Revamping Pace Distribution: A Case Study on Elevating the Men's 400 m Track and Field Japanese National Record After 32 Years.

Chiba, Y, Sato, K, Yoshimoto, T, Ohnuma, H, Yamanaka, R, Takahashi, K, Kobayashi, K, Matsubayashi, T, and Takai, Y. Revamping pace distribution: A case study on elevating the men's 400 m track and field Japanese national record after 32 years. J Strength Cond Res XX(X): 000-000, 2024-Many studies have investigated the 400-m sprint, and the optimal pacing strategy is subject to debate.

Effect of tasks on intramuscular regional differences in rectus femoris elasticity during isometric contraction: An ultrasound shear wave elastography study.

Purpose: This study aimed to investigate intramuscular regional differences and task specificity of rectus femoris (RF) elasticity during isometric contraction.

Methods: Sixteen healthy males (aged 24.3 ± 4.

Variabilities of salivary human herpesvirus 6, 7, and secretory immunoglobulin A levels from pre- to post-competition periods in baseball players.

Background: Persistent physical fatigue (PPhF) accompanying daily intensive training often results in underperformance. While salivary secretory immunoglobulin A (SIgA) has been traditionally used as an immunological marker, salivary human herpesvirus 6 and/or 7 (HHV-6/7) have recently been presented as "microbiological" markers of PPhF. This study aimed to examine the monthly variabilities of salivary HHV-6/7 levels and the difference with SIgA along the training periodization.

Injury Characteristics Among Japanese International Athletes: Report on the Pre-competition Medical Check-Up Data of the Japanese Olympic Committee.

Introduction Injury trends among international athletes across sports remain underexplored in out-of-competition settings, particularly among Asians. The aim of this descriptive epidemiological study is to investigate the characteristics of injuries among Japanese international athletes during pre-competition medical check-ups from 2008 to 2019. Methods We analyzed the medical check-up data of candidates for international multi-sport events according to the International Olympic Committee consensus statement.

Resveratrol Can Differentiate Human Melanoma Stem-like Cells from Spheroids Treated With All-trans Retinoic Acid.

Background/aim: Stem-like cancer cells are believed to be the leading cause of therapy resistance in malignant melanoma (MM). All-trans retinoic acid (ATRA) differentiation therapy is considered a promising approach to eradicate stem-like cancer cells, but some melanoma cells are resistant to ATRA. This study aimed to examine whether resveratrol (RS), a natural polyphenol compound, could improve the response of MM stem-like cells to ATRA and explore the possible underlying mechanisms.

Inertial One-Leg Squat Training and Drop Jump Biomechanics in Athletes With Anterior Cruciate Ligament Reconstruction After Return to Sport.

Henderson, FJ and Shimokochi, Y. Inertial one-leg squat training and drop jump biomechanics in athletes with anterior cruciate ligament reconstruction after return to sport. J Strength Cond Res XX(X): 000-000, 2024-Athletes with anterior cruciate ligament reconstruction (ACLR) display altered jumping mechanics persisting long after returning to sport (RTS).

Agreement between 2D Visual- and 3D Motion Capture-based Assessment of Foot Strike Pattern.

Background: Foot strike patterns during running are typically categorized into two types: non-rearfoot strike (NRFS) and rearfoot strike (RFS), or as three distinct types: forefoot strike (FFS), midfoot strike (MFS), and RFS, based on which part of the foot lands first. Various methods, including two-dimensional (2D) visual-based methods and three-dimensional (3D) motion capture-based methods utilizing parameters such as the strike index (SI) or strike angle (SA), have been employed to assess these patterns. However, the consistency between the results obtained from each method remains debatable.

Effect of 1-Week Weight Loss While Maintaining Total Body Water on Jump Performance.

Jumping performance is influenced by body composition and excess fat mass impairs performance. Maintaining optimal fat mass and fat-free mass (FFM) is crucial for enhancing jump height. However, there is limited evidence on short-term weight loss programs that reduce fat mass without water restriction and their effects on muscle function and jumping performance.

Evaluation of Trunk Oblique Muscle Activities in Baseball Batters Using T2-Weighted Magnetic Resonance Imaging.

Yanaka, T, Imawaka, T, Kojima, C, Otomo, M, Ohnishi, T, and Hoshikawa, M. Evaluation of trunk oblique muscle activities in baseball batters using T2-weighted magnetic resonance imaging. J Strength Cond Res 39(1): 48-53, 2025-This study investigated abdominal oblique muscle activity using T2-weighted imaging in baseball batting.

Age- and sex-dependence of muscle quality: Influence of intramuscular non-contractile tissues.

Purpose: Muscle quality is explained by the ratio between muscle size and strength. Conventionally, muscle size is evaluated without considering the composition of contractile and non-contractile tissues in muscle, hence the influence of non-contractile tissues on muscle quality is not fully understood, especially within aging muscle. This study investigated the differences in intramuscular non-contractile tissues between different age and sex groups, and investigated their influence on muscle quality.

Age-dependence of semitendinosus tendon properties used for anterior cruciate ligament reconstruction differs in males and females.

Background: The semitendinosus tendon is one of the most used autografts in anterior cruciate ligament reconstruction. Although recent evidence indicates that young patients, especially in females, may experience high rates of revision and residual instability, the reasons for the inferior outcomes in these patients remain unclear. To address this issue, we aimed to compare the mechanical properties of the semitendinosus tendon used for anterior cruciate ligament reconstruction in male and female patients of various ages.

Acute salivary antimicrobial peptide secretion response to different exercise intensities and durations.

Antimicrobial peptides, key players of innate mucosal immunity in the oral cavity, exert antibacterial and bacteriolytic effects. This study aimed to clarify the effects of acute exercise at different intensities and durations on salivary antimicrobial peptide levels. In a randomized crossover trial, 14 young healthy untrained men performed intensity trials [cycling at 35%, 55%, and 75% of maximal oxygen uptake (V̇o) for 30 min] and duration trials (cycling at 55% V̇o for 30, 60, and 90 min).

Attitude and experience of obstetricians and gynecologists toward eating disorders assessment and management in Japan: A nationwide survey.

Aim: To investigate the attitudes and experiences of obstetricians and gynecologists in treating women with eating disorders (EDs) in Japan.

Methods: Members of the Japan Society of Obstetrics and Gynecology were invited to participate in a web-based survey from March 1 to 31, 2022. We asked about the attitudes of obstetricians and gynecologists toward women with weight loss-related amenorrhea and their experiences in treating EDs.

Evaluation of Energy Balance Estimated From Total Energy Expenditure and Body Composition Changes in Junior Sumo Wrestlers: An Observational Study Over Six Months.

Background Sumo is a sport that requires wrestlers to develop their physique from childhood for athletic advantage. However, the energy expenditure and energy balance required for the growth of junior Sumo wrestlers remain unclear. This study aimed to determine the energy balance of junior Sumo wrestlers over six months using doubly labeled water (DLW) and bioelectrical impedance analysis (BIA).

Biceps femoris long head stiffens after 2 weeks of training cessation in highly trained sprinters.

Purpose: Most athletes experience short-term training cessation because of illness, injury, post-season vacation, or other reasons. Passive muscle stiffness is a potential risk factor for a sprint-type hamstring strain injury, but limited information is available about the effect of short-term training cessation on passive muscle stiffness. The present study aimed to identify whether and how passive muscle stiffness of the biceps femoris long head (BFlh) would vary due to 2 weeks of training cessation in sprinters.

Skating techniques of ladies' world-class long-distance speed skaters to shorten curved-section time during the official 3,000 m race.

This study aimed to identify the factors contributing to expedited passage through curved sections in skating by analyzing centripetal acceleration and skating motions during curving in a 3,000 m race for ladies' world-class speed skating. It included 14 elite skaters participating in the ladies' 3,000 m race held during the World Cup. The recorded area consisted of the first inner curve lane.

Difference in badminton-specific endurance evaluated by a newly developed on-court test between competitive levels: A pilot study of female players.

We developed a test to evaluate badminton-specific endurance. The study included 10 female badminton players. Five participants were ranked in Japan's top 100 national rankings (ranked), whereas the others were unranked (unranked).

Effect of 6-Week Sprint Training on Long-Distance Running Performance in Highly Trained Runners.

Purpose: Long-distance running performance has been reported to be associated with sprint performance in highly trained distance runners. Therefore, we hypothesized that sprint training could enhance distance running and sprint performance in long-distance runners. This study examined the effect of 6-week sprint training on long-distance running and sprint performance in highly trained distance runners.

Relationship between jump height and lower limb joint kinetics and kinematics during countermovement jump in elite male athletes.

This study aims to identify the relationship between jump height and the kinetic and kinematic parameters of the hip, knee, and ankle joints during countermovement jump (CMJ) in elite male athletes. Sixty-six elite male athletes from various sports (strength and power, winter downhill, combat, ball game, and aquatic) performed maximal effort CMJs with hands and arms crossed against their chests on force platforms. Jumping motion in the sagittal plane was recorded using video analysis and the peak torque, power, and angular velocity of the right hip, knee, and ankle joints were calculated during the propulsive phase.

Glycated hemoglobin (HbA1c) is independently associated with the bioelectrical impedance phase angle in junior sumo wrestlers: A pilot study.

The study explores the relationship between phase angle (PhA), an indicator of cellular health, and metabolic health parameters among junior sumo wrestlers in Japan. Given the demanding lifestyle and high-energy diets of sumo wrestlers that predispose them to metabolic syndrome post-retirement, this study focuses on a younger cohort. The primary aim is to evaluate if PhA could serve as an early indicator of metabolic health issues within this unique demographic.

Inhibition of Ironic Errors and Facilitation of Overcompensation Errors Under Pressure: An Investigation Including Perceived Weakness.

The conflicting predictions of ironic process theory and the implicit overcompensation hypothesis have been presented as a framework to explain the characteristics of errors that occur when a certain behavior is prohibited. The former predicts that instructions prohibiting a particular behavior will increase the likelihood of an outcome that should be avoided (ironic error), whereas the latter predicts that the likelihood of an outcome opposite of that to be avoided (overcompensation error) will increase. We examined how these errors, which negatively affect performance, are influenced by pressure and perceived weakness.

Effects of different exercise intensities or durations on salivary IgA secretion.

Purpose: This study aimed to examine changes in salivary immunoglobulin A (s-IgA) secretion at different intensities or durations of acute exercise.

Methods: Twelve healthy untrained young males were included in randomized crossover trials in Experiment 1 (cycling exercise for 30 min at a work rate equivalent to 35%, 55%, and 75% maximal oxygen uptake [ O]) and Experiment 2 (cycling exercise at 55% O intensity for 30, 60, and 90 min). Saliva samples were collected at baseline, immediately after, and 60 min after each exercise.