Effects of reducing sedentary behaviour by increasing physical activity, on cognitive function, brain function and structure across the lifespan: a systematic review and meta-analysis.

OBJECTIVE: To examine the acute and chronic effects of reducing prolonged sedentary time (ST) with physical activity (PA) on cognitive and brain health. DESIGN: Systematic review and meta-analysis. DATA SOURCES: PubMed, Scopus, CINAHL, PsycINFO, SPORTDiscus, Web of Science, and ProQuest Dissertation and Theses. ELIGIBILITY CRITERIA: Randomised controlled trials (RCTs) published from inception to 17 June 2024, with healthy participants without cognitive impairment or neurological conditions that affect cognitive functioning, aged ≥4 years, testing acute and chronic effects of reducing ST and/or prolonged ST by reallocating ST to PA on cognitive function, brain function, and structure. RESULTS: We included 25 RCTs (n=1289) investigating acute (21 studies) and chronic (4 studies) effects on cognitive function (acute: n=20, chronic: n=4) and brain function (acute: n=7, chronic: n=1); there were no studies on brain structure. Acutely interrupting continuous ST with either multiple or a single PA bout improved cognitive function measured from 3 hours to three consecutive days based on 91 effect sizes (g=0.17, 95% CI: 0.05 to 0.29, p=0.005, I 2=45.5%). When comparing single versus multiple PA bouts, only multiple PA bouts yielded a positive effect on cognitive function based on 72 effect sizes (g=0.20, 95% CI: 0.06 to 0.35, p=0.006; I 2=48.8%). Chronic studies reported null findings on cognitive function (n=4), with some evidence of improved neural efficiency of the hippocampus (n=1). CONCLUSION: Interrupting ST with PA acutely improves cognitive function. The evidence from chronic studies remains inconclusive. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020200998.

Resistance training reduces depressive and anxiety symptoms in older women: a pilot study.

OBJECTIVES: The purposes of this study were to analyze the effect of resistance training (RT) on depressive and anxiety symptomsand examine the possible consequences of age, cognitive alterations, and muscular strength on such symptoms.Method: Forty-one older women (68 ± 8 years) composed a training group (TG) or a control group (CG). The TG was submitted to a supervised, progressive RT program over 12 weeks, involving eight whole-body exercises performed with three sets of 8-12 repetitions, three days per week, whereas CG remains with no intervention for the same period. Muscular strength (one-repetition maximum tests), cognitive function (Montreal Cognitive Assessment - MoCA; Verbal Fluency Tests), depression (15-item eriatric Depression Scale - GDS-15), and anxiety (Beck Anxiety Inventory - BAI) were assessed before and after the intervention period. RESULTS: There were observed significant (P < 0.001) RT-induced improvements on total muscular strength (TG: pre = 122.4 ± 24.1/post = 134.3 ± 36.7; CG: pre = 105.4 ± 15.4/post = 99.2 ± 17.1) and MoCA (TG: pre =21.7 ± 4.5/post = 22.5 ± 4.7; CG: pre = 20.3 ± 3.7/post = 19.3 ± 4.1). Depressive and anxiety symptoms (even when adjusted by chronological age and changes in muscular strength or cognitive function) were reduced with RT according to GDS-15 (TG: pre = 2.26 ± 1.53/post = 1.92 ± 1.68; CG: pre =2.68 ± 1.13/post = 2.25 ± 1.18) and BAI (TG: pre = 4.07 ± 5.68/post = 2.33 ± 3.71; CG: pre = 5.18 ± 7.70/post = 9.81 ± 7.10). The time x group interactions were significant for depressive and anxiety symptoms. CONCLUSIONS: Our results suggest that a 12-week RT program reduces depressive and anxiety symptoms, regardless of age, muscular strength, and cognition function in older women.

Sarcopenia and fall-related injury among older adults in five low- and middle-income countries.

Sarcopenia is a common condition in older people and increasing evidence suggests that it can be considered as a potential risk factor for falls and fractures. However, no studies on this topic from low- and middle-income countries (LMICs) are available. Thus, we assessed this association among older adults from five LMICs (China, India, Ghana, Mexico, and Russia). Community-based, nationally representative, cross-sectional data of the Study on Global Aging and Adult Health were analyzed. Sarcopenia was defined as the presence of low skeletal muscle mass based on indirect population formula, and either slow gait or low handgrip strength. The presence of fall-related injury was ascertained through self-reported information. Multivariable logistic regression analysis and meta-analysis were conducted. The sample consisted of 13,101 individuals aged ≥65 years (mean (SD) age 72.6 (11.3) years; 45% males). The prevalence of fall-related injury was higher among those with sarcopenia than in those without this condition (e.g., Mexico 9.8% vs. 2.7%). Adjusted analyses showed that sarcopenia was associated with a 1.85 (95%CI = 1.24-2.77) times higher odds for fall-related injury, with a low level of between-country heterogeneity. Future studies of longitudinal design may shed light on whether sarcopenia in LMICs may be considered as a risk factor for falls.