Exercise interventions for older adults: A systematic review of meta-analyses

Background:The evidence concerning which physical exercise characteristics are most effective for older adults is fragmented.We aimed to characterize the extent of this diversity and inconsistency and identify future directions for research by undertaking a systematic review of metaanalyses of exercise interventions in older adults.Methods:We searched the Cochrane Database of Systematic Reviews,PsycInfo,MEDLINE,Embase,CINAHL,AMED,SPORTDiscus,and Web of Science for articles that met the following criteria:(1)meta-analyses that synthesized measures of improvement(e.g.,effect sizes)on any outcome identified in studies of exercise interventions;(2)participants in the studies meta-analyzed were adults aged 65+or had a mean age of 70+;(3)meta-analyses that included studies of any type of exercise,including its duration,frequency,intensity,and mode of delivery;(4)interventions that included multiple components(e.g.,exercise and cognitive stimulation),with effect sizes that were computed separately for the exercise component;and(5)meta-analyses that were published in any year or language.The characteristics of the reviews,of the interventions,and of the parameters improved through exercise were reported through narrative synthesis.Identification of the interventions linked to the largest improvements was carried out by identifying the highest values for improvement recorded across the reviews.The study included 56 meta-analyses that were heterogeneous in relation to population,sample size,settings,outcomes,and intervention characteristics.Results:The largest effect sizes for improvement were found for resistance training,meditative movement interventions,and exercise-based active videogames.Conclusion:The review identified important gaps in research,including a lack of studies investigating the benefits of group interventions,the characteristics of professionals delivering the interventions associated with better outcomes,and the impact of motivational strategies and of significant others(e.g.,carers)on intervention delivery and outcomes.

Electrocortical and Hemodynamic Changes within the Brain during Incremental Bicycle Exercise in Normoxia and Hypoxiam--A Combined EEG/NIRS Study

The correlation of NIRS （near-infrared spectroscopy） and EEG （electro-cortical activity） in exercise studies has never been shown. Eight sport students performed an incremental bicycle exercise test under normoxic and hypoxic （12.7% 02） conditions respectively. EEG and NIRS recordings of the prefrontal cortex （PFC, Brodmarm area 10.46） were performed synchronously to shed light on their correlation. ANOVA revealed a higher absolute workload （231.3 ＋ 37.2 W）, and relative PFC oxygenation under normoxic conditions, whereas hypoxic conditions resulted in earlier exhaustion （200 ~ 26.7 W） and reduced PFC oxygenation. NIRS parameters increased remarkably with exercise intensity （P 〈 0.001） and differed between conditions （O2Hb： P 〈 0.001; HHb： P = 0.023; tHb： P = 0.016） and hemispheres （O2Hb： P = 0.023）. For EEG, higher prefrontal cortical current density during compared to pre and post exercise was revealed for both conditions （P 〈 0.001）. No difference between conditions and hemispheres were found. In conclusion, brain cortical activity is not impaired by hypoxia. No correlation between NIRS and EEG, but a moderate correlation between EEG and cardio-vascular parameters and a moderate to high correlation between NIRS and cardio-vascular parameters were found. The results emphasize that the transfer of EEG and NIRS results need to be done with caution.

简析对金属软管的认识误区

众所周知,发动机工作时的振动需要有柔性足够的连接管来吸收屏蔽,以保护下游的管道和消音器,否则发动机和固定在底盘上的消音器将因剧烈振动而损坏;因此,这根关键的缓冲连接管必须具备良好的柔性,同时还要兼备一定的气密性。