Benefits of regular aerobic exercise for executive functioning in healthy populations

Cognition and gait in older people

Cognitive difficulties and gait abnormalities both increase with age. We review normal and pathologic changes in both gait and cognition in older adults. Gait performance in older individuals is linked to specific cognitive changes, in particular in executive function. Structural and functional assays highlight the shared anatomic control of cognitive and gait function, mostly in the prefrontal cortices. Cognitive impairment can be used to predict incident gait difficulties. Changes in gait, especially decreased gait velocity, may be a harbinger of impending cognitive decline. The combination of slow gait and cognitive complaints (the Motoric Cognitive Risk syndrome) is a powerful new clinical tool to identify those at high risk of developing dementia and therefore may be used to target interventions. Evidence is limited, but cognitive training and targeted physical activity may be useful to mitigate or prevent gait and cognitive decline with age.

Acute aerobic exercise helps overcome emotion regulation deficits

Although colloquial wisdom and some studies suggest an association between regular aerobic exercise and emotional well-being, the nature of this link remains poorly understood. We hypothesised that aerobic exercise may change the way people respond to their emotions. Specifically, we tested whether individuals experiencing difficulties with emotion regulation would benefit from a previous session of exercise and show swifter recovery than their counterparts who did not exercise. Participants (N = 80) completed measures of emotion response tendencies, mood, and anxiety, and were randomly assigned to either stretch or jog for 30 minutes. All participants then underwent the same negative and positive mood inductions, and reported their emotional responses. Analyses showed that more perceived difficulty generating regulatory strategies and engaging in goal-directed behaviours after the negative mood induction predicted more intense and persistent negative affect in response to the stressor, as would be expected. Interactions revealed that aerobic exercise attenuated these effects. Moderate aerobic exercise may help attenuate negative emotions for participants initially experiencing regulatory difficulties. This study contributes to the literature on aerobic exercise's therapeutic effects with experimental data, specifically in the realm of emotional processing.

Aerobic Exercise in People with Schizophrenia: Neural and Neurocognitive Benefits

Schizophrenia is characterized by extensive neurocognitive deficits, which are linked to greater disability, poorer functional outcome, and have been suggested to impact daily functioning more than clinical symptoms. Aerobic exercise (AE) has emerged as a potential intervention. This review examines the impact of AE on brain structure and function along with neurocognitive performance in individuals with schizophrenia. Preliminary evidence indicates that AE can increase hippocampal volume and cortical thickness, in addition to exerting a neuroprotective effect against hippocampal volume decrease and cortical thinning. There is also evidence that AE is able to significantly increase serum brain-derived neurotrophic factor (BDNF) levels, which are implicated in neurogenesis, neuroplasticity, and cognitive improvement. Finally, evidence suggests that AE plays a significant role in improving overall cognition, including improvements in processing speed, working memory, and visual learning. The authors discuss the implications of the findings and provide recommendations for future research and areas of inquiry.

Long-term effects of physically active academic lessons on physical fitness and executive functions in primary school children

Integrating physical activity into the curriculum has potential health and cognitive benefits in primary school children. The aim of this study was to investigate the effects of physically active academic lessons on cardiovascular fitness, muscular fitness and executive functions. In the current randomized controlled trial, 499 second and third graders within 12 primary schools (mean age = 8.1 ± 0.7) were randomized to the intervention (n = 249) or control condition (n = 250). The physically active academic lessons were given for 2 consecutive school years, 22 weeks per year, three times a week, with a duration of 20-30 min per lesson. Multiple tests were administered before, between and after the intervention period, measuring cardiovascular fitness, muscular fitness and executive functions. Multilevel analysis accounted for the nested structure of the children within classes and schools. Results showed a larger improvement in speed-coordination (B = -0.70,P = 0.002) and a lower improvement in static strength (B = -0.92,P < : 0.001) for the intervention group compared with the control group. The current lessons did not result in a significant change in executive functions.

Effect of Standing or Walking at a Workstation on Cognitive Function: A Randomized Counterbalanced Trial

OBJECTIVE

In the present study, we examined the effect of working while seated, while standing, or while walking on measures of short-term memory, working memory, selective and sustained attention, and information-processing speed.

BACKGROUND

The advent of computer-based technology has revolutionized the adult workplace, such that average adult full-time employees spend the majority of their working day seated. Prolonged sitting is associated with increasing obesity and chronic health conditions in children and adults. One possible intervention to reduce the negative health impacts of the modern office environment involves modifying the workplace to increase incidental activity and exercise during the workday. Although modifications, such as sit-stand desks, have been shown to improve physiological function, there is mixed information regarding the impact of such office modification on individual cognitive performance and thereby the efficiency of the work environment.

METHOD

In a fully counterbalanced randomized control trial, we assessed the cognitive performance of 45 undergraduate students for up to a 1-hr period in each condition.

RESULTS

The results indicate that there is no significant change in the measures used to assess cognitive performance associated with working while seated, while standing, or while walking at low intensity.

CONCLUSION

These results indicate that cognitive performance is not degraded with short-term use of alternate workstations.

Physical activity and neurocognitive functioning in aging - a condensed updated review

This condensed review gives an overview about two methodological approaches to study the impact of physical activity on cognition in elderly, namely cross-sectional studies and randomized controlled intervention studies with pre- and post-measures. Moreover, this review includes studies investigating different types of physical activity and their relation to cognitive functions in older age. Behavioral data are considered but the main focus lies on neuroscientific methods like event-related potentials (ERPs) and functional magnetic resonance imaging (fMRI).

Association between accelerometer-determined physical activity and flavonoid-rich fruit and vegetable consumption among a national sample of U.S. adults

Few population studies have examined the association between accelerometer-assessed physical activity and dietary behavior. Further, no studies have systematically examined the association between accelerometer-assessed physical activity and flavonoid rich fruits and vegetables in a national sample. As a result, the purpose of this study was to examine the association between objectively measured physical activity and consumption of flavonoid rich fruits and vegetables among a national sample of U.S. adults. Data from the 2003–2006 National Health and Nutrition Examination Survey (NHANES) were used (N = 2949). Physical activity was measured via accelerometry and fruit and vegetable consumption was measured from the NHANES Food Frequency Questionnaire. After adjustments, moderate-to-vigorous physical activity was positively associated (p < 0.05) with apples (β = 0.30), grapes (β = 0.27), strawberries (β = 0.32), oranges (β = 0.35), raw greens (β = 0.19), carrots (β = 0.23), peppers (β = 0.29) and an overall flavonoid index variable (β = 2.34). Future studies employing a longitudinal design are needed to better understand the direction of the observed associations. If future studies do indeed support the possibility that physical activity may help to foster changes in dietary behavior, then this will have strong implications for health behavior interventions, particularly among individuals finding it difficult to change multiple health behaviors concurrently.

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A national sample was employed.

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An objective measure of physical activity was used.

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More active adults consumed more flavonoid-rich fruits/vegetables.

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Mechanistic work on this topic is needed.

Acute Exercise Improves Prefrontal Cortex but not Hippocampal Function in Healthy Adults

The effects of acute aerobic exercise on cognitive functions in humans have been the subject of much investigation; however, these studies are limited by several factors, including a lack of randomized controlled designs, focus on only a single cognitive function, and testing during or shortly after exercise. Using a randomized controlled design, the present study asked how a single bout of aerobic exercise affects a range of frontal- and medial temporal lobe-dependent cognitive functions and how long these effects last. We randomly assigned 85 subjects to either a vigorous intensity acute aerobic exercise group or a video watching control group. All subjects completed a battery of cognitive tasks both before and 30, 60, 90, or 120 min after the intervention. This battery included the Hopkins Verbal Learning Test-Revised, the Modified Benton Visual Retention Test, the Stroop Color and Word Test, the Symbol Digit Modalities Test, the Digit Span Test, the Trail Making Test, and the Controlled Oral Word Association Test. Based on these measures, composite scores were formed to independently assess prefrontal cortex- and hippocampal-dependent cognition. A three-way mixed Analysis of Variance was used to determine whether differences existed between groups in the change in cognitive function from pre- to post-intervention testing. Acute exercise improved prefrontal cortex- but not hippocampal-dependent functioning, with no differences found between delay groups. Vigorous acute aerobic exercise has beneficial effects on prefrontal cortex-dependent cognition and these effects can last for up to 2 hr after exercise.

A perspective on the future role of brain pet imaging in exercise science

Positron Emission Tomography (PET) bears a unique potential for examining the effects of physical exercise (acute or chronic) within the central nervous system in vivo, including cerebral metabolism, neuroreceptor occupancy, and neurotransmission. However, application of Neuro-PET in human exercise science is as yet surprisingly sparse. To date the field has been dominated by non-invasive neuroelectrical techniques (EEG, MEG) and structural/functional magnetic resonance imaging (sMRI/fMRI). Despite PET having certain inherent disadvantages, in particular radiation exposure and high costs limiting applicability at large scale, certain research questions in human exercise science can exclusively be addressed with PET: The "metabolic trapping" properties of (18)F-FDG PET as the most commonly used PET-tracer allow examining the neuronal mechanisms underlying various forms of acute exercise in a rather unconstrained manner, i.e. under realistic training scenarios outside the scanner environment. Beyond acute effects, (18)F-FDG PET measurements under resting conditions have a strong prospective for unraveling the influence of regular physical activity on neuronal integrity and potentially neuroprotective mechanisms in vivo, which is of special interest for aging and dementia research. Quantification of cerebral glucose metabolism may allow determining the metabolic effects of exercise interventions in the entire human brain and relating the regional cerebral rate of glucose metabolism (rCMRglc) with behavioral, neuropsychological, and physiological measures. Apart from FDG-PET, particularly interesting applications comprise PET ligand studies that focus on dopaminergic and opioidergic neurotransmission, both key transmitter systems for exercise-related psychophysiological effects, including mood changes, reward processing, antinociception, and in its most extreme form 'exercise dependence'. PET ligand displacement approaches even allow quantifying specific endogenous neurotransmitter release under acute exercise interventions, to which modern PET/MR hybrid technology will be additionally fruitful. Experimental studies exploiting the unprecedented multimodal imaging capacities of PET/MR in human exercise sciences are as yet pending.

Better movers and thinkers (BMT): A quasi-experimental study into the impact of physical education on children's cognition-A study protocol

This study will extend on a pilot study and will evaluate the impact of a novel approach to PE, Better Movers and Thinkers (BMT), on students' cognition, physical activity habits, and gross motor coordination (GMC). The study will involve six mainstream state schools with students aged 9-11 years. Three schools will be allocated as the intervention condition and three as the control condition. The design of the study is a 16-week intervention with pre-, post- and 6 month follow-up measurements taken using the 'Cognitive Assessment System (CAS)' GMC tests, and the 'Physical Activity Habits Questionnaire for Children (PAQ-C).' Qualitative data will be gathered using student focus groups and class teacher interviews in each of the six schools. ANCOVA will be used to evaluate any effect of intervention comparing pre-test scores with post-test scores and then pre-test scores with 6 month follow-up scores. Qualitative data will be analysed through an iterative process using grounded theory. This protocol provides the details of the rationale and design of the study and details of the intervention, outcome measures, and the recruitment process. The study will address gaps within current research by evaluating if a change of approach in the delivery of PE within schools has an effect on children's cognition, PA habits, and GMC within a Scottish setting.

Relationship between physical activity and cognitive function in apparently healthy young to middle-aged adults: A systematic review

OBJECTIVES

There is increasing evidence that physical activity (PA) positively affects cognitive function (CF). Existing research has focussed on this association in children and the elderly, with less research available in young to middle-aged adults who constitute a substantial proportion of the population.

DESIGN

A systematic review investigating the relationship between habitual PA (≥12 months) and CF in young to middle-aged adults (18-50 years).

METHODS

A search was conducted using AMED, CINAHL, MEDLINE, PsychINFO, AUSPORT MED and SPORTDiscus databases. Eligible studies had to report descriptive statistics for CF and PA levels in healthy participants 18-50 years. Effect sizes (ES) (Hedges g) were calculated where possible.

RESULTS

The initial search netted 26,988 potentially relevant manuscripts, with four more identified through hand searching. Fourteen were included for review. A range of validated platforms assessed CF across three domains: executive function (12 studies), memory (four studies) and processing speed (seven studies). Habitual PA was assessed via questionnaire/self-report methods (n=13, 8 validated) or accelerometers (n=1). In studies of executive function, five found a significant ES in favour of higher PA, ranging from small to large. Although three of four studies in the memory domain reported a significant benefit of higher PA, there was only one significant ES, which favoured low PA. Only one study examining processing speed had a significant ES, favouring higher PA.

CONCLUSIONS

A limited body of evidence supports a positive effect of PA on CF in young to middle-aged adults. Further research into this relationship at this age stage is warranted.

Executive Dysfunction 25 Years after Treatment with Cranial Radiotherapy for Pediatric Lymphoid Malignancies

The first cohorts to survive childhood lymphoid malignancies treated with cranial irradiation are now aging into adulthood, and concerns are growing about the development of radiotherapy-induced cognitive deficits in the aging brain. These deficits are hypothesized to increase over time. Their impact on daily functioning of older survivors, and the accompanying need for interventions, should be anticipated. By describing a detailed profile of executive function deficits and their associations with age, specific targets for neuropsychological intervention can be identified. Fifty survivors of childhood lymphoid malignancies and 58 related controls were assessed with the Amsterdam Neuropsychological Tasks program. The survivors were on average 31.1 (4.9) years old, treated with 22.5 (6.8) Gy cranial irradiation, and examined on average 25.5 (3.1) years after diagnosis. The survivors showed significantly decreased response speed, irrespective of the task at hand. Furthermore, we found deficits in working memory capacity, inhibition, cognitive flexibility, executive visuomotor control, attentional fluctuations, and sustained attention. Older age was associated with poorer performance on executive visuomotor control and inhibition. On executive visuomotor control, 50% of female survivors performed more than 1.5 SD below average, versus 15.4% of male survivors. The combination of visuospatial working memory problems and decreasing executive visuomotor control could result in difficulty with learning new motor skills at older ages, like walking with a cane. Deterioration of executive control and inhibition may result in decreased behavioral and emotional regulation in aging survivors. Especially the deficiency in executive visuomotor control in female survivors should be considered for (prophylactic) intervention.

Brain activation during dual-task processing is associated with cardiorespiratory fitness and performance in older adults

Higher cardiorespiratory fitness is associated with better cognitive performance and enhanced brain activation. Yet, the extent to which cardiorespiratory fitness-related brain activation is associated with better cognitive performance is not well understood. In this cross-sectional study, we examined whether the association between cardiorespiratory fitness and executive function was mediated by greater prefrontal cortex activation in healthy older adults. Brain activation was measured during dual-task performance with functional magnetic resonance imaging in a sample of 128 healthy older adults (59–80 years). Higher cardiorespiratory fitness was associated with greater activation during dual-task processing in several brain areas including the anterior cingulate and supplementary motor cortex (ACC/SMA), thalamus and basal ganglia, right motor/somatosensory cortex and middle frontal gyrus, and left somatosensory cortex, controlling for age, sex, education, and gray matter volume. Of these regions, greater ACC/SMA activation mediated the association between cardiorespiratory fitness and dual-task performance. We provide novel evidence that cardiorespiratory fitness may support cognitive performance by facilitating brain activation in a core region critical for executive function.

An ecological approach to cognitive enhancement: complex motor training

Cognitive training has received a lot of attention recently, yielding findings that can be conflicting and controversial. In this paper, we present a novel approach to cognitive training based on complex motor activities. In a randomized controlled design, participants were assigned to one of three conditions: aerobic exercise, working memory training or designed sport--an intervention specifically tailored to include both physical and cognitive demands. After training for eight weeks, the designed sport group showed the largest gains in all cognitive measures, illustrating the efficacy of complex motor activities to enhance cognition. Designed sport training also revealed impressive health benefits, namely decreased heart rate and blood pressure. In this period of skepticism over the efficacy of computerized cognitive training, we discuss the potential of ecological interventions targeting both cognition and physical fitness, and propose some possible applications.

SMART: physical activity and cerebral metabolism in older people: study protocol for a randomised controlled trial

Background

Physical activity exerts a variety of long-term health benefits in older adults. In particular, it is assumed to be a protective factor against cognitive decline and dementia.

Methods/design

Randomised controlled assessor blinded 2-armed trial (n = 60) to explore the exercise- induced neuroprotective and metabolic effects on the brain in cognitively healthy older adults. Participants (age ≥ 65), recruited within the setting of assisted living facilities and newspaper advertisements are allocated to a 12-week individualised aerobic exercise programme intervention or a 12-week waiting control group. Total follow-up is 24 weeks. The main outcome is the change in cerebral metabolism as assessed with Magnetic Resonance Spectroscopic Imaging reflecting changes of cerebral N-acetyl-aspartate and of markers of neuronal energy reserve. Imaging also measures changes in cortical grey matter volume. Secondary outcomes include a broad range of psychometric (cognition) and movement-related parameters such as nutrition, history of physical activity, history of pain and functional diagnostics. Participants are allocated to either the intervention or control group using a computer-generated randomisation sequence. The exercise physiologist in charge of training opens sealed and opaque envelopes and informs participants about group allocation. For organisational reasons, he schedules the participants for upcoming assessments and exercise in groups of five. All assessors and study personal other than exercise physiologists are blinded.

Discussion

Magnetic Resonance Spectroscopic Imaging gives a deeper insight into mechanisms of exercise-induced changes in brain metabolism. As follow-up lasts for 6 months, this study is able to explore the mid-term cerebral metabolic effects of physical activity assuming that an individually tailored aerobic ergometer training has the potential to counteract brain ageing.

Trial registration

NCT02343029 (clinicaltrials.gov; 12 January 2015).

Impact of the Baltimore Experience Corps Trial on cortical and hippocampal volumes

INTRODUCTION

There is a substantial interest in identifying interventions that can protect and buffer older adults from atrophy in the cortex and particularly, the hippocampus, a region important to memory. We report the 2-year effects of a randomized controlled trial of an intergenerational social health promotion program on older men's and women's brain volumes.

METHODS

The Brain Health Study simultaneously enrolled, evaluated, and randomized 111 men and women (58 interventions; 53 controls) within the Baltimore Experience Corps Trial to evaluate the intervention impact on biomarkers of brain health at baseline and annual follow-ups during the 2-year trial exposure.

RESULTS

Intention-to-treat analyses on cortical and hippocampal volumes for full and sex-stratified samples revealed program-specific increases in volumes that reached significance in men only (P's ≤ .04). Although men in the control arm exhibited age-related declines for 2 years, men in the Experience Corps arm showed a 0.7% to 1.6% increase in brain volumes. Women also exhibited modest intervention-specific gains of 0.3% to 0.54% by the second year of exposure that contrasted with declines of about 1% among women in the control group.

DISCUSSION

These findings showed that purposeful activity embedded within a social health promotion program halted and, in men, reversed declines in brain volume in regions vulnerable to dementia.

CLINICAL TRIAL REGISTRATION

NCT0038.

Key beliefs related to decisions for physical activity engagement among first-in-family students transitioning to university

The current study investigated key beliefs related to decisions for physical activity (PA) engagement among first-in-family (FIF) students transitioning to university. FIF students (n = 157) completed an online questionnaire assessing standard theory of planned behaviour constructs and belief-based items. One week later, participants completed a follow-up questionnaire assessing self-reported PA during the previous week. Results identified a range of behavioural, normative, and control beliefs that were significantly correlated with both PA intention and behaviour. Various key beliefs were also identified in relation to FIF students' decisions to be regularly physically active, with behavioural beliefs such as "take up too much time", normative beliefs including "friends outside of university", and control beliefs such as "cost", identified. Finally, frequencies of those who strongly or fully accepted these beliefs were analysed, demonstrating that typically, a large number of FIF students did not hold the beliefs, and as such, these are relevant to target in resultant interventions. The current study effectively highlights a number of key beliefs that can be targeted in programs aimed at encouraging FIF students' PA. Further, the study addresses a gap in the literature of targeting FIF students, a cohort at risk for inactivity, and utilises a sound theoretical framework to identify the unique set of beliefs guiding decisions for PA for this at-risk community group.

Effects of physical activity on executive function and motor performance in children with ADHD

Children with Attention-Deficit/Hyperactivity Disorder (ADHD) often show major deficits in motor and cognitive abilities. Pharmacological treatment is commonly used to reduce ADHD symptoms. However, non-pharmacologic treatment methods would be preferred by parents, children and psychiatrists. Physical activity (PA) has been demonstrated to improve cognitive functioning in healthy populations. It can be hypothesized that there are similar beneficial effects in children with ADHD, however, very little is known about this issue. The purpose of the present study was to determine whether PA improves cognitive performance in children with ADHD. A total of 43 children with ADHD (32 boys and 11 girls) aged between seven and 12 years took part in the study. To investigate whether potential effects on executive functioning depend on the kind of PA, two different 12-week training programs were implemented. The study-design consisted of two experimental groups (EG1, n=13; EG2, n=14) and a wait-list control group (CG, n=16). Participants in EG1 took part in a training which focused on the abilities ball handling, balance and manual dexterity. Participants in EG2 group were trained in sports without a specific focus. The children in the CG group received no intervention. Participants completed assessments of working memory (WM) and motor performance before, immediately after the first training week and one week after the last session. After the 12-week intervention period, several measures of the EG1 and EG2s significantly improved over time. Furthermore, between group comparisons demonstrated significant improvements in both EG1 and EG2 compared to the CG in variables assessing WM performance and motor performance. These findings support the hypothesis that long-term PA has a positive effect on executive functions of children with ADHD, regardless of the specificity of the PA. The outcomes indicated that regular PA can be used as a complementary or alternative non-pharmacologic treatment for ADHD.

Higher levels of cardiovascular fitness are associated with better executive function and prefrontal oxygenation in younger and older women

AIM

Many studies have suggested that physical exercise training improves cognition and more selectively executive functions. There is a growing interest to clarify the neurophysiological mechanisms that underlie this effect. The aim of the current study was to evaluate the neurophysiological changes in cerebral oxygenation associated with physical fitness level and executive functions.

METHOD

In this study, 22 younger and 36 older women underwent a maximal graded continuous test (i.e., [Formula: see text]O2max ) in order to classify them into a fitness group (higher vs. lower fit). All participants completed neuropsychological paper and pencil testing and a computerized Stroop task (which contained executive and non-executive conditions) in which the change in prefrontal cortex oxygenation was evaluated with near infrared spectroscopy (NIRS).

RESULTS

Our findings revealed a Fitness × Condition interaction (p < 0.05) such that higher fit women scored better on measures of executive functions than lower fit women. In comparison to lower fit women, higher fit women had faster reaction times in the Executive condition of the computerized Stroop task. No significant effect was observed in the non-executive condition of the test and no interactions were found with age. In measures of cerebral oxygenation (ΔHbT and ΔHbO2), we found a main effect of fitness on cerebral oxygenation during the Stroop task such that only high fit women demonstrated a significant increase in the right inferior frontal gyrus.

DISCUSSION/CONCLUSION

Higher fit individuals who demonstrate better cardiorespiratory functions (as measured by [Formula: see text]O2max ) show faster reaction times and greater cerebral oxygenation in the right inferior frontal gyrus than women with lower fitness levels. The lack of interaction with age, suggests that good cardiorespiratory functions can have a positive impact on cognition, regardless of age.

Role of adult hippocampal neurogenesis in cognition in physiology and disease: pharmacological targets and biomarkers

Adult hippocampal neurogenesis is a remarkable form of brain structural plasticity by which new functional neurons are generated from adult neural stem cells/precursors. Although the precise role of this process remains elusive, adult hippocampal neurogenesis is important for learning and memory and it is affected in disease conditions associated with cognitive impairment, depression, and anxiety. Immature neurons in the adult brain exhibit an enhanced structural and synaptic plasticity during their maturation representing a unique population of neurons to mediate specific hippocampal function. Compelling preclinical evidence suggests that hippocampal neurogenesis is modulated by a broad range of physiological stimuli which are relevant in cognitive and emotional states. Moreover, multiple pharmacological interventions targeting cognition modulate adult hippocampal neurogenesis. In addition, recent genetic approaches have shown that promoting neurogenesis can positively modulate cognition associated with both physiology and disease. Thus the discovery of signaling pathways that enhance adult neurogenesis may lead to therapeutic strategies for improving memory loss due to aging or disease. This chapter endeavors to review the literature in the field, with particular focus on (1) the role of hippocampal neurogenesis in cognition in physiology and disease; (2) extrinsic and intrinsic signals that modulate hippocampal neurogenesis with a focus on pharmacological targets; and (3) efforts toward novel strategies pharmacologically targeting neurogenesis and identification of biomarkers of human neurogenesis.

Cognitive control in the self-regulation of physical activity and sedentary behavior

Cognitive control of physical activity and sedentary behavior is receiving increased attention in the neuroscientific and behavioral medicine literature as a means of better understanding and improving the self-regulation of physical activity. Enhancing individuals' cognitive control capacities may provide a means to increase physical activity and reduce sedentary behavior. First, this paper reviews emerging evidence of the antecedence of cognitive control abilities in successful self-regulation of physical activity, and in precipitating self-regulation failure that predisposes to sedentary behavior. We then highlight the brain networks that may underpin the cognitive control and self-regulation of physical activity, including the default mode network, prefrontal cortical networks and brain regions and pathways associated with reward. We then discuss research on cognitive training interventions that document improved cognitive control and that suggest promise of influencing physical activity regulation. Key cognitive training components likely to be the most effective at improving self-regulation are also highlighted. The review concludes with suggestions for future research.

A Daily Process Analysis of Physical Activity, Sedentary Behavior, and Perceived Cognitive Abilities

OBJECTIVES

This study evaluated the role of both physical activity and sedentary behavior in daily perceptions of cognitive abilities and whether these relations exist within-person, between-person, or both.

DESIGN

Non-experimental, intensive longitudinal research using ecological momentary assessments.

METHOD

College students wore accelerometers and provided end-of-day reports on physical activity, sedentary behavior, and perceived cognitive abilities for 14 days.

RESULTS

Across self-reports and objective measures of behavior, daily deviations in physical activity were positively associated with perceived cognitive abilities. Daily deviations in self-reported, but not objectively-assessed, sedentary behavior also were negatively associated with perceived cognitive abilities. Contrary to previous research, overall levels of physical activity and sedentary behaviors were not associated with perceived cognitive abilities.

CONCLUSIONS

These findings indicate that physical activity has a within- rather than between-person association with perceived cognitive abilities although between-person associations effects may require longer monitoring periods to manifest. Further research is needed to establish the direction of causality and resolve whether the nature (rather than quantity) of sedentary activities influences cognition.

Lifestyle factors associated with cognitive functioning in breast cancer survivors

OBJECTIVE

Weight, physical activity, and sleep are modifiable lifestyle factors that impact cognitive functioning in noncancer populations but have yet to be examined in cancer survivors. The aim of the study was to assess the relationship of obesity, physical activity, and sleep, with cognitive functioning among breast cancer survivors.

METHODS

Participants were 136 early-stage postmenopausal breast cancer survivors who completed an assessment of neuropsychological testing, height, weight, physical activity, and sleep. Linear regression models examined the associations of the seven neuropsychological domains with obesity, physical activity, and sleep. Logistic regression models examined odd of impairment in each domain. All models controlled for breast cancer treatment variables and relevant demographic and clinical variables.

RESULTS

Obese participants had significantly worse performance (β = -5.04, standard error (SE) = 2.53) and were almost three times more likely to be impaired (odds ratio (OR) = 2.87; 95% CI: 1.02-8.10) on the Information processing domain. The highest tertile of physical activity was significantly related to better performance on the executive functioning domain (β = 5.13, SE = 2.42) and attention domain (β = 4.26, SE = 2.07). The middle tertile of physical activity was significantly related to better performance (β = 9.00, SE = 3.09) and decreased odds of impairment (OR = 0.89, 95% CI: 0.07-0.91) on the visual-spatial domain. More hours of sleep per night was significantly associated with better performance (β = 2.69, SE = 0.98) and decreased odds of impairment (OR = 0.52; 95% CI: 0.33-0.82) on the verbal functioning domain.

CONCLUSIONS

These findings suggest that obesity, physical activity, and sleep are related to cognitive functioning among breast cancer survivors and have potential to be intervention targets to improve cognitive functioning.

The associations of objectively measured physical activity and sedentary time with cognitive functions in school-aged children

Low levels of physical activity among children have raised concerns over the effects of a physically inactive lifestyle, not only on physical health but also on cognitive prerequisites of learning. This study examined how objectively measured and self-reported physical activity and sedentary behavior are associated with cognitive functions in school-aged children. The study population consisted of 224 children from five schools in the Jyväskylä school district in Finland (mean age 12.2 years; 56% girls), who participated in the study in the spring of 2011. Physical activity and sedentary time were measured objectively for seven consecutive days using the ActiGraph GT1M/GT3X accelerometer. Self-reported moderate to vigorous physical activity (MVPA) and screen time were evaluated with the questions used in the "WHO Health Behavior in School-aged Children" study. Cognitive functions including visual memory, executive functions and attention were evaluated with a computerized Cambridge Neuropsychological Test Automated Battery by using five different tests. Structural equation modeling was applied to examine how objectively measured and self-reported MVPA and sedentary behavior were associated with cognitive functions. High levels of objectively measured MVPA were associated with good performance in the reaction time test. High levels of objectively measured sedentary time were associated with good performance in the sustained attention test. Objectively measured MVPA and sedentary time were not associated with other measures of cognitive functions. High amount of self-reported computer/video game play was associated with weaker performance in working memory test, whereas high amount of computer use was associated with weaker performance in test measuring shifting and flexibility of attention. Self-reported physical activity and total screen time were not associated with any measures of cognitive functions. The results of the present study propose that physical activity may benefit attentional processes. However, excessive video game play and computer use may have unfavorable influence on cognitive functions.

The effects of chronic exercise on attentional networks

The aim of this study was to test the hypothesis that chronic physical exercise improves attentional control in young healthy participants. To do this, we compared the performance of physically active and passive participants in the Attentional Network Task, which allows for the assessment of the executive, orienting and alerting networks. The results showed a selective positive effect of exercise on the executive network. These results extend the evidence gathered in children, older adults and certain clinical populations suggesting that exercise can also improve attentional control in healthy young adults.

The impact of exercise on the cognitive functioning of healthy older adults: a systematic review and meta-analysis

Data from epidemiological, cross-sectional, and neuroimaging research show a relationship between higher levels of exercise and reduced risk of cognitive decline but evidence from randomised controlled trials (RCTs) is less consistent. This review examines the impact of aerobic exercise, resistance training, and Tai Chi on the cognitive function of older adults without known cognitive impairment. We investigate explanations for inconsistent results across trials and discrepancies between evidence from RCTs and other research data. Twenty-five RCTs were included in the review. Meta-analysis results revealed significant improvements for resistance training compared to stretching/toning on measures of reasoning (p<0.005); and for Tai Chi compared to 'no exercise' controls on measures of attention (p<0.001) and processing speed (p<0.00001). There were no significant differences between exercise and controls on any of the remaining 26 comparisons. Results should be interpreted with caution however as differences in participant profiles, study design, exercise programmes, adherence rates, and outcome measures contribute to both discrepancies within the exercise research literature and inconsistent results across trials.

The effects of increased therapy time on cognition and mood in frail patients with a stroke who rehabilitate on rehabilitation units of nursing homes in the Netherlands: a protocol of a comparative study

Background

Recovery after stroke is dependent on how much time can be spent on rehabilitation. Recently, we found that therapy time for older stroke patients on a rehabilitation unit of a nursing home could be increased significantly from 8.6 to at least 13 hours a week. This increase was attained by the implementation of interventions, focused on strength, mobility and balance. Nurses carried out these exercises with the patients during their daily activities. The aim of the present study is to investigate if increased therapy time has a positive effect on cognition, mood (depression and anxiety), and ADL in stroke patients.

Methods

A comparative single blind controlled study will be applied. Patients suffering from a stroke and staying on one of the rehabilitation units of the nursing homes are eligible for participation. Participants belong to the intervention group if they stay in two nursing homes where four interventions of the Clinical Nursing Rehabilitation Stroke Guideline were implemented. Participants who stay in two nursing homes where therapy is given according to the Dutch stroke Guideline, are included in the control group. Clinical neuropsychologists will assess patients’ cognitive functioning, level of depression (mood) and anxiety. Nurses will assess a Barthel Index score on a weekly basis (ADL). These variables are measured at baseline, after 8 weeks and at the moment when participants are discharged from the nursing home.

Discussion

The present study evaluates the effect of increased therapy time on cognition, mood (level of depression and anxiety), and ADL in stroke patients. When positive effects will be found this study can guide policy makers and practitioners on how to implement more therapy time on rehabilitation wards of nursing homes.

Trial registration

TNR Our study has been documented in the Dutch Trial Registration, TC = 3871.

Physical activity, fitness, and gray matter volume

In this review, we explore the association among physical activity, cardiorespiratory fitness, and exercise on gray matter volume in older adults. We conclude that higher cardiorespiratory fitness levels are routinely associated with greater gray matter volume in the prefrontal cortex and hippocampus and less consistently in other regions. We also conclude that physical activity is associated with greater gray matter volume in the same regions that are associated with cardiorespiratory fitness including the prefrontal cortex and hippocampus. Some heterogeneity in the literature may be explained by effect moderation by age, stress, or other factors. Finally, we report promising results from randomized exercise interventions that suggest that the volume of the hippocampus and prefrontal cortex remain pliable and responsive to moderate intensity exercise for 6 months-1 year. Physical activity appears to be a propitious method for influencing gray matter volume in late adulthood, but additional well-controlled studies are necessary to inform public policies about the potential protective or therapeutic effects of exercise on brain volume.

Chronic exercise keeps working memory and inhibitory capacities fit

Padilla et al. (2013) recently showed that chronic aerobic exercise in young adults is associated with better inhibitory control as measured by the strategic Stop Signal Task (SST). The aim of the current study was to explore whether better inhibitory abilities, associated with high levels of physical fitness, were also associated with higher working memory capacity (WMC) in young healthy adults. Participants aged between 18 and 30 years and showing different levels of fitness confirmed by the Rockport 1-mile walking fitness test took part in this study. Active and passive participants were administered the SST to measure inhibitory control, and the Automatic Operation Span (AOSPAN) to measure verbal WMC. We first replicated Padilla et al.'s results showing that exercise specifically modulates strategic inhibitory processes. Our results also showed that active participants presented with better WMC than sedentary ones, showing a better capacity to manage simultaneously two verbal tasks and to inhibit interference. The results point to an association between chronic exercise, inhibitory abilities, and WMC. The theoretical relationship between these variables will be discussed.

Aerobic exercise interacts with neurotrophic factors to predict cognitive functioning in adolescents

Recent findings have suggested that aerobic exercise may have a positive effect on brain functioning, in addition to its well-recognized beneficial effects on human physiology. This study confirmed the cognitive effects of aerobic exercise on the human brain. It also examined the relationships between exercise and the serum levels of neurotrophic factors (BDNF, IGI-1, and VEGF). A total of 91 healthy teens who exercised regularly participated in this study. A between-group design was adopted to compare cognitive functioning subserved by the frontal and temporal brain regions and the serum levels of neurotrophic factors between 45 regular exercisers and 46 matched controls. The exercisers performed significantly better than the controls on the frontal and temporal functioning parameters measured. This beneficial cognitive effect was region-specific because no such positive cognitive effect on task-tapping occipital functioning was observed. With respect to the serum levels of the neurotrophic factors, a negative correlation between neurotrophic factors (BDNF and VEGF) with frontal and medial-temporal lobe function was revealed. Furthermore, the levels of BDNF and VEGF interacted with exercise status in predicting frontal and temporal lobe function. This is the first report of the interaction effects of exercise and neurotrophic factors on cognitive functioning. Herein, we report preliminary evidence of the beneficial effects of regular aerobic exercise in improving cognitive functions in teens. These beneficial effects are region-specific and are associated with the serum levels of neurotrophic factors. Our findings lay the path for future studies looking at ways to translate these beneficial effects to therapeutic strategies for adolescents.

Artificial gravity exposure impairs exercise-related neurophysiological benefits

Artificial gravity (AG) exposure is suggested to counteract health deconditioning, theoretically complementing exercise during space habitations. Exercise-benefits on mental health are well documented (i.e. well-being, enhanced executive functions). Although AG is coherent for the integrity of fundamental physiological systems, the effects of its exposure on neurophysiological processes related to cognitive performance are poorly understood and therefore characterize the primary aim of this study. 16 healthy males participated in two randomly assigned sessions, AG and exercise (30minute each). Participants were exposed to AG at continuous +2Gz in a short-arm human centrifuge and performed moderate exercise (cycling ergometer). Using 64 active electrodes, resting EEG was recorded before (pre), immediately after (post), and 15min after (post15) each session. Alpha (7.5-12.5Hz) and beta frequencies (12.5-35.0Hz) were exported for analysis. Cognitive performance and mood states were assessed before and after each session. Cognitive performance improved after exercise (p<0.05), but not after AG. This was reflected by typical EEG patterns after exercise, however not after AG. Frontal alpha (post p<0.01, post15 p<0.001) and beta activity (post15 p<0.001) increased after AG compared to a decrease in frontal alpha (post15 p<0.05) and beta activity (post p<0.01) after exercise. Relaxed cortical states were indicated after exercise, but were less apparent after AG. Changes in mood states failed significance after both sessions. Summarized, the benefits to mental health, recorded after exercise, were absent after AG, indicating that AG might cause neurocognitive deconditioning.

Age-related changes of myocardial ATP supply and demand mechanisms

In advanced age, the resting myocardial oxygen consumption rate (MVO2) and cardiac work (CW) in the rat remain intact. However, MVO2, CW and cardiac efficiency achieved at high demand are decreased with age, compared to maximal values in the young. Whether this deterioration is due to decrease in myocardial ATP demand, ATP supply, or the control mechanisms that match them remains controversial. Here we discuss evolving perspectives of age-related changes of myocardial ATP supply and demand mechanisms, and critique experimental models used to investigate aging. Specifically, we evaluate experimental data collected at the level of isolated mitochondria, tissue, or organism, and discuss how mitochondrial energetic mechanisms change in advanced age, both at basal and high energy-demand levels.

Bridging animal and human models of exercise-induced brain plasticity

Significant progress has been made in understanding the neurobiological mechanisms through which exercise protects and restores the brain. In this feature review, we integrate animal and human research, examining physical activity effects across multiple levels of description (neurons up to inter-regional pathways). We evaluate the influence of exercise on hippocampal structure and function, addressing common themes such as spatial memory and pattern separation, brain structure and plasticity, neurotrophic factors, and vasculature. Areas of research focused more within species, such as hippocampal neurogenesis in rodents, also provide crucial insight into the protective role of physical activity. Overall, converging evidence suggests exercise benefits brain function and cognition across the mammalian lifespan, which may translate into reduced risk for Alzheimer's disease (AD) in humans.

Synaptic regulation of affective behaviors; role of BDNF

Brain derived neurotrophic factor (BDNF), a neurotrophin essential for nervous system development and synaptic plasticity, has been found to have a significant influence on affective behaviors. The notion that an impairment in BDNF signaling might be involved in affective disorders is originated primarily from the opposing effects of antidepressants and stress on BDNF signaling. Antidepressants enhance BDNF signaling and synaptic plasticity. On the other hand, negative environmental factors such as severe stress suppress BDNF signaling, impair synaptic activity and increase susceptibility to affective disorders. Postmortem studies provided strong support for decreased BDNF signaling in depressive disorders. Remarkably, studies in humans with a single nucleotide polymorphism in the BDNF gene, the BDNF Val66Met which affects regulated release of BDNF, showed profound deficits in hippocampal and prefrontal cortical (PFC) plasticity and cognitive behaviors. BDNF regulates synaptic mechanisms responsible for various cognitive processes including attenuation of aversive memories, a key process in the regulation of affective behaviors. The unique role of BDNF in cognitive and affective behaviors suggests that cognitive deficits due to altered BDNF signaling might underlie affective disorders. Understanding how BDNF modulates synapses in neural circuits relevant to affective behaviors, particularly the medial prefrontal cortical (mPFC)-hippocampus-amygdala pathway, and its interaction with development, sex, and environmental risk factors might shed light on potential therapeutic targets for affective disorders. This article is part of the Special Issue entitled 'BDNF Regulation of Synaptic Structure, Function, and Plasticity'.