Crandall, C. J., Yildiz, V., Wactawski-Wende, J., Johnson, K. C., Chen, Z., & Going, S. B. (2015). Postmenopausal weight change and incidence of fracture: post-hoc findings from the Women’s Health Initiative Observational Study and Clinical Trials. British Medical Journal.
Treuth, M. S., Schmitz, K., Catellier, D. J., McMurray, R. G., Murray, D. M., Almeida, M. J., Going, S., Norman, J. E., & Pate, R. (2004). Defining accelerometer thresholds for activity intensities in adolescent girls. Medicine and Science in Sports and Exercise, 36(7), 1259-1266.
PMID: 15235335;PMCID: PMC2423321;Abstract:
Purpose: To derive a regression equation that estimates metabolic equivalent (MET) from accelerometer counts, and to define thresholds of accelerometer counts that can be used to delineate sedentary, light, moderate, and vigorous activity in adolescent girls. Methods: Seventy-four healthy 8th grade girls, age 13-14 yr, were recruited from urban areas of Baltimore, MD, Minneapolis/St. Paul, MN, and Columbia, SC, to participate in the study. Accelerometer and oxygen consumption (V̇O2) data for 10 activities that varied in intensity from sedentary (e.g., TV watching) to vigorous (e.g., running) were collected. While performing these activities, the girls wore two accelerometers, a heart rate monitor and a Cosmed K4b2 portable metabolic unit for measurement of V̇O2. A random-coefficients model was used to estimate the relationship between accelerometer counts and V̇O2. Activity thresholds were defined by minimizing the false positive and false negative classifications. Results: The activities provided a wide range in V̇O2 (3-36 mL·kg -1·min-1) with a correspondingly wide range in accelerometer counts (1-3928 counts·30 s-1). The regression line for MET score versus counts was MET = 2.01 + 0.00171 (counts·30 s-1) (mixed model R2 = 0.84, SEE = 1.36). A threshold of 1500 counts·30 s-1 defined the lower end of the moderate intensity (∼4.6 METs) range of physical activity. That cutpoint distinguished between slow and brisk walking, and gave the lowest number of false positive and false negative classifications. The threshold ranges for sedentary, light, moderate, and vigorous physical activity were found to be 0-50, 51-1499, 1500-2600, and >2600 counts·30 s-1, respectively. Conclusion: The developed equation and these activity thresholds can be used for prediction of MET score from accelerometer counts and participation in various intensities of physical activity in adolescent girls.
Taber, D. R., Pratt, C., Charneco, E. Y., Dowda, M., Phillips, J. A., & Going, S. B. (2013). Participation in Vigorous Sports, Not Moderate Sports, is Positively Associated With Cardiorespiratory Fitness Among Adolescent Girls. Journal of Physical Activity & Health.
Farr, J. N., Going, S. B., Lohman, T. G., Rankin, L., Kasle, S., Cornett, M., & Cussler, E. (2008). Physical activity levels in patients with early knee osteoarthritis measured by accelerometry. Arthritis Care and Research, 59(9), 1229-1236.
Abstract:
Objective. Physical activity (PA) is recommended for osteoarthritis (OA) management to reduce pain and improve function. The purpose of this study was to objectively assess the level and pattern of PA in male and female knee OA patients to determine adherence to Centers for Disease Control and Prevention/American College of Sports Medicine and Exercise and Physical Activity Conference recommendations for PA. Methods. Early OA patients (n = 255, 76% women, mean ± SD age 54.6 ± 7.1 years, mean ± SD body mass index 27.8 ± 4.3 kg/m 2) with Kellgren/Lawrence-defined grade II (no higher) radiographic OA in at least 1 knee wore an accelerometer for 6-7 contiguous days. Light (LPA), moderate (MPA), and vigorous (VPA) PA intensities were defined as accelerometer recordings of 100-2,224, 2,225-5,950, and >5,950 counts per minute, respectively. Results. Patients wore accelerometers for a mean ± SD of 6.8 ± 0.3 days and 13.8 ± 2.2 hours/day, and spent much more time (P 0.001) in MPA (23.6 ± 17.2 minutes/day) than VPA (0.95 ± 3.5 minutes/day). Men spent significantly (P 0.05) more time in all PA intensities than women. Only 30% of patients achieved recommended PA levels. The proportion of men (47%) achieving the recommendation was significantly (P = 0.04) higher than women (24%). Conclusion. Knee OA patients accumulate little VPA and most (70%) do not achieve recommended levels for MPA or greater. New strategies to increase levels of PA in this population are needed. © 2008, American College of Rheumatology.
Milliken, L. A., Cussler, E., Zeller, R. A., Choi, J. -., Metcalfe, L., Going, S. B., & Lohman, T. G. (2009). Changes in soft tissue composition are the primary predictors of 4-year bone mineral density changes in postmenopausal women. Osteoporosis International, 20(2), 347-354.
PMID: 18607670;Abstract:
Summary: Changes in body weight influence bone mineral density, but the role of body composition is not clear in postmenopausal women. Body weight and soft tissue composition predicted bone changes independent of calcium supplementation and exercise frequency, indicating that soft tissue composition should be measured in clinical trials. Introduction: The purpose of this study was to examine the relationship between changes in body weight and composition and changes in 4-year bone mineral density (BMD) after accounting for age, 4-year exercise frequency (EX), and 4-year calcium supplement intake (CA) in postmenopausal women with and without hormone therapy (HT). Methods: Postmenopausal women (aged 40-65 years) either using HT (for 1-3.9 years) or not using HT (for ≥1 year) were recruited to the study. EX and CA was monitored throughout the study and 167 women completed 4 years. BMD and soft tissue composition measurements were made using dual-energy X-ray absorptiometry. Regression was used to predict 4-year BMD changes from EX, CA, age, baseline and 4-year changes in body weight and composition. HT users (n = 115, 55.3 ± 4.3 years) and non-users (n = 52, 57.5 ± 4.7 years) were analyzed separately. Results: The models predicting regional BMD changes that included soft tissue composition changes explained the most variation compared with those with body weight or EX and CA alone. Larger amounts of variation in BMD changes were explained in the no HT group. Conclusion: Body composition changes are important positive predictors of BMD changes independent of EX and CA supplementation, but their contribution varies according to bone site and with HT use. © 2008 International Osteoporosis Foundation and National Osteoporosis Foundation.
