Ten months of exercise improves general and visceral adiposity, bone, and fitness in black girls.

OBJECTIVE: The goal of this study was to evaluate the impact of a 10-month after-school physical activity (PA) program on body composition and cardiovascular (CV) fitness in young black girls. RESEARCH METHODS AND PROCEDURES: Subjects were 8- to 12-year-olds recruited from elementary schools. Body composition was measured using anthropometrics {waist circumference and BMI, DXA [percentage body fat (%BF)] and bone mineral density (BMD)}, and magnetic resonance imaging [visceral adipose tissue (VAT)]. CV fitness was measured using a graded treadmill test. The intervention consisted of 30 minutes homework/healthy snack time and 80 minutes PA (i.e., 25 minutes skills instruction, 35 minutes aerobic PA, and 20 minutes strengthening/stretching). Analyses were adjusted for age, baseline value of the dependent variable, and sexual maturation (pediatrician observation). RESULTS: Mean attendance was 54%. Compared with the control group, the intervention group had a relative decrease in %BF (p < 0.0001), BMI (p < 0.01), and VAT (p < 0.01) and a relative increase in BMD (p < 0.0001) and CV fitness (p < 0.05). Higher attendance was associated with greater increases in BMD (p < 0.05) and greater decreases in %BF (p < 0.01) and BMI (p < 0.05). Higher heart rate during PA was associated with greater increases in BMD (p < 0.05) and greater decreases in %BF (p < 0.005). DISCUSSION: An after-school PA program can lead to beneficial changes in body composition and CV fitness in young black girls. It is noteworthy that the control and intervention groups differed in change in VAT but not waist circumference. This suggests that changes in central adiposity can occur in response to PA, even in young children, but that waist circumference may not be a good indicator of central adiposity.

Correlates of adherence to a physical activity program in young African-American girls.

OBJECTIVE: The goal was to identify correlates of adherence to a structured physical activity (PA) program. RESEARCH METHODS AND PROCEDURES: Subjects were 136 8- to 12-year-old African-American girls. Potential correlates at baseline were: 1) fitness index (FI: % body fat from DXA and cardiovascular fitness from treadmill test), and 2) self-esteem, anxiety, attitude to school and teachers, relationship with parents, and interpersonal relations (Behavioral Assessment System for Children). The 10-month PA program included 80 minutes of PA offered 5 days/wk. Regression tree classification was used to model attendance. RESULTS: Six splits occurred (34% total variance explained). Less anxious subjects attended more often than highly anxious subjects (3 days/wk vs. 1.5 days/wk) did. Subjects with a healthier FI attended more often than those with a less healthy FI (3 days/wk vs. 0.5 days/wk) did. Younger subjects attended more often than older ones (3 days/wk vs. 2.5 days/wk) did. The next two splits were again with anxiety (3.5 days/wk vs. 3 days/wk) and FI (3 days/wk vs. 2.5 days/wk). Finally, subjects with higher levels of self-esteem attended more often than those with lower levels (3.5 days/wk vs. 2 days/wk) did. DISCUSSION: Subjects who were self-confident, younger, fitter, and less anxious were more likely to participate regularly. This suggests that children who may be more likely to benefit from a PA program are less likely to participate. To enhance participation in PA programs, especially in older African-American girls: 1) psychological concerns should be identified and addressed before enrollment, and 2) programs should be designed to be appealing to children of all fitness levels.

Evaluation of internal medicine residents as exercise role models and associations with self-reported counseling behavior, confidence, and perceived success.

BACKGROUND: Patients perceive physicians who practice healthy personal behaviors as more credible and better able to motivate patients to make healthy lifestyle choices. PURPOSES: To evaluate internal medicine resident physicians as role models for promoting exercise by an assessment of physician physical activity behavior, cardiovascular fitness, physical activity knowledge, personal use of behavior modification techniques, attitudes toward personal physical activity practice, and confidence (i.e., self-efficacy) in the knowledge and personal utilization of behavior modification techniques and to explore the associations with self-reported patient counseling behavior, confidence, and perceived success. METHODS: Cross-sectional study of internal medicine resident physicians with a self-administered survey, treadmill fitness testing, and a 7-day physical activity recall. RESULTS: Fifty-one resident physicians agreed to participate (response rate = 81%). Fitness levels were below average for 60%, average for 25%, and above average or excellent for 15%. The mean energy expenditure was 234 kcal/kg/week, with 41% of physicians meeting recommended physical activity guidelines. Few reported high self-efficacy (33%) or perceived success (25%) in the ability to be regularly active. Few demonstrated adequate knowledge useful for patient counseling (e.g., listing 3 ways to integrate physical activity into daily life [27%], calculating target heart rate [29%], and identifying personal exercise stages of change [25%]). Personal use of behavior modification techniques was reported infrequently. Although 88% reported confidence in the knowledge of exercise benefits, less than half reported confidence in the knowledge of local facilities, American College of Sports Medicine (ACSM) guidelines, and behavior modification techniques. Multiple linear regression demonstrated that a higher level of training (p = .02) and a greater confidence in the knowledge of ACSM guidelines (p = .048, total R2 = .21) independently predicted more frequent self-reported counseling. Sex (i.e., male; p = .01) and greater physical activity self-efficacy (p = .017, total R2 = .23) independently predicted greater perceived counseling success. Greater physical activity enjoyment (p = .03) and greater perceived success at engaging in regular physical activity (p = .028, total R2 = .28) independently predicted greater counseling self-efficacy. CONCLUSIONS: Most internal medicine resident physicians may not be adequate role models for promoting exercise adherence. Confidence in the knowledge of current guidelines, personal physical activity enjoyment, and perceived success and self-efficacy in engaging in regular physical activity may be useful targets for enhancing resident physician physical activity counseling for their patients.

Relations of black mothers' and daughters' body fatness, physical activity beliefs and behavior.

OBJECTIVES: 1) Examine the association between Black mothers' and daughters' body fatness, physical activity (PA) beliefs and levels of PA, and daughters' PA behavior; 2) determine whether family sociodemographic factors influence these relationships. DESIGN AND SETTING: Cross-sectional; Black girls recruited from elementary schools in a low socioeconomic area. Data collected at the Georgia Prevention Institute. PARTICIPANTS: 133 Black girls (8-12 years of age) and their mothers (24-66 years of age). ANALYSES: Spearman correlations, regressions. OUTCOME MEASURES: Body mass index (BMI) as a measure of body fatness. Moderate and vigorous PA collected from a 7-d recall. Beliefs about PA collected from questionnaires. RESULTS: There was a positive relation between mothers' and daughters' BMI (rs=0.34, P<.0001). Mothers' and daughters' PA beliefs were positive but not significantly related. A significant inverse relation was seen between vigorous PA (rs=-0.16, P<.05); and a non-significant correlation between moderate PA (rs=0.05). Mothers' body fatness, PA beliefs and behavior did not predict daughters' PA. The BMI association was stronger when spouse lived in household (P<.01). Daughters' BMI was lower (P<.05) and intent to be active higher (P<.05) when more people lived in the household. Family income accentuated the relation of mothers' belief in the usefulness of PA and daughters' PA physical outcomes beliefs (P=.1). Mothers' age and education had no significant influence on daughters' PA beliefs and behaviors. CONCLUSION: Mothers and daughters believed PA to have beneficial outcomes. Mothers' body fatness, PA beliefs and behaviors were not associated with daughters' PA. Family income and structure appeared to influence these relationships.

A physician fitness program: enhancing the physician as an "exercise" role model for patients.

BACKGROUND: Physically active physicians are more apt to counsel patients about exercise. PURPOSES: The purpose of this study was to determine the effect of a physician fitness program on resident physician cardiovascular fitness, physical activity behavior/stage of change, and physical activity counseling behavior/attitudes. METHODS: A prospective, intervention study with measurements at baseline (before intervention), 3 months (immediately after intervention), and 6 months (3 months after intervention) evaluated a multifaceted exercise program for 48 internal medicine residents. Resident physician cardiovascular fitness, energy expenditure, physical activity stage of change, knowledge, attitudes, and counseling behavior were measured. RESULTS: Resident physician fitness significantly declined over time (baseline VO(2)-170 = 29.1 ml/kg/min, first follow-up VO(2)-170 = 27.3 ml/kg/min, and second follow-up VO(2)-170 = 26.2 ml/kg/min; p = .001). Although there was no change in overall energy expenditure, the number of resident physicians in the precontemplation or contemplation stage of change significantly declined with a corresponding increase in the number in a "higher" stage of change at first (p = .0034) and second follow-up (p = .024). There was a nonsignificant increase in self-reported patient counseling. Resident physician counseling confidence and perceived success significantly improved at first follow-up only (p = .01 and p = .03, respectively). CONCLUSION: Although resident physician fitness and energy expenditure did not improve after intervention, a significant improvement in resident physician physical activity stage of change and attitudes toward patient counseling was noted. Randomized controlled trials are needed to confirm whether these changes are attributable to the intervention.

Influence of physical training on plasma leptin in obese youths.

Little is known about the effects of different intensities of physical training on plasma leptin. This study examined the effect of two intensities of physical training on leptin in obese teenagers, and explored correlates at baseline and in response to 8 months of physical training. The participants were 55 obese youths 12-16 years of age who completed both baseline and posttesting. The youths were randomized to engage in lifestyle education only (LSE), moderate-intensity physical training and LSE, or high-intensity physical training and LSE. Baseline leptin was positively associated with fat mass. Girls had higher leptin levels at lower levels of fasting insulin than boys. The 8-mo physical training doses prescribed to obese teenagers did not result in significant group differences in mean change in leptin, although there was large variability in individual response. The change in leptin was inversely associated with baseline leptin and change in cardiovascular fitness. Diet, physical activity level, visceral adiposity, and glucose concentrations were not associated with leptin, neither at baseline nor in response to physical training. At baseline, total fat mass rather than visceral adiposity was associated with higher leptin levels. Over the 8-mo intervention period, regardless of group membership, youths who had the lowest increase in cardiovascular fitness tended to have the highest increase in leptin.

Physical training improves insulin resistance syndrome markers in obese adolescents.

INTRODUCTION: The purpose of this study was to test the hypothesis that physical training (PT), especially high-intensity PT, would have a favorable effect on components of the insulin resistance syndrome (IRS) in obese adolescents. METHODS: Obese 13- to 16-yr-olds (N = 80) were randomly assigned to one of the following 8-month interventions; 1) lifestyle education (LSE)-alone every 2 wk, 2) LSE+moderate-intensity PT, and 3) LSE+high-intensity PT. PT was offered 5 d x wk(-1). Plasma triacylglycerol (TAG), total cholesterol (TC), high-density lipoprotein cholesterol (HDLC), very low-density lipoprotein cholesterol (VLDLC), low-density lipoprotein cholesterol (LDLC), low-density lipoprotein (low density lipoprotein (LDL)) particle size, apolipoproteins AI and B, glucose, insulin, and blood pressure were measured with standardized methods. RESULTS: The intent-to-treat analyses for all subjects who completed pre- and post-tests regardless of their adherence to the interventions showed that the LSE+high-intensity PT group had more favorable changes than the LSE-alone group in TAG level (P = 0.012), TC/HDLC (P = 0.013), and diastolic blood pressure (P = 0.031). For efficacy analyses, all PT subjects who attended at least 2 d x wk(-1) (40%) were combined into one group (LSE+PT) and compared with the LSE-alone group. These two-group analyses showed significant interactions (P < 0.001) between baseline values and group membership for deltaTAG, deltaVLDLC, and deltaTC/HDLC, such that subjects who had the least favorable baseline values showed the most beneficial impact of the PT. Of particular interest was a favorable effect of the PT on LDL particle size. CONCLUSION: PT, especially high-intensity PT, had a favorable effect on several IRS markers in obese adolescents.

Hemostatic and inflammatory markers in obese youths: effects of exercise and adiposity.

OBJECTIVES: To determine the relation of hemostatic markers to cardiovascular fitness and adiposity and the effect of physical training (PT) on these markers. STUDY DESIGN: Seventy-four obese teenagers were randomly assigned to 8 months of lifestyle education (LSE), LSE plus moderate-intensity PT, or LSE plus high-intensity PT. Measures included fibrinogen, plasminogen activator inhibitor-1 (PAI-1), D-dimer, C-reactive protein (CRP), fitness, percent body fat (%BF), and visceral adiposity (VAT). RESULTS: At baseline, fibrinogen and CRP were significantly correlated with %BF and VAT (0.27

Effects of exercise intensity on cardiovascular fitness, total body composition, and visceral adiposity of obese adolescents.

BACKGROUND: Little is known about how the intensity of exercise influences cardiovascular fitness and body composition, especially in obese adolescents. OBJECTIVE: Our goal was to determine the effects of physical training intensity on the cardiovascular fitness, percentage of body fat (%BF), and visceral adipose tissue (VAT) of obese adolescents. DESIGN: Obese 13-16-y-olds (n = 80) were assigned to 1) biweekly lifestyle education (LSE), 2) LSE + moderate-intensity physical training, or 3) LSE + high-intensity physical training. The intervention lasted 8 mo. Physical training was offered 5 d/wk, and the target energy expenditure for all subjects in physical training groups was 1047 kJ (250 kcal)/session. Cardiovascular fitness was measured with a multistage treadmill test, %BF with dual-energy X-ray absorptiometry, and VAT with magnetic resonance imaging. RESULTS: The increase in cardiovascular fitness in the high-intensity physical training group, but not in the moderate-intensity group, was significantly greater than that in the LSE alone group (P = 0.009); no other comparisons of the 3 groups were significant. Compared with the LSE alone group, a group composed of subjects in both physical training groups combined who attended training sessions >or=2 d/wk showed favorable changes in cardiovascular fitness (P < 0.001), %BF (P = 0.001), and VAT (P = 0.029). We found no evidence that the high-intensity physical training was more effective than the moderate-intensity physical training in enhancing body composition. CONCLUSIONS: The cardiovascular fitness of obese adolescents was significantly improved by physical training, especially high-intensity physical training. The physical training also reduced both visceral and total-body adiposity, but there was no clear effect of the intensity of physical training.