Journal of science and medicine in sport最新文献

Objectives: Our purpose is to investigate the relative weight of prenatal determinants on children's and adolescents' physical fitness outcomes at different ages.

Design: Cross-sectional study with retrospectively collected data.

Methods: We obtained data from 1188 children (571 girls) aged 6-11 years and 1020 adolescents (495 girls) aged 12-17 years. Maternal prenatal determinants were self-reported by mothers. The ALPHA fitness test battery for youth was used to assess offspring's physical fitness (motor fitness, cardiorespiratory fitness and muscular strength). Regression analyses were performed to examine the different physical fitness outcomes.

Results: Higher maternal BMI before pregnancy was positively associated with lower physical fitness levels in offspring, regardless of age and sex; offspring of mothers who were physically active before to and during pregnancy exhibited higher physical fitness levels, specifically in female adolescents (all p < 0.05). The length of gestation was positively associated with physical fitness in male adolescents and absence of gestational anemia was related to higher physical fitness levels in female children (all p < 0.05).

Conclusions: Our results show the strongest prenatal determinants of physical fitness in children and adolescents and can contribute to the development of health promotion programs that could start even before children are born.

Objectives: To systematically review the outcomes of sport-related concussion in soccer players.

Design: Systematic review.

Methods: A systematic literature search was conducted in MEDLINE, PsycINFO, Academic Search Premier, EMBASE, Scopus, and CINAHL. Two reviewers independently screened articles against inclusion criteria and assessed risk of bias. Studies published before 13 February 2025 that investigated post-concussive symptoms, symptom duration and resolution, return-to-play (RTP) time, or neurocognitive outcomes following soccer-related concussion (SoRC) were included.

Results: A total of 23 studies met the inclusion criteria. Head-to-player contact was the most common mechanism of injury. Defenders and midfielders had the highest total number of concussions, whilst goalkeepers had the highest risk relative to their numbers on the field. Common post-concussive symptoms included headache, dizziness, nausea, and confusion. These symptoms generally resolved within one to four weeks, although prevalence and duration varied across studies. RTP time ranged from one week to three weeks in adults and was longer in youth, with some evidence of slower RTP in females. Neurocognitive outcomes were inconsistent, with some studies reporting poorer performance on tasks involving attention, memory, planning, and visuoperception, whilst others found no significant changes.

Conclusion: The literature on outcomes following SoRC remains mixed. The limited and inconsistent evidence across symptoms, recovery, and neurocognitive domains highlights the need for standardised measures and more longitudinal studies to guide clinical management and the development of RTP protocols. PROSPERO Registration Number CRD42024519427.

Objectives: To compare age at key performance milestones between technical whole-body endurance sports and performance levels.

Design: Longitudinal big data analysis.

Methods: All top 30 swimmers, cross-country (XC) skiers and biathletes, who competed at the latest World championships (WC) were included and their ages at specific performance milestones (debut, first 17-30 rank, 9-16 rank, top 8) at junior (JWC) and adult WC were extracted from databases (719 women and 850 men). Athletes were divided into various performance levels based on their best individual ranking from adult competitions and compared using linear mixed model analysis.

Results: Only ~40% of the WC swimmers had competed in the JWC compared to ~90% of XC skiers and biathletes. Swimmers were, on average, 2 and 4 years younger at JWC and WC, respectively, than XC skiers and biathletes. In all three sports, there was an age gap (p < 0.05) between the highest junior performance milestone and adult WC debut (3-4 years) but no age difference (p > 0.05) between the performance milestones or performance levels at JWC. On average, female swimmers reached performance milestones one year earlier than their male counterparts, while there was no sex difference in XC skiing and biathlon.

Conclusions: The present findings encourage reassessment of sport-specific stereotypes regarding long-term athlete development. Although overall development patterns are similar between men and women, sex-specific training and competition planning is necessary at key junior career stages. Analyzing key structural elements of development systems across three technical whole-body endurance sports provides insights to develop future strategies for long-term athlete development.

Objectives: To examine how decision-makers managed the planning process of the Tokyo 2020 and Beijing 2022 Olympic Games, identifying challenges and lessons from planning events during a respiratory pandemic.

Design: Multi-method qualitative case study.

Methods: This study conducted a document review of Olympic Playbooks, which outline the COVID-19 countermeasures for Tokyo 2020 and Beijing 2022, and key informant interviews with 12 participants who were directly involved in planning one or both Games. Findings were analyzed using inductive and deductive coding strategies.

Results: Content analysis of the Olympic Playbooks highlighted mitigation strategies and measures such as bubble approaches, regular testing programs, quarantine and isolation measures, masking and vaccination. Analysis of interviews identified four themes that represent challenges encountered during the development and implementation of the Playbooks for Tokyo 2020 and Beijing 2022. Themes include navigating complexities of multi-stakeholder environments; ensuring feasibility and equity; responding to uncertainty and opposition; and strengthening operational systems for the event and within the host country. These themes reflect the complexities of organizing a global mass gathering during a respiratory pandemic and contribute to the overarching theme of negotiating public health priorities amid uncertainty and complexity.

Conclusions: Synthesizing insights based on individual experiences from high-profile events such as the Olympics provides a unique perspective into balancing the requirements for hosting mass gatherings under normal conditions and under epidemic or pandemic contexts. Findings highlighted the importance of evidence-informed planning, transparent decision-making, sustained stakeholder engagement and investing in operational data and surveillance systems.

Objectives: Post activation potentiation (PAP) is the phenomenon where muscle force-generating capacity during explosive activities increases after sustained activation. Alternatively, fatigue refers to the decrease in muscle force-generating capacity following sustained activation. The level to which muscles are fatigued or potentiated may influence whether performance is enhanced or decreased. While PAP has been well-documented in able-bodied athletes, few studies have examined PAP in athletes with spinal cord injuries (SCI). Therefore the objective of this study was to examine the influence of warmup protocol intensity on workload production during a 15-second handcycling sprinting task in athletes with SCI.

Design: Within-subject design with repeated measures, n = 19 wheelchair users.

Methods: We examined the power output, work, and kinetics during a maximal effort task (handcycling sprinting) before and after high and moderate intensity exercise to determine the acute effects of different warmup intensities on work production during sprinting.

Results: Potentiation (defined as a >7.5% increase in total work completed during sprinting compared to baseline) was observed after both moderate (p = 0.0001) and high intensity exercises (p = 0.001), with more participants potentiated following moderate (n = 11) compared to high intensity (n = 10). Increases in work completed during the sprints can be traced back to increases in tangential force applied at the handle at the beginning of the sprint test.

Conclusions: Most participants were not fatigued following either exercise protocol, which is encouraging for recommending both protocols for people with SCI. Additionally, warmups for handcycling, especially handcycling sprinting, should be moderate intensity to potentiate the muscles rather than interval cycling or "ramp-up" activities.

Objectives: The purpose of this study was to examine the associations between upper body strength and endurance (UMSE) and academic achievement in youth.

Design: Cross-sectional study included 5th (N = 25,025) and 8th grade (N = 14,988) students in South Carolina.

Methods: Academic achievement was measured using a statewide assessment and classified into two categories (meets/exceeds standards or does not meet/approaches standards). Achievement in mathematics and English Language Arts was assessed. UMSE was measured as part of the South Carolina FitnessGram project and expressed as Healthy Fitness Zone (HFZ) or Needs Improvement - Health Risk. Student demographic characteristics were derived from a database maintained by the South Carolina Department of Education. Multiple logistic regression analyses were used to examine the association between UMSE and academic achievement. Analyses were performed separately by grade level and academic subject. Adjustments were made for student demographic characteristics, and a final model was adjusted for cardiorespiratory fitness (CRF).

Results: Students achieving the HFZ for UMSE were significantly more likely than students not achieving that standard to meet academic standards for both mathematics and English Language Arts in both 5th and 8th grades. Adjustment for CRF attenuated, but did not eliminate, the influence of upper body muscular strength on academic outcomes.

Conclusions: These findings indicate that UMSE is positively associated with academic achievement in elementary and middle school students. Future research should include experimental trials examining the effects of increasing muscular strength on academic achievement.