Examining the effects of light versus moderate to vigorous physical activity on cognitive function in African American adults

Accelerometry measures of physical activity and sedentary behavior: Associations with cognitive functioning in MS

BACKGROUND

Cognitive dysfunction is a pervasive symptom of multiple sclerosis (MS). Correlational evidence on the relationships between physical activity, sedentary behavior, and cognition has been mixed and limited to a few activity measures. The collinearity of accelerometry-based metrics has precluded an assessment of the full activity spectrum. Here, we aimed to examine the rich set of activity measures using analytic approaches suitable for collinear metrics. We investigated the combination of physical activity, sedentary, and clinicodemographic measures that explain the most variance in composite scores of working memory/processing speed, visual memory, and verbal memory.

METHODS

We analyzed baseline accelerometry and neuropsychological data (n = 80) from a randomized controlled trial of pedometer tracking. Using partial least squares regression (PLSR), we built three models to predict latent scores on the three domains of cognition using 12 activity metrics, sex, education, and Expanded Disability Status Scale (EDSS) scores. Significance was assessed using linear regression models with model component scores as predictors and cognitive composites as outcomes.

RESULTS

The latent component was significant for working memory/processing speed but was not significant for visual memory and verbal memory after Bonferroni correction. Working memory/processing speed was positively associated with average kilocalories, moderate-to-vigorous physical activity (MVPA), steps, and sex (i.e., higher scores in males) and negatively related to duration of long sedentary bouts and EDSS.

CONCLUSIONS

These findings suggest that increasing overall energy expenditure through walking and MVPA, while decreasing prolonged sedentary time may positively benefit working memory/processing speed in people with MS.

TRIAL REGISTRATION

This RCT #NCT03244696 was registered on Clinicaltrials.gov (https://www.

CLINICALTRIALS

gov/ct2/show/NCT03244696).

Effect of aerobic exercise training on EEG: event-related potential and neuropsychological functions in depressed elderly with mild cognitive impairment

Increased depressive severity has been linked to neurocognitive impairment. Aerobic exercise (AE) is an efficient technique for improving cognitive function. However, studies indicating the importance of AE to neurophysiological and neuropsychological functions in the depressed elderly using event-related potentials (ERPs) are scarce.

Objectives

This study aimed to identify the potential benefits of AE on neurophysiological and neuropsychological functions.

Methods

A total of 30 depressed older adults (AE group: n=15; control group (CG): n=14) were recruited based on the inclusion and exclusion criteria. The AE group was subjected to an 8-week-period AE program (3 times/week for 30 min per session) at moderate intensity, determined using heart rate maximum (HRmax). The training intensity was set at 50% HRmax and increased by 5% in subsequent weeks. Pre- and post-training measures for neurophysiological function were tested using ERP-P300 (amplitude-μV and latency-ms) and also for neuropsychological functions using the trail making test (TMT), mini mental status examination (MMSE), and everyday cognition questionnaire (ECog).

Results

In the experimental group, statistically significant improvements were observed when analyzed for all 3 (group-by-time interaction effect, main effect of time, and main effect of group), in both neurophysiological functions (*p<0.001) and neuropsychological functions (*p<0.001), except for ECog scores, where the results were insignificant for the main effect of a group. Correlation analysis demonstrated no association between neurophysiological and neuropsychological functions (*p>0.05).

Conclusion

Findings showed that 8 weeks of AE training may be a promising approach to improve cognitive functions in depressed older adults. However, considering relatively small number of patients, the question arises for effectiveness in other populations.

Associations between physical activity and proactive control and the modulating role of working memory

Accumulating evidence indicates positive associations between physical activity (PA) and cognitive control. Proactive control, the ability to maintain goal-relevant information in preparation of upcoming task demands, is a critical component of cognitive control. However, little research has examined the association between PA and proactive control. To address this issue, a total of 132 university students were recruited and divided into two groups based on reported regular PA during past week. All participants completed two common cognitive control tasks: the AX Continuous Performance Task (AX-CPT) and the Cued Task-Switching Paradigm (CTS). In comparison with the low PA group, the high PA group showed greater proactive control efficiency on both tasks. Moreover, proactive control indices significantly correlated between the two tasks for the high but not for the low PA group. Further, working memory significantly modulated the association between PA and proactive control efficiency of CTS. Although the present cross-section design does not allow us to test the causal relationship between PA and proactive control, these findings may have important implications for developing effective intervention strategies which aim to promote proactive control through increasing PA or to promote PA through increasing proactive control. Moreover, individual differences in working memory are important to consider when we aim to design such interventions.

An Intense Bout of Acute Aerobic Exercise, but Not a Carbohydrate Supplement, Improves Cognitive Task Performance in a Sample of Black, Indigenous, and People of Color (BIPOC) Student Athletes

BACKGROUND

There are contradictory findings in the literature on whether an acute bout of aerobic exercise leads to a post-exercise improvement in cognitive function (CF). Moreover, participants used in the published literature are not representative of the racial make-up of sport or tactical populations.

METHODS

A randomized crossover design was incorporated, with participants randomly consuming water or a carbohydrate sports drink within the first 3 min of a graded maximal exercise test (GMET) conducted in a laboratory. Twelve self-identified African American participants, (seven males, five females, age = 21.42 ± 2.38 years, height = 174.94 ± 12.55 cm, mass = 82.45 ± 33.09 kg) completed both testing days. Participants completed the CF tests immediately pre- and post-GMET. CF was assessed with the Stroop color and word task (SCWT) and concentration task grid (CTG). Participants completed the GMET when they reported a score of 20 on the Borg ratings of perceived exertion scale.

RESULTS

Time to complete the SCWT incongruent task (p < 0.001) and CTG performance (p < 0.001) significantly improved post-GMET in both conditions. VO_2max was positively correlated with pre- and post-GMET SCWT performance.

CONCLUSIONS

The findings of our study suggest that an acute bout of maximal exercise significantly improves CF. Additionally, cardiorespiratory fitness is positively associated with CF in our sample of student athletes from a historically Black college and university.

The Association Between Objectively-Measured Physical Activity and Cognitive Functioning in Middle-Aged and Older People Living with HIV

Middle-aged and older people living with HIV (PWH) are at higher risk for cognitive impairment and engage in lower levels of physical activity (PA) than seronegative counterparts. Research examining the association between objectively-measured PA and cognitive function in this population is scarce. This cross-sectional study examined the association between accelerometry-measured PA and cognitive functioning among 75 PWH (mean age 55.63). Light PA was the PA variable with the most consistent associations with cognition, with more minutes per week of light PA (performed in bouts of ≥ 10 min) being associated with better executive function, working memory/attention, and speed of processing performance, adjusted for age and current CD4 count. Findings suggest that although middle-aged and older PWH engage in more light than moderate-to-vigorous PA, light PA may be beneficial to cognition. Longitudinal studies are needed to understand PA dose-response associations with cognitive trajectories, cognitive domain specificity of PA effects, and underlying neural mechanisms of PA.

Association between intensity or accumulating pattern of physical activity and executive function in community-dwelling older adults: A cross-sectional study with compositional data analysis

Objective

Previous studies have suggested a positive association between physical activity (PA) and executive function in older adults. However, they did not adequately consider the compositional nature of daily time use and accumulated PA patterns. Therefore, this study aimed to examine the association between intensity or accumulated PA patterns and executive functions (inhibitory control, working memory, and cognitive flexibility) in community-dwelling older adults, considering the interaction of daily time spent in PA, sedentary behavior (SB), and sleep.

Method

This cross-sectional study used baseline data from a randomized controlled trial on the effect of exercise on cognitive function conducted between 2021 and 2022. Data from 76 community-dwelling older adults were used in the analysis. The time spent in PA and SB was assessed using an accelerometer, and sleep duration was self-reported. The Stroop task (inhibitory control), N-back task (working memory), and task-switching task (cognitive flexibility) were conducted to evaluate the subcomponents of executive function. Considering various potential confounders, compositional multiple linear regression analysis and compositional isotemporal substitution were performed to examine the association of PA with executive function and to estimate predicted changes in executive function in response to the hypothetical time-reallocation of movement behaviors, respectively.

Results

A longer time spent in light-intensity PA (LPA), relative to remaining behaviors, was associated with better Stroop task performance. Moreover, this association was stronger in LPA lasting longer than 10 min than in sporadic LPA. Additionally, theoretical 30 min/day time reallocation from SB or sleep to LPA was associated with better Stroop task performance (corresponding to approximately a 5%-10% increase). On the other hand, no significant associations of time spent in moderate- to vigorous-intensity PA with any subcomponents of executive function were observed.

Conclusion

LPA was positively associated with inhibitory control, and this association was stronger in bouts of LPA than in sporadic LPA. Moreover, reducing the time spent in SB or sleep and increasing the time spent in LPA, especially long-bout LPA, could be important measures for managing inhibitory control in late life. Future large longitudinal and intervention studies are needed to confirm these associations and reveal the causality and underlying mechanisms.

Walking and Sitting Outdoors: Which Is Better for Cognitive Performance and Mental States?

Myriad research indicates that physical activity and natural environments enhance cognitive performance and mental health. Much of this research is cross-sectional or involves physical activity in outdoor environments, rendering it difficult to ascribe the results to a particular condition. This study utilized electroencephalography (EEG) and established cognitive performance tasks to determine the impact of a short intervention including either walking or sitting in an outdoor environment. In this experiment, a total of 50 participants were randomized into walking and sitting groups, with cognitive performance measured before, after, and 10 min post intervention. Both groups demonstrated improvements in cognitive performance, with no significant difference between groups. Elevated levels of relaxation during the intervention were the best predictor of post-test performance. Participants reporting a higher connection to nature, as well as state-based mindfulness during the outdoor intervention, also reported lower levels of frontal theta (i.e., rumination) during the interaction, while the walking group demonstrated higher relaxation. These findings provide a direct connection to neural mechanisms influenced by physical activity and the natural environment, and their impact on cognitive performance. This supports Attention Restoration Theory and the effectiveness of short outdoor interventions incorporating physical activity as a method of restoring mental attention.

Association between Accelerometer-Measured Light-Intensity Physical Activity and Cognitive Function in Older Adults

OBJECTIVES

This study aimed to investigate whether accelerometer-measured light physical activity (LPA) is associated with cognitive function and whether engaging in ≥3 h/day of LPA can reduce the chance of cognitive impairment among a sample of older adults in Taiwan.

DESIGN

Cross-sectional study.

SETTING

An outpatient department in a medical center.

PARTICIPANTS

Participants were community-dwelling older adults aged 65 years and older who were able to walk independently from September 2020 to March 2021.

MEASUREMENTS

A tri-axial accelerometer was used to measure LPA for 7 consecutive days, and the Mini-Mental State Examination (MMSE) scale was used to assess the chance of cognitive impairment. Multiple linear regression model and binary logistic regression model were performed to examine the association between LPA and MMSE scores.

RESULTS

145 older Taiwanese adults (51.7% men; 81.2±6.8 years; 6.9% at chance of cognitive impairment) were included. After adjusting for moderate-to-vigorous physical activity (MVPA) and wear time, we found that there was a significant association between LPA and cognitive function (95% confidence interval [CI]: 0.64-1.65; P<0.001), and further found that those who engaged in LPA ≥3 h/day were at reduced chance of cognitive impairment compared with people who engaged in LPA <3 h/day (odds ratio [OR]: 0.16; 95% CI: 0.03-0.80; P=0.025).

CONCLUSION

This study demonstrated that engaging in LPA ≥3 h/day could be viewed as a protective factor for maintaining cognitive function in older adults. We recommend further longitudinal research to elucidate the association between intensity-specific LPA and cognitive function.

Effects of Lifestyle Factors on Cognition in Minority Population of Older Adults: A Review

The onset of dementia and Alzheimer's disease (AD) is projected to expand over the next several decades in the United States as the population ages. However, the cognitive health burden is not equally distributed among the population, as Hispanics and African Americans are at higher risk of AD when compared with Non-Hispanic Whites. There is some evidence to indicate that cognitive decline may be associated with lifestyle factors and that interventions in these domains may prevent or delay this decline. These lifestyle factors include social engagement, physical activity, both aerobic and strength training, dietary intake, sleep and stress. This review summarizes, in general, what is known about the relationship between risk factors and cognition and, in particular what is known about this relationship in minority populations. The results show that the relationship between these risk factors and cognitive decline is stronger for some of the factors such as physical activity and dietary intake and weaker for the other factors depending on what is measured and in what populations. It does appear, however, that the studies in minority populations is limited and warrants more targeted research and interventions.

Physical Activity and Cognitive Function in African American Older Adults Living With HIV

The purpose of the current study was to investigate the association between self-reported physical activity (minutes/week) and cognitive functioning in a sample of African American older adults living with HIV. A secondary analysis of baseline data collected from clinically stable African American older adults living with HIV (aged >50 years; N = 124) enrolled in the Rush Center of Excellence on Disparities in HIV and Aging study was conducted. Participants completed a battery of 19 cognitive function tests that were used to create summary scores of global cognition and five cognitive domains. Physical activity was measured using a modified self-report questionnaire derived from a national health survey. Average self-reported number of weekly minutes spent in light physical activity was 290.6 minutes and for moderate/vigorous physical activity was 314.67 minutes. Number of weekly minutes of light physical activity was significantly positively associated with visuospatial ability; however, no associations were found between moderate/vigorous physical activity and any cognitive domain. Contrary to expectations, our findings do not support a relationship between moderate/vigorous physical activity and cognitive function in African American older adults living with HIV. [Journal of Gerontological Nursing, 47(12), 27-34.].

The Association Between Light Physical Activity and Cognition Among Adults: A Scoping Review

Background

The physical and cognitive benefits of moderate-vigorous intensity physical activity (MVPA) for adults have been well documented. Recently, there has been increasing interest in the independent health benefits of light-intensity physical activity (LPA). This research has primarily focused on the relationship between LPA and morbidity and mortality risk, with few studies investigating cognitive associations. The purpose of this scoping review was to catalog existing evidence on the association between device-based or technologically measured LPA and cognition among adults, identify trends in the literature, and recommend future areas for research.

Methods

Six electronic databases were searched between January and June 2020. Forty published studies met the inclusion criteria, which included both healthy and clinical young and older adult populations. Among the 40 articles were 14 acute exercise studies, 4 randomized control trials (RCTs), 18 cross-sectional studies, and 4 longitudinal studies.

Results

7/14 (50%) acute, 3/4 (75%) RCT, 10/18 (56%) cross-sectional, and 2/4 (50%) longitudinal studies reported a significant, positive relationship between LPA and one or more cognitive outcomes. These heterogeneous findings can largely be attributed to the diverse study designs and populations, as well as the numerous assessments used to test the cognitive domains.

Conclusion

These collective findings suggest LPA may be a potential lifestyle intervention to improve cognition across adulthood. However, the inconsistent approaches used among these studies suggest a more concerted, unified scientific approach is needed to further understand the LPA-cognition relationship.

The Influence of the BDNF Val66Met Polymorphism on the Association of Regular Physical Activity With Cognition Among Individuals With Diabetes

INTRODUCTION

Diabetes is associated with cognitive dysfunction that comes with substantial lifetime consequences, such as interference with diabetes self-management and reduced quality of life. Although regular physical activity has been consistently shown to enhance cognitive function among healthy subjects, significant interpersonal differences in exercise-induced cognitive outcomes have been reported among brain-derived neurotrophic factor (BDNF) Val/Val vs. Met carriers. However, the evidence on how the BDNF Val66Met variant influences the relationship between regular physical activity and cognition among individuals with diabetes is currently lacking.

METHODS

A total of 3,040 individuals with diabetes were included in this analysis using data from the Health and Retirement Study. Associations among moderate and vigorous physical activities (MVPA) and measures of cognitive function were evaluated using multivariable linear regression models within each stratum of the Val66Met genotypes.

RESULTS

MVPA was more strongly associated with total cognitive score, mental status, and words recall among Met/Met carriers, compared to Val/Val and Val/Met carriers.

CONCLUSIONS

This study provided preliminary findings on how BDNF variants may modulate the exercise-induced cognitive benefits among mid-aged and older adults with diabetes. Given the limitations of the current study, it is necessary for randomized controlled trials to stratify by BDNF genotypes to more conclusively determine whether Met carriers benefit more from increased physical activity. In addition, future research is needed to examine how the interplay of BDNF Val66Met variants, DNA methylation, and physical activity may have an impact on cognitive function among adults with diabetes.