International journal of sports medicine最新文献

The effects of estradiol and progesterone fluctuations during the menstrual cycle (MC) on strength and fatigue remain unclear. This study investigated their impact on peak torque and fatigue in isokinetic tests. Eleven strength-trained women performed five knee extensions and flexions to assess maximum peak torque, rating of perceived exertion (RPE), and rating of perceived pain (RPP). A separate protocol of 60 repetitions was used to evaluate peak torque, total work, percentage of work fatigue, RPE, RPP, and blood lactate concentration before and after exercise. MC phases were determined using a combination of calendar tracking, urinary ovulation tests, and serum hormone analysis. A one-way repeated-measures analysis of variance, followed by Bonferroni's post hoc tests and effect size calculations (partial eta-square), analyzed differences across six MC phases. No significant differences were observed in peak torque, RPE, or RPP during knee extension and flexion (p>0.05). Similarly, fatigue parameters assessed during the 60-repetition test showed no significant variation across MC phases (p>0.05). However, blood lactate concentrations were significantly higher postexercise than preexercise (p<0.05). These findings suggest that strength performance and muscle fatigue are not influenced by hormonal fluctuations across the MC in strength-trained women.

Osteoarthritis (OA) is a common, multi-factorial and -aetiological condition, causing pain, disability and reduced function. Post-traumatic OA (PTOA) is more common in younger populations, especially after anterior cruciate ligament (ACL) or meniscal injury. Identifying those at increased risk of PTOA using molecular, imaging and biomechanical biomarkers is a research priority. This systematic review aims to identify functional tasks used to assess knee kinematics and kinetics at least a year from injury, describe any differences found between the injured and uninjured contralateral and control knees and identify associations with PTOA. Searches were performed on Medline, CINAHL and EMBASE, with reference lists reviewed. The initial search yielded 2504 studies, with six more detected from reference lists. Thirty-three studies involving 1251 participants (n=737 injured, all ACL, mean age 25.1, 49.9% male, 1-13 yr post-injury) were included. Studies included the following dynamic tasks: landing (n=25), jumping (n=3), cutting (n=5) or squatting (n=3). Overall, reductions in knee flexion and extension angles and moments, increased knee valgus and energy absorption were demonstrated in injured knees. However, this was inconsistent across studies, with data heterogeneity preventing direct comparison and meta-analysis. Changes in biomechanics are present from 1-year post-injury, persisting for several years; however, consensus regarding core outcome sets is required.

This study investigated whether, 24 hours after the exercise-induced muscle damage protocol (EIMDP), melatonin administration performed 30 minutes prior to the protocol exhibited responses about inflammatory and redox status. Control (CG), exercised (EG), and exercised+melatonin (EMG) groups were submitted to the incremental test through swimming exercise to determine the intensity of the maximal aerobic capacity (iMAC). Melatonin (10 mg kg^-1) was administered, and after 30 min, the EIMDP was induced through swimming exercise (10 sets of 1 min with 30-s interval at 120% of iMAC, followed by 20 minutes continuous exercise at 100% of iMAC). The animals were euthanized 24 hours after the EIMDP. No effect on superoxide dismutase but lower activities (p<0.05) of glutathione S-transferase for EMG in relation to EG and of catalase for EMG in relation to CG were observed. EMG showed lower (p<0.05) carbonylated protein and lipid peroxidation in relation to EG and CG, respectively. Hematoxylin-eosin (HE) demonstrated higher connective tissue for EG in relation to EMG. Integrated Biomarker Responses version 2 attested the melatonin capacity in reducing antioxidant enzyme activity and muscle oxidative damage. This study demonstrated the protective role of melatonin in reducing muscle oxidative stress caused after 24 hours of the EIMDP.

The After-Career Consultation (ACC) was developed to empower the physical, mental and social health of retired professional footballers and effectively address their specific health challenges. The objective of this study was to describe the clinical outcomes (e.g., prevalence of health conditions) and recommendations to retired professional footballers who undertook the ACC. A quasi-experimental study was conducted. Forty-seven retired male professional footballers underwent ACCs. Ten participants had a diagnosis of osteoarthritis (21.3%), 4 (8.5%) met the criteria for a diagnosis of generalised anxiety disorder, 7 (14.9%) met the criteria for a diagnosis of depression and 7 (14.9%) met the criteria for Stage 1 hypertension. Health-related quality of life scores among retired footballers undergoing the ACC were above average compared to the general population. Clinical recommendations were made to participants in relation to their musculoskeletal (n=12, 25.5%), cardiovascular (n=12, 25.5%), mental (n=10, 21.3%) and lifestyle (n=20, 42.6%) health. Eleven participants (23.4%) were referred for further investigations, and secondary referral to other specialists was arranged for 4 (8.5%). Participants reported high satisfaction with the ACC. The ACC could complement existing player welfare strategies to provide a well-rounded approach to managing the long-term health of professional footballers throughout the lifespan.

Resistance training is an effective strategy for combating geriatric syndromes, including frailty, sarcopenia, and cognitive impairment. Performing instability resistance training (IRT) (e.g., weight-bearing, machine-based, or free-weight exercises using unstable surfaces) may provide additional benefits on health outcomes in middle-aged and older adults. With this in mind, we examined the impact of IRT on physical and cognitive functioning (primary outcomes), fall risk, and quality of life (secondary outcomes). We searched three specific databases from inception to October 2024. We included peer-reviewed, randomized trials that analysed the effects of intervention on outcomes of interest among adults aged 50 years or older. Risk of bias and quality of reporting were ascertained using validated checklists. We performed a random-effects meta-analysis using robust variance estimation. 18 studies with participants from Brazil, Spain, Germany, and South Korea (n=528, %women: 35-100%) were included in the qualitative review, and 12 studies in the meta-analysis. We found that IRT had a medium-to-large-sized effect on physical and cognitive functioning. Studies had a high quality of reporting but presented significant heterogeneity and low-to-moderate risk of bias. Our findings suggest that IRT is a promising strategy for promoting physical and cognitive benefits in middle-aged and older adults.

Physiological responses to stressors provide insight into future disease risk and sex differences in response to and recovery from stressors, such as a hypertensive stimulus, provide understanding of cardiovascular control. The purpose of this study was to determine sex specific responses to an acute resistance exercise bout in central and peripheral blood pressures and arterial stiffness. Twenty-five young males and females who had not engaged in resistance training over the previous year underwent measurements of aortic, carotid, and brachial blood pressures, and carotid and aortic arterial stiffness measurements before, immediately after, and 30 minutes following a full-body resistance exercise bout. Resistance exercise resulted in increased carotid systolic pressure and increased aortic in males only. Both males and females increased carotid stiffness, but males had a greater increase in stiffness that remained elevated while females returned to baseline by 30 minutes post. These findings highlight that blood pressure and arterial stiffness responses to an acute bout of resistance exercise are sex-specific and vary based on measurement timing and location within the arterial tree. Females do not display the same increases in aortic stiffness and central pressures and did not have the same magnitude of carotid stiffness increases as seen in males.

This meta-analysis aimed to compare the acute physiological, physical, and technical demands in soccer players during different sided game formats (1v1 to 10v10). This review included studies on soccer players with a competitive or developmental level, focusing on games with at least one comparison of sided formats. Outcomes assessed included physiological parameters (e.g., heart rate and blood lactate levels), physical demands (e.g., distance and accelerations), and technical actions (e.g., passes). The risk of bias assessment tool for nonrandomized studies of interventions (RoBANS 2) and (Grading of Recommendations, Assessment, Development and Evaluation) were used to evaluate the risk of bias and the certainty of evidence. The search across PubMed, Scopus, and Web of Science identified 2,545 records, of which 72 studies were included. Meta-analyses found that 2v2 and 3v3 formats were more physiologically intense, showing higher perceived exertion and blood lactate levels, with 3v3 also having higher heart rates. The 4v4 and 3v3 formats resulted in greater physical demands compared to the 2v2 format, with increased distances covered at various speeds, although differences were minimal beyond the 4v4 format. Smaller formats promoted ball possession, while the 3v3 format resulted in more successful shots, dribbles, and passes. In conclusion, small-sided games (< 3v3) were more physiologically demanding, mid-sized formats (> 4v4) increased locomotor demands, and smaller formats improved technical skills, although the findings should be interpreted cautiously due to study limitations.

The economic impact of physical activity has been extensively investigated among adults, but few studies have analyzed this issue in pediatric populations. To analyze the relationship of costs attributed to medicine use with the time spent in different intensities of physical activity and sports participation among adolescents. A sample of 92 adolescents were tracked for 28 weeks. The main outcome was the overall cost attributed to medicine use (assessed weekly [US$]). Independent variables were moderate-to-vigorous physical activity outside sports and sportive moderate-to-vigorous physical activity, assessed in three time points (baseline, 14 weeks and 28 weeks) using accelerometers (min/day). A total of 53 boys and 39 girls, with a mean age of 14.54 (1.96) years, were evaluated. Sedentary time (rho=0.217 [95%CI: 0.006 to 0.420]) and moderate-to-vigorous physical activity+Sportive moderate-to-vigorous physical activity (- 0.250 [95%CI:-0.447 to-0.130]) were related to costs attributed to medicine use. When the multivariate model considered sedentary time as a covariate, the relationship between moderate-to-vigorous physical activity+Sportive moderate-to-vigorous physical activity and costs attributed to medicine use became non-significant (beta=- 0.007 [95%CI:-0.017 to 0.004]; p-value=0.206). The time spent in moderate-to-vigorous physical activity was inversely related to the medication costs accumulated through the follow-up period, while sedentary time appears to counteract these benefits.

In 1991, I published a physiological model of marathon running performance. My model predicted that it might be possible for a human to run the marathon in less than 2 hours. In this article, I review the genesis of my thinking at that time, share my perspective about what has changed over the last 30 plus years, and speculate about what the future might hold.

A growing body of sports psychology research has focused on mindfulness-based training in sports environments. This study examined the effects of a 6-day online Mindful Sport Performance Enhancement program on mental health, emotion regulation (reappraisal and suppression), and athletic performance in student-athletes. Fifty-three participants were randomly assigned to experimental or waitlist control groups. Pre- and post-test data were collected using the Sports Mental Health Continuum-Short Form, Emotion Regulation Scale for Athletes, and a Self-rated Performance Questionnaire. Additionally, eight participants from the experimental group joined a post-intervention focus group interview. Results from 2×2 mixed-design ANOVAs revealed significant interaction effects for the mental health continuum (η _p ²=0.242) and reappraisal (η _p ²=0.240), suggesting improved emotional regulation and protection against mental health declines. However, suppression (η _p ²=0.008), subjective well-being (η _p ²=0.055), and self-rated performance (η _p ²=0.005) showed no significant improvements. Qualitative findings highlighted perceived benefits of the intervention, such as increased mindfulness, better emotional control, and improved focus and performance. In conclusion, although statistical improvements were limited to select outcomes, the 6-day online MSPE intervention appears to be a brief, feasible approach for supporting the psychological functioning of student-athletes.