Victor Selvarajah Selvanayagam

The positive correlation between physical activity and cognitive function has been increasingly documented, while the underlying mechanisms remain unclear. This study aimed to investigate the association among physical activity (PA), functional fitness, and cognitive function in community-dwelling older adults, and to examine whether functional fitness mediates this association. This study utilized a cross-sectional design, encompassing 224 participants aged 65 or above, with 41.07% male and 58.93% female. The data were collected in 2023 using the Mini-Mental State Examination, Physical Activity Scale for the Elderly, and Senior Fitness Test. Pearson correlation analysis was conducted to assess associations among the variables, and mediation analysis was performed using the PROCESS macro for SPSS. The results indicated that PA had a moderate positive correlation with cognitive function (r = 0.437, p < 0.01) and with most functional fitness domains. In addition, significant positive correlations were found among most functional fitness domains and cognitive function. The association between PA and cognitive function was partially mediated by cardiorespiratory endurance (Effect = 0.0519, 95% CI= [0.0205, 0.0889]). This study demonstrated a positive correlation between PA and cognitive function in older adults, with cardiorespiratory endurance mediating this association. Our study provides valuable preliminary evidence that cardiorespiratory endurance exerts a mediating role between PA and cognitive function. Future longitudinal research is warranted to elucidate the causal relationship and underlying mechanisms between PA and cognitive function.

This study examined the number of contractions required for an isometric plantar flexion familiarization. Twenty-six males were separated into two independent Groups: Group A: where five contractions were initiated on the dominant limb (right) followed by the contralateral limb; and Group B, initiated by the non-dominant limb (left) followed by the dominant limb. Participants carried out a 5-s maximum voluntary contraction (MVC), with an interpolated twitch administered to the tibial nerve. In Group A, both the dominant and non-dominant limbs required two contractions for familiarization, whereas in Group B, the dominant limb required two contractions, and the non-dominant limb required three (p < 0.05). A strong relationship between MVC and voluntary activation (VA) was observed in Group A for the D (r = 0.91, p < 0.05) and in Group B for the ND limb (r = 0.99, p < 0.05). The results demonstrated evidence of cross-limb transfer from the dominant to the non-dominant limb (p < 0.05). This phenomenon implicates central involvement, substantiated by VA responses that mirror the changes in MVC. Practitioners and researchers should consider the impact of cross-limb transfer during a single familiarization session when assessing strength to avoid overestimation of the gains. Future cross-education/cross-limb transfer studies could investigate the central mechanisms involved during familiarization.

Background: Exercise interventions for mild cognitive impairment (MCI) have been extensively studied. However, there is no bibliometric study on exercise interventions for MCI. This study aimed to identify the collaborative networks, research hotspots, evolution trends, and future directions. Methods: Relevant documents were retrieved from the Web of Science Core Collection database. VOSviewer was used to analyze the co-authorship of the author, countries and institutions, and the keywords co-occurrence. CiteSpace was used to detect burst keywords’ research trends. Results: A total of 569 articles were included and showed an overall increasing trend in annual publications. The most influential subject categories, authors, journals, country, and institutions were “geriatrics gerontology,” “Doi, Takehiko and Shimada, Hiroyuki,” “ Journal of Alzheimer’s Disease ,” USA, and “Veterans Health Administration,” respectively. The research hotspots are “effectiveness,” “neural mechanism” and “correlation” of exercise interventions, and the emerging trend is “intervention quality.” Conclusion: This area is in a rapid development phase, whereby research hotpots are focused and the research trend is clear. The highly productive authors and institutions have made outstanding contributions and the subject categories present an interdisciplinary trend. However, there is weak cooperation between countries and institutions, and a substantial research gap exists between developed and developing countries. Future research may highlight the intervention quality, emphasizing the combination with virtual reality technology.

The ability to accurately identify proximity to momentary failure during a set of resistance exercise might be important to maximise training adaptations. This study examined the association between perceptual fatigue and the accuracy of the estimated repetitions to failure (ERF). Twenty-seven males and eleven females performed sets of 10 repetitions at specific loads for the chest press and leg-press. Following the completion of 10 repetitions, participants rated their fatigue and ERF and then proceeded to concentric failure (actual repetitions to failure) to determine the ERF accuracy (i.e., error-ERF). Small correlations were found between perceptual fatigue and error-ERF for the chest-press (r = −0.26, p = 0.001) and the leg-press (r = −0.18, p = 0.013). For actual repetitions to failure and error-ERF, a strong correlation was found for the chest-press (r = 0.68, p < 0.001) and a very strong correlation was foundfor the leg-press (r = 0.73, p < 0.001). Moderate correlations were found between perceptual fatigue and actual repetitions to failure for the chest-press (r = −0.42, p < 0.001) and leg-press (r = −0.40, p < 0.001). Overall, findings suggest that the accuracy of the estimated repetitions to failure is more strongly associated with proximity to task repetition failure rather than subjective feelings of fatigue.

Tion of trained forces. Methods In experiment 1 (n = 10), we tested the direction of force exerted in an isometric aiming task before and after 40 repetitions of 2-s maximal-force ballistic contractions toward a single directional target. In experiment 2 (n = 12), each participant completed three training conditions in a counterbalanced crossover design. In two conditions, both the aiming task and the training were conducted in the same (neutral) forearm posture. In one of these conditions, the training involved weak forces to determine whether the level of neural drive during training influences the degree of bias. In the third condition, high-force training contractions were performed in a 90° pronated forearm posture, whereas the low-force aiming task was performed in a neutral forearm posture. This dissociated the extrinsic training direction from the pulling direction of the trained muscles during the aiming task. Results In experiment 1, we found that aiming direction was biased toward the training direction across a large area of the work space (approximately ±135°; tested for 16 targets spaced 22.5° apart), whereas in experiment 2, we found systematic bias in aiming toward the training direction defined in extrinsic space, but only immediately after high-force contractions. Conclusion Our findings suggest that bias effects of training involving strong neural drive generalize broadly to untrained movement directions and are expressed according to extrinsic rather than muscle-based coordinates....