Search PubMed⌕ Search

Biomedical subjects

E McAuley

Publications and source records attributed to E McAuley.

At least 19 recordsLinked to original sources
PubMed2006

Is the current BMI obesity classification appropriate for black and white postmenopausal women?

OBJECTIVE: To evaluate the relation between body fatness (%Fat) and body mass index (BMI) and to evaluate the validity of the BMI standards for obesity established by the NIH in older black and white postmenopausal women. RESEARCH METHODS: Height, weight, BMI, and %Fat, assessed by DXA, were determined for 296 healthy, independently living women ranging in age from 50 to 80 years (M+/-s.d.; 64.4+/-7.8 years). RESULTS: Per NIH guidelines, 32% were classified as obese (> or = 30 kg/m2, mean BMI = 28.1+/-5.5 kg/m2). In contrast, using the %Fat criterion of 38% advocated by Lohman to define obesity, 47% of our sample was obese (mean %Fat=37.3+/-6.2%). A moderately high curvilinear relation existed between BMI and %Fat (R = 0.82, SEE = 3.57 %Fat, P<0.05). Race added meaningfully to the prediction of %Fat (P<0.05) such that for the same BMI, black women will have 1% lower body fatness than white women. Based on a %Fat > or = 38 as the criterion for obesity, receiver operating characteristic (ROC) analysis, performed separately by race, indicated that the currently accepted BMI cutpoint for obesity produced low sensitivity (69% and 61% for black and white women, respectively). Alternatively, BMI values > or = 28.4 kg/m2 for black women and > or = 26.9 kg/m2 for white women to define obesity maximized classification accuracy. CONCLUSION: We conclude that current BMI categories may not be appropriate for identifying obesity among postmenopausal women. Furthermore, the relation between BMI and %Fat is different in black compared to white women but remains constant from the sixth through the eighth decade of life.

Absorptiometry, Photon↗
PubMed2002

Physical activity and physique anxiety in older adults: fitness, and efficacy influences.

Employing a randomized controlled trial, this study documents the effects of six months of physical activity and six month follow-up on reduction in social physique anxiety (SPA) in older adults. In addition, the role played by changes in behavioral, physiological, and psychological predictors of changes in SPA were examined. Participants (n = 174, mean age = 65 yrs) were randomly assigned to one of two activity groups and engaged in a six-month structured exercise program. Measures of physique anxiety were taken at baseline, six and twelve months. Latent growth curve analyses revealed significant reductions in SPA over the course of the 12-month period. Structural analyses controlling for treatment condition indicated that improvements in self-efficacy and fitness were significant predictors of changes in SPA but that changes in body fat and exercise frequency did not contribute to variation in SPA. Overall this model accounted for 19% of the variation in SPA changes. The extent to which changes in SPA may contribute to continued physical activity participation in older adults and how exercise programs might effectively influence predictors of SPA are discussed.

Aged↗
PubMed2001

General and task-specific frontal lobe recruitment in older adults during executive processes: a fMRI investigation of task-switching.

Performance deteriorates when subjects must shift between two different tasks relative to performing either task separately. This switching cost is thought to result from executive processes that are not inherent to the component operations of either task when performed alone. Medial and dorsolateral frontal cortices are theorized to subserve these executive processes. Here we show that larger areas of activation were seen in dorsolateral and medial frontal cortex in both younger and older adults during switching than repeating conditions, confirming the role of these frontal brain regions in executive processes. Younger subjects activated these medial and dorsolateral frontal cortices only when switching between tasks; in contrast, older subjects recruited similar frontal regions while performing the tasks in isolation as well as alternating between them. Older adults recruit medial and dorsolateral frontal areas, and the processes computed by these areas, even when no such demands are intrinsic to the current task conditions. This neural recruitment may be useful in offsetting the declines in cognitive function associated with ageing.

Adult↗
PubMed2001

Tai Chi, self-efficacy, and physical function in the elderly.

Using Tai Chi as an exercise mode, this study examined the association between self-efficacy and physical function. Ninety-four healthy, physically inactive older adults (M age = 72.8 years, SD = 5.1) were randomly assigned to either a 6-month, twice a week, Tai Chi condition or a wait-list control condition. Outcome variables included self-reports of movement efficacy and physical function assessed at baseline, middle, and termination of the study. Multisample latent curve analyses revealed a significant rate of change attributable to the Tai Chi intervention in both self-efficacy and physical function, with participants experiencing significant improvements over the course of the intervention. Analyses also showed a positive association between self-efficacy and physical function, indicating that improvements in older adults' self-efficacy of movement as a function of Tai Chi were related to increased levels of perceived physical capability. This study uncovered the need for further exploration of the relationship between exercise self-efficacy and physical function for enhancing health-related quality of life in older adults.

Activities of Daily Living↗
PubMed2001

An evaluation of the effects of Tai Chi exercise on physical function among older persons: a randomized contolled trial.

This study was designed to determine whether a 6-month Tai Chi exercise program can improve self-reported physical functioning limitations among healthy, physically inactive older individuals. Ninety-four community residents ages 65 to 96 (Mage = 72.8 years, SD = 5.1) volunteered to participate in the study. Participants were randomly assigned to either a 6-month experimental (Tai Chi) group (n = 49), which exercised twice per week for 60 min, or a wait-list control group (n = 45). A 6-item self-report physical functioning scale, assessing the extent of behavioral dysfunction caused by health problems, was used to evaluate change in physical functioning limitations as a result of Tai Chi intervention. Results indicated that compared to the control group, participants in the Tai Chi group experienced significant improvements in all aspects of physical functioning over the course of the 6-month intervention. Overall, the experimental group had 65% improvement across all 6 functional status measures ranging from daily activities such as walking and lifting to moderate-vigorous activities such as running. It was concluded that the 6-month Tai Chi exercise program was effective for improving functional status in healthy, physically inactive older adults. A self-paced and self-controlled activity such as Tai Chi has thepotential to be an effective, low-cost means of improving functional status in older persons.

Activities of Daily Living↗
PubMed2000

Social relations, physical activity, and well-being in older adults.

BACKGROUND: A randomized controlled trial was conducted to examine: (a) the effect of two physical activity modes on changes in subjective well-being (SWB) over the course of a 12-month period in older, formerly sedentary adults (N = 174, M age = 65.5 years) and (b) the role played by physical activity participation and social support in changes in SWB over time. METHOD: Participants were randomized into either an aerobic activity group or a stretching and toning group. Structural equation modeling was employed to conduct multiple sample latent growth curve analyses of individual growth in measures of SWB (happiness, satisfaction with life, and loneliness) over time. RESULTS: A curvilinear growth pattern was revealed with well-being significantly improving over the course of the intervention followed by significant declines at the 6-month follow-up. Subsequent structural analyses were conducted showing that frequency of exercise participation was a significant predictor of improvement in satisfaction with life, whereas social relations were related to increases in satisfaction with life and reductions in loneliness. Improvements in social relations and exercise frequency also helped to buffer the declines in satisfaction with life at follow-up. CONCLUSIONS: It appears that social relations integral to the exercise environment are significant determinants of subjective well-being in older adults. Findings are discussed in terms of how physical activity environments might be structured to maximize improvements in more global well-being constructs such as satisfaction with life.

Aged↗
PubMed2000

Physical activity, self-esteem, and self-efficacy relationships in older adults: a randomized controlled trial.

A randomized controlled trial examined the growth and form of multidimensional self-esteem over a 12-month period (6-month exercise intervention and 6-month follow-up) in 174 older adults engaged in either a walking or stretching/toning program. The extent to which changes in physical fitness parameters and physical self-efficacy were related to changes in perceptions of attractive body, strength, physical conditioning, and physical self-worth was also determined. Latent growth curve analyses showed a curvilinear pattern of growth in esteem with significant increases at all levels of self-esteem upon completion of the intervention followed by significant declines at 6 months postintervention in both groups. Frequency of activity and changes in physical fitness, body fat, and self-efficacy were related to improvements in esteem perceptions relative to attractive body, strength, and physical condition. Model fitting procedures suggested that the best fit of the data was to a model in which the influence of changes in efficacy and physical parameters on physical self-worth were mediated by perceptions of attractive body and physical condition.

Aged↗
PubMed2000

An examination of theory and behavior change in randomized clinical trials.

This paper underscores the important role played by theory-based mediating variables in randomized clinical trials. Indeed, it is essential that we know what mediating variables are relevant for particular outcomes in randomized clinical trials and that we design interventions to optimize change in the mediators of interest. Yet, knowledge of the pivotal mediating variables in behavior change does not imply that we know how to intervene effectively. This gap may be due to the fact that existing research typically has been designed to garner support for theory, as opposed to testing support for behavior change strategies that are based on theory. In addition, we argue that there are important mediating variables in behavior change that have not been given systematic attention in theory development. For example, behavior change must be viewed as a collaborative process, and participants' perceptions concerning the feasibility of change is important to motivational processes in randomized clinical trials. Control Clin Trials 2000;21:164S-170S

Aged↗
PubMed2000

Self-efficacy determinants and consequences of physical activity.

This review examines self-efficacy as a determinant of exercise adherence and as an outcome of physical activity. Additionally, studies that have either manipulated self-efficacy or employed efficacy-based interventions to enhance exercise participation are discussed. Finally, recommendations for future applications of social cognitive theory to the physical activity domain are made.

Cooperative Behavior↗
PubMed1999

Effects of 6 months of moderate aerobic exercise training on immune function in the elderly.

The purpose of this study was to determine the effects of 6 months of moderate aerobic exercise on age-dysregulated measures of T lymphocyte and natural killer (NK) cell number and function. Previously sedentary elderly (age = 65 +/- 0.8 years) subjects were randomly assigned to supervised 3 time/week exercise intervention group (EXC, n = 14) or flexibility/toning control group (FT-CON, n = 15). Fasting resting blood samples were drawn prior to and after the 6 month intervention. The EXC group exhibited a significant (P < 0.05) 20% increase in VO2 max, whereas the FT-CON group had a smaller non-significant (P = 0.07) increase (9%). Immune results revealed that, in general, changes in immune function in response to 6 months of exercise training at an average intensity of 52% heart rate reserve (HRR) were similar when compared to FT-CON who exercised at approximately 21% HRR. There were no intervention-induced changes in total white blood cell, neutrophil, lymphocyte, monocyte, eosinophil, or basophil blood counts. Furthermore, the percentage and number of CD3+, CD4+ and CD8+ T cells in the blood remained unchanged. There was a tendency for the percentage and number of CD4+ and CD8+ näive cells (CD45RA+) to increase and for CD4+ memory cells (CD45RO+) to decrease post-intervention, especially in FT-CON. Both groups exhibited a small intervention-induced increase in the T-cell proliferative response to mitogenic stimulation: the percentage change of which was higher in the EXC group at several doses of Con A. Unstimulated NK cell cytolysis versus K562 cells tended to increase (P < 0.1) in the EXC group with little change in FT-CON. We conclude that 6 months of supervised exercise training can lead to nominal increases in some measures of immune function, while not affecting others, in previously sedentary elderly.

Aged↗
PubMed1999

The physical activity scale for the elderly (PASE): evidence for validity.

We assessed the validity of the Physical Activity Scale for the Elderly (PASE) in a sample of sedentary adults (56 men, 134 women, mean age +/- [SD] 66.5+/-5.3 years) who volunteered to participate in a randomized controlled trial on the effect of aerobic conditioning on psychological function. Construct validity was established by correlating PASE scores with physiologic and performance characteristics: peak oxygen uptake, resting heart rate and blood pressure, percent body fat, and balance. The mean PASE scores were higher in men than in women (men = 145.8+/-78.0; women = 123.9+/-66.3, P<0.05), and in those age 55-64 years compared with those age 65 years and over (55-64 = 144.2+/-75.8; 65 and over = 118.9+/-63.9, P<0.05). PASE scores were also significantly higher in those who did not report a chronic health condition (cardiovascular disease, hypertension, cancer, or recent surgery). PASE scores were significantly associated (P<0.05) with peak oxygen uptake (r = 0.20), systolic blood pressure (r = -0.18) and balance score (r = 0.20). No significant associations of PASE score and diastolic blood pressure, resting heart rate, or percent body fat were noted. These results provide additional evidence for the validity of the PASE as a measure of physical activity suitable for use in epidemiology studies on the association of physical activity, health, and physical function in older individuals.

Aged↗
PubMed1999

Exercise intensity and self-efficacy effects on anxiety reduction in healthy, older adults.

The purpose of the present study was to examine the effects of varying exercise intensities and changes in self-efficacy on anxiety reduction in a sample of healthy, older adults. Eighty older adults from a randomized controlled exercise trial participated in this study and completed measures of self-efficacy and the State Anxiety Inventory (SAI) prior to and following light-, moderate-, and high-intensity exercise. Latent growth curve modeling analyses revealed that although anxiety was reduced following the light-intensity condition, no significant changes in anxiety occurred following the moderate-intensity condition, and anxiety increased following the high-intensity condition. In addition, changes in self-efficacy were related to anxiety responses only in the moderate-intensity condition. An analysis of SAI items indicated that although the light-intensity condition resulted in decreased arousal and anxiousness, the high-intensity condition resulted in increased arousal and decreased anxiousness. These results are discussed in terms of social cognitive theory and the appropriateness of the SAI for use in exercise settings.

Aged↗
PubMed1999

Manipulating self-efficacy in the exercise environment in women: influences on affective responses.

Self-efficacy was experimentally manipulated in an exercise context, and its effect on affective responses was examined. College women (N = 46) were randomly assigned to a high- or low-efficacy condition, and efficacy expectations were manipulated by means of bogus feedback and graphs depicting contrived normative data. The manipulation successfully influenced affective responses, with participants in the high-efficacy group reporting more positive and less negative affect than did the low-efficacy group. Efficacy was significantly related to feeling-state responses during and after activity but only in the high-efficacy condition. The results suggest that self-efficacy can be manipulated and that these changes are related to the affective experience associated with exercise. Such findings may have important implications for the roles played by self-efficacy and affect in exercise adherence.

Adult↗
PubMed1999

Mode of physical activity and self-efficacy in older adults: a latent growth curve analysis.

A randomized controlled trial examined the effect of two physical activity modes on changes in self-efficacy over the course of a 12-month period in older, formerly sedentary adults (N = 174, M age = 65.5 years). Participants were randomized into either an aerobic activity group or a stretching and toning group. Structural equation modeling was employed to conduct multiple sample latent growth curve analyses of individual growth in exercise and physical self-efficacy over time. Results revealed a curvilinear growth pattern for both types of efficacy with increases occurring over the first 6 months followed by declines at the 6-month follow-up. There was a significant treatment by mean level growth interaction for exercise efficacy with both groups increasing over time, but the aerobic group evidenced a twofold increase in growth over the stretching group. Structural analyses indicated that frequency of exercise participation was a significant predictor of overall growth in efficacy, and improvements in fitness were only related to exercise efficacy growth in the stretching group. Findings are discussed in terms of social cognitive theory and further application of latent growth curve modeling to studies of physical activity effects in older adults.

Activities of Daily Living↗
PubMed1999

Differential leukocytosis and lymphocyte mitogenic response to acute maximal exercise in the young and old.

UNLABELLED: Despite the increasing use of exercise in the elderly as a means of improving muscle function, little is known regarding the effects of exercise on the senescent immune system. PURPOSE: The purpose of this study was to determine the effects of acute maximal exercise on blood leukocyte numbers, leukocyte subsets, and the T cell mitogenic response in the elderly. METHODS: Previously sedentary elderly (N = 33, 65.3 +/- 0.8 yr) and young (N = 14, 22.4 +/- 0.7 yr) subjects participated in a modified Balke maximal exercise treadmill test. Venous blood samples were collected pre-, immediately post-, and 20 min postexercise. Blood was analyzed for leukocyte counts, leukocyte subsets via immunofluorescence, and whole blood mitogenesis in response to various doses of mitogens. RESULTS: Whereas VO2max was lower in the elderly, maximal RQ, age-predicted heart rates, and times to fatigue were not different, indicating that both groups achieved relative maximal exercise intensity. There were significant exercise-induced leukocytoses in both the elderly and young made up largely of a lymphocytosis and neutrophilia. The magnitude of the leukocytosis was lower in the elderly and failed to return to pre-exercise levels by 20 min postexercise. Acute maximal exercise increased CD8+ (153% vs 112% in young and old, respectively) and CD4+ (57% vs 22% in young and old, respectively) T cells when measured immediately postexercise. By 20 min postexercise, concentrations in the young were not significantly different from baseline, whereas CD8 cell number was still elevated in the old. The elderly had significantly higher percentages of memory (i.e., CD45RO+) and significantly lower percentages of naive (i.e., CD45RA+) CD4 and CD8 T cells pre-exercise, and the young and old recruited approximately equal numbers of CD8+ naive and memory cells to the blood in response to exercise. In contrast, the aged recruited significantly fewer numbers of CD4+ naive and transitional (CD45RA+RO+) cells. At most doses of Con A and PHA, the lymphoproliferative response was lower in the elderly subjects even though they had significantly higher numbers and percentages of CD3+ cells. Interestingly, immediately postexercise, young (but not old) subjects demonstrated reduced proliferative ability on a per CD3+ cell basis. CONCLUSIONS: These data indicate that several blood leukocyte responses to maximal exercise stress are similar in the young and the old. However, the elderly demonstrate a less resilient leukocytosis and a different lympho-proliferative response following acute maximal exercise.

Adult↗