Decline in Physical Activity in Black Girls and White Girls during Adolescence
Sue Y.S. Kimm, M.D., M.P.H., Nancy W. Glynn, Ph.D., Andrea M. Kriska, Ph.D., Bruce A. Barton, Ph.D., Shari S. Kronsberg, M.S., Stephen R. Daniels, M.D., Ph.D., Patricia B. Crawford, Dr.P.H., Zak I. Sabry, Ph.D., and Kiang Liu, Ph.D.
Methods We prospectively followed 1213 black girls and 1166white girls enrolled in the National Heart, Lung, and BloodInstitute Growth and Health Study from the ages of 9 or 10 tothe ages of 18 or 19 years. We used a validated questionnaireto measure leisure-time physical activity on the basis of metabolicequivalents (MET) for reported activities and their frequencyin MET-times per week; a higher score indicated greater activity.
Results The respective median activity scores for black girlsand white girls were 27.3 and 30.8 MET-times per week at baseline and declined to 0 and 11.0 by year 10 of the study (a 100percent decline for black girls and a 64 percent decline forwhite girls, P<0.001). By the age of 16 or 17 years, 56 percentof the black girls and 31 percent of the white girls reportedno habitual leisure-time activity. Lower levels of parentaleducation were associated with greater decline in activity forwhite girls at both younger ages (P<0.001) and older ages(P=0.005); for black girls, this association was seen only atthe older ages (P=0.04). Pregnancy was associated with declinein activity among black girls (P<0.001) but not among whitegirls, whereas cigarette smoking was associated with declinein activity among white girls (P<0.001). A higher body-massindex was associated with greater decline in activity amonggirls of both races (P0.05).
Conclusions Substantial declines in physical activity occurduring adolescence in girls and are greater in black girls thanin white girls. Some determinants of this decline, such as higherbody-mass index, pregnancy, and smoking, may be modifiable.
Since the early 1960s, the prevalence of obesity in female childrenand adolescents in the United States has more than doubled,with the greatest increase among black girls.1 Periodic surveysshow no concomitant increase in food intake.2,3 Analogous informationon trends in activity level in this population is not available.It has been conjectured that adolescents have become less activein recent years, and that this trend may be responsible forthe increased prevalence of obesity.4,5,6,7,8
In cross-sectional studies, activity levels have been reportedto drop by as much as 50 percent during adolescence.7,8 Althoughwhite girls tend to be more active than black girls,7,8,9,10,11,12,13,14both groups become increasingly sedentary with age, beginningas early as the age of 10 years.6,11,12,13,15 However, the factorsassociated with the decline in activity during adolescence remainlargely unknown.15,16
We examined longitudinal changes in physical activity in a large,biracial cohort of adolescent girls and examined racial differencesand other factors associated with these changes.
Methods
Study Population
The National Heart, Lung, and Blood Institute Growth and HealthStudy is a multicenter prospective study of 1213 black girlsand 1166 white girls followed annually from the ages of 9 or10 years (year 1 of the study) to 18 or 19 years (year 10).The participants were recruited from schools near San Franciscoand in Cincinnati and from a health maintenance organization(HMO) in the Washington, D.C., area. The schools were selectedwith the use of census data that showed about equal percentagesof black and white children and minimal disparity in incomeand education between black and white residents of the areasserved by the schools. The subjects from the HMO were randomlyselected from a list of eligible families. Race was definedby self-declaration as either white or black in a racially concordanthousehold. The study design and base-line characteristics ofthe Growth and Health Study have been reported previously.17,18The overall follow-up rate was 89 percent (91 percent for blacksand 88 percent for whites) at the end of the study (year 10).Written informed consent was obtained from all participantsand their parents or guardians. The study protocols were approvedby institutional review boards at each site.
Information Collected
Assessment of Physical Activity
The Habitual Activity Questionnaire (HAQ) is a longitudinallyvalidated instrument used to assess activities of adolescentgirls over the previous year, other than those performed inphysical-education classes during school.19 They included sportsor recreational activities (such as bicycling, basketball, andwalking for exercise) and lessons (such as swimming, dance,and gymnastics) — that is, leisure-time activities thatrequire energy expenditure above that required for activitiesof daily living.20 There were no differences in the types ofactivities most frequently cited by black and white girls. TheHAQ was administered in years 1, 3, 5, 7, 8, 9, and 10 of thestudy.19 A central unit standardized the collection and codingof the HAQ data. All HAQs reporting "zero" activities were verifiedin person by centrally trained interviewers.
The HAQ score was computed by multiplying an estimate of themetabolic equivalents (MET) for each recorded activity by theweekly frequency and the fraction of the year during which itwas performed.19 Weekly tallies for all HAQ items were summed,and an overall average weekly score was calculated as MET-timesper week.19 Typical activities performed during adolescenceand their corresponding values in MET-times per week are asfollows: bicycling one or two times per week for 52 weeks peryear, 8.0 MET-times per week; playing basketball one or twotimes per week for 39 weeks per year, 9.0 MET-times per week;swimming three or more times per week for 13 weeks per year,4.5 MET-times per week; and walking for exercise three or moretimes per week for 39 weeks per year, 9.0 MET-times per week.
Measures of Socioeconomic Status
Information on socioeconomic status, collected at base line(1987 to 1988), included the maximal educational level achievedby either parent and total annual household income. Data oneducation were collapsed into the categories of high schoolor less, some college, and four or more years of college. Dataon annual income were collapsed into the categories of lessthan $20,000, $20,000 to $39,999, and $40,000 or more.
Anthropometric Measurements
The body-mass index (the weight in kilograms divided by thesquare of the height in meters) was derived from annual measurementsof height and weight by centrally trained examiners.
Pregnancy and Smoking
Information on pregnancy and smoking was collected from year6 (age 14 or 15) onward. The girls were asked if they had everbeen pregnant. Smoking status was categorized as positive ifa girl answered yes when asked whether she smoked daily, almostdaily, or weekly.
School Dropout Rates
School dropout rates were tracked annually from year 7 (age15 or 16) onward.
Statistical Analysis
Two-sample t-tests, 2 tests, or Wilcoxon two-sample tests wereused to examine racial differences in descriptive characteristics.21Because of the skewed distribution of HAQ scores, median ratherthan mean scores were used. Because a higher rate of pregnancycould confound the steeper decline in activity among black girls,the changes in HAQ scores were examined with girls who becamepregnant excluded. In years 1 through 8, HAQ scores did notchange significantly even when those who became pregnant wereexcluded; therefore, the final analysis included all girls,regardless of pregnancy history. Because school enrollment couldalso affect activity, HAQ scores for year 8 were compared includingand excluding those who were out of school.
Only data from the first eight study years were analyzed, becausethe median HAQ score fell to zero for black girls by year 8.Race-specific longitudinal generalized estimating equationswere used to determine whether changes in activity scores fromyear 1 to year 5 differed from those from year 5 to year 8.21,22Because the rate of decline in activity differed significantlybetween the two periods, and also because information on pregnancyand cigarette smoking was collected in the latter half of thestudy, final analyses were based on separate models for thesetwo periods.
Initial analyses included race as an independent variable aswell as interactions between race and all the predictor variables.These analyses showed the following to be significant: race(P<0.001) and interactions of race with parental education(for younger ages, P=0.006), living in a single-parent household(for older ages, P=0.02), and cigarette smoking (for older ages,P=0.045). Therefore, the final analyses were race-specific.
Race-specific generalized-estimating-equation models were constructedseparately for years 1 to 5 (encompassing HAQ scores at years1, 3, and 5) and years 5 to 8 (encompassing HAQ scores at years5, 7, and 8).21 The outcome measure was the change in HAQ scoresbetween successive follow-up intervals (e.g., the year 3 scoreminus the year 1 score and the year 5 score minus the year 3score). A similar approach was used for years 5 to 8, exceptthat the change in the HAQ score from year 5 to year 7 was dividedby 2 so that it represented an annualized change, to be consistentwith the change from year 7 to year 8.
Predictor variables for each model included household income(reference category, $40,000 or more), parental level of education(reference category, four or more years of college), numberof parents in the household (reference category, two parents),body-mass index, and the HAQ score at the outset of each successivefollow-up interval. Pregnancy (reference category, never pregnant)and smoking (reference category, nonsmoker) were examined foryears 5 to 8. The final model excluded income or education ifthe effect was not statistically significant.
Results
Study Population
Throughout the study, black girls had significantly higher body-massindex values. By the age of 16 or 17 years (year 8), the frequencyof pregnancy was higher among black girls and the frequencyof cigarette smoking was higher among white girls (Table 1).A greater proportion of black girls came from single-parenthouseholds and had parents with lower levels of education andhousehold income. Although school dropout rates in year 7 weresimilar in the two groups, 5.7 percent of black girls had droppedout of school by year 8, as compared with 3.7 percent of whitegirls (P=0.04).
Table 1. Cohort Characteristics According to Race.
Decline in Activity
HAQ scores were skewed toward the lower end of the distributionat base line for both groups and shifted more to the left withtime (Figure 1). Racial differences became more notable at olderages, particularly at the lower end of the distributions.
Figure 1. Frequency Distribution of Habitual Activity Questionnaire Scores According to Year of Study and Race.
Scores are expressed in MET-times per week. Solid circles represent black girls, and open circles white girls.
The median activity score for the whole group decreased by 83percent from year 1 (age, 9 or 10 years) to year 10 (age, 18or 19 years) (Figure 2). During the same period, the decreasein median HAQ scores for black girls was 100 percent, as comparedwith 64 percent for white girls (P<0.001). For both races,the mean annual decline in scores was greater at older ages(years 5 to 8: 4.1 MET-times per week for black girls and 3.5MET-times per week for white girls) than at younger ages (years1 to 5: 3.5 MET-times per week for black girls and 2.7 MET-timesper week for white girls) (Figure 2). Even at year 1, activitylevels were lower for black girls than for white girls (P=0.008).By year 8 (age, 16 or 17 years), 56 percent of black girls and31 percent of white girls reported no habitual leisure-timeactivity (HAQ scores of zero). School enrollment had no effecton HAQ scores at year 8 for either white or black girls.
Figure 2. Median Habitual Activity Questionnaire Scores According to Year of Study and Race.
Scores are expressed in MET-times per week. Solid circles represent black girls, and open circles white girls. Values in parentheses are the 25th and 75th percentiles.
Predictors of Decline from Year 1 to Year 5
Because in all the generalized-estimating-equation analyseshousehold income was not significantly associated with changesin HAQ scores, the final analyses excluded income. For year1 to year 5, parental education was associated with the extentof decline in activity among white girls, but not among blackgirls (Table 2). Among white girls, those for whom the maximallevel of parental education was "some college" had a greaterdecline in physical activity than those who had at least oneparent with four or more years of college. The decline was mostmarked in girls whose parents had attended high school only.Living in a single-parent household was not associated withdecline in activity among either black girls or white girls.
Table 2. Determinants of Changes in HAQ Scores According to Period.
The body-mass index at base line was directly associated withdeclines in activity scores for both races (P=0.006 for blackgirls and P=0.03 for white girls). For each additional 1 unitin body-mass index, the yearly decrease in activity scores was0.17 MET-time per week for black girls and 0.21 MET-time perweek for white girls. For each additional 1 MET-time per weekin HAQ score at the outset, the yearly decline in activity scoreswas, on average, 0.79 MET-time per week for black girls and0.82 MET-time per week for white girls (P<0.001).
Predictors of Decline from Year 5 to Year 8
Parental education continued to be inversely associated withthe extent of decline in activity among white girls in years5 to 8, although this association was less marked than duringyears 1 to 5 (Table 2). In this older age group, parental educationwas also inversely associated with decline in activity amongblack girls. As among white girls, the decline was greater forthose whose parents had only a high-school education or lessor some college education than for those with at least one college-educatedparent.
In contrast to years 1 to 5, in years 5 to 8 living in a single-parenthousehold was associated with a greater decline in activitythan living in a two-parent household for white girls in thisolder age group; this association with household compositionwas not observed in older black girls. Higher body-mass indexremained associated with a decline in activity among both blackgirls and white girls (Table 2). Higher HAQ scores were alsoassociated with a decline in activity (P<0.001 for both groups).
Pregnancy was associated with a decrease in physical activityamong black girls (P<0.001) but not among white girls, whereascigarette smoking was associated with a decrease in activityamong white girls only (P<0.001) (Table 2).
Discussion
Our findings suggest that levels of physical activity declineprecipitously in girls in the United States during adolescence.Although the decline in our study began at the outset of adolescence,its rate accelerated so that by the ages of 18 and 19 years,the majority of the girls engaged in virtually no habitual physicalactivities other than those performed during school.
Because the study prospectively assessed physical activity inthe same cohort of about 2400 girls, the natural history anddeterminants of this steep decline could be tracked throughadolescence. Race was a factor, with black girls having a declinein activity twice that of white girls. Behavioral risk factorssuch as smoking (for white girls) and pregnancy (for black girls)also affected the decline in activity. Although informationon the correlates of decline in activity among adults is limited,both childbirth (in Swedish women) and cigarette smoking (inU.S. men and women) have been found to be significant risk factorsfor inactivity and for a decline in leisure-time activities.23,24In our study, living in a single-parent household was a riskfactor for a decline in activity among older white girls butnot older black girls. A similar racial difference in the effectof household composition on obesity was reported previously.25Heavier girls of both races also had a greater decline in activitythan less heavy girls. Higher body-mass index has been observedas a barrier to activity in other studies.26,27,28
The relation between parental education and decline in physicalactivity differed according to race. For white girls, the levelof parental education was inversely associated with the declinein activity throughout adolescence but became less pronouncedat older ages. This observation suggests that as white girlsget older, physical activity may become more self-motivatedand less influenced by parents. In contrast, for black girls,an inverse association between parental education and declinein activity was manifested only at older ages.
It is uncertain why parental education was not related to theextent of decline in activity among black girls at younger ages.In a previous report from the National Heart, Lung, and BloodInstitute Growth and Health Study, it was found that 9- and10-year-old black girls felt socially accepted regardless oftheir degree of adiposity, and white girls with greater adiposityfelt rejected.29 Although there was less obesity among 9- and10-year-old white girls from better-educated families, no suchvariation in obesity according to level of parental educationwas seen among black girls.25 We speculate that as black girlsbecome older, their ideal body image may evolve to be more consonantwith that in the popular culture. Girls with better-educatedparents may be better informed about or more encouraged to participatein physical activity to achieve this goal.
Annual household income, although generally correlated witheducational level, was not associated with the decline in activity.The association of parental education, but not income, withhealth and behavior among white girls has been consistentlyfound in other reports from the Growth and Health Study.25,30,31In addition, a previous report noted a lower prevalence of obesityamong black mothers with higher levels of education, but notamong those with higher income.24 National data have also linkedlower levels of education, but not of income, to physical inactivityand obesity in both white and black women.12,13 The effect ofeducation on activity among adolescent girls in this study andamong U.S. women, regardless of race, suggests that educationalunderattainment has an important role in the development ofsedentary lifestyles.
Some limitations of our measure of physical activity shouldbe noted. The HAQ scores do not take into account the durationof the activities performed. This is because pilot testing indicatedthat girls 9 or 10 years of age were relatively unaware of theduration of activities, even when they were provided with wristwatches.Also, activities such as nonrecreational walking are not includedin this measure. However, omission of these activities wouldnot be expected to account for racial differences or observeddeclines in activity over time.
We documented a precipitous drop in levels of activity duringadolescence among both black girls and white girls, and thedrop was particularly marked among black girls. These findingsshould sound an alarm, given the current epidemic of obesity.Some of the identified risk factors for declining activity couldbe helpful in prioritizing resources to reach more vulnerablegirls. Moreover, some determinants of declining activity levels,such as teenage pregnancy and cigarette smoking, are possibletargets of structured interventions to increase physical activityamong adolescents.
Supported by grants (N01-HC-55023-26 and U01-HL48941-44) fromthe National Heart, Lung, and Blood Institute.
We are indebted to Drs. Seymour Grufferman and William J. Hallfor their editorial guidance.
Source Information
From the Department of Family Medicine, University of Pittsburgh School of Medicine, Pittsburgh (S.Y.S.K., N.W.G.); the University of Pittsburgh Graduate School of Public Health, Department of Epidemiology, Pittsburgh (A.M.K.); Maryland Medical Research Institute, Baltimore (B.A.B., S.S.K.); Division of Cardiology, Children's Hospital Medical Center, Cincinnati (S.R.D.); the University of California, Berkeley (P.B.C., Z.I.S.); and the Department of Preventive Medicine, Northwestern University Medical School, Chicago (K.L.).
Address reprint requests to Dr. Kimm at the University of Pittsburgh School of Medicine, Department of Family Medicine, 3518 Fifth Ave., Pittsburgh, PA 15261, or at kimm{at}pitt.edu.
References
Troiano RP, Flegal KM, Kuczmarski RJ, Campbell SM, Johnson CL. Overweight prevalence and trends for children and adolescents: the National Health and Nutrition Examination Surveys, 1963 to 1991. Arch Pediatr Adolesc Med 1995;149:1085-1091. [Abstract]
Carroll MD, Abraham S, Dresser CM. Dietary intake source data: United States, 1976-80. Advance data from vital and health statistics. No. 231. Hyattsville, Md.: National Center for Health Statistics, 1983. (DHHS publication no. [PHS] 83-1681.)
McDowell MA, Briefel RR, Alaimo K, et al. Energy and macronutrient intakes of persons ages 2 months and over in the United States: Third National Health and Nutrition Examination Survey, Phase 1, 1988-91. Advance data from vital and health statistics. No. 255. Hyattsville, Md.: National Center for Health Statistics, 1994:1-24. (DHHS publication no. [PHS] 94.)
Kann L, Kinchen SA, Williams BI, et al. Youth risk behavior surveillance — United States, 1997. MMWR Morb Mortal Wkly Rep CDC Surveill Summ 1998;47:SS-3:1-89.
Sallis JF, Simons-Morton BG, Stone EJ, et al. Determinants of physical activity and interventions in youth. Med Sci Sports Exerc 1992;24:Suppl 6:S248-S257. [ISI][Medline]
Department of Health and Human Services. Physical activity and health: a report of the Surgeon General. Atlanta: Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, 1996.
Heath GW, Pratt M, Warren CW, Kann L. Physical activity patterns in American high school students: results from the 1990 Youth Risk Behavior Survey. Arch Pediatr Adolesc Med 1994;148:1131-1136. [Abstract]
Aaron DJ, Kriska AM, Dearwater SR, et al. The epidemiology of leisure physical activity in an adolescent population. Med Sci Sports Exerc 1993;25:847-853. [CrossRef][ISI][Medline]
Sallis JF, Zakarian JM, Hovell MF, Hofstetter CR. Ethnic, socioeconomic, and sex differences in physical activity among adolescents. J Clin Epidemiol 1996;49:125-134. [CrossRef][ISI][Medline]
Trost SG, Pate RR, Saunders R, Ward DS, Dowda M, Felton G. A prospective study of the determinants of physical activity in rural fifth-grade children. Prev Med 1997;26:257-263. [CrossRef][ISI][Medline]
Washburn RA, Kline G, Lackland DT, Wheeler FC. Leisure time physical activity: are there black/white differences? Prev Med 1992;21:127-135. [CrossRef][ISI][Medline]
Crespo CJ, Smit E, Andersen RE, Carter-Pokras O, Ainsworth BE. Race/ethnicity, social class and their relation to physical inactivity during leisure time: results from the Third National Health and Nutrition Examination Survey, 1988-1994. Am J Prev Med 2000;18:46-53. [CrossRef][ISI][Medline]
Crespo CJ, Ainsworth BE, Keteyian SJ, Heath GW, Smit E. Prevalence of physical inactivity and its relation to social class in U.S. adults: results from the Third National Health and Nutrition Examination Survey, 1988-1994. Med Sci Sports Exerc 1999;31:1821-1827. [ISI][Medline]
Wolf AM, Gortmaker SL, Cheung L, Gray HM, Herzog DB, Colditz GA. Activity, inactivity, and obesity: racial, ethnic, and age differences among schoolgirls. Am J Public Health 1993;83:1625-1627. [Free Full Text]
Sallis JF, Alcaraz JE, McKenzie TL, Hovell MF. Predictors of change in children's physical activity over 20 months: variations by gender and level of adiposity. Am J Prev Med 1999;16:222-229. [CrossRef][ISI][Medline]
Sallis JF, Prochaska JJ, Taylor WC. A review of correlates of physical activity of children and adolescents. Med Sci Sports Exerc 2000;32:963-975. [ISI][Medline]
Obesity and cardiovascular disease risk factors in black and white girls: the NHLBI Growth and Health Study. Am J Public Health 1992;82:1613-1620. [Free Full Text]
Kimm SYS, Barton BA, Obarzanek E, et al. Racial divergence in adiposity during adolescence: the NHLBI Growth and Health Study. (Accessed July 1, 2002, at http://www.pediatrics.org/cgi/content/full/107/3/e34.)
Kimm SY, Glynn NW, Kriska AM, et al. Longitudinal changes in physical activity in a biracial cohort during adolescence. Med Sci Sports Exerc 2000;32:1445-1454. [ISI][Medline]
Kriska AM, Casperson CJ. Introduction to a collection of physical activity questionnaires. Med Sci Sports Exerc 1997;29:Suppl 6:S5-S9.
SAS/STAT user's guide, version 8. Cary, N.C.: SAS Institute, 1999.
Draper NR, Smith H. Applied regression analysis. New York: Wiley, 1966.
Barnekow-Bergkvist M, Hedberg G, Janlert U, Jansson E. Physical activity pattern in men and women at the ages of 16 and 34 and development of physical activity from adolescence to adulthood. Scand J Med Sci Sports 1996;6:359-370. [ISI][Medline]
Lazarus NB, Kaplan GA, Cohen RD, Leu DJ. Smoking and body mass in the natural history of physical activity: prospective evidence from the Alameda County Study, 1965-1974. Am J Prev Med 1989;5:127-135. [ISI][Medline]
Kimm SY, Obarzanek E, Barton BA, et al. Race, socioeconomic status, and obesity in 9- to 10-year-old girls: the NHLBI Growth and Health Study. Ann Epidemiol 1996;6:266-275. [CrossRef][ISI][Medline]
Kimm SYS, Glynn NW, McMahon RP, Streigel-Moore R, Voorhees C. Barriers to physical activity in a biracial cohort of adolescent girls: perception or reality? Ann Behav Med 1999;21:Suppl:S206-S206.
Ball K, Crawford D, Owen N. Too fat to exercise? Obesity as a barrier to physical activity. Aust N Z J Public Health 2000;24:331-333. [ISI][Medline]
Trost SG, Kerr LM, Ward DS, Pate RR. Physical activity and determinants of physical activity in obese and non-obese children. Int J Obes Relat Metab Disord 2001;25:822-829. [ISI][Medline]
Kimm SYS, Barton BA, Berhane K, Ross JW, Payne GH, Schreiber GB. Self-esteem and adiposity in black and white girls: the NHLBI Growth and Health Study. Ann Epidemiol 1997;7:550-560. [CrossRef][ISI][Medline]
Crawford PB, Obarzanek E, Schreiber GB, et al. The effects of race, household income, and parental education on nutrient intake of 9- and 10-year-old girls: NHLBI Growth and Health Study. Ann Epidemiol 1995;5:360-368. [CrossRef][Medline]
McNutt SW, Hu Y, Schreiber GB, Crawford PB, Obarzanek E, Mellin L. A longitudinal study of the dietary practices of black and white girls 9 and 10 years old at enrollment: the NHLBI Growth and Health Study. J Adolesc Health 1997;20:27-37. [CrossRef][ISI][Medline]
Young, D. R., Steckler, A., Cohen, S., Pratt, C., Felton, G., Moe, S. G., Pickrel, J., Johnson, C. C., Grieser, M., Lytle, L. A., Lee, J. -S., Raburn, B.
(2008). Process evaluation results from a school- and community-linked intervention: the Trial of Activity for Adolescent Girls (TAAG). Health Educ Res
0: cyn029v1-cyn029
[Abstract][Full Text]
JASIK, C. B., LUSTIG, R. H.
(2008). Adolescent Obesity and Puberty: The "Perfect Storm". Ann. N. Y. Acad. Sci.
1135: 265-279
[Abstract][Full Text]
D'Alonzo, K. T., Fischetti, N.
(2008). Cultural Beliefs and Attitudes of Black and Hispanic College-Age Women Toward Exercise. J Transcult Nurs
19: 175-183
[Abstract]
LaFontaine, T.
(2008). Physical Activity: The Epidemic of Obesity and Overweight Among Youth: Trends, Consequences, and Interventions. AMERICAN JOURNAL OF LIFESTYLE MEDICINE
2: 30-36
[Abstract]
Rosamond, W., Flegal, K., Furie, K., Go, A., Greenlund, K., Haase, N., Hailpern, S. M., Ho, M., Howard, V., Kissela, B., Kittner, S., Lloyd-Jones, D., McDermott, M., Meigs, J., Moy, C., Nichol, G., O'Donnell, C., Roger, V., Sorlie, P., Steinberger, J., Thom, T., Wilson, M., Hong, Y., for the American Heart Association Statistics Comm,
(2008). Heart Disease and Stroke Statistics--2008 Update: A Report From the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Circulation
117: e25-e146
[Full Text]
Gidding, S. S.
(2007). Special Article: Physical Activity, Physical Fitness, and Cardiovascular Risk Factors in Childhood. AMERICAN JOURNAL OF LIFESTYLE MEDICINE
1: 499-505
[Abstract]
Stevens, J., Murray, D. M., Baggett, C. D., Elder, J. P., Lohman, T. G., Lytle, L. A., Pate, R. R., Pratt, C. A., Treuth, M. S., Webber, L. S., Young, D. R.
(2007). Objectively Assessed Associations between Physical Activity and Body Composition in Middle-School Girls: The Trial of Activity for Adolescent Girls. Am J Epidemiol
166: 1298-1305
[Abstract][Full Text]
Hayman, L. L., Meininger, J. C., Daniels, S. R., McCrindle, B. W., Helden, L., Ross, J., Dennison, B. A., Steinberger, J., Williams, C. L.
(2007). Primary Prevention of Cardiovascular Disease in Nursing Practice: Focus on Children and Youth: A Scientific Statement From the American Heart Association Committee on Atherosclerosis, Hypertension, and Obesity in Youth of the Council on Cardiovascular Disease in the Young, Council on Cardiovascular Nursing, Council on Epidemiology and Prevention, and Council on Nutrition, Physical Activity, and Metabolism. Circulation
116: 344-357
[Full Text]
Snitker, S., Le, K. Y., Hager, E., Caballero, B., Black, M. M.
(2007). Association of Physical Activity and Body Composition With Insulin Sensitivity in a Community Sample of Adolescents. Arch Pediatr Adolesc Med
161: 677-683
[Abstract][Full Text]
Caballero, B.
(2007). The Global Epidemic of Obesity: An Overview. Epidemiol Rev
0: mxm012v1-
[Full Text]
Nordstrom, P., Neovius, M., Nordstrom, A.
(2007). Early and Rapid Bone Mineral Density Loss of the Proximal Femur in Men. J. Clin. Endocrinol. Metab.
92: 1902-1908
[Abstract][Full Text]
Brodersen, N. H., Steptoe, A., Boniface, D. R, Wardle, J., Hillsdon, M.
(2007). Trends in physical activity and sedentary behaviour in adolescence: ethnic and socioeconomic differences * COMMENTARY. Br. J. Sports. Med.
41: 140-144
[Abstract][Full Text]
Rosamond, W., Flegal, K., Friday, G., Furie, K., Go, A., Greenlund, K., Haase, N., Ho, M., Howard, V., Kissela, B., Kittner, S., Lloyd-Jones, D., McDermott, M., Meigs, J., Moy, C., Nichol, G., O'Donnell, C. J., Roger, V., Rumsfeld, J., Sorlie, P., Steinberger, J., Thom, T., Wasserthiel-Smoller, S., Hong, Y., for the American Heart Association Statistics Comm,
(2007). Heart Disease and Stroke Statistics--2007 Update: A Report From the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Circulation
115: e69-e171
[Full Text]
Saksvig, B. I., Catellier, D. J., Pfeiffer, K., Schmitz, K. H., Conway, T., Going, S., Ward, D., Strikmiller, P., Treuth, M. S.
(2007). Travel by Walking Before and After School and Physical Activity Among Adolescent Girls. Arch Pediatr Adolesc Med
161: 153-158
[Abstract][Full Text]
Taveras, E. M., Field, A. E., Berkey, C. S., Rifas-Shiman, S. L., Frazier, A. L., Colditz, G. A., Gillman, M. W.
(2007). Longitudinal Relationship Between Television Viewing and Leisure-Time Physical Activity During Adolescence. Pediatrics
119: e314-e319
[Abstract][Full Text]
Kuo, J., Voorhees, C. C., Haythornthwaite, J. A., Young, D. R.
(2007). Associations Between Family Support, Family Intimacy, and Neighborhood Violence and Physical Activity in Urban Adolescent Girls. Am. J. Public Health
97: 101-103
[Abstract][Full Text]
MITRAKOU, A.
(2006). Women's Health and the Metabolic Syndrome. Ann. N. Y. Acad. Sci.
1092: 33-48
[Abstract][Full Text]
Young, D. R., Phillips, J. A., Yu, T., Haythornthwaite, J. A.
(2006). Effects of a Life Skills Intervention for Increasing Physical Activity in Adolescent Girls. Arch Pediatr Adolesc Med
160: 1255-1261
[Abstract][Full Text]
Pate, R. R., Stevens, J., Pratt, C., Sallis, J. F., Schmitz, K. H., Webber, L. S., Welk, G., Young, D. R.
(2006). Objectively Measured Physical Activity in Sixth-Grade Girls. Arch Pediatr Adolesc Med
160: 1262-1268
[Abstract][Full Text]
DeBar, L. L., Ritenbaugh, C., Aickin, M., Orwoll, E., Elliot, D., Dickerson, J., Vuckovic, N., Stevens, V. J., Moe, E., Irving, L. M.
(2006). YOUTH: A Health Plan-Based Lifestyle Intervention Increases Bone Mineral Density in Adolescent Girls. Arch Pediatr Adolesc Med
160: 1269-1276
[Abstract][Full Text]
Gidding, S. S., Barton, B. A., Dorgan, J. A., Kimm, S. Y.S., Kwiterovich, P. O., Lasser, N. L., Robson, A. M., Stevens, V. J., Van Horn, L., Simons-Morton, D. G.
(2006). Higher Self-reported Physical Activity Is Associated With Lower Systolic Blood Pressure: The Dietary Intervention Study in Childhood (DISC). Pediatrics
118: 2388-2393
[Abstract][Full Text]
Nelson, M. C., Neumark-Stzainer, D., Hannan, P. J., Sirard, J. R., Story, M.
(2006). Longitudinal and Secular Trends in Physical Activity and Sedentary Behavior During Adolescence. Pediatrics
118: e1627-e1634
[Abstract][Full Text]
Kasa-Vubu, J. Z., Ye, W., Borer, K. T., Rosenthal, A., Meckmongkol, T.
(2006). Twenty-Four Hour Growth Hormone and Leptin Secretion in Active Postpubertal Adolescent Girls: Impact of Fitness, Fatness, and Age at Menarche. J. Clin. Endocrinol. Metab.
91: 3935-3940
[Abstract][Full Text]
Richmond, T. K., Hayward, R. A., Gahagan, S., Field, A. E., Heisler, M.
(2006). Can school income and racial/ethnic composition explain the racial/ethnic disparity in adolescent physical activity participation?. Pediatrics
117: 2158-2166
[Abstract][Full Text]
Audrain-McGovern, J., Rodriguez, D., Wileyto, E. P., Schmitz, K. H., Shields, P. G.
(2006). Effect of team sport participation on genetic predisposition to adolescent smoking progression.. Arch Gen Psychiatry
63: 433-441
[Abstract][Full Text]
Thom, T., Haase, N., Rosamond, W., Howard, V. J., Rumsfeld, J., Manolio, T., Zheng, Z.-J., Flegal, K., O'Donnell, C., Kittner, S., Lloyd-Jones, D., Goff, D. C. Jr, Hong, Y., Members of the Statistics Committee and Stroke Sta, , Adams, R., Friday, G., Furie, K., Gorelick, P., Kissela, B., Marler, J., Meigs, J., Roger, V., Sidney, S., Sorlie, P., Steinberger, J., Wasserthiel-Smoller, S., Wilson, M., Wolf, P.
(2006). Heart Disease and Stroke Statistics--2006 Update: A Report From the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Circulation
113: e85-e151
[Full Text]
Saunders, R. P., Moody, J.
(2006). Community Agency Survey Formative Research Results From the TAAG Study. Health Educ Behav
33: 12-24
[Abstract]
Grieser, M., Vu, M. B., Bedimo-Rung, A. L., Neumark-Sztainer, D., Moody, J., Young, D. R., Moe, S. G.
(2006). Physical Activity Attitudes, Preferences, and Practices in African American, Hispanic, and Caucasian Girls. Health Educ Behav
33: 40-51
[Abstract]
Staten, L. K., Birnbaum, A. S., Jobe, J. B., Elder, J. P.
(2006). A Typology of Middle School Girls: Audience Segmentation Related to Physical Activity. Health Educ Behav
33: 66-80
[Abstract]
American Heart Association, , Gidding, S. S., Dennison, B. A., Birch, L. L., Daniels, S. R., Gilman, M. W., Lichtenstein, A. H., Rattay, K. T., Steinberger, J., Stettler, N., Van Horn, L.
(2006). Dietary Recommendations for Children and Adolescents: A Guide for Practitioners. Pediatrics
117: 544-559
[Abstract][Full Text]
Stein, E. M, Laing, E. M, Hall, D. B, Hausman, D. B, Kimlin, M. G, Johnson, M. A., Modlesky, C. M, Wilson, A. R, Lewis, R. D
(2006). Serum 25-hydroxyvitamin D concentrations in girls aged 4-8 y living in the southeastern United States. Am. J. Clin. Nutr.
83: 75-81
[Abstract][Full Text]
Marshall, M C Jr
(2005). Diabetes in African Americans. Postgrad. Med. J.
81: 734-740
[Abstract][Full Text]
Endorsed by the American Academy of Pediatrics, , Gidding, S. S., Dennison, B. A., Birch, L. L., Daniels, S. R., Gilman, M. W., Lichtenstein, A. H., Rattay, K. T., Steinberger, J., Stettler, N., Van Horn, L.
(2005). Dietary Recommendations for Children and Adolescents: A Guide for Practitioners: Consensus Statement From the American Heart Association. Circulation
112: 2061-2075
[Abstract][Full Text]
Pate, R. R., Ward, D. S., Saunders, R. P., Felton, G., Dishman, R. K., Dowda, M.
(2005). Promotion of Physical Activity Among High-School Girls: A Randomized Controlled Trial. Am. J. Public Health
95: 1582-1587
[Abstract][Full Text]
Huhman, M., Potter, L. D., Wong, F. L., Banspach, S. W., Duke, J. C., Heitzler, C. D.
(2005). Effects of a Mass Media Campaign to Increase Physical Activity Among Children: Year-1 Results of the VERB Campaign. Pediatrics
116: e277-e284
[Abstract][Full Text]
Bonhauser, M., Fernandez, G., Puschel, K., Yanez, F., Montero, J., Thompson, B., Coronado, G.
(2005). Improving physical fitness and emotional well-being in adolescents of low socioeconomic status in Chile: results of a school-based controlled trial. HEALTH PROMOT INT
20: 113-122
[Abstract][Full Text]
Spadano, J. L, Bandini, L. G, Must, A., Dallal, G. E, Dietz, W. H
(2005). Longitudinal changes in energy expenditure in girls from late childhood through midadolescence. Am. J. Clin. Nutr.
81: 1102-1109
[Abstract][Full Text]
Barton, M.
(2005). Aging and biomedicine 2005: Where should we go from here?. Cardiovasc Res
66: 187-189
[Full Text]
Laufs, U., Wassmann, S., Czech, T., Munzel, T., Eisenhauer, M., Bohm, M., Nickenig, G.
(2005). Physical Inactivity Increases Oxidative Stress, Endothelial Dysfunction, and Atherosclerosis. Arterioscler. Thromb. Vasc. Bio.
25: 809-814
[Abstract][Full Text]
Ievers-Landis, C. E., Burant, C., Drotar, D., Morgan, L., Trapl, E. S., Colabianchi, N., Kwoh, C. K.
(2005). A Randomized Controlled Trial for the Primary Prevention of Osteoporosis Among Preadolescent Girl Scouts: 1-Year Outcomes of a Behavioral Program. J Pediatr Psychol
30: 155-165
[Abstract][Full Text]
Styne, D. M
(2005). Obesity in childhood: what's activity got to do with it?. Am. J. Clin. Nutr.
81: 337-338
[Full Text]
Kasa-Vubu, J. Z., Lee, C. C., Rosenthal, A., Singer, K., Halter, J. B.
(2005). Cardiovascular Fitness and Exercise as Determinants of Insulin Resistance in Postpubertal Adolescent Females. J. Clin. Endocrinol. Metab.
90: 849-854
[Abstract][Full Text]
Lavie, C. J., Kuruvanka, T., Milani, R. V., Prasad, A., Ventura, H. O.
(2004). Exercise Capacity in Adult African-Americans Referred for Exercise Stress Testing: Is Fitness Affected by Race?. Chest
126: 1962-1968
[Abstract][Full Text]
Long, J. A., Chang, V. W., Ibrahim, S. A., Asch, D. A.
(2004). Update on the Health Disparities Literature. ANN INTERN MED
141: 805-812
[Full Text]
Pate, R. R., Pfeiffer, K. A., Trost, S. G., Ziegler, P., Dowda, M.
(2004). Physical Activity Among Children Attending Preschools. Pediatrics
114: 1258-1263
[Abstract][Full Text]
Hayman, L. L., Williams, C. L., Daniels, S. R., Steinberger, J., Paridon, S., Dennison, B. A., McCrindle, B. W.
(2004). Cardiovascular Health Promotion in the Schools: A Statement for Health and Education Professionals and Child Health Advocates From the Committee on Atherosclerosis, Hypertension, and Obesity in Youth (AHOY) of the Council on Cardiovascular Disease in the Young, American Heart Association. Circulation
110: 2266-2275
[Full Text]
Zametkin, A. J., Zoon, C. K., Klein, H. W., Munson, S.
(2004). Psychiatric Aspects of Child and Adolescent Obesity: A Review of the Past 10 Years. Focus
2: 625-641
[Abstract][Full Text]
Robbins, B. W.
(2004). Fitness Lessens Effects of Metabolic Syndrome in Adults. AAP Grand Rounds
12: 47-48
[Full Text]
Egede, L. E., Poston, M. E.
(2004). Racial/Ethnic Differences in Leisure-Time Physical Activity Levels Among Individuals With Diabetes. Diabetes Care
27: 2493-2494
[Full Text]
Motl, R. W., Dishman, R. K., Saunders, R. P., Dowda, M., Pate, R. R.
(2004). Measuring Social Provisions for Physical Activity among Adolescent Black and White Girls. Educational and Psychological Measurement
64: 682-706
[Abstract]
Alleyne, S. I., LaPoint, V.
(2004). Obesity among Black Adolescent Girls: Genetic, Psychosocial, and Cultural Influences. Journal of Black Psychology
30: 344-365
[Abstract]
Ghandour, R. M., Overpeck, M. D., Huang, Z. J., Kogan, M. D., Scheidt, P. C.
(2004). Headache, Stomachache, Backache, and Morning Fatigue Among Adolescent Girls in the United States: Associations With Behavioral, Sociodemographic, and Environmental Factors. Arch Pediatr Adolesc Med
158: 797-803
[Abstract][Full Text]
Novotny, R., Daida, Y. G., Acharya, S., Grove, J. S., Vogt, T. M.
(2004). Dairy Intake Is Associated with Lower Body Fat and Soda Intake with Greater Weight in Adolescent Girls. J. Nutr.
134: 1905-1909
[Abstract][Full Text]
Diabetes in Children Adolescents Work Group of the,
(2004). An Update on Type 2 Diabetes in Youth From the National Diabetes Education Program. Pediatrics
114: 259-263
[Full Text]
Slyper, A. H.
(2004). The Pediatric Obesity Epidemic: Causes and Controversies. J. Clin. Endocrinol. Metab.
89: 2540-2547
[Abstract][Full Text]
Rodriguez, D., Audrain-McGovern, J.
(2004). Team Sport Participation and Smoking: Analysis with General Growth Mixture Modeling. J Pediatr Psychol
29: 299-308
[Abstract][Full Text]
Ekelund, U., Yngve, A., Brage, S., Westerterp, K., Sjostrom, M.
(2004). Body movement and physical activity energy expenditure in children and adolescents: how to adjust for differences in body size and age. Am. J. Clin. Nutr.
79: 851-856
[Abstract][Full Text]
Dekkers, J C., Podolsky, R. H, Treiber, F. A, Barbeau, P., Gutin, B., Snieder, H.
(2004). Development of general and central obesity from childhood into early adulthood in African American and European American males and females with a family history of cardiovascular disease. Am. J. Clin. Nutr.
79: 661-668
[Abstract][Full Text]
Bloomgarden, Z. T.
(2004). Type 2 Diabetes in the Young: The evolving epidemic. Diabetes Care
27: 998-1010
[Full Text]
Biddle, S. J., Gorely, T., Marshall, S. J, Murdey, I., Cameron, N.
(2004). Physical activity and sedentary behaviours in youth: issues and controversies. The Journal of the Royal Society for the Promotion of Health
124: 29-33
[Abstract]
Audrain-McGovern, J., Rodriguez, D., Moss, H. B.
(2003). Smoking Progression and Physical Activity. Cancer Epidemiol. Biomarkers Prev.
12: 1121-1129
[Abstract][Full Text]
Richardson, L. P., Davis, R., Poulton, R., McCauley, E., Moffitt, T. E., Caspi, A., Connell, F.
(2003). A Longitudinal Evaluation of Adolescent Depression and Adult Obesity. Arch Pediatr Adolesc Med
157: 739-745
[Abstract][Full Text]
Sommer, A.
(2003). Epidemiology, Ethnicity, Race, and Risk. Arch Ophthalmol
121: 1194-1194
[Full Text]
Ekelund, U., Aman, J., Yngve, A., Westerterp, K., Sjostrom, M.
(2003). Reply to AD Salbe et al. Am. J. Clin. Nutr.
78: 194-195
[Full Text]
Pi-Sunyer, X.
(2003). A Clinical View of the Obesity Problem. Science
299: 859-860
[Abstract][Full Text]
Teutsch, S.
(2003). The Cost of Preventing Diabetes: What do we know and what do we need to know?. Diabetes Care
26: 238-239
[Full Text]
(2002). Depression, Obesity, and Physical Activity in Adolescents. JWatch Psychiatry
2002: 11-11
[Full Text]
(2002). Activity Levels Plummet as Girls Get Older. JWatch Women's Health
2002: 5-5
[Full Text]
Kimm, S. Y.S., Obarzanek, E.
(2002). Childhood Obesity: A New Pandemic of the New Millennium. Pediatrics
110: 1003-1007
[Full Text]
(2002). Girls Exercise Less as They Get Older. Journal Watch Cardiology
2002: 1-1
[Full Text]
(2002). Depression, Obesity, and Physical Activity in Adolescents. JWatch General
2002: 3-3
[Full Text]
Thompson, P. D.
(2002). Additional Steps for Cardiovascular Health. NEJM
347: 755-756
[Full Text]
0.05). 
2 tests, or Wilcoxon two-sample tests were used to examine racial differences in descriptive characteristics.21 Because of the skewed distribution of HAQ scores, median rather than mean scores were used. Because a higher rate of pregnancy could confound the steeper decline in activity among black girls, the changes in HAQ scores were examined with girls who became pregnant excluded. In years 1 through 8, HAQ scores did not change significantly even when those who became pregnant were excluded; therefore, the final analysis included all girls, regardless of pregnancy history. Because school enrollment could also affect activity, HAQ scores for year 8 were compared including and excluding those who were out of school. 
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