Physical activity-related individual differences in functional human connectome are linked to fluid intelligence in older adults.

The study examined resting state functional connectivity (rs-FC) associated with moderate-to-vigorous physical activity (MV-PA), sedentary time (ST), TV viewing, computer use, and their relationship to cognitive performance in older adults. We used pre-intervention data from 119 participants from the Fit & Active Seniors trial. Multivariate pattern analysis revealed two seeds associated with MV-PA: right superior frontal gyrus (SFG; spanning frontoparietal [FPN] and ventral attention networks [VAN]) and right precentral (PrG) and postcentral gyri (PoG) of the somatosensory network (SN). A positive correlation between the right SFG seed and a cluster spanning default mode (DMN), dorsal attention (DAN), FPN, and visual networks (VIS) was linked to higher fluid intelligence, as was FC between the right PrG/PoG seed and a cluster in VIS. No significant rs-FC patterns associated with ST, TV viewing, or computer use were found. Our findings suggest that greater functional integration within networks implementing top-down control and within those supporting visuospatial abilities, paired with segregation between networks critical and those not critical to top-down control, may help promote cognitive reserve in more physically active seniors.

Mind-body practices, interoception and pain: a scoping review of behavioral and neural correlates.

OBJECTIVE: Chronic pain is a significant source of suffering in the United States, and many individuals increasingly turn towards yoga for pain relief. However, little is known regarding how yoga improves pain. Herein we seek to examine the scope of the literature linking mind-body practices, pain and interoception; an emerging mechanism by which yoga may improve chronic pain. METHODS: This scoping review followed the five-stage methodological framework proposed by Arksey and O'Malley to examine behavioral and neural correlates of interoception in mind-body practices and pain. A broad search of the Pubmed, CINAHL, SportDiscus, Scopus, PsychInfo, and SocIndex databases was conducted, utilizing three clusters of search terms: (1) interoceptive terms, (2) mind-body terms, and (3) pain terms. RESULTS: A combined total of 690 articles were screened, and 24 findings included for analysis. Sixteen studies examined interoceptive outcomes in response to mind-body practices for chronic pain, and 8 studies examined interoceptive outcomes in response to evoked-pain tasks in experienced mind-body practitioners. Only three studies linked yoga, interoception and pain. CONCLUSION: This review relied on the broader mind-body literature to inform our analyses as the literature examining yoga, pain and interoception remains limited. Interoceptive techniques including attending to and acceptance of bodily sensations, appear to be key therapeutic mechanisms in mind-body practices for chronic pain. Future yoga-based interventions would benefit examining interoceptive outcomes and integrating interoceptive strategies to facilitate the pain-modulating benefits of yoga.

Mind-Body Practice and Family Caregivers' Subjective Well-Being: Findings From the Midlife in the United States (MIDUS) Study.

Objectives: Informal caregiving has been associated with higher stress and lower levels of subjective well-being. Mind-body practices including yoga, tai chi, and Pilates also incorporate stress reducing activities. The current study aimed to examine the association between mind-body practice and subjective well-being among informal family caregivers. Methods: A sample of informal caregivers were identified in the Midlife in the United States study (N = 506, M ± SDage = 56 ± 11, 67% women). We coded mind-body practice into three categories, including regular practice (participating in one or more of them "a lot" or "often"), irregular (participating "sometimes" and "rarely") and no practice ("never"). Subjective well-being was measured using the 5-item global life satisfaction scale and the 9-item mindfulness scale. We used multiple linear regression models to examine associations between mind-body practice and caregivers' subjective well-being, controlling for covariates of sociodemographic factors, health, functional status, and caregiving characteristics. Results: Regular practice was associated with both better mindfulness-related well-being (b = 2.26, p < .05) and better life satisfaction (b = 0.43, p < .05), after controlling for covariates. Discussion: Future research should examine whether there is a selection effect of caregivers with higher well-being being more likely to choose these activities, and/or if mind-body practices are effective non-pharmacological interventions to improve family caregivers' quality of life.

Differentiating the influence of sedentary behavior and physical activity on brain health in late adulthood.

Public health messaging calls for individuals to be more physically active and less sedentary, yet these lifestyle behaviors have been historically studied independently. Both physical activity (PA) and sedentary behavior (SB) are linked through time-use in a 24-hour day and are related to health outcomes, such as neurocognition. While the benefits of PA on brain health in late adulthood have been well-documented, the influence of SB remains to be understood. The purpose of this paper was to critically review the evolving work on SB and brain health in late adulthood and emphasize key areas of consideration to inform potential research. Overall, the existing literature studying the impact of SB on the components and mechanisms of brain health are mixed and inconclusive, provided largely by cross-sectional and observational work employing a variety of measurement techniques of SB and brain health outcomes. Further, many studies did not conceptually or statistically account for the role of PA in the proposed relationships. Therefore, our understanding of the way in which SB may influence neurocognition in late adulthood is limited. Future efforts should include more prospective longitudinal and randomized clinical trials with intentional methodological approaches to better understand the relationships between SB and the brain in late adulthood, and how these potential links are differentiated from PA.

Symmetric data-driven fusion of diffusion tensor MRI: Age differences in white matter.

In the past 20 years, white matter (WM) microstructure has been studied predominantly using diffusion tensor imaging (DTI). Decreases in fractional anisotropy (FA) and increases in mean (MD) and radial diffusivity (RD) have been consistently reported in healthy aging and neurodegenerative diseases. To date, DTI parameters have been studied individually (e.g., only FA) and separately (i.e., without using the joint information across them). This approach gives limited insights into WM pathology, increases the number of multiple comparisons, and yields inconsistent correlations with cognition. To take full advantage of the information in a DTI dataset, we present the first application of symmetric fusion to study healthy aging WM. This data-driven approach allows simultaneous examination of age differences in all four DTI parameters. We used multiset canonical correlation analysis with joint independent component analysis (mCCA + jICA) in cognitively healthy adults (age 20-33, n = 51 and age 60-79, n = 170). Four-way mCCA + jICA yielded one high-stability modality-shared component with co-variant patterns of age differences in RD and AD in the corpus callosum, internal capsule, and prefrontal WM. The mixing coefficients (or loading parameters) showed correlations with processing speed and fluid abilities that were not detected by unimodal analyses. In sum, mCCA + jICA allows data-driven identification of cognitively relevant multimodal components within the WM. The presented method should be further extended to clinical samples and other MR techniques (e.g., myelin water imaging) to test the potential of mCCA+jICA to discriminate between different WM disease etiologies and improve the diagnostic classification of WM diseases.

Yoga, aerobic and stretching exercise effects on neurocognition: Randomized controlled trial protocol.

As the global population ages, the prevalence of cognitive decline and dementia is expected to rise, creating a significant health and economic burden. The purpose of this trial is to rigorously test, for the first time, the efficacy of yoga training as a physical activity intervention to mitigate age-related cognitive decline and impairment. We are conducting a 6-month randomized controlled trial (RCT) of exercise among 168 middle aged and older adults to compare the efficacy of yoga vs. aerobic exercise on cognitive function, brain structure and function, cardiorespiratory fitness, and circulating inflammatory and molecular markers. Using a single-blind, three arm RCT, 168 older adults ages 55-79 will be assigned to either: a Hatha yoga group, an aerobic exercise group or a stretching-toning active control group. Participants will engage in hour long group exercise 3x/week for 6-months. A comprehensive neurocognitive test battery, brain imaging, cardiovascular fitness test, and a blood draw will take place at baseline; end of the 6-month intervention, and at 12-month follow-up. Our primary outcomes of interest are brain regions, such as hippocampal volume and prefrontal cortex, and cognitive functions, such as episodic memory, working memory and executive functions, that are typically affected by aging and Alzheimer's disease. Not only will this RCT test whether yoga is a means to mitigate age-related cognitive decline, but it may also offer an alternative to aerobic exercise, which could be particularly appealing to older adults with compromised physical functioning. ClinicalTrials.gov Identifier: NCT04323163.

Designing home-based physical activity programs for rural cancer survivors: A survey of technology access and preferences.

Background: While technology advances have increased the popularity of remote interventions in underserved and rural cancer communities, less is understood about technology access and preferences for home-based physical activity programs in this cancer survivor population. Purpose: To determine access, preferences, and needs, for a home-based physical activity program in rural cancer survivors. Methods: A Qualtrics Research Panel was recruited to survey adults with cancer across the United States. Participants self-reported demographics, cancer characteristics, technology access and usage, and preferences for a home-based physical activity program. The Godin Leisure Time Exercise Questionnaire (GLTEQ) assessed current levels of physical activity. Descriptive statistics included means and standard deviations for continuous variables, and frequencies for categorical variables. Independent samples t-tests explored differences between rural and non-rural participants. Results: Participants (N=298; mean age=55.2 ± 16.5) had a history of cancer (mean age at diagnosis=46.5), with the most commonly reported cancer type being breast (25.5%), followed by prostate (16.1%). 74.2% resided in rural hometowns. 95% of participants reported accessing the internet daily. On a scale of 0-100, computer/laptop (M=63.4) and mobile phone (M=54.6) were the most preferred delivery modes for a home-based physical activity intervention, and most participants preferred balance/flexibility (72.2%) and aerobic (53.9%) exercises. Desired intervention elements included a frequency of 2-3 times a week (53.5%) for at least 20 minutes (75.7%). While there were notable rural disparities present (e.g., older age at diagnosis, lower levels of education; ps<.001), no differences emerged for technology access or environmental barriers (ps>.08). However, bias due to electronic delivery of the survey should not be discounted. Conclusion: These findings provide insights into the preferred physical activity intervention (e.g., computer delivery, balance/flexibility exercises) in rural cancer survivors, while highlighting the need for personalization. Future efforts should consider these preferences when designing and delivering home-based interventions in this population.

Physical Activity Programming for Older Adults in Assisted Living: Residents' Perspectives.

Decreasing sedentary behavior and increasing light physical activity could promote the maintenance of functional abilities for older adults in assisted living (AL). The purpose of this qualitative study was to gather residents' recommendations about a proposed self-efficacy enhancing intervention to replace sedentary behavior with light physical activity. We interviewed 20 residents (mean age 83.1; 60% women). Topics included their current activities and thoughts about physical activity. We presented the intervention and asked questions to inform its modification. Data were analyzed with content and thematic analysis. Specific recommendations included shorter one-hour sessions and framing the intervention as increasing light physical activity rather than decreasing sedentary behavior. The thematic analysis identified multiple factors that could influence intervention implementation, including motivation to be active, safety concerns, ageist attitudes about physical activity, varying abilities of residents, social influences, and limited opportunities for physical activity. These results will inform physical activity intervention implementation for AL residents.

Yoga Impacts Cognitive Health: Neurophysiological Changes and Stress Regulation Mechanisms.

Yoga, a physical and contemplative practice, offers the practitioner a unique mind-body exercise experience demonstrating preliminary efficacy in improving cognitive health. We examine the evidence for underlying mechanisms that explain the yoga-cognition relationship in healthy older adults. The cognitive benefits of yoga may be the result of improved stress regulation and neurocognitive resource efficiency that facilitate bidirectional brain-body communication.

Brain Structure and Function Predict Adherence to an Exercise Intervention in Older Adults.

INTRODUCTION: Individual differences in brain structure and function in older adults are potential proxies of brain reserve or maintenance and may provide mechanistic predictions of adherence to exercise. We hypothesized that multimodal neuroimaging features would predict adherence to a 6-month randomized controlled trial of exercise in 131 older adults (age, 65.79 ± 4.65 yr, 63% female), alone and in combination with psychosocial, cognitive, and health measures. METHODS: Regularized elastic net regression within a nested cross-validation framework was applied to predict adherence to the intervention in three separate models (brain structure and function only; psychosocial, health, and demographic data only; and a multimodal model). RESULTS: Higher cortical thickness in somatosensory and inferior frontal regions and less surface area in primary visual and inferior frontal regions predicted adherence. Higher nodal functional connectivity (degree count) in default, frontoparietal, and attentional networks and less nodal strength in primary visual and temporoparietal networks predicted exercise adherence ( r = 0.24, P = 0.004). Survey and clinical measures of gait and walking self-efficacy, biological sex, and perceived stress also predicted adherence ( r = 0.17, P = 0.056); however, this prediction was not significant when tested against a null test statistic. A combined multimodal model achieved the highest predictive strength ( r = 0.28, P = 0.001). CONCLUSIONS: Our results suggest that there is a substantial utility of using brain-based measures in future research into precision and individualized exercise interventions older adults.

Resting state functional connectivity provides mechanistic predictions of future changes in sedentary behavior.

Sedentary behaviors are increasing at the cost of millions of dollars spent in health care and productivity losses due to physical inactivity-related deaths worldwide. Understanding the mechanistic predictors of sedentary behaviors will improve future intervention development and precision medicine approaches. It has been posited that humans have an innate attraction towards effort minimization and that inhibitory control is required to overcome this prepotent disposition. Consequently, we hypothesized that individual differences in the functional connectivity of brain regions implicated in inhibitory control and physical effort decision making at the beginning of an exercise intervention in older adults would predict the change in time spent sedentary over the course of that intervention. In 143 healthy, low-active older adults participating in a 6-month aerobic exercise intervention (with three conditions: walking, dance, stretching), we aimed to use baseline neuroimaging (resting state functional connectivity of two a priori defined seed regions), and baseline accelerometer measures of time spent sedentary to predict future pre-post changes in objectively measured time spent sedentary in daily life over the 6-month intervention. Our results demonstrated that functional connectivity between (1) the anterior cingulate cortex and the supplementary motor area and (2) the right anterior insula and the left temporoparietal/temporooccipital junction, predicted changes in time spent sedentary in the walking group. Functional connectivity of these brain regions did not predict changes in time spent sedentary in the dance nor stretch and tone conditions, but baseline time spent sedentary was predictive in these conditions. Our results add important knowledge toward understanding mechanistic associations underlying complex out-of-session sedentary behaviors within a walking intervention setting in older adults.

Feasibility of a yoga, aerobic and stretching-toning exercise program for adult cancer survivors: the STAYFit trial.

BACKGROUND: The use of yoga as a mind-body practice has become increasingly popular among clinical populations and older adults who use this practice to manage age and chronic disease-related symptoms. Although yoga continues to gain popularity among practitioners and researchers, pilot studies that examine its feasibility and acceptability, especially among cancer survivors, are limited. Feasibility studies play a critical role in determining whether the target population is likely to engage with larger scale efficacy and effectiveness trials. In this paper we present feasibility and acceptability data from a 12-week randomized controlled trial (RCT) conducted with adult cancer survivors. METHODS: Participants n = 78 (Mean age: 55 years) were randomized to one of three groups: a Hatha yoga, aerobic exercise, or stretching-toning control group with group exercise classes held for 150 min/week for 12 weeks. Herein we report feasibility and acceptability, including enrollment rates, attendance, attrition and adverse events, and participant feedback and satisfaction data. RESULTS: Of the 233 adults screened, 109 were eligible and 78 randomized to one of the three intervention arms. Session attendance was high for all groups (75.5-89.5%) and 17 participants dropped out during the 12-week intervention. Program satisfaction was high (4.8 or higher out of 5) and no adverse events were reported. One cohort (n = 15) of the intervention transitioned to remote intervention delivery due to the COVID-19 pandemic. Feasibility data from these participants suggested that synchronized group exercise classes via Zoom with a live instructor were acceptable and enjoyable. Participant feedback regarding most and least helpful aspects of the program as well as suggestions for future yoga interventions are summarized. CONCLUSIONS: Overall, the yoga intervention was highly feasible and acceptable. The feasibility parameters from this trial can aid researchers in estimating recruitment rates for desired sample sizes to successfully randomize and retain cancer survivors in short- and long-term yoga-based efficacy and effectiveness trials. The findings also provide evidence to clinicians who can recommend up to 150 min of a combination of exercises-aerobic, yoga, or stretching-toning to their cancer patients in order to improve health and wellbeing during cancer survivorship.

Effects of a DVD-delivered randomized controlled physical activity intervention on functional health in cancer survivors.

BACKGROUND: Supervised physical activity interventions improve functional health during cancer survivorship, but remain costly and inaccessible for many. We previously reported on the benefits of a DVD-delivered physical activity program (FlexToBa™) in older adults. This is a secondary analysis of the intervention effects among cancer survivors in the original sample. METHODS: Low active, older adults who self-reported a history of cancer (N = 46; M time since diagnosis = 10.7 ± 9.4 years) participated in a 6-month, home-based physical activity intervention. Participants were randomized to either the DVD-delivered physical activity program focused on flexibility, toning, and balance (FlexToBa™; n = 22) or an attentional control condition (n = 24). Physical function was assessed by the Short Physical Performance Battery (SPPB) at baseline, end of intervention, and at 12 and 24 months after baseline. RESULTS: Repeated measures linear mixed models indicated a significant group*time interaction for the SPPB total score (ß = - 1.14, p = 0.048), driven by improved function from baseline to six months in the FlexToBa™ group. The intervention group also had improved balance (ß = - 0.56, p = 0.041) compared with controls. Similar trends emerged for the SPPB total score during follow-up; the group*time interaction from 0 to 12 months approached significance (ß = - 0.97, p = 0.089) and was significant from 0 to 24 months (ß = - 1.84, p = 0.012). No significant interactions emerged for other outcomes (ps > 0.11). CONCLUSIONS: A DVD-delivered physical activity intervention designed for cancer-free older adults was capable of eliciting and maintaining clinically meaningful functional improvements in a subgroup of cancer survivors, with similar effects to the original full sample. These findings inform the dissemination of evidence-based physical activity programs during survivorship. TRIAL REGISTRATION: ClinicalTrials.gov NCT01030419 . Registered 11 December 2009.

White matter plasticity in healthy older adults: The effects of aerobic exercise.

White matter deterioration is associated with cognitive impairment in healthy aging and Alzheimer's disease. It is critical to identify interventions that can slow down white matter deterioration. So far, clinical trials have failed to demonstrate the benefits of aerobic exercise on the adult white matter using diffusion Magnetic Resonance Imaging. Here, we report the effects of a 6-month aerobic walking and dance interventions (clinical trial NCT01472744) on white matter integrity in healthy older adults (n = 180, 60-79 years) measured by changes in the ratio of calibrated T1- to T2-weighted images (T1w/T2w). Specifically, the aerobic walking and social dance interventions resulted in positive changes in the T1w/T2w signal in late-myelinating regions, as compared to widespread decreases in the T1w/T2w signal in the active control. Notably, in the aerobic walking group, positive change in the T1w/T2w signal correlated with improved episodic memory performance. Lastly, intervention-induced increases in cardiorespiratory fitness did not correlate with change in the T1w/T2w signal. Together, our findings suggest that white matter regions that are vulnerable to aging retain some degree of plasticity that can be induced by aerobic exercise training. In addition, we provided evidence that the T1w/T2w signal may be a useful and broadly accessible measure for studying short-term within-person plasticity and deterioration in the adult human white matter.

Device-measured sedentary behavior in oldest old adults: A systematic review and meta-analysis.

Sedentary behavior contributes to health decline and frailty in older adults, especially the oldest old. The purpose of this systematic review was to synthesize evidence describing the volume of device-measured sedentary behavior and factors that influence sedentary behavior in community-dwelling adults aged 80 and older. Four electronic databases were searched in August 2018; the search was updated in September 2019 and December 2020. Twenty-one articles representing 16 unique datasets from six countries met inclusion criteria. Various devices and data processing methods were used to measure sedentary behavior; the most common device was the ActiGraph accelerometer. Sedentary time during the waking day ranged from 7.6 to 13.4 h/day. Studies using similar measurement methods (hip-worn ActiGraph with uniaxial cut-point <100 counts per minute) had a weighted mean of 10.6 h/day. Subgroup analyses revealed that male gender and age ≥85 may contribute to increased sedentary behavior. Only seven individual articles examined factors that influence sedentary behavior in the 80 and older age group; older age, male gender, non-Hispanic white race/ethnicity, social disadvantage, and declining cognitive function (in men) were associated with increased sedentary behavior. In conclusion, the oldest old are highly sedentary and little is known about factors that influence their sedentary behavior.

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.

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

BACKGROUND: Physical activity (PA) recommendations for older adults often endorse participation in moderate to vigorous intensity (MVPA). However, health disparities are evident such that African Americans engage in lower levels of MVPA, have a higher prevalence of chronic health and cognitive impairments. The purpose of this cross-sectional study was to examine the role of light PA in addition to MVPA and their associations with measures of executive function among African American older adults. METHODS: One hundred and ten participants (mean age = 64.78 ± 5.7, males = 14) completed measures of cognitive functioning, including the Trail making, Flanker and the N-back tasks. Additionally, participants completed a 6-minute walk test to estimate their cardiovascular fitness and were given an Actigraph accelerometer for 7-days to objectively assess their light and MVPA. RESULTS: Regression analyses controlling for age, fitness and education showed that higher levels of light PA but not MVPA predicted better cognitive performance on the incongruent flanker reaction time (ß=-.24), trails B (ß=-.24) and 1-back accuracy (ß=.28). Both light PA and MVPA predicted faster reaction times on the 1-back and 2-back conditions of the n-back (light PA: ß's=-.22-.23; MVPA: ß's=-.28). CONCLUSIONS: Light PA demonstrated similar or better associations than MVPA with cognitive functions which are known to decline with age. Designing and promoting light PA interventions in African American older adults maybe more feasible given the prevalence of disability and functional health disparities. Intervention studies testing the efficacy and effectiveness of light PA are needed and could have a significant public health impact among aging African Americans.

Effects of yoga, aerobic, and stretching and toning exercises on cognition in adult cancer survivors: protocol of the STAY Fit pilot randomized controlled trial.

BACKGROUND: Cancer survivors experience compromised quality of life due to impaired cognitive function as a result of cancer diagnosis and treatment. Although exercise has proven to be effective in improving cognitive function across the lifespan, interventions comprehensively testing the effectiveness for cancer survivors are limited. The STAY Fit Trial is a three-armed pilot randomized controlled trial designed to compare the effects of a 12-week yoga, aerobic walking, and stretch and tone intervention on cognitive function among adult cancer survivors. METHODS: This pilot study aims to recruit 75 adult cancer survivors who will complete assessments of cognitive function, cardiovascular fitness, physical activity, and psychosocial measures at baseline and after the 12-week intervention. The aims of STAY Fit are (1) to assess the efficacy of yoga to improve cognitive function among cancer survivors, compared to aerobic exercise and an active control group; (2) to examine changes in cardiovascular fitness as a result of the interventions; and (3) to assess changes in quality of life among our population as a result of the exercise interventions. DISCUSSION: The STAY Fit Trial will test the effectiveness of yoga, aerobic exercise, and stretching and toning exercises in improving cognitive function and fitness among adult cancer survivors. The results of this pilot study will enable us to understand the most effective physical activity modality to improve cognitive function in this population and potentially combat cancer-related cognitive impairment. TRIAL REGISTRATION: ClinicalTrials.gov NCT03650322 . Registered on 28 August 2018.

Sensor-measured sedentariness and physical activity are differentially related to fluid and crystallized abilities in aging.

Aerobic exercise and physical activity (PA) are known to benefit cognition in adulthood. However, a typical older adult spends most of the day sedentary or in light PA, behaviors that are typically poorly captured by questionnaires. To better understand the associations between time spent in different intensities of lifestyle PA and cognition, we measured average time spent daily in sedentariness, light, and moderate to vigorous PA using hip-worn sensors (ActiGraph accelerometers). We studied baseline data from 228 cognitively normal adults (Age 60-80) who took part in a clinical trial (clinical study identifier: NCT01472744). Fluid (processing speed, memory, and reasoning) and crystallized abilities (vocabulary knowledge) were assessed with the Virginia Cognitive Aging Battery. Adjusting for age, sex, and several modifiable socioeconomic, physical and functional health factors, time spent daily in moderate to vigorous PA was positively related with fluid abilities (perceptual speed and reasoning). Furthermore, we found that those spending more time sedentary performed better on vocabulary knowledge and reasoning tasks. In contrast, time spent in light PA was not related to either fluid or crystallized abilities. Our results add to the previous literature by providing the first sensor-based evidence that crystallized and fluid abilities in older age may be associated with engagement in different intensities of daily activity. Moreover, our findings suggest that the behavior of moderate to vigorous PA is at least as important in relation to cognition as the desirable long-term physiological effects of higher intensity PA and exercise. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Occupational Physical Stress Is Negatively Associated With Hippocampal Volume and Memory in Older Adults.

Our jobs can provide intellectually and socially enriched environments but also be the source of major psychological and physical stressors. As the average full-time worker spends >8 h at work per weekday and remains in the workforce for about 40 years, occupational experiences must be important factors in cognitive and brain aging. Therefore, we studied whether occupational complexity and stress are associated with hippocampal volume and cognitive ability in 99 cognitively normal older adults. We estimated occupational complexity, physical stress, and psychological stress using the Work Design Questionnaire (Morgeson and Humphrey, 2006), Quantitative Workload Inventory and Interpersonal Conflict at Work Scale (Spector and Jex, 1998). We found that physical stress, comprising physical demands and work conditions, was associated with smaller hippocampal volume and poorer memory performance. These associations were independent of age, gender, brain size, socioeconomic factors (education, income, and job title), duration of the job, employment status, leisure physical activity and general stress. This suggests that physical demands at work and leisure physical activity may have largely independent and opposite effects on brain and cognitive health. Our findings highlight the importance of considering midlife occupational experiences, such as work physical stress, in understanding individual trajectories of cognitive and brain aging.