Nutritional supplements have been extensively used as health interventions for the elderly. However, with the spread of COVID-19, no consensus exists on whether nutritional interventions could improve muscle mass and physical activity in community-dwelling older adults. To conduct a systematic review and meta-analysis to explore the effects of different nutritional interventions on muscle mass and physical performance in the elderly, we searched PubMed, Web of Science, Elsevier, and Cochrane databases from their founding dates to December 2023. The meta-analysis was performed using RevMan5.3 software. Only randomized controlled trials (RCTs) were considered, and the overall mean difference (MD) or standardized mean difference (SMD) with 95% confidence interval (CI) was calculated. There were 33 studies comprising 3579 elderly persons meeting the inclusion criteria. Comprehensive analysis suggested that the intervention effect of fat-free mass (FFM), appendix skeletal muscle mass (ASMM), handgrip strength (HGS), gait speed, and short physical performance battery (SPPB) score was higher in the nutritional supplement group than in the control group. The results of subgroup analysis demonstrated that protein supplementation (SMD = 0.82, p < 0.0001) had an optimal effect on ASMM (SMD = 0.89, p < 0.0001) and FFM (MD = 2.09, p < 0.0001) in the elderly. Vitamin D supplementation (SMD = 0.52, p < 0.0001) had a marginal effect on ASMM, and energy supplementation (SMD = 0.39, p = 0.0005) had the lowest effect. Moreover, nutritional interventions had the most significant impact on HGS (MD = 1.06, p < 0.0001) and TUG (MD = 0.14, p < 0.0001) in individuals aged 65–75 years old, with positive effects on FFM (MD = 1.62, p < 0.0001) and HGS (MD = 0.82, p < 0.0001) when compared to healthy elderly individuals, and had greater effect on ASMM (SMD = 0.69, p < 0.0001) than on the elderly with sarcopenia. Nutritional supplements can enhance muscle mass and physical performance in the elderly, while protein is recommended for muscle function. The golden period for implementing nutritional interventions to improve muscle function is before the age of 75 years. However, the impact of nutritional interventions varies with age and population. Given the limited evidence on nutritional interventions, more detailed and high-quality studies are highly warranted in the future.

The application of multi-tasking (MT), especially dual-tasking (DT), in frail older adults is currently gaining attention. The aim was to review the application of the MT mode on cognition and lower limb function in frail older adults, including the MT test and MT training. By searching five electronic databases, Scopus, PubMed, PEDro, Web of Science and the Chinese electronic database, a total of 18 studies were finally included in this study, with 7 articles on MT testing and 11 articles on MT training. The results of the study showed that the current testing and training of MT is mainly based on the DT mode, with a wide variety of test types and protocols, as well as a variety of outcomes. The included studies suggested that DT can be used as a test to assess cognitive and lower limb function in the frail population and that an MT (DT) training program with an intervention period of ≥3 months or a duration of ≥60 min per session could improve cognitive and lower limb function in the frail population, thereby reducing the risk of falls. Further research is required to explore the effects of different types of MT and task prioritization in frail older adults.

Introduction: Tai Chi has been shown to exert beneficial effects on cognitive function in older adults; however, the mechanisms underlying its improvement of postural control and mobility remain unclear. This study aimed to investigate the effects of a 3-month Tai Chi training intervention on cognitive function and postural control in older adults, thereby providing a scientific basis for exercise recommendations for this population. Method: This study aimed to evaluate the effects of 8 forms of Tai Chi training over a period of 3 months on gait characteristics. A total of 34 older adults (25 females) completed the full study protocol. Walking kinematic data were collected using the MyoMotion 3D motion analysis system under single-task and three dual-task conditions (walking while counting, carrying water, and naming). Spatiotemporal parameters, including step length, cadence, and lower limb joint angles, were extracted through gait cycle analysis. The control group maintained their habitual daily activities. Repeated measures analysis of variance (ANOVA) was used to compare differences between groups and across time points (pre- and post-intervention), with the significance level set at 0.05. Result: Baseline characteristics were comparable between groups (p >0.05). Post-intervention, the experimental group demonstrated significant improvements in gait spatial parameters, characterized by increased normalized step and stride lengths and decreased step width compared to controls (p <0.05). Temporally, the experimental group exhibited an increased percentage of stance phase. Kinematically, the intervention significantly enhanced hip range of motion (p <0.01) and altered knee and ankle joint angles at specific gait events. Notably, a significant group-by-task interaction was observed for maximum hip extension (p <0.05), indicating that Tai Chi training differentially optimized hip mechanics across varying dual-task conditions. Additionally, the experimental group showed significantly improved overall cognitive function (p < 0.01). Conclusion: The Tai Chi intervention effectively improved gait stability, balance, and overall gait performance under dual-task conditions in older adults with MCI, thereby reducing the risk of falls. These findings support Tai Chi as a safe, cost-effective, and scalable non-pharmacological intervention for fall prevention in this population.