Differential exercise effects on quality of life and health-related quality of life in older adults: a randomized controlled trial.

PURPOSE: Maintaining quality of life (QOL) and physical and mental health status are important outcomes throughout the aging process. Although cross-sectional studies suggest a relationship between global QOL and physical activity, it is unclear whether such a relationship exists as a function of exercise training. METHODS: We examined the effects of two exercise intervention arms on health-related quality of life (HRQOL) and global QOL. Low-active, older adults (n = 179) were randomly assigned to either a 12-month aerobic walking group or a strengthening and flexibility group. HRQOL and QOL were measured at baseline, 6, and 12 months. RESULTS: There was a significant group by time effect on QOL [F(2,176) = 3.11, p = 0.047, η (2) = 0.03]. There was also a significant overall group by time effect for HRQOL [F(4,174) = 2.46, p = 0.047, η (2) = 0.05], which was explained by the significant group by time interaction for mental health status (p = 0.041, η (2) = 0.02) favoring the walking condition. Further analyses using latent class analysis revealed three classes of individuals with differential patterns of change in QOL and HRQOL across time. These classes reflected no change, declines, and improvements in these constructs across time. CONCLUSIONS: Walking appears to enhance the mental aspect of HRQOL and global QOL when compared to a non-aerobic intervention. Additionally, the patterns of change in QOL and HRQOL were not linear over time. Our findings are in contrast to previous reports that these outcomes change a little or not at all in randomized trials.

Preliminary validation of the short physical performance battery in older adults with multiple sclerosis: secondary data analysis.

BACKGROUND: There are relatively few standard, objective measures for studying physical function among older adults with multiple sclerosis (MS), yet such measures are necessary considering the shift in prevalence and associated consequences of both MS and older age on physical function. We undertook a preliminary examination of the construct validity of Short Physical Performance Battery (SPPB) scores in older adults with MS based on an expected differential pattern of associations with measures of lower and upper extremity function. METHODS: The sample included 48 persons with MS aged 50 years and older who were enrolled in a pilot, randomized controlled trial of exercise training. Participants completed the SPPB and other objective and self-report measures of lower and upper extremity function as part of baseline testing. RESULTS: SPPB scores demonstrated strong associations with measures of lower extremity function (|r s| = .66-.79), and weak associations with measures of upper extremity function (|r s| = .03-.33). CONCLUSIONS: We provide preliminary evidence that supports the validity of scores from the SPPB as a measure of lower extremity function for inclusion in clinical research and practice involving older adults with MS.

Physical activity levels and patterns in older adults: the influence of a DVD-based exercise program.

The use of multimedia to influence health behaviors offers unique advantages over more traditional center-based programs, however, little is known about the effectiveness of such approaches in improving physical activity levels over time. The purpose of this study was to examine the efficacy of a progressive and age-appropriate, DVD-delivered exercise program in promoting physical activity levels among older adult cohorts. Community dwelling older adults (N = 307, Mean age = 71 years) were randomized to one of two groups: a 6-month home-based DVD-delivered exercise (i.e., FlexToBa™) intervention group or a healthy aging DVD control group. Physical activity was assessed objectively using a standard 7-day accelerometer wear period and subjectively using the Godin Leisure Time Exercise Questionnaire, at baseline and follow-up. Analysis of covariances indicated a statistically significant treatment effect for subjectively [F(1,250) = 8.42, P = .004, η(2) = .03] and objectively [F(1,240) = 3.77, P = .05, η(2) = .02] measured physical activity. The older cohort (>70) in the FlexToBa condition further had significantly larger improvements in physical activity levels compared to their younger counterparts. From a public health perspective, media-delivered interventions such as the FlexToBa program might prove to be cost-effective, have a broader reach and at the same time be effective in improving physical activity levels in older adults.

II. Physical activity: measurement and behavioral patterns in children and youth.

With physical activity levels among children and adolescents at an all-time low, there is a critical need for scientists and public health officials alike to further examine the physical activity behaviors of this population. Accordingly, this chapter will act as an entrée to the rest of the monograph by providing a general overview of the epidemiology of physical activity among youth in the United States. In so doing, we discuss the following: public health guidelines for youth-based physical activity, current rates and trends of physical activity participation in youth, issues related to physical education rates in school systems, lifestyle practices that encourage sedentary behaviors and attendant disease states, a synopsis of the health-related benefits of a physically active lifestyle, promotion of and opportunities for increased engagement, and comparisons of objective and subjective methods of measuring physical activity.

Exercise training increases size of hippocampus and improves memory.

The hippocampus shrinks in late adulthood, leading to impaired memory and increased risk for dementia. Hippocampal and medial temporal lobe volumes are larger in higher-fit adults, and physical activity training increases hippocampal perfusion, but the extent to which aerobic exercise training can modify hippocampal volume in late adulthood remains unknown. Here we show, in a randomized controlled trial with 120 older adults, that aerobic exercise training increases the size of the anterior hippocampus, leading to improvements in spatial memory. Exercise training increased hippocampal volume by 2%, effectively reversing age-related loss in volume by 1 to 2 y. We also demonstrate that increased hippocampal volume is associated with greater serum levels of BDNF, a mediator of neurogenesis in the dentate gyrus. Hippocampal volume declined in the control group, but higher preintervention fitness partially attenuated the decline, suggesting that fitness protects against volume loss. Caudate nucleus and thalamus volumes were unaffected by the intervention. These theoretically important findings indicate that aerobic exercise training is effective at reversing hippocampal volume loss in late adulthood, which is accompanied by improved memory function.

Influence of allowable interruption period on estimates of accelerometer wear time and sedentary time in older adults.

The criteria one uses to reduce accelerometer data can profoundly influence the interpretation of research outcomes. The purpose of this study was to examine the influence of 3 different interruption periods (i.e., 20, 30, and 60 min) on the amount of data retained for analyses and estimates of sedentary time among older adults. Older adults (N = 311, M age = 71.1) wore an accelerometer for 7 d and reported wear time on an accelerometer log. Accelerometer data were downloaded and scored using 20-, 30-, and 60-min interruption periods. Estimates of wear time, derived using each interruption period, were compared with self-reported wear time, and descriptive statistics were used to compare estimates of sedentary time. Results showed a longer interruption period (i.e., 60 min) yields the largest sample size and the closest approximation of self-reported wear time. A short interruption period (i.e., 20 min) is likely to underestimate sedentary time among older adults.

The influence of aerobic fitness on cerebral white matter integrity and cognitive function in older adults: results of a one-year exercise intervention.

Cerebral white matter (WM) degeneration occurs with increasing age and is associated with declining cognitive function. Research has shown that cardiorespiratory fitness and exercise are effective as protective, even restorative, agents against cognitive and neurobiological impairments in older adults. In this study, we investigated whether the beneficial impact of aerobic fitness would extend to WM integrity in the context of a one-year exercise intervention. Further, we examined the pattern of diffusivity changes to better understand the underlying biological mechanisms. Finally, we assessed whether training-induced changes in WM integrity would be associated with improvements in cognitive performance independent of aerobic fitness gains. Results showed that aerobic fitness training did not affect group-level change in WM integrity, executive function, or short-term memory, but that greater aerobic fitness derived from the walking program was associated with greater change in WM integrity in the frontal and temporal lobes, and greater improvement in short-term memory. Increases in WM integrity, however, were not associated with short-term memory improvement, independent of fitness improvements. Therefore, while not all findings are consistent with previous research, we provide novel evidence for correlated change in training-induced aerobic fitness, WM integrity, and cognition among healthy older adults.

Neurobiological markers of exercise-related brain plasticity in older adults.

The current study examined how a randomized one-year aerobic exercise program for healthy older adults would affect serum levels of brain-derived neurotrophic factor (BDNF), insulin-like growth factor type 1 (IGF-1), and vascular endothelial growth factor (VEGF) - putative markers of exercise-induced benefits on brain function. The study also examined whether (a) change in the concentration of these growth factors was associated with alterations in functional connectivity following exercise, and (b) the extent to which pre-intervention growth factor levels were associated with training-related changes in functional connectivity. In 65 participants (mean age=66.4), we found that although there were no group-level changes in growth factors as a function of the intervention, increased temporal lobe connectivity between the bilateral parahippocampus and the bilateral middle temporal gyrus was associated with increased BDNF, IGF-1, and VEGF for an aerobic walking group but not for a non-aerobic control group, and greater pre-intervention VEGF was associated with greater training-related increases in this functional connection. Results are consistent with animal models of exercise and the brain, but are the first to show in humans that exercise-induced increases in temporal lobe functional connectivity are associated with changes in growth factors and may be augmented by greater baseline VEGF.

Physical activity and quality of life in older adults: an 18-month panel analysis.

PURPOSE: Although physical activity has been associated with quality of life (QOL), the empirical evidence regarding the mechanisms underlying this relationship is limited. In the present study, we examined the mediating roles played by self-efficacy and health status in the physical activity-QOL relationship from baseline to 18-month follow-up in a sample of community-dwelling older adults. METHODS: Community-dwelling adults (N = 321, M age = 63.8 years) were recruited to participate in a cross-sectional study and were later contacted to participate in an 18-month follow-up. Individuals completed a battery of questionnaires assessing physical activity, self-efficacy, physical self-worth, disability limitations, and quality of life. A panel analysis within a covariance modeling framework was used to analyze the data. RESULTS: Overall, the model was a good fit to the data (χ(2) = 61.00, df = 29, p < 0.001, standardized root mean residual = 0.05, Comparative Fit Index = 0.97) with changes in physical activity indirectly influencing change in life satisfaction from baseline to 18 months via changes in exercise self-efficacy, physical self-worth, and disability limitations independent of baseline relationships and demographic factors. Specifically, increases in physical activity were associated with increases in exercise self-efficacy which, in turn, was associated with higher physical self-worth and fewer disability limitations which were associated with greater life satisfaction. CONCLUSIONS: The findings from this study suggest the relationship between physical activity and global QOL in older adults may be mediated by more proximal modifiable outcomes that can be targeted in physical activity programs and interventions.

A profile for predicting attrition from exercise in older adults.

The purpose of this study was to determine a profile for predicting attrition among older adults involved in a 12-month exercise program. The parent study was a single-blinded randomized controlled trial. The study took place between 2006 and 2009 within a university setting. Older adults (N = 179) completed baseline assessments of functional performance and psychosocial measures. Participants who were randomized, elected to receive treatment, and did not complete the exercise program were considered "dropouts" (n = 35). Those who completed the program (n = 144) were classified as "completers." A latent profile analysis revealed two distinct patterns of memory complaints, self-efficacy to overcome barriers to exercise, balance performance, and stair performance. Dropouts were nearly twice as likely to be members of the profile that exhibited a higher degree of memory complaints, lower self-efficacy for overcoming exercise barriers, poorer single leg balance, and longer times to walk down stairs. The results provide an initial validation of a profile for discriminating between "dropouts" and "completers," one that may have considerable utility for screening older adults prior to study entry.

The association between aerobic fitness and executive function is mediated by prefrontal cortex volume.

Aging is marked by a decline in cognitive function, which is often preceded by losses in gray matter volume. Fortunately, higher cardiorespiratory fitness (CRF) levels are associated with an attenuation of age-related losses in gray matter volume and a reduced risk for cognitive impairment. Despite these links, we have only a rudimentary understanding of whether fitness-related increases in gray matter volume lead to elevated cognitive function. In this cross-sectional study, we examined whether the association between higher aerobic fitness levels and elevated executive function was mediated by greater gray matter volume in the prefrontal cortex (PFC). One hundred and forty-two older adults (mean age=66.6 years) completed structural magnetic resonance imaging (MRI) scans, CRF assessments, and performed Stroop and spatial working memory (SPWM) tasks. Gray matter volume was assessed using an optimized voxel-based morphometry approach. Consistent with our predictions, higher fitness levels were associated with: (a) better performance on both the Stroop and SPWM tasks, and (b) greater gray matter volume in several regions, including the dorsolateral PFC (DLPFC). Volume of the right inferior frontal gyrus and precentral gyrus mediated the relationship between CRF and Stroop interference while a non-overlapping set of regions bilaterally in the DLPFC mediated the association between CRF and SPWM accuracy. These results suggest that specific regions of the DLPFC differentially relate to inhibition and spatial working memory. Thus, fitness may influence cognitive function by reducing brain atrophy in targeted areas in healthy older adults.

Validity of the multidimensional outcome expectations for exercise scale in continuing-care retirement communities.

OBJECTIVE: The current study examined the psychometric properties and validity of the Multidimensional Outcome Expectations for Exercise Scale (MOEES) in a sample of older adults with physical and functional comorbidities. METHODS: Confirmatory factor analysis was used to examine the hypothesized 3-factor model in 108 older adults (M age 85 yr) residing in continuing-care retirement communities. RESULTS: Analyses supported the 3-factor structure of the MOEES reflecting physical, social, and self-evaluative outcome expectations, with a 12-item model providing the best fit. Theorized bivariate associations between outcome expectations and physical activity, self-efficacy, and functional performance were all supported. CONCLUSIONS: The 12-item version of the MOEES appears to be a reliable and valid measure of outcome expectations for exercise in this sample of older adults with physical and functional comorbidities. Further examination of the factor structure and the longitudinal properties of this measure in older adults is warranted.

Internet intervention for increasing physical activity in persons with multiple sclerosis.

BACKGROUND: Physical activity has been associated with improvements in walking mobility and quality of life in persons with multiple sclerosis (MS), and yet this population is largely sedentary and inactive compared with the general population. OBJECTIVES: We conducted a pilot, randomized controlled trial (RCT) for examining the effect of an Internet intervention based on social cognitive theory (SCT) for favorably increasing physical activity among persons with MS. We further examined variables from SCT as possible mediators of the Internet intervention. METHODS: We randomly allocated 54 persons with MS into either an Internet intervention condition or a waitlist control condition. The participants completed measures of physical activity, self-efficacy, outcome expectations, functional limitations, and goal setting before and after the 12-week period. RESULTS: The intervention group reported a statistically significant (p = 0.01) and large increase in physical activity over time (d = 0.72), whereas the control group had a small (d = 0.04) and non-significant change in physical activity (p = 0.71). The intervention group further reported a statistically significant (p = 0.001) and large increase in goal setting over time (d = 0.97), whereas the control group had a small (d = -0.13) and non-significant change (p = 0.17). The change in goal setting over time mediated the effect of the Internet intervention on physical activity behavior. CONCLUSIONS: This pilot study sets the stage for a subsequent RCT that includes a larger sample of persons with MS, longer intervention period along with a follow-up, objective measure of physical activity, and secondary outcomes of walking mobility and QOL.

Measuring enjoyment of physical activity in older adults: invariance of the physical activity enjoyment scale (paces) across groups and time.

The purpose of this study was to validate the Physical Activity Enjoyment Scale (PACES) in a sample of older adults. Participants within two different exercise groups were assessed at two time points, 6 months apart. Group and longitudinal invariance was established for a novel, 8-item version of the PACES. The shortened, psychometrically sound measure provides researchers and practitioners an expedited and reliable instrument for assessing the enjoyment of physical activity.

Longitudinal invariance and construct validity of the abbreviated late-life function and disability instrument in healthy older adults.

OBJECTIVE: To cross-validate the psychometric properties of the abbreviated Late-Life Function and Disability Instrument (LL-FDI), a measure of perceived functional limitations and disability. DESIGN: Baseline and 12-month follow-up assessments conducted across the course of a 12-month exercise program. SETTING: University research community. PARTICIPANTS: Older healthy adults (N=179; mean ± SD age, 66.43±5.67y) at baseline; 145 were retained at follow-up. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: LL-FDI and functional performance measures. RESULTS: Factor analyses confirmed the factor structure of the abbreviated LL-FDI, and all subscales met minimal criteria for temporal invariance. Significant correlations also were found between functional limitations subscales and an array of physical function performance measures, supporting the scale's construct validity. CONCLUSIONS: The abbreviated LL-FDI with some modifications appears to be temporally invariant in community-dwelling older adults. Additionally, moderate relationships between functional limitations and functional performance provide further support for these being conceptually distinct constructs.

Trajectories of change in self-esteem in older adults: exercise intervention effects.

This 12-month, 2 arm, single blind randomized controlled exercise trial examined relationships among changes in multidimensional self-esteem as a function of intervention mode (i.e., walking vs. flexibility-toning-balance). Data were collected on three equidistant occasions (baseline, 6 and 12 months). One-hundred seventy-nine older adults (M(age) = 66.38) began the study and 145 completed assessments at all time points. Participants completed measures of physical and global self-esteem as well as demographic information. There were no significant group differences at baseline on these demographic indicators or esteem variables. Data were analyzed using linear and parallel process growth modeling procedures. Results supported the position that across both groups, domain-level (i.e., physical self-worth) was dependent upon sub-domain-level (i.e., perceived attractiveness, strength, and condition) esteem change. Furthermore, greater improvements were observed in the flexibility-toning-balance group, in terms of perceived strength and attractiveness esteem, compared to the walking group. Our findings support theoretically-based predictions and extend the literature showing unique psychological responses conditional on specific types of physical activities.

Validation of the multidimensional outcome expectations for exercise scale in ambulatory, symptom-free persons with multiple sclerosis.

UNLABELLED: McAuley E, Motl RW, White SM, Wójcicki TR. Validation of the Multidimensional Outcome Expectations for Exercise Scale in ambulatory, symptom-free persons with multiple sclerosis. OBJECTIVE: To determine the psychometric properties of the 3-factor Multidimensional Outcome Expectations for Exercise Scale in a sample of ambulatory, symptom-free persons with multiple sclerosis (MS). DESIGN: Cross-sectional validation study. SETTING: Midwestern university. PARTICIPANTS: Community-dwelling adults (N=242) with an established definite diagnosis of MS, as corroborated by the participant's neurologist, who were relapse free for the last 30 days and ambulatory with minimal assistance. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Multidimensional Outcome Expectations for Exercise Scale, physical activity, self-efficacy, and physical health status. Confirmatory factor analyses using covariance modeling and correlational analyses were used to establish factorial and construct validity. RESULTS: Analyses showed excellent factorial validity for the hypothesized factor structure reflecting physical, social, and self-evaluative outcome expectations. All 3 subscales were internally consistent. Theoretically, relevant correlations between outcome expectations and self-efficacy, physical activity, and physical health status were all supported. CONCLUSIONS: The Multidimensional Outcome Expectations for Exercise Scale appears to be a reliable and valid measure of outcome expectations for exercise in this limited sample of community-dwelling adults with MS. Further validation in clinical samples is warranted.

Construct validation of a non-exercise measure of cardiorespiratory fitness in older adults.

BACKGROUND: Cardiorespiratory fitness (CRF) is associated with a decreased risk of all-cause mortality but is rarely assessed in medical settings due to burdens of time, cost, risk, and resources. The purpose of this study was to test the construct validity of a regression equation developed by Jurca and colleagues (2005) to estimate CRF without exercise testing in community dwelling older adults. METHODS: Participants (n = 172) aged 60 to 80 years with no contraindications to submaximal or maximal exercise testing completed a maximal graded exercise test (GXT) and the submaximal Rockport 1-mile walk test on separate occasions. Data included in the regression equation (age, sex, body mass index, resting heart rate, and physical activity) were obtained via measurement or self-report. Participants also reported presence of cardiovascular conditions. RESULTS: The multiple R for the regression equation was .72, p < .001 and CRF estimated from this equation was significantly correlated with the MET value from the GXT (r = 0.66) and with CRF estimated from submaximal field testing (r = 0.67). All three CRF indices were significantly and inversely associated with reporting more cardiovascular conditions. CONCLUSIONS: This research provides preliminary evidence that a non-exercise estimate of CRF is at least as valid as field test estimates of CRF and represents a low-risk, low-cost, and expedient method for estimating fitness in older adults.

Internet-delivered physical activity intervention for college students with mental health disorders: a randomized pilot trial.

The prevalence of mental health disorders among college students is rising and the increasing rates of anxiety and depression have important societal implications. Physical activity has been proposed as an adjuvant to traditional treatment approaches (i.e. psychotherapy or pharmacotherapy), and the internet is a potentially useful means of delivering physical activity information to the college-aged population. This randomized pilot trial examined the effects of an internet-based physical activity intervention on physical activity, self-efficacy, depression, and anxiety in college students (n = 47) receiving mental health counseling. Physical activity, depression, anxiety, exercise self-efficacy, and barriers self-efficacy were assessed at baseline and post-intervention. There was a significant time effect for physical activity, with both groups increasing their physical activity levels across the 10-week intervention but with a larger increase in the intervention condition (d = 0.68) than the control condition (d = 0.05). Exercise and barriers self-efficacy declined across the intervention, but more so in the control than intervention condition. Effects on depression and anxiety were nonsignificant. Finally, correlation analyses showed increases in physical activity were associated with increases in exercise self-efficacy (r = 0.62) and barriers self-efficacy (r = 0.63) and decreases in depression (r = -0.44) in the intervention condition, but not in the control condition. These results suggest that an internet-delivered physical activity intervention may be a promising approach to promoting physical activity among college students undergoing mental health counseling.

Aerobic fitness is associated with hippocampal volume in elderly humans.

Deterioration of the hippocampus occurs in elderly individuals with and without dementia, yet individual variation exists in the degree and rate of hippocampal decay. Determining the factors that influence individual variation in the magnitude and rate of hippocampal decay may help promote lifestyle changes that prevent such deterioration from taking place. Aerobic fitness and exercise are effective at preventing cortical decay and cognitive impairment in older adults and epidemiological studies suggest that physical activity can reduce the risk for developing dementia. However, the relationship between aerobic fitness and hippocampal volume in elderly humans is unknown. In this study, we investigated whether individuals with higher levels of aerobic fitness displayed greater volume of the hippocampus and better spatial memory performance than individuals with lower fitness levels. Furthermore, in exploratory analyses, we assessed whether hippocampal volume mediated the relationship between fitness and spatial memory. Using a region-of-interest analysis on magnetic resonance images in 165 nondemented older adults, we found a triple association such that higher fitness levels were associated with larger left and right hippocampi after controlling for age, sex, and years of education, and larger hippocampi and higher fitness levels were correlated with better spatial memory performance. Furthermore, we demonstrated that hippocampal volume partially mediated the relationship between higher fitness levels and enhanced spatial memory. Our results clearly indicate that higher levels of aerobic fitness are associated with increased hippocampal volume in older humans, which translates to better memory function.