Journal of Strength and Conditioning Research This is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog.

Normative Values for Health-Related Physical Fitness in First-Year Police Officers
Štefan, L, Kasović, M, and Culej, M. Normative values for health-related physical fitness in first-year police officers. J Strength Cond Res 36(9): 2530–2535, 2022—The main aim of the study was to develop normative values for health-related physical fitness tests in first-year police officers. In this cross-sectional study, we recruited 773 police officers aged 19–28 years old (mean age ± SD = 22 ± 3 years, 34% women). Health-related physical fitness included: (a) polygon backwards (agility), (b) standing broad jump (explosive power of lower extremities), (c) sit-and-reach test (flexibility), and (d) 2.4 km run (...
Source: Journal of Strength and Conditioning Research - August 30, 2022 Category: Sports Medicine Tags: Original Research Source Type: research

Development and Validation of a Dynamically Updated Prediction Model for Attrition From Marine Recruit Training
This study aimed to derive a prediction model for dynamically updated estimation of conditional dropout probabilities for Marine recruit training. We undertook a landmarking analysis in a Cox proportional hazard model using longitudinal data from 744 recruits from existing databases of the Marine Training Center in the Netherlands. The model provides personalized estimates of dropout from Marine recruit training given a recruit's baseline characteristics and time-varying mental and physical health status, using 21 predictors. We defined nonoverlapping landmarks at each week and developed a supermodel by stacking the landma...
Source: Journal of Strength and Conditioning Research - August 30, 2022 Category: Sports Medicine Tags: Original Research Source Type: research

Impact of Time Restricted Feeding on Markers of Cardiometabolic Health and Oxidative Stress in Resistance-Trained Firefighters
This study investigated the impact of a 6-week TRF intervention (14:10; fasting:feeding) in resistance-trained firefighters. Blood was analyzed for several markers of inflammation, OS, and cardiometabolic health: insulin, ghrelin, leptin, glucagon, adiponectin, resistin, advanced glycated end products (AGE), advanced oxidation protein products, total nitrite-nitrate levels, tumor necrosis factor-α, interleukin (IL)-6, IL-8, IL-10, as well as glucose and lipid levels. A graded exercise test was also conducted before and after the TRF intervention, and substrate oxidation rates were calculated and compared before and after ...
Source: Journal of Strength and Conditioning Research - August 30, 2022 Category: Sports Medicine Tags: Original Research Source Type: research

Polygenic Profile of Elite Strength Athletes
Moreland, E, Borisov, OV, Semenova, EA, Larin, AK, Andryushchenko, ON, Andryushchenko, LB, Generozov, EV, Williams, AG, and Ahmetov, II. Polygenic profile of elite strength athletes. J Strength Cond Res 36(9): 2509–2514, 2022—Strength is a heritable trait with unknown polygenic nature. So far, more than 200 DNA polymorphisms associated with strength/power phenotypes have been identified majorly involving nonathletic populations. The aim of the present study was to investigate individually and in combination the association of 217 DNA polymorphisms previously identified as markers for strength/power phenotypes with elit...
Source: Journal of Strength and Conditioning Research - August 30, 2022 Category: Sports Medicine Tags: Original Research Source Type: research

A 3-Week, Low-Carbohydrate, High-Fat Diet Improves Multiple Serum Inflammatory Markers in Endurance-Trained Males
This study examined the effects of a low-carbohydrate, high-fat diet (LCHF) on inflammatory marker responses in middle-aged endurance athletes. Eight male runners maintained their habitual mixed diet (HMD) in the first phase of the study before switching to a noncalorically restricted LCHF diet (∼70% of kcals from fat; carbohydrate (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - August 30, 2022 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of Multi-ingredient Preworkout Supplements on Physical Performance, Cognitive Performance, Mood State, and Hormone Concentrations in Recreationally Active Men and Women
This study investigated the acute effects of 2 multi-ingredient preworkout supplements (MIPS), with beta-alanine and caffeine (BAC) and without (NBAC), compared with placebo (PLA) on anaerobic performance, endurance capacity, mood state, cognitive function, vascular function, and anabolic hormones. Thirty exercise-trained individuals (24.4 ± 4.9 years, 15 men and 15 women) completed a fatiguing exercise protocol on 3 separate occasions, 30 minutes after ingestion of BAC, NBAC, or PLA. Outcomes were analyzed using one-way or two-way repeated-measures analysis of variance, as appropriate (alpha = 0.05). Anaerobic power was ...
Source: Journal of Strength and Conditioning Research - August 30, 2022 Category: Sports Medicine Tags: Original Research Source Type: research

Effect of Caffeine on Endurance Performance in Athletes May Depend on HTR2A and CYP1A2 Genotypes
Guest, NS, Corey, P, Tyrrell, PN, and El-Sohemy, A. Effect of caffeine on endurance performance in athletes may depend on HTR2A and CYP1A2 genotypes. J Strength Cond Res 36(9): 2486–2492, 2022—This investigation determined whether variation in the HTR2A (serotonin receptor) gene modifies the ergogenic effects of caffeine on endurance and further modifies performance by the CYP1A2 genotype. Male athletes (n = 100; 25 ± 4 years) completed 10-km cycling time trials under 3 conditions as follows: 0, 2, or 4 mg of caffeine per kg body mass. Using a randomized, double-blinded, placebo-controlled design, data were analyzed u...
Source: Journal of Strength and Conditioning Research - August 30, 2022 Category: Sports Medicine Tags: Original Research Source Type: research

Ischemic Preconditioning Attenuates Rating of Perceived Exertion But Does Not Improve Maximal Oxygen Consumption or Maximal Power Output
ter Beek, F, Jokumsen, PS, Sloth, BN, Thomas Stevenson, AJ, and Larsen, RG. Ischemic preconditioning attenuates rating of perceived exertion but does not improve maximal oxygen consumption or maximal power output. J Strength Cond Res 36(9): 2479–2485, 2022—Brief consecutive periods of limb ischemia and reperfusion, known as ischemic preconditioning (IPC), have been reported to increase maximal power output (MPO) during cycling. However, the underlying mechanisms are unclear. Therefore, the purpose of the study was to investigate the effects of IPC on MPO, maximal oxygen consumption (V̇o2max), muscle oxygenation, and r...
Source: Journal of Strength and Conditioning Research - August 30, 2022 Category: Sports Medicine Tags: Original Research Source Type: research

Increased Joint Mobility Is Associated With Impaired Transversus Abdominis Contraction
Mitchell, UH, Owen, PJ, Rantalainen, T, and Belavý, DL. Increased joint mobility is associated with impaired transversus abdominis contraction. J Strength Cond Res 36(9): 2472–2478, 2022—Increased joint mobility is a risk factor for joint injury, but muscle function may be able to compensate for it. Current evidence suggests reduced force production capacity in people with hypermobility. However, little is known about the lumbar spine. The purpose of this cross-sectional study was to assess whether there was a link between joint mobility and transverse abdominis and multifidus muscles contraction, muscles ascribed a c...
Source: Journal of Strength and Conditioning Research - August 30, 2022 Category: Sports Medicine Tags: Original Research Source Type: research

A New Portable Device to Reliably Measure Maximal Strength and Rate of Force Development of Hip Adduction and Abduction
This study shows that portable dynamometry can be used to concurrently measure hip adduction and abduction maximal and explosive strength, with levels of reliability that are similar to previously described methods. (Source: Journal of Strength and Conditioning Research)
Source: Journal of Strength and Conditioning Research - August 30, 2022 Category: Sports Medicine Tags: Original Research Source Type: research

Compression Socks Reduce Running-Induced Intestinal Damage
This study aimed to explore if exercise-associated intestinal damage was influenced by wearing compression garments, which may improve central blood flow. Subjects were randomly allocated to wear compression socks (n = 23) or no compression socks (control, n = 23) during a marathon race. Blood samples were collected 24 hours before and immediately after marathon and analyzed for intestinal fatty acid–binding protein (I-FABP) concentration as a marker of intestinal damage. The magnitude of increase in postmarathon plasma I-FABP concentration was significantly greater in control group (107%; 95% confidence interval [CI], 7...
Source: Journal of Strength and Conditioning Research - August 30, 2022 Category: Sports Medicine Tags: Original Research Source Type: research

Application of a Floss Band at Differing Pressure Levels: Effects at the Ankle Joint
Galis, J and Cooper, DJ. Application of a floss band at differing pressure levels: Effects at the ankle joint. J Strength Cond Res 36(9): 2454–2460, 2022—The study aimed to examine the effects of different levels of pressure on ankle range of motion (ROM), strength, and power performance. A parallel-group design was used, and subjects were divided into 3 groups. After a warm-up and preintervention testing (ankle goniometry using a manual handheld goniometer and isokinetic dynamometry using a HUMAC NORM isokinetic dynamometer), subjects had underwrap (control) or a tissue flossing band, at 150 mm Hg (FLOSS150) or 200 mm...
Source: Journal of Strength and Conditioning Research - August 30, 2022 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of Fatigue on Functional Movement Efficiency in Physically Active Adults
Hanes, CE, Schilling, BK, Mulvenon, SW, and Radzak, KN. Effects of fatigue on functional movement efficiency in physically active adults. J Strength Cond Res 36(9): 2448–2453, 2022—Functional movement tests to identify faulty movement patterns and compensations have become common place in sports medicine and sport performance; however, this testing is often performed in a rested state, despite athletes being often injured when in a state of neuromuscular fatigue. Therefore, the purpose of our study was to examine the effects of neuromuscular fatigue on a functional movement test in health, physically active adults. Twe...
Source: Journal of Strength and Conditioning Research - August 30, 2022 Category: Sports Medicine Tags: Original Research Source Type: research

Effects of Dynamic Stretching Velocity on Joint Range of Motion, Muscle Strength, and Subjective Fatigue
Mizuno, T. Effects of dynamic stretching velocity on joint range of motion, muscle strength, and subjective fatigue. J Strength Cond Res 36(9): 2440–2447, 2022—The purpose of this study was to determine the effects of 2 different dynamic stretching (DS) velocities on joint range of motion (ROM), isometric muscle strength, and subjective fatigue during DS. Fifteen healthy male subjects performed DS at 2 different velocities: maximal active ankle plantar flexion-dorsiflexion velocity (DS100) and 50% of maximal velocity (DS50). A passive dorsiflexion test and isometric maximal voluntary contractions (MVCs) of the ankle pl...
Source: Journal of Strength and Conditioning Research - August 30, 2022 Category: Sports Medicine Tags: Original Research Source Type: research

The Deceleration Deficit: A Novel Field-Based Method to Quantify Deceleration During Change of Direction Performance
Clarke, R, Read, PJ, De Ste Croix, MBA, and Hughes, JD. The deceleration deficit: a novel field-based method to quantify deceleration during change of direction performance. J Strength Cond Res 36(9): 2434–2439, 2022—The study investigated the relationship between linear and change of direction (COD) speed performance components and the individual differences between deceleration deficit (DD) and COD deficit (CODD). Thirty-six subjects (mean ± SD: age = 20.3 ± 2.9 years; stature = 175.2 ± 7.7 cm; and body mass = 78.0 ± 16.7 kg) completed 3 trials of a 505 test in both turning directions (dominant [D]; nondominant [...
Source: Journal of Strength and Conditioning Research - August 30, 2022 Category: Sports Medicine Tags: Original Research Source Type: research