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Purpose: We aimed to assess whether total daily physical activity (PA), PA intensities, sedentary time (ST), and prolonged ST are associated with differences in the gut microbiota composition or short-chain fatty acid (SCFA) profile of adults with overweight or obesity. Methods: Cross-sectional associations between total daily PA (counts per minute), PA intensities (light and moderate-to-vigorous (MVPA)), ST, prolonged ST, and fecal microbiota composition were assessed in adults (n = 124) between 25 and 45 yr of age with body mass index ≥25 kg·m−2. Fecal microbiota composition was assessed with 16S rRNA gene sequencing. Daily PA and ST were measured with a hip-worn ActiGraph wGT3X-BT accelerometer. Results: Daily PA volume and intensity were positively associated with relative abundance of Faecalibacterium (P = 0.04) and negatively associated with the abundances of Alistipes , Parabacteroides , and Gemmiger (P = 0.003–0.04) as well as the concentrations of acetate, butyrate, and total SCFA (all P = 0.04). Conversely, ST was negatively associated with abundance of Faecalibacterium but positively associated with the abundances of taxa, including Ruminococcaceae, Parabacteroides , Alistipes , and Gemmiger. Clustering of participants based on whether they met PA recommendations suggested that SCFA profiles differed between individuals who did and did not meet PA recommendations. K-means clustering based on percent of time spent in MVPA and ST also identified differences in fecal microbiota composition between cluster 1 (lower MVPA, higher ST) and cluster 2 (higher MVPA, lower ST), including a higher abundance of Alistipes in cluster 1. Conclusions: The current analysis suggests a beneficial association of daily PA on the fecal microbiota and a negative association of ST, particularly with respect to the associations of these variables with the genera Faecalibacterium , a butyrate-producing taxon. [ABSTRACT FROM AUTHOR]

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., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Using a Biocultural Model of Maturity-Associated Variance in physical activity (PA) as a conceptual framework, the main and interactive effects of biological maturity status and perceived peer acceptance on PA and health-related quality of life (HRQoL) in adolescent girls were examined., Methods: Three hundred forty-two female British students in years 7 to 9 (13.2±0.83 years) participated in the study. All participants completed the PA Questionnaire for Adolescents and KIDSCREEN-10, a measure of HRQoL. Self-reported perceptions of peer acceptance were measured by items from the National Longitudinal Study of Adolescent Health.Maturity status was estimated as the percentage of predicted adult (mature) height attained at the time of observation., Results: Analysis of covariance suggested an influence of peer acceptance on maturity-associated differences in PA, but not on HRQoL. Girls early and "on time" in maturation with higher perceptions of peer acceptance reported greater involvement in PA than girls early and "on time" in maturation with lower perceptions of peer acceptance. A reverse association was observed for late-maturing girls., Conclusions: Peer acceptance is an important moderator of maturity-associated variation in PA.