Chomistek, A. K., Manson, J. E., Stefanick, M. L., Lu, B., Sands-Lincoln, M., Going, S. B., Garcia, L., Allison, M. A., Sims, S. T., LaMonte, M. J., Johnson, K. C., & Eaton, C. B. (2013). Relationship of sedentary behavior and physical activity to incident cardiovascular disease: results from the Women's Health Initiative. Journal of American College of Cardiology, 61(23), 2346-54.
Cussler, E. C., Lohman, T. G., Going, S. B., Houtkooper, L. B., Metcalfe, L. L., Flint-Wagner, H. G., Harris, R. B., & Teixeira, P. J. (2003). Weight lifted in strength training predicts bone change in postmenopausal women. Medicine and Science in Sports and Exercise, 35(1), 10-17.
PMID: 12544629;Abstract:
Purpose: The aim of this study was to examine the relationship between weight lifted in 1 yr of progressive strength training and change in bone mineral density (BMD) in a group of calcium-replete, postmenopausal women. Methods: As part of a large clinical trial, 140 calcium-supplemented women, 44-66 yr old, were randomized to a 1-yr progressive strength-training program. Half of the women were using hormone replacement therapy. Three times weekly, subjects completed two sets of six to eight repetitions in eight core exercises at 70-80% of one repetition maximum. BMD was measured at baseline and 1 yr. Results: In multiple linear regression, the increase in femur trochanter (FT) BMD was positively related to total weight lifted (0.001 g·cm-2 for a SD of weight lifted, P0.01) after adjusting for age, baseline factors, HRT status, weight change, cohort, and fitness center. The weighted squats showed the strongest (0.002 g·cm-2 for a SD of weight lifted, P0.001), whereas the back extension exhibited the weakest (0.0005 g·cm-2 for a SD of weight lifted, P0.26) association with change in FT BMD. The amount of weight lifted in the weighted march exercise was significantly related to total body BMD (0.0006 g·cm-2 for a SD of weight lifted, P0.01). The associations between weight lifted and BMD for the femur neck or lumbar spine were not significant. Conclusion: Evidence of a linear relationship between BMD change and total and exercise-specific weight lifted in a 1-yr strength-training program reinforces the positive association between this type of exercise and BMD in postmenopausal women.
Laddu, D. R., Farr, J. N., Laudermilk, M. J., Lee, V. R., Blew, R. M., Stump, C., Houtkooper, L., Lohman, T. G., & Going, S. B. (2013). Longitudinal relationships between whole body and central adiposity on weight-bearing bone geometry, density, and bone strength: A pQCT study in young girls. Archives of Osteoporosis, 8(1-2).
PMID: 24113839;Abstract:
Longitudinal relationships between adiposity (total body and central) and bone development were assessed in young girls. Total body and android fat masses were positively associated with bone strength and density parameters of the femur and tibia. These results suggest adiposity may have site-specific stimulating effects on the developing bone. Introduction: Childhood obesity may impair bone development, but the relationships between adiposity and bone remain unclear. Failure to account for fat pattern may explain the conflicting results. Purpose: Longitudinal associations of total body fat mass (TBFM) and android fat mass (AFM) with 2-year changes in weight-bearing bone parameters were examined in 260 girls aged 8-13 years at baseline. Peripheral quantitative computed tomography was used to measure bone strength index (BSI, square milligrams per quartic millimeter), strength-strain index (SSI, cubic millimeters), and volumetric bone mineral density (vBMD, milligrams per cubic centimeter) at distal metaphyseal and diaphyseal regions of the femur and tibia. TBFM and AFM were assessed by dual-energy x-ray absorptiometry. Results: Baseline TBFM and AFM were positively associated with the change in femur BSI (r = 0.20, r = 0.17, respectively) and femur trabecular vBMD (r = 0.19, r = 0.19, respectively). Similarly, positive associations were found between TBFM and change in tibia BSI and SSI (r = 0.16, r = 0.15, respectively), and femur total and trabecular vBMD (r = 0.12, r = 0.14, respectively). Analysis of covariance showed that girls in the middle thirds of AFM had significantly lower femur trabecular vBMD and significantly higher tibia cortical vBMD than girls in the highest thirds of AFM. All results were significant at p 0.05. Conclusions: Whereas baseline levels of TBFM and AFM are positive predictors of bone strength and density at the femur and tibia, higher levels of AFM above a certain level may impair cortical vBMD growth at weight-bearing sites. Future studies in obese children will be needed to test this possibility. NIH/NICHD #HD-050775. © 2013 International Osteoporosis Foundation and National Osteoporosis Foundation.
Welk, G. J., Going, S. B., Morrow Jr., J. R., & Meredith, M. D. (2011). Development of new criterion-referenced fitness standards in the FITNESSGRAM ® program: Rationale and conceptual overview. American Journal of Preventive Medicine, 41(4 SUPPL. 2), S63-S67.
Maurer, J., Harris, M. M., Stanford, V. A., Lohman, T. G., Cussler, E., Going, S. B., & Houtkooper, L. B. (2005). Dietary iron positively influences bone mineral density in postmenopausal women on hormone replacement therapy. Journal of Nutrition, 135(4), 863-869.
PMID: 15795448;Abstract:
The associations of dietary intakes of iron and calcium on change in bone mineral density (BMD) were examined over 1 y in healthy nonsmoking postmenopausal women (mean age 55.6 ± 4.6 y) stratified by hormone replacement therapy (HRT) use (HRT, n = 116; no HRT, n = 112). BMD was measured at lumbar spine L2-L4, trochanter, femur neck, Ward's triangle, and total body using dual-energy X-ray absorptiometry at baseline and 1 y. Mean nutrient intakes were assessed using 8-d diet records. All women received 800 mg/d of supplemental elemental calcium. Regression analyses examined the effects of iron and calcium intakes on BMD change adjusting for years past menopause, baseline BMD, weight change, exercise, and energy intake. The interaction of iron with calcium on BMD change was assessed using tertiles of iron and calcium intake and estimated marginal mean change in BMD. Iron was associated (P 0.05) with greater positive BMD change at the trochanter and Ward's triangle in women using HRT. Calcium was associated (P 0.05) with BMD change at the trochanter and femur neck for women not using HRT. In women using HRT in the lowest tertile of calcium intake, change in femur neck BMD increased linearly as iron intake increased. In women not using HRT, BMD increased in the women in the highest tertile of calcium intake. We conclude that HRT use appears to influence the associations of iron and calcium on change in BMD. © 2005 American Society for Nutritional Sciences.
