Introduction: This study systematically evaluated the effectiveness of elastic band resistance training (EBT) in improving lower limb strength and balance function in older adults with different health status. Methods: A comprehensive literature search was conducted across Scopus, EBSCO, Web of Science, PubMed, and Cochrane Library to identify randomized controlled trials (RCTs) published through December 30, 2024. Eligible studies included older adults in which the control group received either no intervention or basic treatment, and the experimental group received EBT in addition to the control protocol. Results: A total of 25 studies involving 1,318 participants were included. Meta-analysis demonstrated significant improvements in the EBT group compared with controls across multiple outcomes: leg extension test [SMD = 1.01, 95% CI (0.36, 1.66), p = 0.002], chair stand test [SMD = 2.04, 95% CI (0.60, 3.48), p = 0.006], timed up and go test [SMD = –1.41, 95% CI (–2.33, −0.49), p = 0.003] and functional reach test [SMD = 1.63, 95% CI (0.36, 2.90), p = 0.012]. Conclusion: Elastic band resistance training may improve lower limb strength and balance function in older adults with different health conditions. Longer intervention durations may yield greater benefits in strength, while balance improvements can occur with shorter programs. Further high-quality studies are needed to confirm these effects. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/view/CRD420251021955 , PROSPERO CRD420251021955.

Background: Negative emotions among college students, particularly those who are physically weak, have raised concerns due to their impact on mental health and, in some cases, the development of suicidal tendencies. Limited physical activity exacerbates these mental health risks. It is essential to explore the relationship between physical activity, sleep quality, and negative emotions in this population.Objective: To examine the relationship between physical activity, sleep quality, and negative emotions among physically weak college students.Methods: A stratified sampling approach was employed to select 1,248 first- and second-year students from a university in Beijing. Physical activity levels were assessed using the International Physical Activity Questionnaire Short Form (IPAQ-SF), sleep quality was evaluated with the Pittsburgh Sleep Quality Index (PSQI), and depression, anxiety, and stress were measured via the Depression Anxiety Stress Scales (DASS-21). Chi-square tests and logistic regression analyses were conducted to explore associations among these variables. Additionally, a mediation effect model was utilized to examine the mediating role of sleep quality between physical activity and negative emotions.Results: The incidence of negative emotions was significantly higher among physically weak college students compared to their peers (p < 0.05). Binary logistic regression results indicated that increased physical activity intensity was associated with a lower occurrence of negative emotions (OR = 0.514, 95% CI: 0.367–0.719). Linear regression analysis showed a significant positive correlation between higher physical activity intensity and better sleep quality (a = −0.185, p < 0.01). The mediation effect analysis revealed that sleep quality partially mediated the relationship between physical activity and negative emotions, with total, direct, and indirect effects of −0.67, −0.60, and −0.097, respectively. Sleep quality accounted for 14.6% of the total effect in this relationship.Conclusion: The incidence of negative emotions among physically weak college students is significantly higher than among their peers and increased physical activity intensity is significantly associated with a decrease in negative emotions. Sleep quality plays a crucial mediating role in this relationship. These findings provide a theoretical foundation for developing targeted mental health interventions for physically weak college students and highlight the importance of sleep quality in improving their mental health.

Purpose: This study aimed to assess the psychological disturbance profiles of Chinese mine rescuers and identify associated risk factors. Methods: A stratified whole-group sampling method was employed to select 150 members of the Datong Mine Rescue Team in China as survey participants. These participants completed the following 6 assessment tools: the Injury Assessment Questionnaire for Mine Rescuers, the Symptom Checklist-90 (SCL-90), the Self-Rating Anxiety Scale (SAS), the Self-Rating Depression Scale (SDS), the Pittsburgh Sleep Quality Index (PSQI), and the Perceived Stress Scale (PSS). The relationships between sociodemographic variables, risk factors, and psychological disturbances were analyzed using logistic regression analysis. Results: Based on the cut-off scores for the SAS, SDS, and SCL-90, the sample was categorized into high- and low-risk groups. Among the 150 participants of the Datong Mine Rescue Team in China, the prevalences of anxiety, depression, and psychological distress were 15.3%, 17.3%, and 43.3%, respectively. Logistic regression analysis revealed that self-perception of stress (OR=4.359, p=0.005), sleep quality (OR=4.338, p=0.010), training-related injuries history (OR=5.609, p=0.040), and training frequency (OR=3.013, p=0.047) were risk factors for anxiety among mine rescuers. Additionally, self-perception of stress (OR=7.371, p< 0.001) was identified as a risk factor for depression, while sleep quality (OR=4.844, p< 0.001) was a risk factor for psychological disturbance based on the SCL-90. Training with existing injuries was found to be a risk factor for interpersonal sensitivity (OR=10.054, p=0.006), depression (OR=4.698, p=0.033), anxiety (OR=6.472, p=0.027), hostility (OR=3.864, p=0.047), and other factor (OR=3.736, p=0.020) among rescuers. Conclusion: Nearly half of the rescuers from the Datong Mine Rescue Team exhibited adverse psychological symptoms. Associated risk factors included self-perceived stress, sleep quality, training frequency, history of training-related injuries, and training with existing injuries. To promote mental health among rescuers, it is crucial to manage training-related injuries and proactively prevent training with under existing injury conditions.

Objective: This study aimed to explore the molecular response mechanisms of differential blood metabolites before and after 8 weeks of threshold and polarized training models using metabolomics technology combined with changes in athletic performance. Methods: Twenty-four male rowers aged 14–16 were randomly divided into a THR group and a POL group (12 participants each). The THR group followed a threshold training model (72%, 24%, and 4% of training time in low-, moderate-, and high-intensity zones, respectively), while the POL group followed a polarized training model (78%, 8%, and 14% training-intensity distribution). Both groups underwent an 8-week training program. Aerobic endurance changes were assessed using a 2 km maximal rowing performance test, and untargeted metabolome analysis was conducted to examine blood metabolomic changes before and after the different training interventions. Aerobic endurance changes were assessed through a 2 km maximal rowing test. Non-targeted metabolomics analysis was employed to evaluate changes in blood metabolome profiles before and after the different training interventions. Results: After 8 weeks of training, both the THR and POL groups exhibited significant improvements in 2 km maximal rowing performance (p < 0.05), with no significant differences between the groups. The THR and POL groups had 46 shared differential metabolites before and after the intervention, primarily enriched in sphingolipid metabolism, glutathione metabolism, and glycine, serine, and threonine metabolism pathways. Nine unique differential metabolites were identified in the THR group, mainly enriched in pyruvate metabolism, glycine, serine, and threonine metabolism, glutathione metabolism, and sphingolipid metabolism. A total of 14 unique differential metabolites were identified in the POL group, predominantly enriched in sphingolipid metabolism, glycine, serine, and threonine metabolism, aminoacyl-tRNA biosynthesis, and glutathione metabolism. Conclusions: The 8-week THR and POL training models demonstrated similar effects on enhancing aerobic performance in adolescent male rowers, indicating that both training modalities share similar blood metabolic mechanisms for improving aerobic endurance. Furthermore, both the THR group and the POL group exhibited numerous shared metabolites and some differential metabolites, suggesting that the two endurance training models share common pathways but also have distinct aspects in enhancing aerobic endurance.

Objective: The purpose of this study was to investigate the relationship between bilateral lower extremity explosive strength asymmetry and non-contact low back injuries in mine rescue workers, a specialized occupational group. Methods: A single-leg countermovement jump (SLCMJ) test was performed on 101 rescue members who had participated in frontline rescue missions, using a force platform. The collected force platform data were used to calculate lower limb asymmetry. Injury incidence was measured by recording all non-contact low back injuries occurring during routine training or rescue operations over a 12-month follow-up period. Jump metrics (including eccentric peak force, vertical velocity at takeoff, peak takeoff acceleration, and takeoff peak force) associated with non-contact low back injuries were identified through Poisson regression analysis, and the optimal threshold for predicting injuries was determined using the receiver operating characteristic (ROC) curve. Results: Bilateral takeoff peak force asymmetry significantly increased the risk of non-contact low back injury. Each 1% increase in asymmetry raised the injury risk by 18.5% (RR = 1.185, 95% CI: 1.091–1.288, p < 0.001), equivalent to an absolute increase of 3.2% (RD = 0.032, 95% CI: 0.009–0.056). Using the optimal threshold of 7.05% for risk stratification, rescue workers in the high-risk group had a 3.6 times higher injury risk than the low-risk group (RR = 3.64, 95% CI: 1.353–9.832, p = 0.011), corresponding to an absolute risk difference of 24.1% (RD = 0.241, 95% CI: 0.073–0.409). Conclusion: The interlimb asymmetry measured during the single-leg countermovement jump can be used to predict the risk of non-contact low back injuries in mine rescue workers over a 12-month follow-up period. Particular emphasis should be placed on the interlimb asymmetry of takeoff peak force.

Background: University is a critical period for the transition from adolescence to early adulthood, during which lifestyle and physical activity patterns become more stable. This study examines longitudinal changes in physical fitness among university students and evaluates whether trajectories differ by discipline group, baseline grade, and sex. Methods: Annual physical fitness test records from 2023 to 2025 are linked at the student level. A total of 4,406 students contribute 12,795 student-year observations. Multilevel linear mixed-effects models are used to analyze total physical fitness score, with grade-based outcomes and raw item measurements used as complementary analyses. Results: Total physical fitness score declines significantly from 2023 to 2025 in all discipline groups. The year × discipline-group interaction is significant, indicating different longitudinal trajectories. The largest adjusted decline is observed in Science, followed by HSSM and Engineering. Pass rates decline in all groups, while the loss of good-or-excellent status is more pronounced in Science and HSSM. Raw measurements suggest that the decline is concentrated mainly in speed, endurance, lower-limb explosive power, and muscular strength or endurance. Conclusion: University students show a marked decline in physical fitness over 3 years. These findings support the use of linked annual fitness records as a campus health surveillance tool to identify declining fitness trajectories and guide stage-specific, risk-stratified health promotion strategies.