res 32(8): 2227–2232, 2018—The purpose of this study was to investigate the acute effect of capsaicin supplementation on performance, rate of perceived exertion (RPE), and blood lactate concentrations during resistance exercise in healthy trained young men. Ten resistance-trained men (age = 22.7 ± 4.0 years, mass = 82.3 ± 9.6 kg, and...
Source: Journal of Strength and Conditioning Research - July 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Effect of Caffeine on Sprint Cycling in Experienced Cyclists
Anderson, DE, LeGrand, SE, and McCart, RD. Effect of caffeine on sprint cycling in experienced cyclists. J Strength Cond Res 32(8): 2221–2226, 2018—Research regarding the ergogenic effects of caffeine (CAF) in anaerobic activity remains inconclusive. However, some researchers have found significant improvements in anaerobic performance when testing specifically trained athletes. A double-blind, placebo-controlled, counterbalanced, cross-over design was implemented to assess the impact of CAF on a 30-second Wingate Anaerobic Test (WAnT) in experienced cyclists. Nine experienced cyclists volunteered to participat...
Source: Journal of Strength and Conditioning Research - July 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

A Comparison of Bilateral Muscular Imbalance Ratio Calculations Using Functional Tests
This study aimed to compare the bilateral muscular imbalance ratio calculations, using the absolute difference between limbs as the numerator and the 5 different options as reference values. Twenty-three males (21.6 ± 1.9 years, 1.80 ± 0.06 m, 80.5 ± 13.8 kg) and 11 females (20.8 ± 1.5 years, 1.62 ± 0.03 m, 68.0 ± 6.5 kg) performed the one-legged 6-m timed test and the one-legged triple-hop distance test. The 5 possible combinations were compared with a 2 (sex) × 2 (functional test) × 5 (calculation method) analysis of variance for each test. Significant differences (p ...
Source: Journal of Strength and Conditioning Research - July 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Acute Effect of Foam Rolling and Dynamic Stretching on Flexibility and Jump Height
Smith, JC, Pridgeon, B, and Hall, MC. Acute effect of foam rolling and dynamic stretching on flexibility and jump height. J Strength Cond Res 32(8): 2209–2215, 2018—Dynamic stretching (DS) can acutely improve vertical jump (VJ) performance but its effect lasts no more than 5 minutes. Foam rolling (FR), a form of self-myofascial release, can acutely increase range of motion (ROM) with this effect lasting less than 10 minutes. Therefore, the purpose of this study was to evaluate the time course of these effects, separately and combined, on VJ height and ROM. Twenty-nine university students completed 4 different s...
Source: Journal of Strength and Conditioning Research - July 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Acute Effects of Active, Ballistic, Passive, and Proprioceptive Neuromuscular Facilitation Stretching on Sprint and Vertical Jump Performance in Trained Young Soccer Players
Oliveira, LP, Vieira, LHP, Aquino, R, Manechini, JPV, Santiago, PRP, and Puggina, EF. Acute effects of active, ballistic, passive, and proprioceptive neuromuscular facilitation stretching on sprint and vertical jump performance in trained young soccer players. J Strength Cond Res 32(8): 2199–2208, 2018—The aim of this study was to compare the acute effects of active (AC), ballistic (BA), passive (PA), and proprioceptive neuromuscular facilitation (PNF) stretching methods on performance in vertical jumping, sit and reach, and sprinting in young soccer players. Twelve trained soccer players (17.67 ± 0.87 y...
Source: Journal of Strength and Conditioning Research - July 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Stretch Could Reduce Hamstring Injury Risk During Sprinting by Right Shifting the Length-Torque Curve
Ruan, M, Li, L, Chen, C, and Wu, X. Stretch could reduce hamstring injury risk during sprinting by right shifting the length-torque curve. J Strength Cond Res 32(8): 2190–2198, 2018—It was hypothesized that static stretch would shift the length-torque curve to the right, which may reduce the risk of muscle strain injuries. The purpose of this study was to evaluate the acute effects of static stretching of hamstring (SSH) on the risk of hamstring injury during sprinting indicated by the shift of the length–torque relationship. Twelve female college athletes (age: 20.8 ± 0.7 years; height: 1.61 &plus...
Source: Journal of Strength and Conditioning Research - July 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

The Effects of Recovery Duration During High-Intensity Interval Exercise on Time Spent at High Rates of Oxygen Consumption, Oxygen Kinetics, and Blood Lactate
In conclusion, aerobic metabolism attains its upper functional limits with either 2, or 3 or 4 minutes of recovery during the 4 × 4-minute HIIE; thus, all rest durations could be used for the enhancement of aerobic capacity in sports, fitness, and clinical settings. The short (2 minutes) compared with longer (4 minutes) recovery, however, evokes greater cardiovascular and metabolic stress and activates to a greater extent anaerobic glycolysis and hence, could be used by athletes to induce greater overall physiological challenge. (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - July 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Hypoxia During Resistance Exercise Does Not Affect Physical Performance, Perceptual Responses, or Neuromuscular Recovery
This study aimed to determine whether performing resistance exercise in hypoxia affects markers of physical performance, perceptual responses, and neuromuscular function. Fourteen male subjects (age: 24.6 ± 2.7 years; height: 179.7 ± 5.9 cm; body mass: 84.6 ± 11.6 kg) with>2 years resistance training experience performed moderate-load resistance exercise in 2 conditions: normoxia (FIO2 = 0.21) and hypoxia (FIO2 = 0.16). Resistance exercise comprised 3 sets of 10 repetitions of back squats and deadlifts at 60% of 1 repetition maximum (1RM), with 60 seconds inter-set rest. Physical performance was ass...
Source: Journal of Strength and Conditioning Research - July 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Can Neck Strength be Measured Using a Single Maximal Contraction in a Simulated Contact Position?
Salmon, DM, Handcock, PJ, Sullivan, SJ, Rehrer, NJ, and Niven, BE. Can neck strength be measured using a single maximal contraction in a simulated contact position? J Strength Cond Res 32(8): 2166–2173, 2018—Neck strengthening has been postulated to potentially reduce the incidence and severity of concussions and neck injuries in collision-based sports. A quick and reliable method to assess neck strength would permit identification of those at risk and tracking of progress after injury. The purpose of this study was to determine if neck strength could be reliably assessed in a simulated contact posture using a ...
Source: Journal of Strength and Conditioning Research - July 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Effect of Three Different Muscle Action Training Protocols on Knee Strength Ratios and Performance
Ruas, CV, Brown, LE, Lima, CD, Costa, PB, and Pinto, RS. Effect of three different muscle action training protocols on knee strength ratios and performance. J Strength Cond Res 32(8): 2154–2165, 2018—Hamstring to quadriceps (H:Q) ratios are often used to assess strength imbalances. The aims of this study were to compare 3 different muscle action training protocols on H:Q strength balance and functional performance. Forty untrained men (age: 22.87 ± 2.28 years, mass: 70.66 ± 11.049 kg, ht: 174.29 ± 6.90 cm) performed 6 weeks of training on an isokinetic dynamometer. They were randomly assign...
Source: Journal of Strength and Conditioning Research - July 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Effort Index as a Novel Variable for Monitoring the Level of Effort During Resistance Exercises
This study aimed to analyze the acute mechanical and metabolic response to resistance exercise protocols (REPs) defined by 2 variables: the first repetition's mean velocity and the percentage of velocity loss (%VL) over the set. The product of these 2 variables was termed the effort index (EI) and was used as an indicator of the degree of fatigue induced during each REP. Twenty-one resistance-trained men (11 in full squat [SQ] and 10 in bench press [BP]) performed 16 REPs separated by 72 hours. Relative loads used (50, 60, 70, and 80% 1-repetition maximum) were determined from the load-velocity relationship for the SQ and ...
Source: Journal of Strength and Conditioning Research - July 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Comparison of Acute Physiological and Psychological Responses Between Moderate-Intensity Continuous Exercise and Three Regimes of High-Intensity Interval Training
This study compared physiological and perceptual responses between MICT and 3 regimes of HIIT. Nineteen active adults (age = 24.0 ± 3.3 years) unfamiliar with HIIT initially performed ramp exercise to exhaustion to measure maximal oxygen uptake (V[Combining Dot Above]O2max) and determine workload for subsequent sessions, whose order was randomized. Sprint interval training (SIT) consisted of six 20-second bouts of “all-out” cycling at 140% of maximum watts (Wmax). Low-volume HIIT (HIITLV) and high-volume HIIT (HIITHV) consisted of eight 60-second bouts at 85% Wmax and six 2-minute bouts at 70% Wmax, resp...
Source: Journal of Strength and Conditioning Research - July 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

An Investigation Into the Effects of Excluding the Catch Phase of the Power Clean on Force-Time Characteristics During Isometric and Dynamic Tasks: An Intervention Study
This study clearly demonstrates that neither the inclusion nor exclusion of the catch phase of the PC derivatives results in any preferential adaptations over two 4-week, in-season strength and power, mesocycles. (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - July 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Improved Functional Power Over a 5-Week Period: Comparison of Combined Weight Training to Flexible Barbell Training
Caterisano, A, Hutchison, R, Parker, C, James, S, and Opskar, S. Improved functional power over a 5-week period: Comparison of combined weight training with flexible barbell training. J Strength Cond Res 32(8): 2109–2115, 2018—Previous studies demonstrated increased power development with various resistance-training modes over short training periods of 4–7 weeks through neuromuscular adaptations. The purpose of this study was to compare 2 different power-training regimens over a 5-week period: combined weight training program (CT) using speed-lifts and plyometrics vs. flexible barbell (FB) training. Colle...
Source: Journal of Strength and Conditioning Research - July 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Restrictive Breathing Mask Reduces Repetitions to Failure During a Session of Lower-Body Resistance Exercise
Andre, TL, Gann, JJ, Hwang, PS, Ziperman, E, Magnussen, MJ, and Willoughby, DS. Restrictive breathing mask reduces repetitions to failure during a session of lower-body resistance exercise. J Strength Cond Res 32(8): 2103–2108, 2018—The purpose of this study was to determine the effect of restrictive breathing mask (RBM) on muscle performance, hemodynamic, and perceived stress variables during a session of lower-body resistance exercise. In a crossover design, 10 participants performed 2 separate testing sessions, RBM and no mask, consisting of squat, leg press, and leg extension. The paired-samples t-test was ...
Source: Journal of Strength and Conditioning Research - July 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Author Response to: Is Elevation Training Mask a Strategy to Increase Lactate Clearance Through Respiratory Muscle Loading?
No abstract available (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - June 26, 2018 Category: Sports Medicine Tags: Manuscript Clarification Source Type: research

Sexual Dimorphism in the Estimation of Upper-Limb Blood Flow Restriction in the Seated Position
Borges, A, Teodósio, C, Matos, P, Mil-Homens, P, Pezarat-Correia, P, Fahs, C, and Mendonca, GV. Sexual dimorphism in the estimation of upper-limb blood flow restriction in the seated position. J Strength Cond Res 32(7): 2096–2102, 2018—Arterial occlusion pressure (AOP) is typically used to normalize blood flow restriction (BFR) during low-intensity BFR exercise. Despite strong evidence for sexual dimorphism in muscle blood flow, sex-related differences in AOP estimation remain a controversial topic. We aimed at determining whether the relationship of upper-limb AOP with arm circumference and systolic blo...
Source: Journal of Strength and Conditioning Research - June 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Low Second-To-Fourth Digit Ratio Has High Explosive Power? A Prepubertal Study
This study analyzed the relationship between the 2D:4D ratio and explosive power. Explosive power of the lower limbs was assessed using the standing long jump (SLJ) test. The lengths of the second and fourth fingers of the right hand were measured to calculate the 2D:4D ratio. The SLJ length was correlated with the 2D:4D ratios (r = −0.144, p = 0.015) in boys. After controlling for age and the body mass index, this correlation remained significant (r = −0.134, p = 0.024). For girls, 2D:4D ratios were not significantly correlated with SLJ scores. These results indicate that the SLJ distance was negatively correl...
Source: Journal of Strength and Conditioning Research - June 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Resistance Exercise Training Is More Effective than Interval Aerobic Training in Reducing Blood Pressure During Sleep in Hypertensive Elderly Patients
In conclusion, resistance training promoted a greater nocturnal fall in BP among hypertensive elderly subjects under treatment compared with IA subjects. (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - June 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Positional Differences in Running and Nonrunning Activities During Elite American Football Training
Ward, PA, Ramsden, S, Coutts, AJ, Hulton, AT, and Drust, B. Positional differences in running and nonrunning activities during elite American football training. J Strength Cond Res XX(X): 000–000, 2017—The aim of this investigation was to describe differences in training loads between position groups within professional American football. Integrated micro technology data were collected on 63 NFL football players during an American football training camp. Five key metrics (total distance, high-speed distance, player load (PL), PL per minute, and total inertial movement analysis [IMA]) served to quantify both run...
Source: Journal of Strength and Conditioning Research - June 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of 2% Dehydration on Lactate Concentration During Constant-Load Cycling
This study examined effects of dehydration on [La] response during constant-load cycling. Recreationally fit (V[Combining Dot Above]O2peak = 48.7 ± 5.2 ml·kg−1·min−1) male participants (n = 9) completed 2 × 40-minute constant-load cycling trials; euhydrated (HYD) and after previous evening passive (water bath) dehydration (2% body weight, DEH) (HYD and DEH counterbalanced). Lactate, heart rate (HR), 10-point Omni ratings of perceived exertion (RPE), and rectal temperature (Trec) were measured after warm-up (WU) and at 10, 20, 30, and 40 minutes. Before cycling, urine specific gravity ...
Source: Journal of Strength and Conditioning Research - June 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Hydration Status and Thermoregulatory Responses in Drivers During Competitive Racing
This study quantified the degree of fluid losses during a competitive event in hot conditions. Nine male stock car drivers (29.6 ± 9.4 years, 177.8 ± 3.0 cm, 81.5 ± 18.5 kg) were studied during a Pro Series Division NASCAR race. Sweat rate (SR) and dehydration was determined through nude body weights (BWs). Prerace BW was 81.5 ± 18.5 kg and decreased to 81.1 ± 18.5 kg after race (p = 0.001). Body weight loss after race was 0.77 ± 0.3% and mean SR was 0.63 ± 0.4 L·h−1. Intestinal core temperature increased from 38.0 ± 0.4 to 38.5 ± 0.4° C after ...
Source: Journal of Strength and Conditioning Research - June 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Race Profiles of Rowers During the 2014 Youth Olympic Games
Cerasola, D, Cataldo, A, Bellafiore, M, Traina, M, Palma, A, Bianco, A, and Capranica, L. Race profiles of rowers during the 2014 Youth Olympic Games. J Strength Cond Res 32(7): 2055–2060, 2018—Among the different factors affecting the outcome of elite rowing competitions, pacing strategy plays a relevant role. The purpose of this study was to analyze the race profiles of youth athletes competing at the 2014 Youth Olympic Games over a distance of 1,000 m. According to the competition outcome of sculling and sweep events, 96 youth (17–18 years) rowers (48 male and 48 female) were divided into winner (W), n...
Source: Journal of Strength and Conditioning Research - June 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Time Course of Oxidative Stress, Inflammation, and Muscle Damage Markers for 5 Days After a Soccer Match: Effects of Sex and Playing Position
This study examined the influence of sex and playing position on the time course of selected oxidative stress, inflammation, and muscle damage markers after an official soccer match. Sixty professional soccer players (30 men and 30 women) were divided into 3 groups, according to their playing position: defenders, midfielders, and attackers. Each group consisted of 10 male and 10 female players. Sixty healthy volunteers (30 men and 30 women) served as control. Blood samples were taken before and after the match and daily for 5 days after the match. Analysis of variance revealed different responses over time between sex and ...
Source: Journal of Strength and Conditioning Research - June 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Manipulating Field Dimensions During Small-sided Games Impacts the Technical and Physical Profiles of Australian Footballers
This study investigated the effect of manipulating field dimensions on the technical and physical profiles of Australian football (AF) players during small-sided games (SSGs). A total of 40 male players (23.9 ± 3.5 years) participated in 3, five-a-side SSGs; defined as “small” (20 × 30 m; 600 m2), “medium” (30 × 40 m; 1,200 m2), and “large” (40 × 50 m; 2,000 m2). Notational analyses enabled the quantification of technical skill indicators, whereas physical activity profiles were measured using microtechnology, resulting in 18 criterion variables. A multivariate a...
Source: Journal of Strength and Conditioning Research - June 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Elite Junior Australian Football Players Experience Significantly Different Loads Across Levels of Competition and Training Modes
Lathlean, TJH, Gastin, PB, Newstead, S, and Finch, CF. Elite junior Australian football players experience significantly different loads across levels of competition and training modes. J Strength Cond Res 32(7): 2031–2038, 2018—Well-developed physical qualities such as high jumping ability, running endurance, acceleration, and speed can help aspiring junior elite Australian football (AF) players transition to the Australian Football League competition. To do so, players need to experience sufficient load to enhance their physical resilience without increasing their risk of negative outcomes in terms of impaire...
Source: Journal of Strength and Conditioning Research - June 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Evaluation of the Most Reliable Procedure of Determining Jump Height During the Loaded Countermovement Jump Exercise: Take-Off Velocity vs. Flight Time
This study aimed to compare the reliability of jump height between the 2 standard procedures of analyzing force-time data (take-off velocity [TOV] and flight time [FT]) during the loaded countermovement (CMJ) exercise performed with a free-weight barbell and in a Smith machine. The jump height of 17 men (age: 22.2 ± 2.2 years, body mass: 75.2 ± 7.1 kg, and height: 177.0 ± 6.0 cm) was tested in 4 sessions (twice for each CMJ type) against external loads of 17, 30, 45, 60, and 75 kg. Jump height reliability was comparable between the TOV (coefficient of variation [CV]: 6.42 ± 2.41%) and FT (CV: 6....
Source: Journal of Strength and Conditioning Research - June 26, 2018 Category: Sports Medicine Tags: Research Note Source Type: research

Lower Extremity Horizontal Work But Not Vertical Power Predicts Lower Extremity Injury in Female Collegiate Dancers
We examined whether these measures were interrelated and whether they predicted LE injury status in dancers using binary logistic regressions and receiver operator characteristic (ROC) curve analyses. Forty-three collegiate female dancers (18 ± 0.7 years; 162.6 ± 5.9 cm; 59.4 ± 7.1 kg) performed single leg hop (SLH, m) and vertical jump (VJ, cm) tests. Single leg hop and VJ distances were used to calculate SLH norm (as a % of body height) and vertical power (vPower, watts). Lower extremity injuries and dance exposure hours (DEhrs) were recorded for 16 weeks. Dancers had 51 injuries resulting in a 3.7/1...
Source: Journal of Strength and Conditioning Research - June 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Evaluation of Seasonal Changes in Fitness, Anthropometrics, and Body Composition in Collegiate Division II Female Soccer Players
Peart, AN, Nicks, CR, Mangum, M, and Tyo, BM. Evaluation of seasonal changes in fitness, anthropometrics, and body composition in collegiate division II female soccer players. J Strength Cond Res 32(7): 2010–2017, 2018—The purpose of this study was to investigate anthropometrics, body composition, aerobic and anaerobic fitness of collegiate Division II female soccer players throughout a calendar year. Eighteen (20 ± 0.9 years) National Collegiate Athletics Association division II female soccer players from the same team participated in the study. Anthropometrics and body composition variables were assess...
Source: Journal of Strength and Conditioning Research - June 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Effect of Match Factors on the Running Performance of Elite Female Soccer Players
Trewin, J, Meylan, C, Varley, MC, Cronin, J, and Ling, D. Effect of match factors on the running performance of elite female soccer players. J Strength Cond Res 32(7): 2002–2009, 2018—The purpose of this study was to examine the effects of match factors on the match running of elite female soccer players. Players from the same women's national team (n = 45) were monitored during 47 international fixtures (files = 606) across 4 years (2012–2015) using 10-Hz global positioning system devices. A mixed model was used to analyze the effects of altitude, temperature, match outcome, opposition ranking, and conge...
Source: Journal of Strength and Conditioning Research - June 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of the Gaelic Athletic Association 15 on Lower Extremity Injury Incidence and Neuromuscular Functional Outcomes in Collegiate Gaelic Games
Schlingermann, BE, Lodge, CA, Gissane, C, and Rankin, PM. Effects of the Gaelic Athletic Association 15 on lower extremity injury incidence and neuromuscular functional outcomes in collegiate Gaelic games. J Strength Cond Res 32(7): 1993–2001, 2018—The purpose of this observational analytical cohort study was to assess the effectiveness of an injury prevention program (IPP)—Gaelic Athletic Association 15 (GAA15)—on the incidence of injury in collegiate Gaelic games. One hundred and thirty-one Gaelic games players (mean age 20.5 years ± SD 3.0) were used for analysis in this study. Participant...
Source: Journal of Strength and Conditioning Research - June 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Association Between Conditioning Capacities and Shooting Performance in Professional Basketball Players: An Analysis of Stationary and Dynamic Shooting Skills
Pojskic, H, Sisic, N, Separovic, V, and Sekulic, D. Association between conditioning capacities and shooting performance in professional basketball players: an analysis of stationary and dynamic shooting skills. J Strength Cond Res 32(7): 1981–1992, 2018—Little is known about the influence of conditioning capacities on shooting performance in basketball. The aim of this study was to examine the relationship between different conditioning capacities and shooting performance in professional basketball players. In this investigation, we examined 38 males (all perimeter players; height: 185.5 ± 6.73 cm; mass...
Source: Journal of Strength and Conditioning Research - June 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Validity of Retrospective Session Rating of Perceived Exertion to Quantify Training Load in youth Athletes
This study aimed to establish the validity of a 24-hour (s-RPE24) and 72-hour (s-RPE72) recall of session rating of perceived exertion (s-RPE) against the criterion measure of s-RPE collected 30 minutes' post training (s-RPE30). Thirty-eight adolescent athletes provided a s-RPE30 following the first field based training session of the week. Approximately 24 hours later subjects were asked to recall the intensity and duration of the previous days training. The following week subjects once again provided an s-RPE30 measure after training before recalling the intensity and duration of the session approximately 72 hours later....
Source: Journal of Strength and Conditioning Research - June 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Analysis of the Effects of Sex and Age on Upper- and Lower-Body Power for Law Enforcement Agency Recruits Before Academy Training
This study investigated upper- and lower-body power in male and female LEA recruits, and recruits of different ages, before academy training. Retrospective analysis of recruit data from one LEA was conducted. The measurements were: vertical jump (VJ) height; peak anaerobic power calculated by the Sayers equation; power-to-body mass ratio (P:BM); seated medicine ball throw (MBT) distance; and MBT distance relative to body mass. Independent-sample t-tests were used to compare the sexes, whereas a 1-way analysis of variance with Bonferroni post hoc compared the pooled data for recruits across different age groups (20–24...
Source: Journal of Strength and Conditioning Research - June 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Muscle Activity and Physiological Responses During Running in Water and on Dry Land at Submaximal and Maximal Efforts
Masumoto, K, Mefferd, KC, Iyo, R, and Mercer, JA. Muscle activity and physiological responses during running in water and on dry land at submaximal and maximal efforts. J Strength Cond Res 32(7): 1960–1967, 2018—We investigated muscle activity, oxygen uptake, heart rate, and rating of perceived exertion during running in water and on dry land at submaximal and maximal efforts. Eleven recreational runners performed deep-water running (DWR) and treadmill running (TMR) graded exercise tests on separate days. On the third-test day, the subjects exercised at their 60, 80, and 100% of maximal oxygen uptake (V[Combini...
Source: Journal of Strength and Conditioning Research - June 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Barriers to the Prescription of Psychological Strategies by Strength and Conditioning Specialists
Radcliffe, JN, Comfort, P, and Fawcett, T. Barriers to the prescription of psychological strategies by strength and conditioning specialists. J Strength Cond Res 32(7): 1948–1959, 2018—The purpose of this article was to explore the barriers to strength and conditioning coaches integrating psychological strategies within the strength and conditioning practice. The sample of accredited strength and conditioning coaches comprised 10 subjects working within the United Kingdom, 3 within the United Sates, and 5 within Australia offering a cross section of experience from a range sporting disciplines and educational b...
Source: Journal of Strength and Conditioning Research - June 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Bilateral Comparison of Vertical Jump Landings and Step-off Landings From Equal Heights
Harry, JR, Silvernail, JF, Mercer, JA, and Dufek, JS. Bilateral comparison of vertical jump landings and step-off landings from equal heights. J Strength Cond Res 32(7): 1937–1947, 2018—The purpose of this investigation was to examine kinetic, kinematic, and temporal parameters during vertical jump landings (VJL) and step-off landings (STL) from equal heights. Five men (25.0 ± 1.6 years; 1.7 ± 0.4 m; 79.7 ± 7.1 kg) and 5 women (20.8 ± 1.6 years; 1.6 ± 0.4 m; 68.5 ± 7.1 kg) performed 15 VJL and 15 STL. Paired-samples t-tests (α = 0.05) compared impact velocity and ...
Source: Journal of Strength and Conditioning Research - June 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Are Change-of-Direction Speed and Reactive Agility Independent Skills Even When Using the Same Movement Pattern?
Čoh, M, Vodičar, J, Žvan, M, Šimenko, J, Stodolka, J, Rauter, S, and Maćkala, K. Are change-of-direction speed and reactive agility independent skills even when using the same movement pattern? J Strength Cond Res 32(7): 1929–1936, 2018—The purpose of this investigation was to determine whether there are differences between the 2 approaches to quantifying agility (preplanned vs. unplanned response) when reacting to a stimulus in an identical spatial scenarios. The study involved 45 male and 31 female trained athletes (age 21.2 ± 1.78 and 20.6 ± 1.27 years, body height 181.6 ± 8.3...
Source: Journal of Strength and Conditioning Research - June 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Comparison of Step-by-Step Kinematics in Repeated 30-m Sprints in Female Soccer Players
van den Tillaar, R. Comparison of step-by-step kinematics in repeated 30-m sprints in female soccer players. J Strength Cond Res 32(7): 1923–1928, 2018—The aim of this study was to compare kinematics in repeated 30-m sprints in female soccer players. Seventeen subjects performed seven 30-m sprints every 30 seconds in one session. Kinematics was measured with an infrared contact mat and laser gun, and running times with an electronic timing device. The main findings were that sprint times increased in the repeated-sprint ability test. The main changes in kinematics during the repeated-sprint ability test were in...
Source: Journal of Strength and Conditioning Research - June 26, 2018 Category: Sports Medicine Tags: Technical Report Source Type: research

Measuring Vertical Stiffness in Sport With Accelerometers: Exercise Caution!
This study aimed to determine the measurement accuracy of triaxial accelerometers, to determine vertical stiffness (Kvert) during overground running, and to examine the influence of device location. Seventeen healthy adults wore 2 triaxial accelerometers (positioned between scapulae and at lumbar spine) during a 2-minute continuous 20-m shuttle run (12 km·h−1), which was repeated 7 days later. Accelerometer-derived Kvert data were compared with that calculated from corresponding force-plate ground contacts (criterion measure). Moderate correlations (r = 0.65–0.66) between the accelerometer and criterion ...
Source: Journal of Strength and Conditioning Research - June 26, 2018 Category: Sports Medicine Tags: Technical Report Source Type: research

Reliability and Validity of a Medicine Ball–Contained Accelerometer for Measuring Upper-Body Neuromuscular Performance
Roe, G, Shaw, W, Darrall-Jones, J, Phibbs, PJ, Read, D, Weakley, JJ, Till, K, and Jones, B. Reliability and validity of a medicine ball–contained accelerometer for measuring upper-body neuromuscular performance. J Strength Cond Res 32(7): 1915–1918, 2018—The aim of the study was to assess the between-day reliability and validity of a medicine ball–contained accelerometer (MBA) for assessing upper-body neuromuscular performance during a throwing task. Ten professional rugby union players partook in the study. Between-day reliability was assessed from the best score attained during 2 sets of 3 throws,...
Source: Journal of Strength and Conditioning Research - June 26, 2018 Category: Sports Medicine Tags: Short Research Report Source Type: research

Potentiation Effects of the French Contrast Method on Vertical Jumping Ability
This study examined the acute effects of the potentiation protocol known as French Contrast Method on the vertical jumping ability measured using a countermovement jump (CMJ). Thirty-one athletes participated in this study (intervention group n = 17 and control group n = 14). The CMJ height was measured using the iOS application My Jump 2.0 before and after the French Contrast protocol, which consisted of 3 sets of isometric partial squats, drop jumps, dynamic half-squats, and hurdle jumps. The CMJ height improved from its baseline values by 5.1 ± 1.1% (p (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - June 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research

Association of Hip and Trunk Strength With Three-Dimensional Trunk, Hip, and Knee Kinematics During a Single-Leg Drop Vertical Jump
Martinez, AF, Lessi, GC, Carvalho, C, and Serrao, FV. Association of hip and trunk strength with three-dimensional trunk, hip, and knee kinematics during a single-leg drop vertical jump. J Strength Cond Res 32(7): 1902–1908, 2018—Kinematic changes have been correlated with different lower-limb injuries. Movement is influenced by multiple factors and strength is one of the contributors that can influence it. Thus, the aim of this study was to evaluate the correlation among trunk and hip isometric strength with trunk and lower-limb kinematics during a single-leg drop vertical jump. Twenty-three healthy recreation...
Source: Journal of Strength and Conditioning Research - June 26, 2018 Category: Sports Medicine Tags: Original Research Source Type: research