***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 Recent research has suggested an important role of lateral prefrontal cortex ( lPFC ) in consistent implementation of positive health behaviors and avoidance of negative health behaviors . Methods We examined whether gray matter volume in the lPFC prospect ively predicts exercise class attendance among older women ( n = 122 ) who underwent either a 52-week or 26-week exercise training intervention .  Structural magnetic resonance imaging determined gray matter volume at baseline . Results Independent of intracranial volume , age , education , body composition , mobility , depressive symptoms , and general cognitive functioning , larger lPFC volume predicted greater exercise class attendance ( all p values < .05 ) . Follow-up whole-brain analyses further confirmed that regions in the lPFC-especially the left middle frontal gyrus ( p < .005)-predicted future exercise adherence as well as identified other regions , especially in the insula and temporal cortex , that predicted exercise adherence . Conclusions These findings suggest that sustained engagement in exercise training might rely in part on functions of the lPFC and that lPFC volume might be a reasonable proxy for such functions The combined effects of hyperventilation and arterial desaturation on cerebral oxygenation ( [ Formula : see text ] ) were determined using near-infrared spectroscopy . Eleven competitive oarsmen were evaluated during a 6-min maximal ergometer row . The study was r and omized in a double-blind fashion with an inspired O2 fraction of 0.21 or 0.30 in a crossover design . During exercise with an inspired O2 fraction of 0.21 , the arterial CO2 pressure ( 35 ± 1 mmHg ; mean ± SE ) and O2 pressure ( 77 ± 2 mmHg ) as well as the hemoglobin saturation ( 91.9 ± 0.7 % ) were reduced ( P < 0.05).[Formula : see text ] was reduced from 80 ± 2 to 63 ± 2 % ( P < 0.05 ) , and the near-infrared spectroscopy-determined concentration changes in deoxy- ( ΔHb ) and oxyhemoglobin ( ΔHbO2 ) of the vastus lateralis muscle increased 22 ± 3 μM and decreased 14 ± 3 μM , respectively ( P < 0.05 ) . Increasing the inspired O2fraction to 0.30 did not affect ventilation ( 174 ± 4 l/min ) , but arterial CO2 pressure ( 37 ± 2 mmHg ) , O2 pressure ( 165 ± 5 mmHg ) , and hemoglobin O2saturation ( 99 ± 0.1 % ) increased ( P < 0.05).[Formula : see text ] remained close to the resting level during exercise ( 79 ± 2 vs. 81 ± 2 % ) , and although the muscle ΔHb ( 18 ± 2 μM ) and ΔHbO2 ( -12 ± 3 μM ) were similar to those established without O2 supplementation , work capacity increased from 389 ± 11 to 413 ± 10 W ( P < 0.05 ) . These results indicate that an elevated inspiratory O2fraction increases exercise performance related to maintained cerebral oxygenation rather than to an effect on the working muscles Background Dementia is more common in older than in younger people , and as a result of the ageing of the population in developed countries , it is becoming more prevalent . Drug treatments for dementia are limited , and the main support offered to people with dementia and their families is generally services to mitigate against loss of function . Physical exercise is a c and i date non-pharmacological treatment for dementia . Methods / Design DAPA is a r and omised controlled trial funded by the National Institute for Health Research Health Technology Assessment programme to estimate the effect of a 4-month , moderate- to hard-intensity exercise training programme and subsequent advice to remain active , on cognition ( primary outcome ) at 12 months in people with mild to moderate dementia . Community-dwelling participants ( with their carers where possible ) , who are able to walk 3 metres without human assistance , able to undertake an exercise programme and do not have any unstable or terminal illness are recruited . Participants are then r and omised by an independent statistician using a computerised r and om number generator to usual care or exercise at a 2:1 ratio in favour of exercise . The exercise intervention comprises 29 , 1-hour-long exercise classes , run twice weekly at suitable venues such as leisure centres , which include aerobic exercise ( on static bikes ) and resistance exercise ( using weights ) . Goals for independent exercise are set while the classes are still running , and supported thereafter with phone calls . The primary outcome is measured using ADAS-cog . Secondary outcome measures include behavioural symptoms , functional ability , quality of life and carer burden . Primary and secondary outcomes will be measured at baseline and at 6 and 12 months after r and omisation , by research ers masked to participant r and omisation in the participants ’ own homes . An economic evaluation will be carried out in parallel to the RCT , as will a qualitative study capturing the experiences of participants , carers and staff delivering the intervention . Discussion The DAPA study will be the first large , r and omised trial of the cognitive effects of exercise on people with dementia . The intervention is design ed to be capable of being delivered within the constraints of NHS service provision , and the economic evaluation will allow assessment of its cost-effectiveness . Trial registration DAPA was registered with the IS RCT N data base on 29 July 2011 , registration number IS RCT N32612072 BACKGROUND Over half of stroke survivors have cognitive impairment , which impedes rehabilitation and functional recovery . Evidence suggests a single session of aerobic exercise improves cognitive functions among healthy adults . Whether this holds true for stroke survivors is unclear . The objective of this study was to examine whether one session of moderate-intensity aerobic exercise improves the cognitive control and attention of stroke survivors . METHODS Nine people with chronic stroke ( ≥6 months poststroke ) performed a modified Eriksen Flanker task with concurrent electroencephalography ( EEG ) before and immediately , 20 minutes , and 40 minutes after 20 minutes of moderate-intensity exercise and after 20 minutes of rest . The sessions were in r and omized order . Accuracy and response time were recorded for congruent and incongruent stimuli . Differences in accuracy , response time , and event-related potentials ( P300 , reflective of decision making ) were analyzed using repeated measures analysis of variance . RESULTS Improvements in EEG measures were noted after exercise . P300 amplitude at Fz was greater 40 minutes after exercise compared with after rest ( P = .007 ) . P300 latency was also shorter at 20 minutes after exercise compared with after rest for both congruent ( 465.8 milliseconds versus 500.0 milliseconds ; P = .02 ) and incongruent ( 468.0 milliseconds versus 532.0 milliseconds ; P = .003 ) conditions at the central electrode on the lesional side . Differences in behavioral performance after exercise were not significant . CONCLUSIONS Preliminary results suggest that aerobic exercise  improves cortical processes underlying cognitive control and attention 20 - 40 minutes postexercise . Future research should confirm results in a larger sample and examine whether attention-dem and ing rehabilitation in this window has improved outcomes UNLABELLED Repeated maximal-intensity short- duration exercise ( sprint interval training , SIT ) can produce muscle adaptations similar to endurance training ( ET ) despite a much reduced training volume . However , most SIT data use cycling , and little is known about its effects on body composition or maximal cardiac output ( Qmax ) . PURPOSE The purpose of this study was to assess body composition , 2000-m run time trial , VO(2max ) , and Q(max ) effects of run SIT versus ET . METHODS Men and women ( n = 10 per group ; mean ± SD : age = 24 ± 3 yr ) trained three times per week for  6 wk with SIT , 30-s all-out run sprints ( manually driven treadmill ) , four to six bouts per session , 4-min recovery per bout , versus ET , 65 % VO(2max ) for 30 to 60 min·d(-1 ) . RESULTS Training improved ( P < 0.05 ) body composition , 2000-m run time trial performance , and VO(2max ) in both groups . Fat mass decreased 12.4 % with SIT ( mean ± SEM ; 13.7 ± 1.6 to 12.0 ± 1.6 kg ) and 5.8 % with ET ( 13.9 ± 1.7 to 13.1 ± 1.6 kg ) . Lean mass increased 1 % in both groups . Time trial performance improved 4.6 % with SIT ( -25.6 ± 8.1 s ) and 5.9 % with ET ( -31.9 ± 6.3 s ) . VO(2max ) increased 11.5 % with SIT ( 46.8 ± 1.6 to 52.2 ± 2.0 mL·kg·(-1)·min(-1 ) ) and 12.5 % with ET ( 44.0 ± 2.0 to 49.5 ± 2.6 mL·kg·(-1)·min(-1 ) ) . None of these improvements differed between groups . In contrast , Q(max ) increased by 9.5 % with ET only ( 22.2 ± 2.0 to 24.3 ± 1.6 L·min(-1 ) ) . CONCLUSIONS Despite a fraction of the time commitment , run SIT induces similar body composition , VO(2max ) , and performance adaptations as ET , but with no effect on Q(max ) . These data suggest that adaptations with ET are of central origin primarily , whereas those with SIT are more Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more Brain-derived neurotrophic factor ( BDNF ) plays a role in the maintenance and function of neurons . Although persons with Alzheimer ’s disease have lower cortical levels of BDNF , evidence regarding the association between circulating BDNF and cognitive function is conflicting . We sought to determine the correlates of BDNF level and whether BDNF level was prospect ively associated with cognitive decline in healthy older adults . We measured serum BDNF near baseline in 912 individuals .  Cognitive status was assessed repeatedly with the modified Mini-Mental Status Examination and the Digit Symbol Substitution test over the next 10 years . We evaluated the association between BDNF and cognitive decline with longitudinal models . We also assessed the association between BDNF level and demographics , comorbidities and health behaviors . We found an association between serum BDNF and several characteristics that are also associated with dementia ( race and depression ) , suggesting that future studies should control for these potential confounders . We did not find evidence of a longitudinal association between serum BDNF and subsequent cognitive test trajectories in older adults , although we did identify a potential trend toward a cross-sectional association . Our results suggest that serum BDNF may have limited utility as a biomarker of prospect i ve cognitive decline Brain blood vessels contain muscarinic receptors that are important for cerebral blood flow ( CBF ) regulation , but whether a cholinergic receptor mechanism is involved in the exercise-induced increase in cerebral perfusion or affects cerebral metabolism remains unknown . We evaluated CBF and cerebral metabolism ( from arterial and internal jugular venous O(2 ) , glucose and lactate differences ) , as well as the middle cerebral artery mean blood velocity ( MCA V(mean ) ; transcranial Doppler ultrasound ) during a sustained static h and grip contraction at 40 % of maximal voluntary contraction ( n = 9 ) and the MCA V(mean ) during ergometer cycling ( n = 8) . Separate , r and omized and counterbalanced trials were performed in control ( no drug ) conditions and following muscarinic cholinergic receptor blockade by glycopyrrolate . Glycopyrrolate increased resting heart rate from approximately 60 to approximately 110 beats min(-1 ) ( P < 0.01 ) and cardiac output by approximately 40 % ( P < 0.05 ) , but did not affect mean arterial pressure . The central cardiovascular responses to exercise with glycopyrrolate were similar to the control responses , except that cardiac output did not increase during static h and grip with glycopyrrolate . Glycopyrrolate did not significantly affect cerebral metabolism during static h and grip , but a parallel increase in MCA V(mean ) ( approximately 16 % ; P < 0.01 ) and CBF ( approximately 12 % ; P < 0.01 ) during static h and grip , as well as the increase in MCA V(mean ) during cycling ( approximately 15 % ; P < 0.01 ) , were abolished by glycopyrrolate ( P < 0.05 ) . Thus , during both cycling and static h and grip , a cholinergic receptor mechanism is important for the exercise-induced increase in cerebral perfusion without affecting the cerebral metabolic rate for oxygen The new and recent advances in neuroelectric and neuroimaging technologies provide a new era for further exploring and underst and ing how brain and cognition function can be stimulated by environmental factors , such as exercise , and particularly to study whether physical exercise influences brain development in early ages . The 
    Output:
    
Conclusion : This systematic review found that moderate physical exercise improves cognition