Fang Wen

National trends in self-reported physical activity and sedentary behaviors among pregnant women: NHANES 1999–2006

OBJECTIVE The aims of this study were to describe the prevalence, trends, and correlates of physical activity among a national sample of pregnant women. METHOD Using data collected from the 1999-2006 National Health and Nutrition Examination Survey, physical activity and sedentary behaviors were collected during interviews with 1280 pregnant women >/=16 years. Estimates were weighted to reflect the United States population. RESULTS Overall 22.8% reported any transportation activity (i.e., to/from work/school), 54.3% reported any moderate to vigorous household activity, and 56.6% reported any moderate to vigorous leisure activity, all in the past month. Participation in any transportation and moderate to vigorous leisure activity was stable over time, while participation in any moderate to vigorous household activities and moderate leisure activities increased from 1999-2002 to 2003-06. Moderate to vigorous leisure activity was significantly higher among those in first trimester compared to third trimester, among non-Hispanic white participants compared to women from other race/ethnic groups, and among those with health insurance compared to those without. From 2003 to 2006, 15.3% of pregnant women reported watching 5 h or more of television or videos per day. CONCLUSION These data could be used to monitor trends and set national goals for physical activity among pregnant women.

Physical activity patterns during pregnancy.

PURPOSE The aim of the study was to describe the mode, frequency, duration, and intensity of physical activity among pregnant women, to explore whether these women reached the recommended levels of activity, and to explore how these patterns changed during pregnancy. METHODS This study, as part of the third phase of the Pregnancy, Infection, and Nutrition Study, investigated physical activity among 1482 pregnant women. A recall of the different modes, frequency, duration, and intensity of physical activity during the past week was assessed in two telephone interviews at 17-22 and 27-30 wk of gestation. RESULTS Most women reported some type of physical activity during both periods. Child and adult care giving, indoor household, and recreational activities constituted the largest proportion of total reported activity. The overall physical activity level decreased during pregnancy, particularly in care giving, outdoor household, and recreational activity. Women who were active during the second and the third trimesters reported higher levels of activity in all modes of activity than those who became active or inactive during pregnancy. The majority did not reach the recommended level of physical activity. CONCLUSION These data suggest that self-reported physical activity decreased from the second to the third trimesters, and only a small proportion reached the recommended level of activity during pregnancy. Further research is needed to explore if physical activity rebounds during the postpartum period.

Prevalence and correlates of objectively measured physical activity and sedentary behavior among US pregnant women.

OBJECTIVE Physical activity is recommended for pregnant women without medical or obstetric complications. This study described the prevalence and correlates of objectively-measured physical activity and sedentary behavior among United States pregnant women. METHODS Using cross-sectional data collected from the 2003 to 2006 National Health and Nutrition Examination Survey (NHANES), 359 pregnant women ≥16 years wore an accelerometer for 1 week. RESULTS Women participated in a mean of 12.0 minutes/day (standard error (SE) 0.86) of moderate activity and 0.3 minutes/day (SE 0.08) of vigorous activity. Mean moderate to vigorous physical activity varied by trimester: 11.5 minutes/day in first trimester, 14.3 minutes/day in second trimester, and 7.6 minutes/day in third trimester. On average, women spent 57.1% of their monitored time in sedentary behaviors. In multivariable adjusted models, moderate to vigorous physical activity was higher in the first (p=0.02) and second (p<0.001) trimesters compared to the third trimester, and among women with higher household income (p=0.03) compared to lower household income. In multivariable adjusted models, average counts/minute was higher in the second compared to the third trimester (p=0.04). CONCLUSION Most pregnant women spent more than half of the monitored day in sedentary behaviors and did not meet recommendations for physical activity.

Associations of adult physical activity with perceived safety and police-recorded crime: the Multi-ethnic Study of Atherosclerosis

BackgroundDue to the inconsistent findings of prior studies, we explored the association of perceived safety and police-recorded crime measures with physical activity.MethodsThe study included 818 Chicago participants of the Multiethnic Study of Atherosclerosis 45 to 84 years of age. Questionnaire-assessed physical activity included a) transport walking; b) leisure walking; and c) non-walking leisure activities. Perceived safety was assessed through an interviewer-administered questionnaire. Police-recorded crime was assessed through 2-year counts of selected crimes (total and outdoor incivilities, criminal offenses, homicides) per 1000 population. Associations were examined using generalized estimating equation logistic regression models.ResultsPerceiving a safer neighborhood was positively associated with transport walking and perceiving lower violence was associated with leisure walking. Those in the lowest tertile of total or outdoor incivilities were more likely to report transport walking. Models with both perceived safety and police-recorded measures of crime as independent variables had superior fit for both transport walking and leisure walking outcomes. Neither perceived safety nor police-recorded measures of crime were associated with non-walking leisure activity.ConclusionsPerceived and police-recorded measures had independent associations with walking and both should be considered in assessing the impact of neighborhood crime on physical activity.

Physical activity and sleep among pregnant women

Sleep disturbances are common among pregnant women and safe treatments to improve sleep are needed. Generally, physical activity improves sleep, but studies are lacking on the associations of physical activity with sleep among pregnant women. Our aim was to investigate the cross-sectional association of various modes of physical activity and activity clusters with sleep quality and duration among 1259 pregnant women. Participants were recruited into the Pregnancy, Infection, and Nutrition Study from prenatal clinics at the University of North Carolina Hospitals. Women self-reported sleep quality and duration and physical activity in the past week. We used cluster analysis to create seven physical activity profiles and multivariable logistic regression analysis, with adjustments for age, race/ethnicity, education, marital status, parity, self-rated general health, anxiety and depressive symptoms. Women with higher levels of occupational physical activity were more likely to report either short or normal sleep duration than longer duration. Women with higher levels of indoor household physical activity were less likely to report normal sleep duration than shorter duration. Women in the recreational-indoor household activity cluster were less likely than women in the inactivity cluster to report normal sleep duration as compared with longer duration. Our data suggest weak associations of physical activity with sleep duration and quality in late pregnancy. Physical activity is recommended to pregnant women for health benefits, yet more research is needed to understand if physical activity should be recommended for improving sleep.

Calibrating physical activity intensity for hip-worn accelerometry in women age 60 to 91 years: The Women's Health Initiative OPACH Calibration Study

Objective We conducted a laboratory-based calibration study to determine relevant cutpoints for a hip-worn accelerometer among women ≥ 60 years, considering both type and filtering of counts. Methods Two hundred women wore an ActiGraph GT3X + accelerometer on their hip while performing eight laboratory-based activities. Oxygen uptake was measured using an Oxycon portable calorimeter. Accelerometer data were analyzed in 15-second epochs for both normal and low frequency extension (LFE) filters. Receiver operating characteristic (ROC) curve analyses were used to calculate cutpoints for sedentary, light (low and high), and moderate to vigorous physical activity (MVPA) using the vertical axis and vector magnitude (VM) counts. Results Mean age was 75.5 years (standard deviation 7.7). The Spearman correlation between oxygen uptake and accelerometry ranged from 0.77 to 0.85 for the normal and LFE filters and for both the vertical axis and VM. The area under the ROC curve was generally higher for VM compared to the vertical axis, and higher for cutpoints distinguishing MVPA compared to sedentary and light low activities. The VM better discriminated sedentary from light low activities compared to the vertical axis. The area under the ROC curves were better for the LFE filter compared to the normal filter for the vertical axis counts, but no meaningful differences were found by filter type for VM counts. Conclusion The cutpoints derived for this study among women ≥ 60 years can be applied to ongoing epidemiologic studies to define a range of physical activity intensities.

Measurement Properties of a Park Use Questionnaire

This study determined the criterion validity and test–retest reliability of a brief park use questionnaire. From five U.S. locations, 232 adults completed a brief survey four times and wore a global positioning system (GPS) monitor for 3 weeks. We assessed validity for park visits during the past week and during a usual week by examining agreement between frequency and duration of park visits reported on the questionnaire to the GPS monitor results. Spearman correlation coefficients (SCC) were used to measure agreement. For past week park visit frequency and duration, the SCC were .62 to .65 and .62 to .67, respectively. For usual week park visit frequency and duration, the SCC were .40 to .50 and .50 to .53, respectively. Usual park visit frequency reliability was .78 to .88 (percentage agreement: 69%-82%) and usual park visit duration was .75 to .84 (percentage agreement: 64%-73%). These results suggest that the questionnaire to assess usual and past week park use had acceptable validity and reliability.

Postpartum physical activity: measuring theory of planned behavior constructs.

OBJECTIVES To produce evidence for factor validity and longitudinal invariance of scales used to examine the theory of planned behavior applied to physical activity. METHODS Self-report questionnaires were administered at 3- (n = 267) and 12-months (n = 333) postpartum. RESULTS A single-factor model fit data from the normative beliefs, perceived behavioral control, and behavioral beliefs scales. Attitude and control beliefs were found to be multidimensional. Longitudinal invariance of all scales was supported. CONCLUSIONS Each scale had strong validity evidence. Future research using these measures will help identify areas for intervention and reveal how changes in these constructs influence physical activity.

Correlates of US adult physical activity and sedentary behavior patterns.

OBJECTIVES Physical activity and sedentary behavior patterns may be differentially associated with socio-demographic and health measures. We explored correlates of day-to-day patterns over a week in accelerometer measured physical activity and sedentary behavior to inform intervention development. DESIGN Cross-sectional study. METHODS National Health and Nutrition Examination Survey (NHANES) adult participants (≥20 years) in 2003-2006 wore an accelerometer for 1 week. Accelerometer data from 7236 participants were used to derive latent classes describing day-to-day patterns over a week of physical activity and sedentary behavior. Correlates of each pattern were identified using multinomial logistic regression from 21 potential variables grouped into four domains: socio-demographic, acculturation, cardiovascular, and health history. RESULTS Older age, female sex, higher body mass index, and history of chronic disease were consistently associated with lower odds of being in a more active compared to the least active class. In contrast, being employed, speaking Spanish at home, and having better self-rated health were associated with higher odds of being in a more active compared to the least active class. CONCLUSIONS Correlates of physical activity and sedentary behavior patterns were identified from all domains (socio-demographic, acculturation, cardiovascular, and health history). Most correlates that were positively associated with physical activity were negatively associated with sedentary behavior. Better understanding of the correlates of physical activity and sedentary behavior patterns can inform interventions to promote physical activity and reduce sedentary behavior.

Association of physical activity in the past year and immediately after in vitro fertilization on pregnancy

OBJECTIVE To estimate the association of physical activity on in vitro fertilization (IVF). DESIGN Prospective cohort study. SETTING Academic infertility clinic. PATIENT(S) Women (n = 121) undergoing nondonor IVF embryo transfer (fresh or frozen). INTERVENTION(S) The women completed a questionnaire on past year physical activity and wore an accelerometer from embryo transfer to serum pregnancy testing. MAIN OUTCOME MEASURE(S) Implantation, intrauterine gestation, and live birth. RESULT(S) Based on self-reported past year physical activity, the adjusted odds of intrauterine gestation was higher among those that had higher continuous active living (odds ratio [OR] 1.96, 95% confidence interval [CI] 1.09-3.50), sports/exercise (OR 1.48, CI 1.02-2.15), and total activity (OR 1.52, 95%CI 1.15-2.01) indices. After embryo transfer, women did almost no vigorous activity (median 0 min/d) as measured by the accelerometer. More of their time was spent in light activity (median 3.0 h/d) and sedentary behaviors (median 9.3 h/d). Accelerometer-measured physical activity and sedentary behavior after embryo transfer were not associated with any IVF outcome. CONCLUSION(S) An active lifestyle in the preceding year favorably impacted the IVF outcome. After embryo transfer, women engaged in mostly light physical activity and sedentary behaviors; therefore, the impact of vigorous physical activity on implantation could not be determined.