Lohman, T. G., Caballero, B., Himes, J. H., Davis, C. E., Stewart, D., Houtkooper, L., Going, S. B., Hunsberger, S., Weber, J. L., Reid, R., & Stephenson, L. (2000). Estimation of body fat from anthropometry and bioelectrical impedance in Native American children. International Journal of Obesity, 24(8), 982-988.
PMID: 10951536;Abstract:
OBJECTIVE: Obesity, as measured by body mass index, is highly prevalent in Native American children, yet there are no valid equations to estimate total body fatness for this population. This study was designed to develop equations to estimate percentage body fat from anthropometry and bioelectrical impedance as a critical part of Pathways, a multisite study of primary prevention of obesity in Native American children. DESIGN: Percentage fat was estimated from deuterium oxide dilution in 98 Native American children (Pima/Maricopa. Tohono O'odham and White Mountain Apache tribes) between 8 and 11 y of age. The mean fat content (38.4% ± 8.1%) was calculated assuming the water content of the fat-free body was 76%. Initial independent variables were height, weight, waist circumference, six skinfolds and whole-body resistance and reactance from bioelectrical impedance (BIA). RESULTS: Using all-possible-subsets regressions with the Mallows C (p) criterion, and with age and sex included in each regression model, waist circumference, calf and biceps skinfolds contributed least to the multiple regression analysis. The combination of weight, two skinfolds (any two out of the four best: triceps, suprailiac, subscapular and abdomen) and bioelectrical impedance variables provided excellent predictability. Equations without BIA variables yielded r2 almost as high as those with BIA variables. The recommended equation predicts percentage fat with a root mean square error = 3.2% fat and an adjusted r2 = 0.840. CONCLUSION: The combination of anthropometry and BIA variables can be used to estimate total body fat in field studies of Native American children. The derived equation yields considerably higher percentage fat values than other skinfold equations in children.
Farr, J. N., Blew, R. M., Lee, V. R., Lohman, T. G., & Going, S. B. (2011). Associations of physical activity duration, frequency, and load with volumetric BMD, geometry, and bone strength in young girls. Osteoporosis International, 22(5), 1419-1430.
PMID: 20694457;PMCID: PMC3152197;Abstract:
More efficacious physical activity (PA) prescriptions for optimal bone development are needed. This study showed that PA duration, frequency, and load were all independently associated with bone parameters in young girls. Increased PA duration, frequency, and load are all important osteogenic stimuli that should be incorporated into future PA interventions. Introduction: This study evaluated the associations of physical activity (PA) duration, frequency, load, and their interaction (total PA score=duration×frequency×load) with volumetric bone mineral density, geometry, and indices of bone strength in young girls. Methods: Four hundred sixty-five girls (aged 8-13 years) completed a past year physical activity questionnaire (PYPAQ) which inquires about the frequency (days per week) and duration (average minutes per session) of leisure-time PA and sports. Load (peak strain score) values were assigned to each activity based on ground reaction forces. Peripheral quantitative computed tomography was used to assess bone parameters at metaphyseal and diaphyseal sites of the femur and tibia of the non-dominant leg. Results: Correlations across all skeletal sites between PA duration, frequency, load and periosteal circumference (PC), bone strength index (BSI), and strength-strain index (SSI) were significant (≤0.05), although low (0.10-0.17). A 2.7-3.7% greater PC across all skeletal sites was associated with a high compared to a low PYPAQ score. Also, a high PYPAQ score was associated with greater BSI (6.5-8.7%) at metaphyseal sites and SSI (7.5-8.1%) at diaphyseal sites of the femur and tibia. The effect of a low PYPAQ score on bone geometric parameters and strength was greater than a high PYPAQ score. Conclusions: PA duration, frequency, and load were all associated with bone geometry and strength, although their independent influences were modest and site specific. Low levels of PA may compromise bone development whereas high levels have only a small benefit over more average levels. © 2010 International Osteoporosis Foundation and National Osteoporosis Foundation.
Bea, J. W., Thomson, C. A., Wallace, R. B., Seguin, R. A., Wu, C., Going, S. B., LaCroix, A., Eaton, C., Ockene, J. K., LaMonte, M. J., Jackson, R., Mysiw, W. J., & Wactawski-Wende, J. (2016). Changes in Physical Activity, Sedentary Time, and Risk of Falling in the Women’s Health Initiative Observational Study. Preventitive Medicine, 95, 103-109. doi:10.1016/j.ypmed.2016.11.025
Lohman, T. G., & Going, S. B. (1993). Multicomponent models in body composition research: opportunities and pitfalls.. Basic life sciences, 60, 53-58.
PMID: 8110163;Abstract:
This paper presents theoretical, methodological, and statistical considerations in the evaluation of multicomponent body composition models. The opportunities for multicomponent approaches to validate new body composition methods, to provide definitive references for FFB composition values of different populations, and to evaluate changes in various components of the body with age and interventions are well-recognized. The pitfalls of the multicomponent approach, however, limit the success of past research efforts. If future investigations evaluate in the same study design the theoretical, methodological and statistical approaches presented, improved multicomponent approaches will be developed, and present controversies surrounding the variability in composition of FFB as well as the validity of new methodologies such as DXA will be resolved.
Kelly, E. B., Parra-Medina, D., Pfeiffer, K. A., Dowda, M., Conway, T. L., Webber, L. S., Jobe, J. B., Going, S., & Pate, R. R. (2010). Correlates of physical activity in black, hispanic, and white middle school girls. Journal of Physical Activity and Health, 7(2), 184-193.
PMID: 20484757;PMCID: PMC2937261;Abstract:
Background: A need exists to better understand multilevel influences on physical activity among diverse samples of girls. This study examined correlates of moderate-to-vigorous physical activity (MVPA) among adolescent girls from different racial/ethnic backgrounds. Methods: 1,180 6th grade girls (24.5% black, 15.7% Hispanic, and 59.8% white) completed a supervised self-administered questionnaire that measured hypothesized correlates of PA. MVPA data were collected for 6 days using the ActiGraph accelerometer. Hierarchical regression analysis was used to examine correlates of PA in each racial/ethnic group. Results: Hispanic girls (n = 185) engaged in 21.7 minutes of MVPA per day, black girls (n = 289) engaged in 19.5 minutes of MVPA per day, and white girls (n = 706) engaged in 22.8 minutes of MVPA per day. Perceived transportation barriers (+; P = .010) were significantly and positively related to MVPA for Hispanic girls. For black girls, Body Mass Index (BMI) (-; P = .005) and social support from friends (+; P = .006) were significant correlates of MVPA. For white girls, BMI (-; P .001), barriers (-; P = .012), social support from friends (+; P = .010), participation in school sports (+; P = .009), and community sports (+; P = .025) were significant correlates of MVPA. Explained variance ranged from 30% to 35%. Conclusions: Correlates of MVPA varied by racial/ ethnic groups. Effective interventions in ethnically diverse populations may require culturally tailored strategies. © 2010 Human Kinetics, Inc.
