Shanghai Research Institute of Sports Science

Studies have shown that vertical jump biomechanics or patterns may be related to physical fitness. This study investigated the relationship between physical fitness and drop vertical jump (DVJ) biomechanics in male college basketball players. Health-related physical fitness was measured by 20s sit-up, core endurance and flexibility test; whilst athletic-related physical fitness by Y-balance test and dominant extremity single-leg hop distance test. Kinetics and kinematics during DVJ were evaluated by VICON. Five-level side bridge correlated negatively with angle displacement of hip adduction (p = 0.014) and positively with moment of knee flexion (p = 0.033); 8-level abdominal bridge correlated positively with moment of knee flexion (p = 0.01); ankle dorsiflexion range of motion correlated negatively with mediolateral ground reaction force (p = 0.025), angle displacement of knee flexion (p = 0.004), moment of ankle plantarflexion (p = 0.009), and positively with angle displacement of ankle plantarflexion (p = 0.015); ankle plantarflexion ROM correlated negatively with angle of knee flexion (p = 0.012); trunk flexion ROM correlated negatively with moment of ankle plantarflexion (p = 0.014). Health-related physical fitness could be the alternatives for DVJ biomechanics assessment.

The coaching of elite athletes in precision sports like shooting and archery is increasingly reliant on data-driven insights. However, existing solutions often fail to integrate real-time performance data, historical records, and domain-specific knowledge into a unified, intelligent system. This paper presents the architectural design of a next-generation Big Data and AI Agent platform tailored for the Hebei Provincial Sports Bureau's Shooting and Archery Center. The architecture is built on a multi-layered, service-oriented model that distinguishes between hot (real-time) and cold (archival) data pathways. Real-time firearm trajectory data captured by YOLOv9 models is processed via a Kafka and Spark Streaming pipeline into ClickHouse for immediate analysis. Historical data and scores are archived in PostgreSQL and MySQL, while unstructured expert knowledge from texts is vectorized and stored in Milvus. The core innovation is an AI Agent, built with a Large Language Model (LLM), that acts as an intelligent orchestrator. This agent interprets natural language queries from coaches, and dynamically invokes specialized tools-Vanna for Text-to-SQL queries on structured data and a RAGflow-based service for knowledge retrieval from the vector database. This dual-tool approach enables the agent to synthesize comprehensive reports that combine quantitative analysis with biomechanical theory, providing coaches with deep, actionable insights for athlete evaluation, selection, and performance optimization.

BackgroundExercise-induced oxidative stress and muscle damage are key factors affecting athletes’ performance and recovery. This meta-analysis aims to assess the effects of different antioxidants on post-exercise muscle damage and oxidative stress in athletes, providing evidence-based support for the development of effective exercise nutrition strategies.MethodsThis meta-analysis strictly followed the PRISMA guidelines. It systematically retrieved the Web of Science, PubMed, Cochrane Library, Embase, and Scopus databases for randomized controlled trials (RCTs) investigating the effects of antioxidants on post-exercise muscle damage and oxidative stress in athletes. Primary outcomes encompassed total antioxidant status (TAS), glutathione peroxidase (GPx), superoxide dismutase (SOD), thiobarbituric acid reactive substances (TBARS), and lactate (LA). Secondary outcomes were interleukin-6 (IL-6), malondialdehyde (MDA), creatine kinase (CK), and nitrates (NOx). Effect sizes were combined via standardized mean difference (SMD). Heterogeneity tests, sensitivity analyses, and subgroup analyses were performed, as well as publication bias evaluations.ResultsTwenty-six RCTs involving 505 athletes were incorporated. The overall analysis indicated that antioxidant supplementation significantly decreased post-exercise LA (SMD: -1.25; 95% CI: -2.06, -0.43; I²=81.7%, p < 0.001) and CK (SMD: -1.88; 95% CI: -2.98, -0.78; I²=86.2%, p < 0.001) levels in athletes. However, the overall effects for TAS, TBARS, SOD, GPx, NOx, IL-6, and MDA exhibited no statistical significance. All outcomes, whether showing significant or nonsignificant effects, demonstrated varying degrees of heterogeneity. Subgroup analyses revealed that region, sex distribution, study type, and athletes’ professional level were important sources of heterogeneity for indicators like LA and SOD. Funnel plot analysis for publication bias revealed no significant asymmetry. Sensitivity analyses confirmed the robustness of major results.ConclusionsThe current study suggests that antioxidant supplementation can effectively reduce post-exercise LA and CK levels in athletes. This reduction may help promote fatigue recovery and alleviate muscle damage. However, the overall effects of antioxidant supplementation on inflammatory biomarkers and other oxidative stress are unclear and are modulated by factors such as region, sex, professional level, and study design. Future research should concentrate on individual differences and more refined intervention regimens to optimize antioxidant use in exercise.Trial registrationPROSPERO, CRD42023460244.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13102-025-01381-2.

To compare lower limb joint angle variability between functional ankle instability (FAI) and healthy controls (CONs) at different running speeds using linear and nonlinear methods. Fifteen males with right-side FAI and fifteen matched CONs ran on a treadmill at self-selected, 20% faster, and 20% slower speeds. From 25 gait cycles, the mean coefficient of variation (CV), Sample Entropy (SampEn), and largest Lyapunov Exponent (LyE) of hip, knee, and ankle angles were computed. A two-way (two groups × three speeds) mixed-design ANOVA was applied (α = 0.05). No significant interaction effects were observed. No significant differences were observed in the CV. SampEn showed group effects: FAI had lower values in hip horizontal, knee sagittal/coronal, and ankle coronal planes, but higher in the hip sagittal plane. Speed effects showed greater SampEn in the ankle sagittal and lower in the hip coronal plane at slow speed. LyE was reduced in FAI for hip, knee, and ankle sagittal planes. Speed effects indicated higher LyE in the knee sagittal and lower in the hip coronal plane at slow speed. FAI showed reduced variability, particularly in the sagittal plane, reflecting rigid control. Slower speeds increased ankle and knee sagittal variability but decreased hip coronal variability.

Sleep plays an important role in human health, and anemia can lead to a continuous deterioration of sleep. However, the association and mechanism between anemia and sleep disturbances remain unclear. This study aimed to examine the relationship between anemia and sleep disturbances among older Chinese adults, in addition to examining the mediating role of handgrip strength in this relationship. This research utilized data from the 2015 China Health and Retirement Longitudinal Study (CHARLS). Following the application of specific inclusion and exclusion criteria, a total of 6,057 Chinese adults aged 60 and above were finally selected as the analysis samples. The dependent variable was sleep disturbances (yes/no), with anemia (present/absent) serving as the main independent variables. Handgrip strength was employed as the mediating factor. Multivariable-adjusted logistic regression analyses were conducted to investigate the relationships among anemia, handgrip strength, and sleep disturbances. Additionally, bootstrap tests were performed to assess the mediating role of handgrip strength in the association between anemia and sleep disturbances. In the unadjusted model, a positive association was observed between anemia and sleep disturbances (OR: 1.22, 95% CI: 1.08-1.38), whereas handgrip strength exhibited a negative association with sleep disturbances (OR: 0.95, 95% CI: 0.93-0.97). These associations persisted even after adjusting for covariates in Models 1, 2, and 3. Furthermore, handgrip strength was found to significantly mediate the link between anemia and sleep disturbances(mediating effect = 5.75x10 -3), with the mediating effect accounting for 15.67% of the association. The study indicate that anemia is positively associated with an increased risk of sleep disturbances among older Chinese individuals, with handgrip strength acting as a significant mediator in this relationship. This study provides valuable references for improving the sleep quality of older adults.

BackgroundThe application of quantitative magnetic resonance imaging (MRI) in skeletal muscle is crucial in rehabilitation medicine and competitive sports training.PurposeTo explore the feasibility of evaluating T2 value, proton density fat fraction (PDFF), and cross-sectional area (CSA) of the quadriceps femoris before and after countermovement jump (CMJ) based on T2 mapping and Fat Analysis and Calculation Technique (FACT).Material and MethodsA total of 32 healthy volunteers were recruited and underwent MRI examination of the thigh muscles, including axial T2 mapping and FACT sequence. The T2 value, PDFF, and CSA of the quadriceps femoris, adductor magnus, and gracilis were measured. The peak torque (PT) of the quadriceps femoris was measured using an isokinetic muscle strength system. The differences in MRI parameters before and after CMJ were compared, as well as the differences between sexes.ResultsThe T2 value and CSA of the quadriceps femoris and adductor magnus increased and PDFF decreased after CMJ (P <0.01). The PDFF of the gracilis was significantly higher than that of the vastus lateralis, and the vastus lateralis had a significantly higher PDFF than the other muscles (P <0.01). PT was highly correlated with the CSA of the quadriceps femoris (P <0.001, r = 0.906). CSA and PT of men were higher than those of women (P <0.001).ConclusionT2 mapping and FACT can quantitatively evaluate the differences of T2 value, PDFF, and CSA of different muscles before and after CMJ, which is an important evaluation method for competitive sports training and disease rehabilitation.

Patients with chronic ankle instability (CAI) have demonstrated altered hip and knee movement strategies during walking and running, but these movement modalities do not involve changes in speed and direction, making it difficult to simulate the conditions of real sports, whereas side-cutting task can provide CAI patients with a more realistic athletic challenge. However, there is limited literature examining the kinematic and kinetic differences in the hip, knee, and ankle joints of CAI patients during the side-cutting task. To assess differences in lower extremity joint kinematics and kinetics during the side-cutting task in individuals with and without CAI. Cross-sectional study. 48 males, 24 in each of the CAI group and healthy control group; 40 females, 20 in each of the CAI group and healthy control group. Lower extremity three-dimensional kinematic and kinetics data were evaluated by using a three-dimensional motion analysis system during the initial contact (IC) and toe off (TO) while side-cutting. Compared with healthy controls, male patients with CAI exhibited greater hip flexion and external rotation angles, knee internal rotation angles, smaller knee flexion angles and ankle inversion angles, greater hip external rotation moments, and greater knee abduction moments; female patients with CAI exhibited smaller hip and knee flexion angles, greater hip external rotation angles, larger ankle inversion angles and internal rotation angles, smaller hip external rotation moments, and greater knee abduction moments. Our findings indicate that patients with CAI exhibit altered lower limb joint kinematics and kinetics during side-cutting task, with significant sex-specific differences. These movement pattern changes involve proximal joint compensation to stabilize the unstable distal ankle joint; however, these compensatory changes are not always favorable. The greater hip external rotation moment and greater knee internal rotation angle demonstrated by male CAI patients, the smaller hip flexion angle and greater ankle internal rotation angle demonstrated by female CAI patients, and the smaller knee flexion angle and greater knee abduction moment common to both sexes may impair the lower limb's ability to effectively absorb and dissipate ground reaction forces, potentially elevating the risk of lower extremity injuries.