Sports Medicine - Open最新文献

Background: Olympic Cross-Country (XCO) mountain biking has evolved since its 1996 Olympic debut, with races becoming up to 40% shorter and more technically demanding. These changes may have altered the physiological demands, challenging the applicability of earlier evidence. This systematic review examines the physiology of contemporary XCO, focusing on athletes' characteristics, race demands, and training interventions.

Methods: A systematic search was conducted in PubMed, Web of Science, Scopus, and Embase. Fifty-three studies involving national to elite-level XCO athletes competing under the current race format were included. Risk of bias was assessed using the JBI Critical Appraisal Tool.

Results: Findings highlight that XCO athletes maintain exceptional aerobic capacity as in the former version of the discipline, but evidence points to a greater importance of high-intensity, short-duration efforts. A more intermittent effort pattern has been reported during races, with athletes spending a quarter of the time above their maximal aerobic power, interspersed with periods of technical riding that impose a high physiological demand as evidenced by a sustained high oxygen uptake. A fast-start pacing strategy is frequently reported, with velocity stabilizing or slightly decreasing in later laps, although the interpretation may be partly influenced by the structure of the start lap. Effective training regimens include high-intensity interval training, sprint interval training, and strength training, although direct performance assessments are scarce.

Conclusions: Overall, the current evidence confirms that the evolution of XCO has reshaped the discipline's physiological profile, shifting towards greater anaerobic contribution while maintaining high aerobic demands. Future research should address the underrepresentation of female athletes and methodological limitations, particularly in participant characterization and control of confounding factors.

Background: Lateral ankle sprains (LAS) are among the most common sports injuries, with up to 40% of individuals developing chronic ankle instability (CAI). While altering neurocognitive demands can affect lower limb biomechanics, the underlying mechanisms in CAI patients remain unclear. This systematic review aimed to summarise evidence on the neurocognitive deficits linked with ligamentous ankle injuries and CAI.

Methods: Following PRISMA guidelines (PROSPERO: CRD42023406395), a comprehensive search of five databases (up to September 24, 2024) identified studies examining neurocognitive performance in adults with LAS or CAI. Inclusion criteria were based on a PICO strategy. Two authors independently selected studies and assessed bias using the QUIPS tool and the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Data were extracted using a standardized form detailing study characteristics, patient data, neurocognitive methods, and statistical outcomes.

Results: This review included 24 studies with 104 LAS and 393 CAI patients, 92 copers, and 317 healthy controls. Eighty-three percent of the included studies showed a high risk of bias. Neurocognitive performance was assessed across nine domains using 27 neurocognitive tasks. CAI patients exhibit deficits in attention, inhibitory control, and visual memory, with mixed results for working memory and processing speed. No deficits were found in language or motor skills. These deficits may contribute to reduced postural stability, particularly under dual-task conditions where cognitive resources are divided. No significant findings were observed for copers.

Discussion: Methodological variability, cross-sectional designs, and limited focus on LAS underscore the need for further research to examine causality and expand generalizability.

Conclusion: This review underscores the association between ligamentous ankle injuries, particularly in CAI, and neurocognitive performance, although more research is needed to unravel the causal direction.

Background: The importance of prescribing individualised exercise programs for all people with cancer has been echoed across the literature. However, there is a notable gap in our understanding of how exercise individualisation is applied in oncology research, what the common individualisation practises of exercise prescription for people with cancer are, and the effects of these practises on common symptoms such as fatigue.

Objectives: The aims of this systematic review and meta-analysis were to elucidate the individualisation prescription methods employed in exercise oncology research, determine whether current studies employ best-practice autoregulatory prescription for people with and following treatment for cancer, and conduct subgroup analyses to determine the influence of exercise individualisation methodology on fatigue severity.

Methods: A systematic literature search was conducted in PubMed, EMBASE, CINAHL, and Web of Science databases. Studies written in English stating they prescribed any form of 'individualised' exercise for people ≥ 18 years with a histologically confirmed diagnosis of cancer were included in this review. Pooled meta-analysis and subgroup meta-analysis were performed using a random-effects model.

Results: Sixty-three studies involving 4472 participants were included. The rationale underpinning why exercise was individualised was predominantly based on objective reasons (41%). Most commonly, exercise was individualised pre-session, and inter-session (25%) via modulation of the exercise prescription, whereby exercise prescriptions were adapted in various heterogenous ways (22%). Autoregulation was only explicitly reported in two (3%) studies. Individualising exercise using subjective reasoning was significantly associated with reduced fatigue severity (SMD = - 0.355, 95% CI - 0.631 to - 0.079; p = 0.0116). Timing exercise individualisation inter-session had a moderate and significant pooled effect on reducing fatigue severity (SMD = - 0.616, 95% CI - 0.962 to - 0.271; p = 0.0005).

Conclusions: This review highlights most exercise oncology studies individualise exercise at baseline only, with this being broadly reported via modulation of the exercise prescription, which may not meet the needs of people with cancer, given their often-fluctuating symptoms and clinical status. Fatigue severity may be reduced by individualising exercise prescription using subjective assessments and by timing the individualisation between sessions.

Protocol registration: The original protocol was registered with the Open Science Framework on 28 April 2022 ( https://osf.io/d6tkv/ ).

Background: Rugby union is a popular contact sport during which high impact collisions frequently occur. There is concern for the overall brain health of those playing the game, as concussion is a potential outcome of high impact collisions. Repeated sub-concussive collisions may compromise rugby players' neurological integrity, but little is known about the effects on young brains. The brain is still developing during adolescence and may generally be more susceptible to injury, but minimal objective research data are available regarding head acceleration events experienced by junior players.

Results: Forty-one adolescent male rugby players underwent pre- and post-season MRI scans and neuro-cognitive assessments. Participants were fitted with instrumented mouthguards to record head acceleration events experienced during the season. Post-season processing of MRI scans focused on within-subject analysis of pre- to post-season changes in white matter as measured by diffusion tensor imaging. Linear mixed models were used to investigate correlations between neurological changes and cumulative head impact loading recorded by the mouthguards. MRI results indicated a non-significant difference between pre- and post-season for data relating to brain structure and function, including white matter microstructure, in response to one season of contact training and match play for under-16 male rugby players, as measured by diffusion tensor imaging. These results held irrespective of level of exposure.

Conclusions: Our data suggest that exposure to one season of rugby does not appear to result in neurological compromise. The statistical non-significance reported for the main outcome measure also held when controlling for variables, such as training age and headgear use. Although pre- to post-season differences were statistically non-significant, the long-term effects of high exposure may be of clinical significance going forward. Further research, particularly using longitudinal designs, is needed to further elucidate the potential for microstructural neurological changes in adolescent rugby players.

Background: Compared with traditional running shoes, Advanced Footwear Technology (AFT) improves the oxygen cost of running (O₂ cost) for athletes competing at fast speeds. Less clear are the effects of these modern shoes at the slower speeds commonly adopted by recreational runners. Therefore, this study's primary aim was to assess the effects of AFT shoes on O₂ cost at slow running speeds.

Methods: Fourteen moderately-trained runners (6 men, 8 women, age 25.5 ± 2.8 years, body mass index 21.7 ± 2.3 kg m^-2, V̇O_2peak 49.8 ± 5.1 ml O₂ kg^-1 min^-1) ran at four speeds (7.5, 9.0, 10.5 and 12.0 km h^-1) with three different footwear conditions: traditional running shoes (On Cloudrunner 2, TRA); AFT shoes (On Cloudboom Echo 3, CBE); and prototype shoes combining AFT and standard features (high compliance, energy return, and mass; On Prototype, MIX). The full protocol was repeated on three different days by each participant.

Results: Combining all tested speeds, O₂ cost was lower for CBE compared with both TRA (-5.4 ml O₂ kg^-1 km^-1, 95% CI: -6.9 to -3.9 ml O₂ kg^-1 km ^-1, p < 0.001) and MIX (-4.1 ml O₂ kg^-1 km^-1, 95% CI: --5.6 to -2.6 ml O₂ kg^-1 km ^-1, p < 0.001), whereas no difference between MIX and TRA could be detected (95% CI: -3.4 to 0.8 ml O₂ kg^-1 km^-1, p = 0.269). Differences in O₂ cost between shoes were independent of speed. Perceived effort was lower for CBE compared with TRA only (-0.2 points, 95% CI -0.4 to -0.1 points), whereas no differences were detected for perceived comfort between any of the shoes (p = 0.377). No clear effect of footwear was detected for cadence, ground contact time, or leg stiffness. Comparing the most and least liked shoe models revealed preference for both lower O₂ cost and higher comfort, with larger effect sizes for comfort.

Conclusion: AFT shoes can provide meaningful metabolic savings even at very low running speeds, with no distinguishable speed-dependence, which cannot be explained by changes in spatiotemporal variables. AFT shoes for recreational runners should be further improved to maintain metabolic efficiency while not sacrificing perceived comfort, which is a stronger determinant of shoe preference.

Background: The consequences of exposure to head acceleration events (HAEs) in collision sports, including Australian Rules football, are a growing concern. Instrumented mouthguards (iMGs) now enable accurate quantification of HAEs in sport; however, little is known about HAE incidence and mechanisms in Australian Rules football. We aimed to measure HAEs in elite Australian Rules football players, and evaluate the influence of playing position and match event on the incidence and magnitude of HAEs in men and women. iMG data were collected from Australian Football League (AFL) and AFL Women's (AFLW) players in 2023 utilising the HIT-IQ Nexus Gen III iMG, targeting 500 player-matches per sex. Match footage was synchronised with iMG data for video verification and match play coding.

Results: Three hundred and eleven players contributed iMG data in the analyses, including 126 men (median matches per player: 3 (interquartile range [IQR: 2-6]) and 185 women (median: 3 [IQR: 1-4]). Men had a higher mean incidence of HAEs ≥ 8 g per match than women (5.7 [95% confidence interval CI: 5.0-6.4] vs. 3.0 [95% CI: 2.8-3.3]), however the incidence was comparable when adjusted for time (3.6/hour [95% CI: 3.2-4.1] vs. 3.1/hour [95% CI: 2.9-3.4]). Men recorded higher maximum single-impact peak linear acceleration (PLA; median 31 g vs. women: median 22 g; p < 0.001) and peak rotational acceleration (PRA; median 3.0 krad/s² vs. women: 2.4 krad/s²; p < 0.001) per match. Conversely, women experienced greater PRA per impact (median 1.4 krad/s² vs. men: 1.2 krad/s²; p < 0.001), while PLA was similar (men: median 14 g, women: median 13 g; p = 0.330). The leading match events resulting in HAEs were marking contests (1.0/hour) in men and contested ball situations (0.8/hour) in women. HAE incidence and magnitude were generally comparable across playing positions, except for men's rucks, who experienced significantly higher incidence of HAEs (6.5/hour) than forwards (3.6/hour), midfielders (3.2/hour), and defenders (2.7/hour).

Conclusions: This study highlights differences in HAE incidence, magnitude, and mechanisms by sex, playing position, and match events in elite-level Australian Rules football. These findings provide insight into impact exposure patterns and may inform targeted skill development and policy adjustments to enhance player safety.

The efficacy of anterior cruciate ligament (ACL) rehabilitation following reconstruction surgery is sub-optimal and the return-to-sport criteria are inconsistent. We examine the hypothesis that the dysfunctional neuroplasticity induced by an ACL injury could be resolved faster when cross-education is combined with innovative paradigms incorporating visual-cognitive tasks to reduce attentional compensation. We posit that the priming effects could be amplified if therapists combined higher force, eccentric based cross-education exercises with visual-cognitive dual-tasking. The overlapping nature of neuroplasticity after an ACL injury and that induced by cross education may provide a pathway to not only address the mechanical muscle strength deficits associated with injury, but the underlying neurological deficits as well. We provide a practical guide to how neuroplasticity-informed ACL rehabilitation that includes cross-education might accelerate recovery from an ACL injury and the subsequent reconstruction surgery.

Background: Cutting-edge dual process health behavior theories propose micro-temporal within-person processes to be critical drivers of physical activity participation. Self-efficacy is the pivotal motivation-oriented correlate of physical activity, a key component across the most prominent health behavior change theories, and has predominantly been researched as stable interpersonal 'trait' factor. However, the micro-temporal within-person 'state' perspective on self-efficacy remains uncharted.

Objectives: To tackle this research gap, we conducted a scoping review and examined (1) time-sensitive (i.e., assessment time span) and (2) theory-conform operationalization of self-efficacy measures as well as (3) within-person variance reports from ecological momentary assessment studies in the physical activity context among healthy adults.

Methods: A scoping review of English articles using PsycINFO, PsycArticles, PSYNDEX, SPORTDiscus and PubMed was conducted up to September 2025. Eligible studies focused on (1) physical activity in (2) healthy adults aged + 18 years and (3) applied multiple within-day, daily or weekly assessments of self-efficacy. Findings were summarized through quantitative analysis of the evidence.

Results: A total of 13 studies was included. Most studies assessed self-efficacy through multiple assessments per day and with a focus on the near future (i.e., next few hours post ecological momentary assessment). The 13 identified self-efficacy items were operationalized according to self-efficacy theory, but varied in semantics, psychometrics, and source. Five studies reported intraclass correlation coefficients that revealed self-efficacy within-person variance to range between 51% and 89%.

Conclusions: Given the pivotal role of self-efficacy across various health-behavior theories and the recent relevance attributed to micro-temporal within-subject processes, thus far surprisingly few studies researched how self-efficacy unfolds within-persons across time. However, the few studies identified provide initial evidence that self-efficacy varies within individuals across time in everyday life, including a tendency towards higher within-person variance for momentary versus day level assessments, and thereby empirically supporting dual process models. Items were assessed dynamically using repeated measures per day and according to theory but differed in conceptual and semantic features. Future research is encouraged to further investigate how self-efficacy unfolds across time, by testing various sampling strategies and applying advanced designs to shed light on the precise timing of effects and to inform adaptive and expedient intervention development.

Sports medicine epidemiology has advanced considerably over the past two decades, with standardized surveillance systems and consensus statements improving the quality of data collection and reporting. Yet the field continues to face structural challenges, including small cohorts, heterogeneous samples, and rare outcomes that undermine reproducibility and limit generalizability. In practice, researchers and clinicians frequently rely on implicit expert judgment to bridge these gaps, but such judgments are often undocumented and irreproducible. Expert elicitation offers a structured, transparent approach to formalizing this knowledge into quantitative priors that can complement empirical data within Bayesian analyses. This commentary introduces expert elicitation to sports medicine epidemiology, drawing on applications of the Sheffield Elicitation Framework (SHELF) in our ongoing work. We highlight three key areas where elicitation can strengthen research and practice: 1) studies involving small, sport-specific cohorts, such as Paralympic athletes; 2) analyses of rare or severe events, including catastrophic injuries and sudden illnesses; and 3) underpowered intervention trials, where structured priors can improve interpretation and guide future prevention and treatment strategies. We also share practical insights from our pilot work, including strategies for framing questions, conducting warm-up and challenge exercises, and using real-time visualization to improve accuracy and engagement. Expert elicitation is not without challenges, requiring careful facilitation and appropriate expertise, but it provides a rigorous, reproducible method for transforming clinical judgment into usable data. Wider adoption of this methodology could accelerate progress in athlete health research by formalizing knowledge that already shapes practice but remains largely untapped.