International journal of sports medicine最新文献

The effects of the two popular strategies, scapular adduction and depression and scapular posterior tilt, on muscle activity of the trapezius and serratus anterior muscles have not been compared. This study demonstrates the effects of additional scapular adduction and depression or scapular posterior tilt movements on the activation of trapezius and serratus anterior muscles and scapular kinematics during arm raising. Eighteen asymptomatic men performed arm raising tasks with and without additional scapular movements, including scapular adduction and depression or scapular posterior tilt. During all tasks, muscle activity of the upper/middle/lower trapezius and serratus anterior were measured using surface electromyography; scapular upward rotation and posterior tilt angles were measured using a smartphone application. Lower trapezius muscle activity significantly increased during arm raising with scapular adduction and depression (p=0.001) or scapular posterior tilt compared to preferred arm raising (p<0.001). However, arm raising with scapular posterior tilt showed significantly greater serratus anterior muscle activity (p=0.002) and scapular posterior tilt angle (p=0.001) together with lesser upper trapezius muscle activity (p=0.027) compared with those of scapular adduction and depression. Scapular posterior tilt may be effective for increasing lower trapezius and serratus anterior muscle activity while reducing upper trapezius muscle activity.

Ischemic stroke is an acute cerebrovascular disease that is one of the leading causes of death and neurological disorders worldwide. Exosomes are a novel class of intercellular signaling regulators containing cell-specific proteins, lipids, and nucleic acids that transmit messages between cells and tissues. MicroRNAs are regulatory non-coding ribonucleic acids that are usually present in exosomes as signaling molecules. Studies have shown that exosomes and exosomal microRNAs can improve the prognosis of ischemic stroke by inhibiting the inflammatory response, reducing apoptosis, improving the imbalance of oxidative and antioxidant systems, and regulating cellular autophagy, among other processes. Previous studies have shown that exercise training can exert neuroprotective effects on ischemic stroke by promoting the release of exosomes and regulating the expression of exosomal microRNAs, which in turn regulate multiple signaling pathways. Exosomes and exosomal microRNAs may be key targets for exercise to promote cerebrovascular health. Therefore, the study of exercise-mediated exosomes and their microRNAs may provide new perspectives for exploring the mechanism of exercise intervention in the prevention and treatment of ischemic stroke.

This study aimed to investigate whether 14 weeks of β-alanine supplementation and high-intensity intermittent training improves brain-derived neurotrophic factor concentrations and cognitive aspects related to executive functions assessed by the Stroop test. Thirteen healthy and active men underwent a 4-week supplementation period (β-alanine: 6.4 g/d or a placebo) followed by 10-week supplementation combined with high-intensity intermittent training, totaling 14 weeks of intervention. Participants underwent a graded exercise test, while the blood samples for brain-derived neurotrophic factor analysis and the Stroop test (cognitive task) were assessed before and after a high-intensity intermittent exercise (10 runs of 1:1 min effort and a pause ratio at 130% of respiratory compensation point). These measurements were performed three times across the study being at baseline, after 4 weeks of supplementation (POST_4weeks) and at the end of the 14 weeks of study (POST_14weeks). Compared to baseline values, there were no improvements in brain-derived neurotrophic factor concentrations or Stroop test performance with either β-alanine or high-intensity intermittent training. Lactate peak concentrations in a high-intensity intermittent exercise session also did not differ between groups. However, high-intensity intermittent training did improve some cardiorespiratory parameters (i.e., intensity associated with V̇O_2max p=0.01 and respiratory compensation point, p=0.01). In conclusion, β-alanine supplementation alone or associated with high-intensity intermittent training did not improve the brain-derived neurotrophic factor concentrations and Stroop test performance in healthy men.

Depression is an important public health issue. In the general adult population, about 6.7% are affected. Little data are available about endurance runners. We conducted a prospective survey study screening for depression using the Patient Health Questionnaire and investigating potential associated risk factors in endurance runners (≥ 21.1-42.2 km) and ultraendurance runners (≥ 42.2 km). Statistical analysis included descriptive statistics, predictive techniques, and regression analysis. A total of n = 601 runners participated (female n=222 and male n=379; mean age [SD]: 42.8 years [± 10.1]). Overall, 11.3% screened positive for major depression, particularly female runners compared to male runners (p=0.002) and endurance runners compared to ultraendurance runners (p=0.023). No significant differences were observed among performance levels (elite vs. nonelite). Mild depression was observed in 21.6% of runners. Factors associated with a higher risk for screening for major depression included age (p<0.001), particularly runners under the age of 28 years, previous self-reported history of depression (p<0.001), more frequent weekly workouts (4-5/wk; p=0.021), weeks lost to injury (p=0.022), and female sex (p=0.025). A third of endurance and ultraendurance runners screened positive for depression, highlighting the importance of creating awareness for mental health issues and potential screening for athletes and providing access to appropriate support services and education.

Cardiopulmonary exercise testing involves collecting variable breath-by-breath data and sometimes requiring data processing of outlier removal, interpolation, and averaging before later analysis. These data processing choices, such as averaging duration, affect calculated values such as ˙VO₂max. However, assessing the implications of data processing without knowing popular methods worth comparing is difficult. In addition, such details aid study reproduction. We conducted a semi-automated scoping review of articles with exercise testing that collected data breath-by-breath from three databases. Of the 8,344 articles, 376 (mean: 4.5% and 95% confidence interval: 4.1-5.0%) and 581 (mean: 7.0% and 95% confidence interval: 6.4-7.5%) described outlier removal and interpolation, respectively. A random subset of 1,078 articles revealed (mean: 60.9% and 95% confidence interval: 57.9-63.7%) the reported averaging methods. The commonly documented outlier cutoffs were±3 or 4 SD (39.1 and 51.6%, respectively). The dominating interpolation duration and procedure were 1 s (93.9%) and linear interpolation (92.5%). Averaging methods commonly described were 30 (30.9%), 60 (12.4%), 15 (11.6%), 10 (11.0%), and 20 (8.1%) second bin averages. This shows that studies collecting breath-by-breath data often lack detailed descriptions of data processing methods, particularly for outlier removal and interpolation. While averaging methods are more commonly reported, improved documentation across all processing steps will enhance reproducibility and facilitate future research comparing data processing choices.

This meta-analysis was aimed to compare the effects of two methods on post-activation performance enhancement (PAPE). We conducted a comprehensive search of PubMed, Web of Science, Cochrane Library, and China National Knowledge Infrastructure from inception to December 2023. Two authors independently selected the included studies, extracted data, and assessed the risk of bias and certainty evidence. The primary meta-analysis compared the effects of blood flow restriction combined with resistance training (BFR-RT) and high-load resistance training (HL-RT) on the indicator jump height (JH) and power output (PO) of PAPE. The secondary meta-analyses compared within-group differences by gender and between-group differences between the optimal combined protocol of arterial occlusion pressure (AOP) combined with resistance load and the HL-RT protocol. This meta-analysis shows that both BFR-RT and HL-RT significantly improved JH (standardized mean difference (SMD)=0.39, 95% confidence interval (CI) [0.20, 0.59]) (SMD=0.34, 95% CI [0.19, 0.48]) and PO (SMD=0.42, 95% CI [0.21, 0.62]) (SMD=0.37, 95%CI [0.19, 0.54]), and there was no significant difference between them. However, subgroup analysis revealed that in terms of gender, BFR-RT was more beneficial for PAPE in females, and in terms of combined protocol, BFR-RT with 50% AOP+30% 1 repetition maximum had the greatest effect compared to HL-RT.BFR-RT can serve as an effective alternative to HL-RT for inducing PAPE.

The purpose of this study was to examine the occurrence of fracture injuries and post-fracture management practices by weight class. A total of 127 male collegiate Taekwondo athletes (64 lightweight athletes, 63 heavyweight athletes) participated in this study. The athletes were classified into lightweight and heavyweight based on their respective competition weight divisions. Logistic regression was used to estimate the odds ratios (OR) and 95% confidence intervals (CI). Athletes had experienced fracture to 54.3%. Athletes were more likely to experience fractures during training and defensive movements. Of the fractures reported, 31.9% necessitated surgical intervention. Although 65.1% of the athletes were primarily concerned about the possibility of re-injury, only 36.2% received specialized rehabilitation. The heavyweight athletes had a higher prevalence (OR=2.40, 95% CI=1.17-4.90) than the lightweight athletes. The heavyweight athletes had a higher prevalence of fractures during the competition (OR=4.83, 95% CI=1.54-15.17), in offensive situations (OR=4.67, 95% CI=1.38-15.99), and in the lower limbs (OR=3.84, 95% CI=1.12-13.14) than the lightweight athletes. The current evidence that fractures are common in Taekwondo athletes and that fracture patterns may differ between heavyweight and lightweight athletes highlights the need for tailored prevention strategies based on weight class.

We compared performing preacher and incline biceps curls on changes in elbow flexors muscle size and strength. This was a between-group repeated measures randomized trial. Sixty-three young women performed preacher biceps curl (PC, n = 30) or incline biceps curl (IC, n = 33) for 8 weeks, twice a week. We measured the muscle thickness of elbow flexors at the proximal, middle, and distal sites. We assessed muscle strength using three repetition maximum (3RM) tests in the preacher curl (3RM-PC) and incline curl (3RM-IC). We observed a greater increase in proximal elbow flexors thickness in the IC compared to the PC (meandiff = 0.08 cm [95% confidence interval (95% CI): 0.02, 0.13 cm]). We observed a greater increase in distal elbow flexor thickness in the PC compared to the IC (meandiff = 0.10 cm [95% CI: 0.04, 0.15 cm]). The PC showed a greater increase in 3RM-PC (meandiff = 1.88 kg [95% CI: 1.14, 2.62 kg]). The IC showed a greater in-crease in 3RM-IC (meandiff = 0.86 kg [95% CI: 0.10, 1.62 kg]). Our findings suggest regional dif-ferences in muscle growth induced by the preacher and incline biceps curls. Strength gains appear to follow the principle of specificity.

This study examines the energy expenditure and physiological responses associated with short-term quadrupedal locomotion compared to bipedal walking in humans. It aims to support evolutionary theory and explore quadrupedal locomotion's potential for enhancing fitness and health. In a randomized crossover design, 12 participants performed quadrupedal and bipedal walking on a treadmill at identical speeds. Physiological responses, including energy expenditure, carbohydrate oxidation rates, respiratory rate, and heart rate, were measured during both forms of locomotion. Quadrupedal walking significantly increased total energy expenditure by 4.15 Kcal/min [95% CI, 3.11 - 5.19 Kcal/min], due to a rise in carbohydrate oxidation of 1.70 g/min [95% CI, 1.02 - 2.24 g/min]. It also increased respiratory and heart rates, indicating higher metabolic demands. The exercise mainly activated upper limb muscles and the gluteus maximus in the lower limbs. Ten minutes of quadrupedal walking at the same speed as bipedal walking resulted in a 254.48% increase in energy consumption. This simple form of locomotion offers a strategy for enhancing physical activity, and supports the idea that energy optimization influenced the evolution of efficient bipedal locomotion.