***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND Few scientific studies have examined movement-based embodied contemplative practice s such as yoga and their effects on cognition . The purpose of this r and omized controlled trial was to examine the effects of an 8-week Hatha yoga intervention on executive function measures of task switching and working memory capacity . METHODS Community-dwelling older adults ( N = 118 ; mean age = 62.0 ) were r and omized to one of two groups : a Hatha yoga intervention or a stretching-strengthening control . Both groups participated in hour-long exercise classes 3 × /week over the 8-week study period . All participants completed established tests of executive function including the task switching paradigm , n-back and running memory span at baseline and follow-up . RESULTS Analysis of covariances showed significantly shorter reaction times on the mixed and repeat task switching trials ( partial η(2 ) = .04 , p < .05 ) for the Hatha yoga group . Higher accuracy was recorded on the single trials ( partial η(2 ) = .05 , p < .05 ) , the 2-back condition of the n-back ( partial η(2 ) = .08 , p < .001 ) , and partial recall scores ( partial η(2 ) = .06 , p < .01 ) of running span task . CONCLUSIONS Following 8 weeks of yoga practice , participants in the yoga intervention group showed significantly improved performance on the executive function measures of working memory capacity and efficiency of mental set shifting and flexibility compared with their stretching-strengthening counterparts . Although the underlying mechanisms need to be investigated , these results dem and larger systematic trials to thoroughly examine effects of yoga on executive function as well as across other domains of cognition , and its potential to maintain or improve cognitive functioning in the aging process OBJECTIVE We evaluated the effects of exercise on neurobehavioral function in healthy older people more than 75 years of age . DESIGN A r and omized controlled trial with 6-month follow-up was conducted . SETTING The study was performed in the rural town of Kahoku , Japan , the population of which is considered representative of the older population of Japan . PARTICIPANTS We studied 42 healthy volunteers ( 18 men and 24 women ; mean age , 79 years ( range 75 to 87 years ) ) who were r and omly assigned to one of two groups , exercise or control . INTERVENTION Subjects assigned to the exercise group were instructed to exercise for 60 minutes twice a week for 6 months . Subjects in the control group were not instructed to engage in an specific exercise regimen . MEASUREMENTS The following measurements were recorded for both groups at baseline and at 6-month follow-up : ( 1 ) Neurobehavioral function as determined by the following tests : Mini-Mental State Exam ( MMSE ) , Hasegawa Dementia Scale Revised ( HDSR ) , Visuospatial Cognitive Performance Test ( VCP-test ) , Button score , Up & Go test , and Functional Reach ; and ( 2 ) Body mass index and blood pressure . RESULTS The effects of exercise were shown in the Up & Go test , and Functional Reach ( ANOVA with repeated measures ) . CONCLUSION This study demonstrates the acceptability and effectiveness of exercise on neurobehavioral function , even in older people more than 75 years of age Physical exercise has been shown to increase brain volume and improve cognition in r and omized trials of non-demented elderly . Although greater social engagement was found to reduce dementia risk in observational studies , r and omized trials of social interventions have not been reported . A representative sample of 120 elderly from Shanghai , China was r and omized to four groups ( Tai Chi , Walking , Social Interaction , No Intervention ) for 40 weeks . Two MRIs were obtained , one before the intervention period , the other after . A neuropsychological battery was administered at baseline , 20 weeks , and 40 weeks . Comparison of changes in brain volumes in intervention groups with the No Intervention group were assessed by t-tests . Time-intervention group interactions for neuropsychological measures were evaluated with repeated- measures mixed models . Compared to the No Intervention group , significant increases in brain volume were seen in the Tai Chi and Social Intervention groups ( p < 0.05 ) . Improvements also were observed in several neuropsychological measures in the Tai Chi group , including the Mattis Dementia Rating Scale score ( p = 0.004 ) , the Trailmaking Test A ( p = 0.002 ) and B ( p = 0.0002 ) , the Auditory Verbal Learning Test ( p = 0.009 ) , and verbal fluency for animals ( p = 0.01 ) . The Social Interaction group showed improvement on some , but fewer neuropsychological indices . No differences were observed between the Walking and No Intervention groups . The findings differ from previous clinical trials in showing increases in brain volume and improvements in cognition with a largely non-aerobic exercise ( Tai Chi ) . In addition , intellectual stimulation through social interaction was associated with increases in brain volume as well as with some cognitive improvements Background Mild cognitive impairment ( MCI ) is a well-recognised risk factor for dementia and represents a vital opportunity for intervening . Exercise is a promising strategy for combating cognitive decline by improving brain structure and function . Specifically , aerobic training ( AT ) improved spatial memory and hippocampal volume in healthy community-dwelling older adults . In older women with probable MCI , we previously demonstrated that resistance training ( RT ) and AT improved memory . In this secondary analysis , we investigated : ( 1 ) the effect of RT and AT on hippocampal volume and ( 2 ) the association between change in hippocampal volume and change in memory . Methods 86 women aged 70–80 years with probable MCI were r and omly assigned to a 6-month , twice-weekly programme of : ( 1 ) AT , ( 2 ) RT or ( 3 ) balance and tone training ( BAT ; ie , control ) . At baseline and trial completion , participants performed a 3 T MRI scan to determine hippocampal volume . Verbal memory and learning were assessed by Rey 's Auditory Verbal Learning Test . Results Compared with the BAT group , AT significantly improved left , right and total hippocampal volumes ( p≤0.03 ) . After accounting for baseline cognitive function and experimental group , increased left hippocampal volume was independently associated with reduced verbal memory and learning performance as indexed by loss after interference ( r=0.42 , p=0.03 ) . Conclusions Aerobic training significantly increased hippocampal volume in older women with probable MCI . More research is needed to ascertain the relevance of exercise-induced changes in hippocampal volume on memory performance in older adults with MCI . Trail registration number NCT00958867 This study aim ed to investigate the effects of a long-term resistance exercise intervention on executive functions in healthy elderly males , and to further underst and the potential neurophysiological mechanisms mediating the changes . The study assessed forty-eight healthy elderly males r and omly assigned to exercise ( n = 24 ) or control ( n = 24 ) groups . The assessment included neuropsychological and neuroelectric measures during a variant of the oddball task paradigm , as well as growth hormone ( GH ) , insulin-like growth factor-1 ( IGF-1 ) , and homocysteine levels at baseline and after either a 12 month intervention of resistance exercise training or control period . The results showed that the control group had a significantly lower accuracy rate and smaller P3a and P3b amplitudes in the oddball condition after 12 months . The exercise group exhibited improved reaction times ( RTs ) , sustained P3a and P3b amplitudes , increased levels of serum IGF-1 , and decreased levels of serum homocysteine . The changes in IGF-1 levels were significantly correlated with the changes in RT and P3b amplitude of the oddball condition in the exercise group . In conclusion , significantly enhanced serum IGF-1 levels after 12 months of resistance exercise were inversely correlated with neurocognitive decline in the elderly . These findings suggest that regular resistance exercise might be a promising strategy to attenuate the trajectory of cognitive aging in healthy elderly individuals , possibly mediated by IGF-1 BACKGROUND Subjects with a mild cognitive impairment ( MCI ) have a memory impairment beyond that expected for age and education yet are not demented . These subjects are becoming the focus of many prediction studies and early intervention trials . OBJECTIVE To characterize clinical ly subjects with MCI  cross-sectionally and longitudinally . DESIGN A prospect i ve , longitudinal inception cohort . SETTING General community clinic . PARTICIPANTS A sample of 76 consecutively evaluated subjects with MCI were compared with 234 healthy control subjects and 106 patients with mild Alzheimer disease ( AD ) , all from a community setting as part of the Mayo Clinic Alzheimer 's Disease Center/Alzheimer 's Disease Patient Registry , Rochester , Minn. MAIN OUTCOME MEASURES The 3 groups of individuals were compared on demographic factors and measures of cognitive function including the  Mini-Mental State Examination , Wechsler Adult Intelligence Scale-Revised , Wechsler Memory Scale-Revised , Dementia Rating Scale , Free and Cued Selective Reminding Test , and Auditory Verbal Learning Test .  Clinical classifications of dementia and AD were determined according to the Diagnostic and Statistical Manual of Mental Disorders , Revised Third Edition and the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer 's Disease and Related Disorders Association criteria , respectively . RESULTS The primary distinction between control subjects and subjects with MCI was in the area of memory , while other cognitive functions were comparable . However , when the subjects with MCI were compared with the patients with very mild AD , memory performance was similar , but patients with AD were more impaired in other cognitive domains as well . Longitudinal performance demonstrated that the subjects with MCI declined at a rate greater than that of the controls but less rapidly than the patients with mild AD . CONCLUSIONS Patients who meet the criteria for MCI can be differentiated from healthy control subjects and those with very mild AD . They appear to constitute a clinical entity that can be characterized for treatment interventions Strength training has been reported as a potentially useful exercise to improve psychological aspects in the elderly , but its effects remain controversial . This study investigated the effectiveness of strength training conducted twice a week for 12 weeks for improving health-related quality of life ( HRQOL ) and executive cognitive function . The study was a single-blind r and omized controlled trial with assessment s before and after intervention . HRQOL and executive function were assessed using the SF-36 Health Status Survey and a computerized neuro-cognitive assessment using task-switch reaction time trials , respectively . Subjects comprised 119 participants > or = 65 years old , r and omized to either strength training ( n=65 ) or health education classes ( controls , n=54 ) . The strength training program was design ed to strengthen the large muscle groups most important for functional activities and to improve balance . The effects of the intervention on the eight dimensions of the SF-36 in the control and training groups were analyzed . Only the mental health scale of the SF-36 was significantly improved for the training group compared with controls after 12 weeks . Task-switch reaction time and correct response rate remained unchanged . Short-term strength training might have modest positive effects on HRQOL , although this training period may not be sufficient to affect executive function in relatively healthy older people The aim of this study was to investigate the effects of a 6-month exercise program on cognitive function and blood viscosity in sedentary elderly men . Forty-six healthy inactive men , aged 60–75 years were r and omly distributed into a control group ( n=23 ) and an experimental group ( n=23 ) . Participants underwent blood analysis and physical and memory evaluation , before and after the 6-month program of physical exercise . The control group was instructed not to alter its everyday activities ; the experimental group took part in the fitness program . The program was conducted using a cycle ergometer , 3 times per week on alternate days , with intensity and volume individualized at ventilatory threshold 1 . Sessions were continuous and maximum duration was 60 min each . There was significant improvement in memory ( 21 % ; P<0.05 ) , decreased blood viscosity ( −19 % ; P<0.05 ) , and higher aerobic capacity ( 48 % ; P<0.05 ) among participants in the experimental group compared with the control group . These data suggest that taking part in an aerobic physical fitness program at an intensity corresponding to ventilatory threshold-1 may be considered a nonmedication alternative to improve physical and cognitive function The aims of this study were to examine the effects of aerobic exercise on measures of executive performance and their relationships with changes in cardiorespiratory fitness , cardiac vagal control ( heart rate variability ) and psychological variables . Thirty-six sedentary seniors aged 60 - 75 years were r and omly assigned to a swimming and aquaerobics program or a stretching program two times a week for 21 weeks . Executive functions ( inhibition , updating of working memory and cognitive flexibility ) and cardiorespiratory fitness ( estimated VO2max ) were assessed at the start , after 10 weeks of program and at the end of the program . Resting HRV and measures of psychological outcomes ( depression , self-efficacy , decisional balance ) were obtained at the start and at the end of the program . Participants of both groups significantly improved their VO2max level , their psychological state and their performance for the 2-back task . Only the participants in the aquaerobics group significantly improved their vagally-mediated HRV and their performance for the Stroop test and the verbal running-span test at the end of the program . Only improvements in cardiac vagal control and in inhibition were shown to be functionally related . These results are discussed in line with the model of neurovisceral integration CONTEXT Evidence suggests that physical activity may be related to the clinical expression of dementia . Whether the association includes low-intensity activity such as walking is not known . 
    Output:
    
When exercise prescription was examined , a duration of 45–60 min per session and at least moderate intensity , were associated with benefits to cognition .
Conclusions Physical exercise  improved cognitive function in the over 50s , regardless of the cognitive status of participants .