Aerobic Exercise Enhances Cognitive Flexibility

An acute bout of aerobic exercise can protect immediate offline motor sequence gains

The present study examined the efficacy of a short bout of moderately intensive exercise to protect knowledge of a newly acquired motor sequence. Previous work revealed that sleep-dependent offline gains in motor sequence performance are reduced by practicing an alternative motor sequence in close temporal proximity to the original practice with the target motor sequence. In the present work, a brief bout of exercise was inserted at two different temporal locations between practice of a to-be-learned motor sequence and the interfering practice that occurred 2 h later. At issue was whether exposure to exercise could reduce the impact of practice with the interfering task which was expected to be manifest as reemergence of offline gain observed in the case in which the learner is not exposed to the interfering practice. Acute exercise did influence the interfering quality of practice with an alternative motor sequence resulting in the return of broad offline gain. However, this benefit was immediate, emerging on the initial test trial, only when exercise was experienced some time after the original period of motor sequence practice and just prior to practice with the interfering motor sequence. Thus, while exercise can contribute to post-practice consolidation, there appears to be a fragile interplay between spontaneous memory consolidation occurring after task practice and the consolidation processes induced via exercise.

A randomised controlled trial investigating the effects of Mediterranean diet and aerobic exercise on cognition in cognitively healthy older people living independently within aged care facilities: the Lifestyle Intervention in Independent Living Aged Care (LIILAC) study protocol [ACTRN12614001133628]

BACKGROUND

The rapid ageing of the population is becoming an area of great concern, both globally and in Australia. On a societal level, the cost of supporting an ageing demographic, particularly with their associated medical requirements, is becoming an ever increasing burden that is only predicted to rise in the foreseeable future. The progressive decline in individuals' cognitive ability as they age, particularly with respect to the ever increasing incidence of Alzheimer's Disease (AD) and other cognitive complications, is in many respects one of the foundation stones of these concerns. There have been numerous observational studies reporting on the positive effects that aerobic exercise and the Mediterranean diet appear to have on improving cognitive ability. However, the ability of such interventions to improve cognitive ability, or even reduce the rate of cognitive ageing, has not been fully examined by substantial interventional studies within an ageing population.

METHODS

The LIILAC trial will investigate the potential for cognitive change in a cohort of cognitively healthy individuals, between the ages of 60 and 90 years, living in independent accommodation within Australian aged care facilities. This four-arm trial will investigate the cognitive changes which may occur as a result of the introduction of aerobic exercise and/or Mediterranean diet into individuals' lifestyles, as well as the mechanisms by which these changes may be occurring. Participants will be tested at baseline and 6 months on a battery of computer based cognitive assessments, together with cardiovascular and blood biomarker assessments. The cardiovascular measures will assess changes in arterial stiffness and central pulse pressures, while the blood measures will examine changes in metabolic profiles, including brain derived neurotrophic factor (BDNF), inflammatory factors and insulin sensitivity.

CONCLUSION

It is hypothesised that exercise and Mediterranean diet interventions, both individually and in combination, will result in improvements in cognitive performance compared with controls. Positive findings in this research will have potential implications for the management of aged care, particularly in respect to reducing the rate of cognitive decline and the associated impacts both on the individual and the broader community.

TRIAL REGISTRATION

Australia New Zealand Clinical Trial Registry- ACTRN12614001133628.

Physical exercise enhances cognitive flexibility as well as astrocytic and synaptic markers in the medial prefrontal cortex

Physical exercise enhances a wide range of cognitive functions in humans. Running-induced cognitive enhancement has also been demonstrated in rodents but with a strong emphasis on tasks that require the hippocampus. Additionally, studies designed to identify mechanisms that underlie cognitive enhancement with physical exercise have focused on running-induced changes in neurons with little attention paid to such changes in astrocytes. To further our understanding of how the brain changes with physical exercise, we investigated whether running alters performance on cognitive tasks that require the prefrontal cortex and whether any such changes are associated with astrocytic, as well as neuronal, plasticity. We found that running enhances performance on cognitive tasks known to rely on the prefrontal cortex. By contrast, we found no such improvement on a cognitive task known to rely on the perirhinal cortex. Moreover, we found that running enhances synaptic, dendritic and astrocytic measures in several brain regions involved in cognition but that changes in the latter measures were more specific to brain regions associated with cognitive improvements. These findings suggest that physical exercise induces widespread plasticity in both neuronal and nonneuronal elements and that both types of changes may be involved in running-induced cognitive enhancement.

Aerobic exercise to improve cognitive function in older people without known cognitive impairment

BACKGROUND

There is increasing evidence that physical activity supports healthy ageing. Exercise is helpful for cardiovascular, respiratory and musculoskeletal systems, among others. Aerobic activity, in particular, improves cardiovascular fitness and, based on recently reported findings, may also have beneficial effects on cognition among older people.

OBJECTIVES

To assess the effect of aerobic physical activity, aimed at improving cardiorespiratory fitness, on cognitive function in older people without known cognitive impairment.

SEARCH METHODS

We searched ALOIS - the Cochrane Dementia and Cognitive Improvement Group's Specialized Register, the Cochrane Controlled Trials Register (CENTRAL) (all years to Issue 2 of 4, 2013), MEDLINE (Ovid SP 1946 to August 2013), EMBASE (Ovid SP 1974 to August 2013), PEDro, SPORTDiscus, Web of Science, PsycINFO (Ovid SP 1806 to August 2013), CINAHL (all dates to August 2013), LILACS (all dates to August 2013), World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (http://apps.who.int/trialsearch), ClinicalTrials.gov (https://clinicaltrials.gov) and Dissertation Abstracts International (DAI) up to 24 August 2013, with no language restrictions.

SELECTION CRITERIA

We included all published randomised controlled trials (RCTs) comparing the effect on cognitive function of aerobic physical activity programmes with any other active intervention, or no intervention, in cognitively healthy participants aged over 55 years.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted the data from included trials. We grouped cognitive outcome measures into eleven categories covering attention, memory, perception, executive functions, cognitive inhibition, cognitive speed and motor function. We used the mean difference (or standardised mean difference) between groups as the measure of the treatment effect and synthesised data using a random-effects model. We conducted separate analyses to compare aerobic exercise interventions with no intervention and with other exercise, social or cognitive interventions. Also, we performed analyses including only trials in which an increase in the cardiovascular fitness of participants had been demonstrated.

MAIN RESULTS

Twelve trials including 754 participants met our inclusion criteria. Trials were from eight to 26 weeks in duration.We judged all trials to be at moderate or high risk of bias in at least some domains. Reporting of some risk of bias domains was poor.Our analyses comparing aerobic exercise to any active intervention showed no evidence of benefit from aerobic exercise in any cognitive domain. This was also true of our analyses comparing aerobic exercise to no intervention. Analysing only the subgroup of trials in which cardiorespiratory fitness improved in the aerobic exercise group showed that this improvement did not coincide with improvements in any cognitive domains assessed. Our subgroup analyses of aerobic exercise versus flexibility or balance interventions also showed no benefit of aerobic exercise in any cognitive domain.Dropout rates did not differ between aerobic exercise and control groups. No trial reported on adverse effects.Overall none of our analyses showed a cognitive benefit from aerobic exercise even when the intervention was shown to lead to improved cardiorespiratory fitness.

AUTHORS' CONCLUSIONS

We found no evidence in the available data from RCTs that aerobic physical activities, including those which successfully improve cardiorespiratory fitness, have any cognitive benefit in cognitively healthy older adults. Larger studies examining possible moderators are needed to confirm whether or not aerobic training improves cognition.

The relation of saturated fats and dietary cholesterol to childhood cognitive flexibility

Identification of health behaviors and markers of physiological health associated with childhood cognitive function has important implications for public health policy targeted toward cognitive health throughout the life span. Although previous studies have shown that aerobic fitness and obesity exert contrasting effects on cognitive flexibility among prepubertal children, the extent to which diet plays a role in cognitive flexibility has received little attention. Accordingly, this study examined associations between saturated fats and cholesterol intake and cognitive flexibility, assessed using a task switching paradigm, among prepubertal children between 7 and 10 years (N = 150). Following adjustment of confounding variables (age, sex, socioeconomic status, IQ, VO2max, and BMI), children consuming diets higher in saturated fats exhibited longer reaction time during the task condition requiring greater amounts of cognitive flexibility. Further, increasing saturated fat intake and dietary cholesterol were correlated with greater switch costs, reflecting impaired ability to maintain multiple task sets in working memory and poorer efficiency of cognitive control processes involved in task switching. These data are among the first to indicate that children consuming diets higher in saturated fats and cholesterol exhibit compromised ability to flexibly modulate their cognitive operations, particularly when faced with greater cognitive challenge. Future longitudinal and intervention studies are necessary to comprehensively characterize the interrelationships between diet, aerobic fitness, obesity, and children's cognitive abilities.

The Correlation between Physical Activity and Grade Point Average for Health Science Graduate Students

Researchers have reported positive associations between physical activity and academic achievement. However, a common belief is that improving academic performance comes at the cost of reducing time for and resources spent on extracurricular activities that encourage physical activity. The purpose of this study was to examine the relationship between self-reported physical activity and grade point average (GPA) for health science graduate students. Graduate students in health science programs completed the International Physical Activity Questionnaire and reported their academic progress. Most participants (76%) reported moderate to vigorous physical activity levels that met or exceeded the recommended levels for adults. However, there was no significant correlation between G PA and level of physical activity. Negative findings for this study may be associated with the limited range of GPA scores for graduate students. Future studies need to consider more sensitive measures of cognitive function, as well as the impact of physical activity on occupational balance and health for graduate students in the health fields.

Effect of aerobic exercise training on chinese population with mild to moderate depression in Hong Kong

Background. Exercise has been suggested to be a viable treatment for depression. This study investigates the effect of supervised aerobic exercise training on depressive symptoms and physical performance among Chinese patients with mild to moderate depression in early in-patient phase. Methods. A randomized repeated measure and assessor-blinded study design was used. Subjects in aerobic exercise group received 30 minutes of aerobic training, five days a week for 3 weeks. Depressive symptoms (MADRS and C-BDI) and domains in physical performance were assessed at baseline and program end. Results. Subjects in aerobic exercise group showed a more significant reduction in depressive scores (MADRS) as compared to control (between-group mean difference = 10.08 ± 9.41; P = 0.026) after 3 weeks training. The exercise group also demonstrated a significant improvement in flexibility (between-group mean difference = 4.4 ± 6.13; P = 0.02). Limitations. There was lack of longitudinal followup to examine the long-term effect of aerobic exercise on patients with depression. Conclusions. Aerobic exercise in addition to pharmacological intervention can have a synergistic effect in reducing depressive symptoms and increasing flexibility among Chinese population with mild to moderate depression. Early introduction of exercise training in in-patient phase can help to bridge the gap of therapeutic latency of antidepressants during its nonresponse period.

Incorporating physical activity into the schools using a 3-tiered approach

BACKGROUND

Public health models have been used to address a number of school-based concerns, notably in the identification and treatment of students at-risk for academic or behavioral deficits. Significant benefits are associated with this model as, compared to a traditional approach, the focus is shifted from remediation to prevention, and from student pathology to student strengths.

METHODS

Although this model has been applied to multiple populations and used across a variety of settings, it has yet to be conceptualized as a framework for the integration of school-based physical activity (PA).

RESULTS

This article first reviews the public health service delivery model as well as the benefits of PA on children's physical health, mental health, and cognitive outcomes. Second, suggestions for incorporating PA into the schools using a 3-tiered system and as barriers to success are discussed.

CONCLUSION

School-based PA is a promising tool-and yet an overlooked and undervalued intervention-for a number of concerns applicable to children's academic achievement and overall mental health.

A single bout of aerobic exercise promotes motor cortical neuroplasticity

Regular physical activity is associated with enhanced plasticity in the motor cortex, but the effect of a single session of aerobic exercise on neuroplasticity is unknown. The aim of this study was to compare corticospinal excitability and plasticity in the upper limb cortical representation following a single session of lower limb cycling at either low or moderate intensity, or a control condition. We recruited 25 healthy adults to take part in three experimental sessions. Cortical excitability was examined using transcranial magnetic stimulation to elicit motor-evoked potentials in the right first dorsal interosseus muscle. Levels of serum brain-derived neurotrophic factor and cortisol were assessed throughout the experiments. Following baseline testing, participants cycled on a stationary bike at a workload equivalent to 57% (low intensity, 30 min) or 77% age-predicted maximal heart rate (moderate intensity, 15 min), or a seated control condition. Neuroplasticity within the primary motor cortex was then examined using a continuous theta burst stimulation (cTBS) paradigm. We found that exercise did not alter cortical excitability. Following cTBS, there was a transient inhibition of first dorsal interosseus motor-evoked potentials during control and low-intensity conditions, but this was only significantly different following the low-intensity state. Moderate-intensity exercise alone increased serum cortisol levels, but brain-derived neurotrophic factor levels did not increase across any condition. In summary, low-intensity cycling promoted the neuroplastic response to cTBS within the motor cortex of healthy adults. These findings suggest that light exercise has the potential to enhance the effectiveness of motor learning or recovery following brain damage.

Exercise frequency is related to psychopathology but not neurocognitive function

INTRODUCTION

In this study, we measured neurocognitive function, perceived stress, quality of life (QOL), and psychopathology in community-dwelling adults, with data contrasted across tertiles of exercise frequency.

METHODS

A group of 998 adults (age 18-85 yr) was measured for neurocognitive function using a computerized neuropsychological test from CNS Vital Signs (Morrisville, NC). They also completed the Brief Symptom Inventory (BSI), which measures psychopathology, as well as the World Health Organization QOL questionnaire and the Perceived Stress Scale. General linear modeling was used to examine relationships between exercise frequency and neurocognitive function, BSI, QOL, and the Perceived Stress Scale. Backward selection in the GLMSELECT procedure in SAS (version 9.1.3; SAS Institute, Inc., Cary, NC) was used to identify confounding variables including age, gender, body mass index, marital status, education level, stress level, alcohol, smoking, and chronic disease. A contrast to test linear trend was performed after adjusting for confounders. Pairwise comparisons were performed across exercise frequency tertiles using the Tukey-Kramer method.

RESULTS

P values for trend tests and pairwise comparisons were nonsignificant for all five cognition function domains across exercise frequency tertiles after adjustment for confounders. Age and education level emerged as the best correlates of neurocognitive function. P values for trend were significant for all BSI domains and indices, QOL, and perceived stress, across exercise frequency tertiles.

CONCLUSIONS

In conclusion, nine BSI psychopathology domains, perceived stress, and QOL but not five neurocognitive function domains were modestly but significantly associated with aerobic exercise frequency in a heterogeneous group of community-dwelling adults after adjustment for demographic and lifestyle factors.

Negative effects of ultrafine particle exposure during forced exercise on the expression of Brain-Derived Neurotrophic Factor in the hippocampus of rats

Exercise improves cognitive function, and Brain-Derived Neurotrophic Factor (BDNF) plays a key role in this process. We recently reported that particulate matter (PM) exposure negatively contributed to the exercise-induced increase in human serum BDNF concentration. Furthermore, PM exposure is associated with neuroinflammation and cognitive decline. The aim of this study was to investigate the effect of exposure to ultrafine particles (UFP) during a single bout of forced exercise on the expression of inflammatory (IL1α, IL1β, TNF, IL6, NOS2, NOS3) and oxidative stress (NFE2L2)-related genes, as well as BDNF in the brain of rats. Four groups (n=6/group) of Wistar rats were exposed for 90 min to one of the following exposure regimes: UFP+exercise, UFP+rest, ambient air+exercise, ambient air+rest (control). Hippocampus, olfactory bulb and prefrontal cortex were collected 24h after exposure. Gene expression changes were analyzed with real-time PCR. In the condition ambient air+exercise, hippocampal expression of BDNF and NFE2L2 was up-regulated, while the expression of IL1α and NOS3 in the prefrontal cortex and IL1α in the olfactory bulb was down-regulated compared to the control. In contrast, gene expression in the condition UFP+exercise did not differ from the control. In the condition UFP+rest, hippocampal expression of NFE2L2 was down-regulated and there was a trend toward down-regulation of BDNF expression compared to the control. This study shows a negative effect of UFP exposure on the exercise-induced up-regulation of BDNF gene expression in the hippocampus of rats.

Aerobic physical exercise as a possible treatment for neurocognitive dysfunction in bipolar disorder

BACKGROUND

Neurocognitive dysfunction associated with bipolar disorder (BD) is pervasive, persistent across illness phases, and is demonstrated to predispose and portend psychosocial impairment. Moreover, no approved therapies for various phases of BD have been shown to reliably improve any dimension of neurocognitive performance. In this article, we emphasize that aerobic physical exercise is a viable neurocognitive-enhancing adjunctive treatment for patients with BD. The overarching aim of this review is to emphasize that aerobic physical exercise is a viable neurocognitive-enhancing adjunctive treatment for patients with BD.

METHODS

We conducted PubMed and Google Scholar searches of all English-language articles published between January 1966 and February 2010 using the search terms bipolar disorder, major depressive disorder, depression, exercise, and physical activity cross-referenced with each other and the following terms: cognition, executive function, learning, memory, attention, emotion, and behavior. Articles selected for review were based on adequacy of sample size, use of standardized experimental procedures, validated assessment measures, and overall quality.

RESULTS

Available studies have documented an array of persisting neurocognitive deficits across disparate bipolar populations. Abnormalities in verbal working memory are highly replicated; deficits in executive function, learning, attention, and processing speed are also a consistent abnormality. The effect sizes of neurocognitive deficits in BD are intermediate between those reported in schizophrenia and major depressive disorder. Several original reports and reviews have documented the neurocognitive-enhancing effects of aerobic exercise in the general population as well as across diverse medical populations and ages. Proposed mechanisms involve nonexclusive effects on neurogenesis, neurotrophism, immunoinflammatory systems, insulin sensitivity, and neurotransmitter systems. Each of these effector systems are implicated in both normal and abnormal neurocognitive processes in BD.

CONCLUSION

Available evidence provides a rationale for empirically evaluating the neurocognitive benefits of aerobic exercise in BD.

Association between executive function and physical performance in older Korean adults: findings from the Korean Longitudinal Study on Health and Aging (KLoSHA)

Reduced executive function and physical performance are common age-related conditions. This study evaluated the associations between executive function and physical performance in a representative sample of older adults. Cross-sectional data were analyzed from a population-based sample of 629 men and women aged 65 or older and living in one typical city in Korea. Specific aspects of executive function were assessed using the trail making test, digit span test, and lexical fluency test to measure set shifting, working memory and cognitive flexibility functions. Physical performance was measured using performance-oriented mobility assessment (POMA) scores and isokinetic muscle strength. Subjects' self-efficacy was also assessed using the activities-specific balance confidence (ABC) scale. Results of the lexical fluency test were associated with POMA scores and muscle strength, independent of age, gender, education, comorbidity, physical activity status, depression, and global cognition, suggesting that reduced cognitive flexibility is associated with reduced physical performance and muscle strength. Self-efficacy was also independently associated with physical performance and muscle strength. Clinicians need to consider the association between executive function and physical performance when working to improve physical functioning in an aged population.

Healthy aging rounds: using healthy-aging mentors to teach medical students about physical activity and social support assessment, interviewing, and prescription

Medical students underestimate the health and functional status of community-dwelling older adults and have little experience in health promotion interviewing or prescribing physical activity. The goal was to provide third-year University of Arizona medical students with an opportunity to gain a broader and evidence-based understanding of healthy aging, with specific focus on physical activity and social engagement. Students engaged in one-on-one conversations with healthy older adult mentors and practiced assessment, interviewing and prescription counseling for physical activity and social support. This 2-hour mandatory interactive educational offering improved student attitudes and knowledge about healthy aging and provided hands-on health promotion counseling experience.

Midlife predictors of Alzheimer's disease

Factors contributing to increased risk for Alzheimer's disease (AD) include age, sex, genes, and family history of AD. Several risk factors for AD are endogenous; however, accumulating evidence implicates modifiable risk factors in the pathogenesis of AD. Although the continued task of identifying new genes will be critical to learning more about the disease, several research findings suggest that potentially alterable environmental factors influence genetic contributions, providing targets for disease prevention and treatment. Here, we review midlife risk factors for AD, and address the potential for therapeutic intervention in midlife.