Hippocampal atrophy is associated with memory impairment and dementia and serves as a key biomarker in the preclinical stages of Alzheimer's disease. Physical activity, one of the most promising behavioral interventions to prevent or delay cognitive decline, has been shown to be associated with hippocampal volume; specifically increased aerobic activity and fitness may have a positive effect on the size of the hippocampus. The majority of older adults, however, are sedentary and have difficulty initiating and maintaining exercise programs. A modestly more active lifestyle may nonetheless be beneficial. This study explored whether greater objectively measured daily walking activity was associated with larger hippocampal volume. We additionally explored whether greater low-intensity walking activity, which may be related to leisure-time physical, functional, and social activities, was associated with larger hippocampal volume independent of exercise and higher-intensity walking activity. Segmentation of hippocampal volumes was performed using FMRIB's Software Library (FSL) and daily walking activity was assessed using a step activity monitor (SAM) on 92, non-demented, older adult participants. After controlling for age, education, body mass index (BMI), cardiovascular disease risk factors, and the Mini Mental State Exam (MMSE), we found that a greater amount, duration, and frequency of total daily walking activity were each associated with larger hippocampal volume among older women, but not men. These relationships were specific to hippocampal volume, compared to the thalamus, used as a control brain region, and remained significant for low-intensity walking activity, independent of moderate- to vigorous-intensity activity and self-reported exercise. This is the first study, to our knowledge, to explore the relationship between objectively measured daily walking activity and hippocampal volume in an older adult sample. Findings suggest the importance of better understanding whether increasing non-exercise, lifestyle physical activities may produce measurable cognitive benefits and effect hippocampal volume through molecular pathways unique to those related to moderate-intensity exercise.

BackgroundAs the population ages, older adults are seeking meaningful, and impactful, post-retirement roles. As a society, improving the health of people throughout longer lives is a major public health goal. This paper presents the design and rationale for an effectiveness trial of Experience Corps™, an intervention created to address both these needs. This trial evaluates (1) whether senior volunteer roles within Experience Corps™ beneficially impact children's academic achievement and classroom behavior in public elementary schools and (2) impact on the health of volunteers.MethodsDual evaluations of (1) an intention-to-treat trial randomizing eligible adults 60 and older to volunteer service in Experience Corps™, or to a control arm of usual volunteering opportunities, and (2) a comparison of eligible public elementary schools receiving Experience Corps™ to matched, eligible control schools in a 1:1 control:intervention school ratio.OutcomesFor older adults, the primary outcome is decreased disability in mobility and Instrumental Activities of Daily Living (IADL). Secondary outcomes are decreased frailty, falls, and memory loss; slowed loss of strength, balance, walking speed, cortical plasticity, and executive function; objective performance of IADLs; and increased social and psychological engagement. For children, primary outcomes are improved reading achievement and classroom behavior in Kindergarten through the 3rd grade; secondary outcomes are improvements in school climate, teacher morale and retention, and teacher perceptions of older adults.SummaryThis trial incorporates principles and practices of community-based participatory research and evaluates the dual benefit of a single intervention, versus usual opportunities, for two generations: older adults and children.

There is compelling evidence supporting the benefits of increased regular physical activity in older adults. The Experience Corps program in Baltimore MD was designed in part as a community based approach to increasing physical activity that would also appeal to older adults who have historically not utilized health promotion programs. The Baltimore Experience Corps program places older volunteers in public elementary schools for 15 h a week in roles designed to improve the academic outcomes of children and, simultaneously, increase the physical, cognitive and social activity of volunteers. This paper reports on the change in physical activity levels among older adults associated with participation in the Baltimore Experience Corps. In a pilot randomized controlled evaluation, older adults were randomly assigned to Experience Corps (EC participants) or a waiting list control group. Ages ranged from 59-86 years, 96% were African American, 94% were women, and 84% had annual incomes less than $15,000. EC participants were required to serve >/=15 h a week. At follow-up after 4-8 months, an analysis of 113 randomized volunteers revealed 53% of the EC participants were more active than the previous year by self-report, as compared to 23% of the controls (p<0.01). When adjusted for age, gender and education, there was a trend toward increased physical activity in the EC participants as calculated by a kilocalorie per week increase of 40%, versus a 16% decrease in the controls (p=0.49). EC participants who reported "low activity" at baseline experienced an average 110% increase in their physical activity at follow-up. Among the controls who were in the "low activity" group at baseline, there was, on average, only a 12% increase in physical activity (p=0.03). Among those who were previously active, there was no significant difference (p=0.30). The pilot results suggest that a high intensity volunteer program that is designed as a health promotion intervention can lead, in the short-term, to significant improvements in the level of physical activity of previously inactive older adult volunteers.

Introduction Older adults with a high number of chronic conditions and who live in environments that do not promote physical activity have great difficulty initiating and adhering to exercise programs. Novel lifestyle activity interventions that can effectively increase physical activity may address disparities in health in these populations. This study evaluates the effects of the Baltimore Experience Corps program, a community-based volunteer program, on walking activity in older adults. Methods The Baltimore Experience Corps Trial is a sex-stratified RCT that recruited participants from 2006 to 2009. Older adult participants aged ≥60 years (n=123) were from a nested objective physical activity trial within the larger Baltimore Experience Corps Trial. Participants randomized to the intervention group were placed as volunteers within the Baltimore public school system for 2 years. The primary study outcome was objectively measured total amount of walking activity measured in steps/day. Differences between intervention and control groups were measured at 12 and 24 months using linear mixed effects models. Data were analyzed in 2014. Results At 24 months, women, but not men, in the intervention group showed an increased amount of walking activity, averaging 1,500.3 (95% CI=77.6, 2,922.9) greater steps/day compared with the control group. Women in the control group declined by 1,191.6 (95% CI= − 2243.7, −139.5) steps/day at 24 months compared to baseline. Conclusions A community-based volunteer intervention increased walking activity among older women, who were at elevated risk for both inactivity and adverse health outcomes.