Page 1. Position Paper of the American Association of Cardiovascular and Pulmonary Rehabilitation... more Page 1. Position Paper of the American Association of Cardiovascular and Pulmonary Rehabilitation Scientific Evidence of the Value of Cardiac Rehabilitation Services with Emphasis on Patients Following Myocardial Infarction ...
The extent to which light-intensity physical activity contributes to health in older adults is no... more The extent to which light-intensity physical activity contributes to health in older adults is not well known. The authors examined associations between physical activity across the intensity spectrum (sedentary to vigorous) and health and well-being variables in older adults. Two 7-day assessments of accelerometry from 2005 to 2007 were collected 6 months apart in the observational Senior Neighborhood Quality of Life Study of adults aged >65 years in Baltimore, Maryland, and Seattle, Washington. Self-reported health and psychosocial variables (e.g., lowerextremity function, body weight, rated stress) were also collected. Physical activity based on existing accelerometer thresholds for moderate/vigorous, high-light, low-light, and sedentary categories were examined as correlates of physical health and psychosocial well-being in mixed-effects regression models. Participants (N ¼ 862) were 75.4 (standard deviation, 6.8) years of age, 56% female, 71% white, and 58% overweight/obese. After adjustment for study covariates and time spent in moderate/vigorous physical activity and sedentary behavior, low-light and high-light physical activity were positively related to physical health (all P < 0.0001) and well-being (all P < 0.001).
Eighty-one sedentary but healthy men aged 30-55 participated in a 1 yr randomized study of the ef... more Eighty-one sedentary but healthy men aged 30-55 participated in a 1 yr randomized study of the effects of exercise on plasma lipoprotein concentrations. Forty-eight were assigned to a running program, while 33 remained as sedentary controls (an approximately 3:2 ratio). After 1 yr the running group had become significantly fitter and leaner than the control group. Lipoprotein concentration changes in the runners (vs. controls) uniformly favored reduced risk of coronary heart disease, but were not significant when all 46 participants with complete data were included. However, the 25 men who averaged at least eight miles (12.9 kilometers) per wk of running increased their plasma high-density-lipoprotein (HDL) cholesterol level by 4.4 mg/dl (p = 0.045) and their HDL2 mass level by 33 mg/dl (p = 0.059), vs. controls. Significant correlations were found for distance run per wk vs. change in plasma HDL-cholesterol (r = 0.48), HDL2 (r = 0.41), and low-density-lipoprotein cholesterol (r = -0.31). Changes in percent body fat and in HDL-cholesterol were correlated (r = -0.47) in runners. There appears to be a threshold at about 8 miles per wk above which a 1-yr running program leads to beneficial lipoprotein changes.
We sought to establish whether cardiorespiratory fitness had important implications for long-term... more We sought to establish whether cardiorespiratory fitness had important implications for long-term cardiovascular risk among individuals classified as low risk by the Framingham Risk Score (10-year coronary heart disease risk <10%). Prognostic factors of long-term cardiovascular risk are needed for low-risk subjects who make up the largest percentage of the US population. The study population was composed of men and women, 30 to 50 years of age, who had a baseline medical exam at the Cooper Clinic, Dallas, TX, between 1970 and 1983. Eligible individuals were defined as at low risk for coronary heart disease by Framingham Risk Score at the time of study entry and had no history of diabetes (n=11 190). Cardiorespiratory fitness was determined by maximum graded exercise treadmill tests. Over an average 27±2-year period, 15% of low-fit (quintile 1) compared to 6% of high-fit (quintile 5) individuals died (P<0.001). A 1-metabolic equivalent level increase in baseline fitness was ass...
Background and Purposes: The rapid growth of mobile technologies is creating new possibilities fo... more Background and Purposes: The rapid growth of mobile technologies is creating new possibilities for the development of behavioral interventions in nursing research. However, it remains unclear as to how to design an effective behavioral intervention using mobile technologies. Thus, we need to understand how to utilize mobile phones effectively in order to develop innovative outreach and intervention strategies aimed at promoting healthy lifestyles or managing chronic illnesses. Fortunately, we have had the opportunity to conduct three mobile health (mHealth) clinical trials involving behavioral interventions to reduce the risk of cardiovascular disease. The purposes of this paper are to describe new insights from these mHealth clinical trials and how to apply mobile technologies to behavioral interventions in a diverse sample of sedentary adults. Methods and Discussions: In our mHealth trails, the mobile phone has been used as a means of delivering behavioral interventions, setting s...
Persons whose body fat is distributed predominantly in the abdomen compared with the hips are at ... more Persons whose body fat is distributed predominantly in the abdomen compared with the hips are at increased risk of several chronic diseases. This study examined the cross-sectional relation of percent body fat, computed from skinfold thickness, and fat distribution, measured by the waist-to-hip girth ratio, to physiologic cardiovascular risk factors in a biracial sample (blacks and whites) of young adults aged 18-30 years. The subjects were persons who were examined at baseline (1984-1986) in the Coronary Artery Risk Development in Young Adults Study in four US metropolitan areas. The two hypotheses tested were that 1) after adjusting for percent body fat, waist-to-hip girth ratio is associated with several physiologic risk factors, and 2) fasting concentrations of serum insulin partly explain such association. Percent body fat was significantly associated with all measured blood lipids, lipoproteins, apolipoproteins, uric acid, and blood pressure. Waist-to-hip girth ratio was signi...
BACKGROUND: Physical activity is essential for chronic disease prevention, yet o40% of overweight... more BACKGROUND: Physical activity is essential for chronic disease prevention, yet o40% of overweight/obese adults meet the national activity recommendations. For time-efficient counseling, clinicians need a brief, easy-to-use tool that reliably and validly assesses a full range of activity levels, and, most importantly, is sensitive to clinically meaningful changes in activity. The Stanford Leisure-Time Activity Categorical Item (L-Cat) is a single item comprising six descriptive categories ranging from inactive to very active. This novel methodological approach assesses national activity recommendations as well as multiple clinically relevant categories below and above the recommendations, and incorporates critical methodological principles that enhance psychometrics (reliability, validity and sensitivity to change). METHODS: We evaluated the L-Cat's psychometrics among 267 overweight/obese women who were asked to meet the national activity recommendations in a randomized behavioral weight-loss trial. RESULTS: The L-Cat had excellent test-retest reliability (k ¼ 0.64, Po0.001) and adequate concurrent criterion validity; each L-Cat category at 6 months was associated with 1059 more daily pedometer steps (95% CI 712-1407, b ¼ 0.38, Po0.001) and 1.9% greater initial weight loss at 6 months (95% CI À 2.4 to À 1.3, b ¼ À 0.38, Po0.001). Of interest, L-Cat categories differentiated from each other in a dose-response gradient for steps and weight loss (Pso0.05) with excellent face validity. The L-Cat was sensitive to change in response to the trial's activity component. Women increased one L-Cat category at 6 months (M ¼ 1.0±1.4, Po0.001); 55.8% met the recommendations at 6 months whereas 20.6% did at baseline (Po0.001). Even among women not meeting the recommendations at both baseline and 6 months (n ¼ 106), women who moved X1 L-Cat categories at 6 months lost more weight than those who did not (M ¼ À 4.6%, 95% CI À 6.7 to À 2.5, Po0.001). CONCLUSIONS: Given strong psychometrics, the L-Cat has timely potential for clinical use such as tracking activity changes via electronic medical records, especially among overweight/obese populations who are unable or unlikely to reach national recommendations.
Treatment for stable ischemic heart disease may include guideline-directed pharmacologic therapy,... more Treatment for stable ischemic heart disease may include guideline-directed pharmacologic therapy, coronary revascularization, and lifestyle and behavioral changes, including structured exercise. Of these, regular exercise is arguably one of the most cost-effective yet underused interventions. Most patients with stable ischemic heart disease are eligible for secondary prevention programs, which should include exercise training regimens, but participation in such programs remains suboptimal. This review emphasizes the importance of education for both patients and providers to enhance participation in lifestyle physical activity, structured exercise, or both.
Objectives. This uncontrolled pilot study assessed changes in pedometer-measured step counts and ... more Objectives. This uncontrolled pilot study assessed changes in pedometer-measured step counts and selfreported physical activity during a 3-week mobile phone-based intervention. We also explored whether age, BMI, and psychosocial factors were associated with changes in step counts.
The effect of weight loss on asthma in obese adults warrants rigorous investigation. To examine a... more The effect of weight loss on asthma in obese adults warrants rigorous investigation. To examine an evidence-based, practical, and comprehensive lifestyle intervention targeting modest weight loss and increased physical activity for asthma control. The trial randomized 330 obese adults with uncontrolled asthma to receive usual care enhanced with a pedometer, a weight scale, information about existing weight management services at the participating clinics, and an asthma education DVD, or with these tools plus the 12-month intervention. The primary outcome was change in Asthma Control Questionnaire (ACQ) scores from baseline to 12 months. Participants (mean [SD] age, 47.6 [12.4] yr) were 70.6% women, 20.0% non-Hispanic black, 20.3% Hispanic/Latino, and 8.2% Asian/Pacific Islander. At baseline, they were obese (mean [SD] body mass index, 37.5 [5.9] kg/m(2)) and had uncontrolled asthma (Asthma Control Test score, 15.1 [3.8]). Compared with control subjects, intervention participants achieved significantly greater mean weight loss (±SE) (intervention, -4.0 ± 0.8 kg vs. control, -2.1 ± 0.8 kg; P = 0.01) and increased leisure-time activity (intervention, 418.2 ± 110.6 metabolic equivalent task-min/wk vs. control, 178.8 ± 109.1 metabolic equivalent task-min/wk; P = 0.05) at 12 months. But between-treatment mean (±SE) differences were not significant for ACQ changes (intervention, -0.3 ± 0.1 vs. control, -0.2 ± 0.1; P = 0.92) from baseline (mean [SD], 1.4 [0.8]), nor for any other clinical asthma outcomes (e.g., spirometric results and asthma exacerbations). Among all participants regardless of treatment assignment, weight loss of 10% or greater was associated with a Cohen d effect of 0.76 and with 3.78 (95% confidence interval, 1.72-8.31) times the odds of achieving clinically significant reductions (i.e., ≥0.5) on ACQ as stable weight (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;3% loss or gain from baseline). The effects of other weight change categories were small. Moderately and severely obese adults with uncontrolled asthma can safely participate in evidence-based lifestyle intervention for weight loss and active living. The modest average weight and activity improvements are comparable to those shown to reduce cardiometabolic risk factors in studies of similar interventions in other populations but are not associated with significant net benefits for asthma control or other clinical asthma outcomes in the current population. Instead, weight loss of 10% or greater may be required to produce clinically meaningful improvement in asthma. Clinical trial registered with www.clinicaltrials.gov (NCT00901095).
To test the feasibility, acceptability, and potential efficacy of after-school dance classes and ... more To test the feasibility, acceptability, and potential efficacy of after-school dance classes and a family-based intervention to reduce television viewing, thereby reducing weight gain, among African-American girls. Twelve-week, 2-arm parallel group, randomized controlled trial. Low-income neighborhoods. Sixty-one 8-10-year-old African-American girls and their parents/guardians. The treatment intervention consisted of after-school dance classes at 3 community centers, and a 5-lesson intervention, delivered in participants' homes, and designed to reduce television, videotape, and video game use. The active control intervention consisted of disseminating newsletters and delivering health education lectures. Implementation and process measures, body mass index, waist circumference, physical activity measured by accelerometry, self-reported media use, and meals eaten with TV. Recruitment and retention goals were exceeded. High rates of participation were achieved for assessments and ...
Physical activity (PA) and cardiorespiratory fitness (CRF) both have inverse relationships to car... more Physical activity (PA) and cardiorespiratory fitness (CRF) both have inverse relationships to cardiovascular (CV) morbidity and mortality. Recent position papers and guidelines have identified the important role of both of these factors in CV health. The benefits of PA and CRF in the prevention of CV disease and risk factors are reviewed. In addition, assessment methodology and utilization in the research and clinical arenas are discussed. Finally, the benefits, methodology, and utilization are compared and contrasted to better understand the two (partly) distinct components and their impact on CV health.
Resistance training increases total energy expenditure and free-living physical activity in older... more Resistance training increases total energy expenditure and free-living physical activity in older adults. J Appl Physiol 89: 977-984, 2000.-The purpose of this study was to determine what effects 26 wk of resistance training have on resting energy expenditure (REE), total free-living energy expenditure (TEE), activity-related energy expenditure (AEE), engagement in free-living physical activity as measured by the activity-related time equivalent (ARTE) index, and respiratory exchange ratio (RER) in 61-to 77-yr-old men (n ϭ 8) and women (n ϭ 7). Before and after training, body composition (four-compartment model), strength, REE, TEE (doubly labeled water), AEE (TEE Ϫ REE ϩ thermic response to meals), and ARTE (AEE adjusted for energy cost of standard activities) were evaluated. Strength (36%) and fat-free mass (2 kg) significantly increased, but body weight did not change. REE increased 6.8%, whereas resting RER decreased from 0.86 to 0.83. TEE (12%) and ARTE (38%) increased significantly, and AEE (30%) approached significance (P ϭ 0.06). The TEE increase remained significant even after adjustment for the energy expenditure of the resistance training. In response to resistance training, TEE increased and RER decreased. The increase in TEE occurred as a result of increases in both REE and physical activity. These results suggest that resistance training may have value in increasing energy expenditure and lipid oxidation rates in older adults, thereby improving their metabolic profiles.
Guidelines established by the National Cholesterol Education Program (NCEP) promote exercise and ... more Guidelines established by the National Cholesterol Education Program (NCEP) promote exercise and weight loss for the treatment of abnormal lipoprotein levels. Little is known, however, about the effects of exercise or the NCEP diet, which is moderately low in fat and cholesterol, in persons with lipoprotein levels that place them at high risk for coronary heart disease. We studied plasma lipoprotein levels in 180 postmenopausal women, 45 through 64 years of age, and 197 men, 30 through 64 years of age, who had low high-density lipoprotein (HDL) cholesterol levels (&lt; or =59 mg per deciliter in women and &lt; or =44 mg per deciliter in men) and moderately elevated levels of low-density lipoprotein (LDL) cholesterol (&gt;125 mg per deciliter but &lt;210 mg per deciliter in women and &gt;125 mg per deciliter but &lt;190 mg per deciliter in men). The subjects were randomly assigned to aerobic exercise, the NCEP Step 2 diet, or diet plus exercise, or to a control group, which received no intervention. Dietary intake of fat and cholesterol decreased during the one-year study (P&lt;0.001), as did body weight, in women and men in either the diet group or the diet-plus-exercise group, as compared with the controls (P&lt;0.001) and the exercise group (P&lt;0.05), in which dietary intake and body weight were unchanged. Changes in HDL cholesterol and triglyceride levels and the ratio of total to HDL cholesterol did not differ significantly among the treatment groups, for subjects of either sex. The serum level of LDL cholesterol was significantly reduced among women (a decrease of 14.5+/-22.2 mg per deciliter) and men (a decrease of 20.0+/-17.3 mg per deciliter) in the diet-plus-exercise group, as compared with the control group (women had a decrease of 2.5+/-16.6 mg per deciliter, P&lt;0.05; men had a decrease of 4.6+/-21.1 mg per deciliter, P&lt;0.001). The reduction in LDL cholesterol in men in the diet-plus-exercise group was also significant as compared with that among the men in the exercise group (3.6+/-18.8 mg per deciliter, P&lt;0.001). In contrast, changes in LDL cholesterol levels were not significant among the women (a decrease of 7.3+/-18.9 mg per deciliter) or the men (10.8+/-18.8 mg per deciliter) in the diet group, as compared with the controls. The NCEP Step 2 diet failed to lower LDL cholesterol levels in men or women with high-risk lipoprotein levels who did not engage in aerobic exercise. This finding highlights the importance of physical activity in the treatment of elevated LDL cholesterol levels.
Stimulated by increasing evidence of an inverse relationship between plasma highdensity lipoprote... more Stimulated by increasing evidence of an inverse relationship between plasma highdensity lipoprotein cholesterol level and frequency of coronary heart disease, we determined concentrations of fasting plasma cholesterol, triglyceride, and lipoproteins in 41 very active men (running > 15 miles/wk for the previous year) 35-59 years of age (mean age, 47) and in a comparison group of men of similar age, randomly selected from three northern California communities. The runners had significantly (p < 0.05) decreased mean plasma triglyceride (70 versus 146 mg/ 100 ml), total plasma cholesterol (200 versus 210 mg/lO0 ml), and low-density lipoprotein (LDL) cholesterol (125 versus 139 mg/lO0 ml) concentrations, and a higher mean level of high-density lipoprotein (HDL) cholesterol (64 versus 43 mg/ 100 ml) than the comparison group (n = 147 for HDL and LDL; n = 743 for total cholesterol and triglycerides).
and dual-photon absorptiometry (DPA) were used to examine associations of regional adiposity with... more and dual-photon absorptiometry (DPA) were used to examine associations of regional adiposity with plasma lipid, lipoprotein, and lipoprotein subfraction mass concentrations in moderately overweight men and women. Among 130 women, waist to thigh girth ratio (WTR) correlated with triglycerides (TG) (r = .33, P < .OOOl) and negatively with high-density lipoprotein (HDL)-cholesterol (HDL-C) (r = -.37, P < .OOOl) concentration, as expected. While WTR did not correlate with low-density lipoprotein (LDL)-cholesterol (LDL-C) it correlated positively with the mass subfraction of small (SF, 0 to 7) LDL (r = .38, P < .OOOl), and negatively with large (SF, 7 to 12) LDL (r = -.31, P < .Ol). Among 133 men, similar though weaker relationships were found. Thigh girth correlated positively with HDL and HDL,-C and mass, and with LDL particle size among women. Multivariate analysis suggests that association of WTR with lipoprotein values known to carry risk of coronary heart disease (CHD) are due at least as much to effects of thigh girth as to deleterious effects of waist girth. Estimates of fat weight in thigh and abdominal regions by DPA support thigh fat as contributing to these effects of thigh girth. Thigh fat may contribute to lipoprotein profiles that predict lower risk of cardiovascular disease.
Previous studies suggest that African Americans (AA) have lower levels of cardiorespiratory fitne... more Previous studies suggest that African Americans (AA) have lower levels of cardiorespiratory fitness (CRF) than their Caucasian (C) counterparts. However, the association between CRF and race/ethnicity in the context of higher socioeconomic status (SES) has not been explored. We evaluated 589 AA (309 men and 203 women) and 33,015 C (19,399 men and 8753 women) enrolled in the Cooper Center Longitudinal Study. Education years and access to a preventive health care examination were used as a proxy for higher SES. Data were collected from a questionnaire, maximal treadmill exercise stress test, and other clinical measures. The outcome variable was CRF, which was stratified into low fit (quintile 1 of CRF) and fit (quintiles 2-5). Multivariable regression was used to compare adjusted mean CRF between groups. P values were adjusted for unbalanced sample size and unequal variance between groups. The mean education years were similar for AA and C men at 16 yr; however, AA women had more years of education than C (15.8 vs 15.2 yr, P = 0.0062). AA men and women had a significantly higher prevalence of being unfit compared with their C counterparts (men 26.7% vs 12.6%, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001; women 21.3% vs 8.4%, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001). The adjusted mean estimated maximal METs were 10.9 vs 11.7 and 8.8 vs 9.8 for AA and C men and women, respectively. Fully adjusted odds ratios revealed that AA men had more than twice the risk of being unfit compared with C men. A trend persisted for AA women to have a lower MET value than their counterparts. Despite comparable higher SES, lower CRF existed among AA men versus C men. These results suggest that CRF may not be mediated strictly by environmental factors related to SES.
Large physical activity surveillance projects such as the UK Biobank and NHANES are using wrist-w... more Large physical activity surveillance projects such as the UK Biobank and NHANES are using wrist-worn accelerometer-based activity monitors that collect raw data. The goal is to increase wear time by asking subjects to wear the monitors on the wrist instead of the hip, and then to use information in the raw signal to improve activity type and intensity estimation. The purposes of this work was to obtain an algorithm to process wrist and ankle raw data and to classify behavior into four broad activity classes: ambulation, cycling, sedentary, and other activities. Participants (N = 33) wearing accelerometers on the wrist and ankle performed 26 daily activities. The accelerometer data were collected, cleaned, and preprocessed to extract features that characterize 2-, 4-, and 12.8-s data windows. Feature vectors encoding information about frequency and intensity of motion extracted from analysis of the raw signal were used with a support vector machine classifier to identify a subject&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s activity. Results were compared with categories classified by a human observer. Algorithms were validated using a leave-one-subject-out strategy. The computational complexity of each processing step was also evaluated. With 12.8-s windows, the proposed strategy showed high classification accuracies for ankle data (95.0%) that decreased to 84.7% for wrist data. Shorter (4 s) windows only minimally decreased performances of the algorithm on the wrist to 84.2%. A classification algorithm using 13 features shows good classification into the four classes given the complexity of the activities in the original data set. The algorithm is computationally efficient and could be implemented in real time on mobile devices with only 4-s latency.
Symptom-limited, graded exercise treadmill testing was performed by 4,968 white and black adults,... more Symptom-limited, graded exercise treadmill testing was performed by 4,968 white and black adults, ages 18-30 yr, during the baseline examination for the CARDIA study. The mean estimated maximal exercise capacity by race/gender, expressed as metabolic units (METS), was: white men 13.8, black men 13.0, white women 11.1, and black women 9.4. Exercise test duration was higher in nonsmokers, positively related to physical activity score and pulmonary function (FEV1.ht-2), and inversely related to body mass index. Men had higher mean values than women for both test duration and a measure of submaximal performance, the workload 130 (WL130, the exercise test duration to a heart rate of 130 beats.min-1). Adjusted for age and education, white men had a longer mean test duration than black men (53 s longer, P less than 0.001), but nearly equal mean WL130. White women had higher mean values than black women for both test duration (114 s longer, P less than 0.001) and WL130 (36 s longer, P less than 0.001). Men had higher mean values than women for both outcome measures (P less than 0.001). Thus, in young adults significant gender and ethnic differences exist for exercise test performance, part of which can be explained by personal habits or traits.
Page 1. Position Paper of the American Association of Cardiovascular and Pulmonary Rehabilitation... more Page 1. Position Paper of the American Association of Cardiovascular and Pulmonary Rehabilitation Scientific Evidence of the Value of Cardiac Rehabilitation Services with Emphasis on Patients Following Myocardial Infarction ...
The extent to which light-intensity physical activity contributes to health in older adults is no... more The extent to which light-intensity physical activity contributes to health in older adults is not well known. The authors examined associations between physical activity across the intensity spectrum (sedentary to vigorous) and health and well-being variables in older adults. Two 7-day assessments of accelerometry from 2005 to 2007 were collected 6 months apart in the observational Senior Neighborhood Quality of Life Study of adults aged >65 years in Baltimore, Maryland, and Seattle, Washington. Self-reported health and psychosocial variables (e.g., lowerextremity function, body weight, rated stress) were also collected. Physical activity based on existing accelerometer thresholds for moderate/vigorous, high-light, low-light, and sedentary categories were examined as correlates of physical health and psychosocial well-being in mixed-effects regression models. Participants (N ¼ 862) were 75.4 (standard deviation, 6.8) years of age, 56% female, 71% white, and 58% overweight/obese. After adjustment for study covariates and time spent in moderate/vigorous physical activity and sedentary behavior, low-light and high-light physical activity were positively related to physical health (all P < 0.0001) and well-being (all P < 0.001).
Eighty-one sedentary but healthy men aged 30-55 participated in a 1 yr randomized study of the ef... more Eighty-one sedentary but healthy men aged 30-55 participated in a 1 yr randomized study of the effects of exercise on plasma lipoprotein concentrations. Forty-eight were assigned to a running program, while 33 remained as sedentary controls (an approximately 3:2 ratio). After 1 yr the running group had become significantly fitter and leaner than the control group. Lipoprotein concentration changes in the runners (vs. controls) uniformly favored reduced risk of coronary heart disease, but were not significant when all 46 participants with complete data were included. However, the 25 men who averaged at least eight miles (12.9 kilometers) per wk of running increased their plasma high-density-lipoprotein (HDL) cholesterol level by 4.4 mg/dl (p = 0.045) and their HDL2 mass level by 33 mg/dl (p = 0.059), vs. controls. Significant correlations were found for distance run per wk vs. change in plasma HDL-cholesterol (r = 0.48), HDL2 (r = 0.41), and low-density-lipoprotein cholesterol (r = -0.31). Changes in percent body fat and in HDL-cholesterol were correlated (r = -0.47) in runners. There appears to be a threshold at about 8 miles per wk above which a 1-yr running program leads to beneficial lipoprotein changes.
We sought to establish whether cardiorespiratory fitness had important implications for long-term... more We sought to establish whether cardiorespiratory fitness had important implications for long-term cardiovascular risk among individuals classified as low risk by the Framingham Risk Score (10-year coronary heart disease risk <10%). Prognostic factors of long-term cardiovascular risk are needed for low-risk subjects who make up the largest percentage of the US population. The study population was composed of men and women, 30 to 50 years of age, who had a baseline medical exam at the Cooper Clinic, Dallas, TX, between 1970 and 1983. Eligible individuals were defined as at low risk for coronary heart disease by Framingham Risk Score at the time of study entry and had no history of diabetes (n=11 190). Cardiorespiratory fitness was determined by maximum graded exercise treadmill tests. Over an average 27±2-year period, 15% of low-fit (quintile 1) compared to 6% of high-fit (quintile 5) individuals died (P<0.001). A 1-metabolic equivalent level increase in baseline fitness was ass...
Background and Purposes: The rapid growth of mobile technologies is creating new possibilities fo... more Background and Purposes: The rapid growth of mobile technologies is creating new possibilities for the development of behavioral interventions in nursing research. However, it remains unclear as to how to design an effective behavioral intervention using mobile technologies. Thus, we need to understand how to utilize mobile phones effectively in order to develop innovative outreach and intervention strategies aimed at promoting healthy lifestyles or managing chronic illnesses. Fortunately, we have had the opportunity to conduct three mobile health (mHealth) clinical trials involving behavioral interventions to reduce the risk of cardiovascular disease. The purposes of this paper are to describe new insights from these mHealth clinical trials and how to apply mobile technologies to behavioral interventions in a diverse sample of sedentary adults. Methods and Discussions: In our mHealth trails, the mobile phone has been used as a means of delivering behavioral interventions, setting s...
Persons whose body fat is distributed predominantly in the abdomen compared with the hips are at ... more Persons whose body fat is distributed predominantly in the abdomen compared with the hips are at increased risk of several chronic diseases. This study examined the cross-sectional relation of percent body fat, computed from skinfold thickness, and fat distribution, measured by the waist-to-hip girth ratio, to physiologic cardiovascular risk factors in a biracial sample (blacks and whites) of young adults aged 18-30 years. The subjects were persons who were examined at baseline (1984-1986) in the Coronary Artery Risk Development in Young Adults Study in four US metropolitan areas. The two hypotheses tested were that 1) after adjusting for percent body fat, waist-to-hip girth ratio is associated with several physiologic risk factors, and 2) fasting concentrations of serum insulin partly explain such association. Percent body fat was significantly associated with all measured blood lipids, lipoproteins, apolipoproteins, uric acid, and blood pressure. Waist-to-hip girth ratio was signi...
BACKGROUND: Physical activity is essential for chronic disease prevention, yet o40% of overweight... more BACKGROUND: Physical activity is essential for chronic disease prevention, yet o40% of overweight/obese adults meet the national activity recommendations. For time-efficient counseling, clinicians need a brief, easy-to-use tool that reliably and validly assesses a full range of activity levels, and, most importantly, is sensitive to clinically meaningful changes in activity. The Stanford Leisure-Time Activity Categorical Item (L-Cat) is a single item comprising six descriptive categories ranging from inactive to very active. This novel methodological approach assesses national activity recommendations as well as multiple clinically relevant categories below and above the recommendations, and incorporates critical methodological principles that enhance psychometrics (reliability, validity and sensitivity to change). METHODS: We evaluated the L-Cat's psychometrics among 267 overweight/obese women who were asked to meet the national activity recommendations in a randomized behavioral weight-loss trial. RESULTS: The L-Cat had excellent test-retest reliability (k ¼ 0.64, Po0.001) and adequate concurrent criterion validity; each L-Cat category at 6 months was associated with 1059 more daily pedometer steps (95% CI 712-1407, b ¼ 0.38, Po0.001) and 1.9% greater initial weight loss at 6 months (95% CI À 2.4 to À 1.3, b ¼ À 0.38, Po0.001). Of interest, L-Cat categories differentiated from each other in a dose-response gradient for steps and weight loss (Pso0.05) with excellent face validity. The L-Cat was sensitive to change in response to the trial's activity component. Women increased one L-Cat category at 6 months (M ¼ 1.0±1.4, Po0.001); 55.8% met the recommendations at 6 months whereas 20.6% did at baseline (Po0.001). Even among women not meeting the recommendations at both baseline and 6 months (n ¼ 106), women who moved X1 L-Cat categories at 6 months lost more weight than those who did not (M ¼ À 4.6%, 95% CI À 6.7 to À 2.5, Po0.001). CONCLUSIONS: Given strong psychometrics, the L-Cat has timely potential for clinical use such as tracking activity changes via electronic medical records, especially among overweight/obese populations who are unable or unlikely to reach national recommendations.
Treatment for stable ischemic heart disease may include guideline-directed pharmacologic therapy,... more Treatment for stable ischemic heart disease may include guideline-directed pharmacologic therapy, coronary revascularization, and lifestyle and behavioral changes, including structured exercise. Of these, regular exercise is arguably one of the most cost-effective yet underused interventions. Most patients with stable ischemic heart disease are eligible for secondary prevention programs, which should include exercise training regimens, but participation in such programs remains suboptimal. This review emphasizes the importance of education for both patients and providers to enhance participation in lifestyle physical activity, structured exercise, or both.
Objectives. This uncontrolled pilot study assessed changes in pedometer-measured step counts and ... more Objectives. This uncontrolled pilot study assessed changes in pedometer-measured step counts and selfreported physical activity during a 3-week mobile phone-based intervention. We also explored whether age, BMI, and psychosocial factors were associated with changes in step counts.
The effect of weight loss on asthma in obese adults warrants rigorous investigation. To examine a... more The effect of weight loss on asthma in obese adults warrants rigorous investigation. To examine an evidence-based, practical, and comprehensive lifestyle intervention targeting modest weight loss and increased physical activity for asthma control. The trial randomized 330 obese adults with uncontrolled asthma to receive usual care enhanced with a pedometer, a weight scale, information about existing weight management services at the participating clinics, and an asthma education DVD, or with these tools plus the 12-month intervention. The primary outcome was change in Asthma Control Questionnaire (ACQ) scores from baseline to 12 months. Participants (mean [SD] age, 47.6 [12.4] yr) were 70.6% women, 20.0% non-Hispanic black, 20.3% Hispanic/Latino, and 8.2% Asian/Pacific Islander. At baseline, they were obese (mean [SD] body mass index, 37.5 [5.9] kg/m(2)) and had uncontrolled asthma (Asthma Control Test score, 15.1 [3.8]). Compared with control subjects, intervention participants achieved significantly greater mean weight loss (±SE) (intervention, -4.0 ± 0.8 kg vs. control, -2.1 ± 0.8 kg; P = 0.01) and increased leisure-time activity (intervention, 418.2 ± 110.6 metabolic equivalent task-min/wk vs. control, 178.8 ± 109.1 metabolic equivalent task-min/wk; P = 0.05) at 12 months. But between-treatment mean (±SE) differences were not significant for ACQ changes (intervention, -0.3 ± 0.1 vs. control, -0.2 ± 0.1; P = 0.92) from baseline (mean [SD], 1.4 [0.8]), nor for any other clinical asthma outcomes (e.g., spirometric results and asthma exacerbations). Among all participants regardless of treatment assignment, weight loss of 10% or greater was associated with a Cohen d effect of 0.76 and with 3.78 (95% confidence interval, 1.72-8.31) times the odds of achieving clinically significant reductions (i.e., ≥0.5) on ACQ as stable weight (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;3% loss or gain from baseline). The effects of other weight change categories were small. Moderately and severely obese adults with uncontrolled asthma can safely participate in evidence-based lifestyle intervention for weight loss and active living. The modest average weight and activity improvements are comparable to those shown to reduce cardiometabolic risk factors in studies of similar interventions in other populations but are not associated with significant net benefits for asthma control or other clinical asthma outcomes in the current population. Instead, weight loss of 10% or greater may be required to produce clinically meaningful improvement in asthma. Clinical trial registered with www.clinicaltrials.gov (NCT00901095).
To test the feasibility, acceptability, and potential efficacy of after-school dance classes and ... more To test the feasibility, acceptability, and potential efficacy of after-school dance classes and a family-based intervention to reduce television viewing, thereby reducing weight gain, among African-American girls. Twelve-week, 2-arm parallel group, randomized controlled trial. Low-income neighborhoods. Sixty-one 8-10-year-old African-American girls and their parents/guardians. The treatment intervention consisted of after-school dance classes at 3 community centers, and a 5-lesson intervention, delivered in participants' homes, and designed to reduce television, videotape, and video game use. The active control intervention consisted of disseminating newsletters and delivering health education lectures. Implementation and process measures, body mass index, waist circumference, physical activity measured by accelerometry, self-reported media use, and meals eaten with TV. Recruitment and retention goals were exceeded. High rates of participation were achieved for assessments and ...
Physical activity (PA) and cardiorespiratory fitness (CRF) both have inverse relationships to car... more Physical activity (PA) and cardiorespiratory fitness (CRF) both have inverse relationships to cardiovascular (CV) morbidity and mortality. Recent position papers and guidelines have identified the important role of both of these factors in CV health. The benefits of PA and CRF in the prevention of CV disease and risk factors are reviewed. In addition, assessment methodology and utilization in the research and clinical arenas are discussed. Finally, the benefits, methodology, and utilization are compared and contrasted to better understand the two (partly) distinct components and their impact on CV health.
Resistance training increases total energy expenditure and free-living physical activity in older... more Resistance training increases total energy expenditure and free-living physical activity in older adults. J Appl Physiol 89: 977-984, 2000.-The purpose of this study was to determine what effects 26 wk of resistance training have on resting energy expenditure (REE), total free-living energy expenditure (TEE), activity-related energy expenditure (AEE), engagement in free-living physical activity as measured by the activity-related time equivalent (ARTE) index, and respiratory exchange ratio (RER) in 61-to 77-yr-old men (n ϭ 8) and women (n ϭ 7). Before and after training, body composition (four-compartment model), strength, REE, TEE (doubly labeled water), AEE (TEE Ϫ REE ϩ thermic response to meals), and ARTE (AEE adjusted for energy cost of standard activities) were evaluated. Strength (36%) and fat-free mass (2 kg) significantly increased, but body weight did not change. REE increased 6.8%, whereas resting RER decreased from 0.86 to 0.83. TEE (12%) and ARTE (38%) increased significantly, and AEE (30%) approached significance (P ϭ 0.06). The TEE increase remained significant even after adjustment for the energy expenditure of the resistance training. In response to resistance training, TEE increased and RER decreased. The increase in TEE occurred as a result of increases in both REE and physical activity. These results suggest that resistance training may have value in increasing energy expenditure and lipid oxidation rates in older adults, thereby improving their metabolic profiles.
Guidelines established by the National Cholesterol Education Program (NCEP) promote exercise and ... more Guidelines established by the National Cholesterol Education Program (NCEP) promote exercise and weight loss for the treatment of abnormal lipoprotein levels. Little is known, however, about the effects of exercise or the NCEP diet, which is moderately low in fat and cholesterol, in persons with lipoprotein levels that place them at high risk for coronary heart disease. We studied plasma lipoprotein levels in 180 postmenopausal women, 45 through 64 years of age, and 197 men, 30 through 64 years of age, who had low high-density lipoprotein (HDL) cholesterol levels (&lt; or =59 mg per deciliter in women and &lt; or =44 mg per deciliter in men) and moderately elevated levels of low-density lipoprotein (LDL) cholesterol (&gt;125 mg per deciliter but &lt;210 mg per deciliter in women and &gt;125 mg per deciliter but &lt;190 mg per deciliter in men). The subjects were randomly assigned to aerobic exercise, the NCEP Step 2 diet, or diet plus exercise, or to a control group, which received no intervention. Dietary intake of fat and cholesterol decreased during the one-year study (P&lt;0.001), as did body weight, in women and men in either the diet group or the diet-plus-exercise group, as compared with the controls (P&lt;0.001) and the exercise group (P&lt;0.05), in which dietary intake and body weight were unchanged. Changes in HDL cholesterol and triglyceride levels and the ratio of total to HDL cholesterol did not differ significantly among the treatment groups, for subjects of either sex. The serum level of LDL cholesterol was significantly reduced among women (a decrease of 14.5+/-22.2 mg per deciliter) and men (a decrease of 20.0+/-17.3 mg per deciliter) in the diet-plus-exercise group, as compared with the control group (women had a decrease of 2.5+/-16.6 mg per deciliter, P&lt;0.05; men had a decrease of 4.6+/-21.1 mg per deciliter, P&lt;0.001). The reduction in LDL cholesterol in men in the diet-plus-exercise group was also significant as compared with that among the men in the exercise group (3.6+/-18.8 mg per deciliter, P&lt;0.001). In contrast, changes in LDL cholesterol levels were not significant among the women (a decrease of 7.3+/-18.9 mg per deciliter) or the men (10.8+/-18.8 mg per deciliter) in the diet group, as compared with the controls. The NCEP Step 2 diet failed to lower LDL cholesterol levels in men or women with high-risk lipoprotein levels who did not engage in aerobic exercise. This finding highlights the importance of physical activity in the treatment of elevated LDL cholesterol levels.
Stimulated by increasing evidence of an inverse relationship between plasma highdensity lipoprote... more Stimulated by increasing evidence of an inverse relationship between plasma highdensity lipoprotein cholesterol level and frequency of coronary heart disease, we determined concentrations of fasting plasma cholesterol, triglyceride, and lipoproteins in 41 very active men (running > 15 miles/wk for the previous year) 35-59 years of age (mean age, 47) and in a comparison group of men of similar age, randomly selected from three northern California communities. The runners had significantly (p < 0.05) decreased mean plasma triglyceride (70 versus 146 mg/ 100 ml), total plasma cholesterol (200 versus 210 mg/lO0 ml), and low-density lipoprotein (LDL) cholesterol (125 versus 139 mg/lO0 ml) concentrations, and a higher mean level of high-density lipoprotein (HDL) cholesterol (64 versus 43 mg/ 100 ml) than the comparison group (n = 147 for HDL and LDL; n = 743 for total cholesterol and triglycerides).
and dual-photon absorptiometry (DPA) were used to examine associations of regional adiposity with... more and dual-photon absorptiometry (DPA) were used to examine associations of regional adiposity with plasma lipid, lipoprotein, and lipoprotein subfraction mass concentrations in moderately overweight men and women. Among 130 women, waist to thigh girth ratio (WTR) correlated with triglycerides (TG) (r = .33, P < .OOOl) and negatively with high-density lipoprotein (HDL)-cholesterol (HDL-C) (r = -.37, P < .OOOl) concentration, as expected. While WTR did not correlate with low-density lipoprotein (LDL)-cholesterol (LDL-C) it correlated positively with the mass subfraction of small (SF, 0 to 7) LDL (r = .38, P < .OOOl), and negatively with large (SF, 7 to 12) LDL (r = -.31, P < .Ol). Among 133 men, similar though weaker relationships were found. Thigh girth correlated positively with HDL and HDL,-C and mass, and with LDL particle size among women. Multivariate analysis suggests that association of WTR with lipoprotein values known to carry risk of coronary heart disease (CHD) are due at least as much to effects of thigh girth as to deleterious effects of waist girth. Estimates of fat weight in thigh and abdominal regions by DPA support thigh fat as contributing to these effects of thigh girth. Thigh fat may contribute to lipoprotein profiles that predict lower risk of cardiovascular disease.
Previous studies suggest that African Americans (AA) have lower levels of cardiorespiratory fitne... more Previous studies suggest that African Americans (AA) have lower levels of cardiorespiratory fitness (CRF) than their Caucasian (C) counterparts. However, the association between CRF and race/ethnicity in the context of higher socioeconomic status (SES) has not been explored. We evaluated 589 AA (309 men and 203 women) and 33,015 C (19,399 men and 8753 women) enrolled in the Cooper Center Longitudinal Study. Education years and access to a preventive health care examination were used as a proxy for higher SES. Data were collected from a questionnaire, maximal treadmill exercise stress test, and other clinical measures. The outcome variable was CRF, which was stratified into low fit (quintile 1 of CRF) and fit (quintiles 2-5). Multivariable regression was used to compare adjusted mean CRF between groups. P values were adjusted for unbalanced sample size and unequal variance between groups. The mean education years were similar for AA and C men at 16 yr; however, AA women had more years of education than C (15.8 vs 15.2 yr, P = 0.0062). AA men and women had a significantly higher prevalence of being unfit compared with their C counterparts (men 26.7% vs 12.6%, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001; women 21.3% vs 8.4%, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001). The adjusted mean estimated maximal METs were 10.9 vs 11.7 and 8.8 vs 9.8 for AA and C men and women, respectively. Fully adjusted odds ratios revealed that AA men had more than twice the risk of being unfit compared with C men. A trend persisted for AA women to have a lower MET value than their counterparts. Despite comparable higher SES, lower CRF existed among AA men versus C men. These results suggest that CRF may not be mediated strictly by environmental factors related to SES.
Large physical activity surveillance projects such as the UK Biobank and NHANES are using wrist-w... more Large physical activity surveillance projects such as the UK Biobank and NHANES are using wrist-worn accelerometer-based activity monitors that collect raw data. The goal is to increase wear time by asking subjects to wear the monitors on the wrist instead of the hip, and then to use information in the raw signal to improve activity type and intensity estimation. The purposes of this work was to obtain an algorithm to process wrist and ankle raw data and to classify behavior into four broad activity classes: ambulation, cycling, sedentary, and other activities. Participants (N = 33) wearing accelerometers on the wrist and ankle performed 26 daily activities. The accelerometer data were collected, cleaned, and preprocessed to extract features that characterize 2-, 4-, and 12.8-s data windows. Feature vectors encoding information about frequency and intensity of motion extracted from analysis of the raw signal were used with a support vector machine classifier to identify a subject&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s activity. Results were compared with categories classified by a human observer. Algorithms were validated using a leave-one-subject-out strategy. The computational complexity of each processing step was also evaluated. With 12.8-s windows, the proposed strategy showed high classification accuracies for ankle data (95.0%) that decreased to 84.7% for wrist data. Shorter (4 s) windows only minimally decreased performances of the algorithm on the wrist to 84.2%. A classification algorithm using 13 features shows good classification into the four classes given the complexity of the activities in the original data set. The algorithm is computationally efficient and could be implemented in real time on mobile devices with only 4-s latency.
Symptom-limited, graded exercise treadmill testing was performed by 4,968 white and black adults,... more Symptom-limited, graded exercise treadmill testing was performed by 4,968 white and black adults, ages 18-30 yr, during the baseline examination for the CARDIA study. The mean estimated maximal exercise capacity by race/gender, expressed as metabolic units (METS), was: white men 13.8, black men 13.0, white women 11.1, and black women 9.4. Exercise test duration was higher in nonsmokers, positively related to physical activity score and pulmonary function (FEV1.ht-2), and inversely related to body mass index. Men had higher mean values than women for both test duration and a measure of submaximal performance, the workload 130 (WL130, the exercise test duration to a heart rate of 130 beats.min-1). Adjusted for age and education, white men had a longer mean test duration than black men (53 s longer, P less than 0.001), but nearly equal mean WL130. White women had higher mean values than black women for both test duration (114 s longer, P less than 0.001) and WL130 (36 s longer, P less than 0.001). Men had higher mean values than women for both outcome measures (P less than 0.001). Thus, in young adults significant gender and ethnic differences exist for exercise test performance, part of which can be explained by personal habits or traits.
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