Scott B Going

Abstract:

Physical inactivity is a risk factor lor weight gain and obesity. Accordingly, increased activity is a focus of the Pathways intervention and an activity assessment plan was developed. Formative assessment showed two methods were feasible: physical activity recall questionnaire (PAO) and accelerometry (TriTrac-R3D motion sensor). Together, they describe activity frequency, type and amount. Moreover, minute-by minute TriTrac outputs allow analysis of activity for any segment of the day. The age-appropriate, culturally-relevant PAQ, developed by a panel of experts with American Indian (AI) input, was designed to assess 24 hr activity type and amount (none, a little, alot) during three segments of the day: before, during and after school. Pilot tests of 117 fourth grade Al children supported PAQ validity since children reported more activity during times of expected activity (before and after school) compared to times of expected inactivity (dining school). TriTrac estimates supported these results, and showed childrens activity levels were more alike within schools than between schools. Using pilot data, algorithms have been developed to speed processing of accelerometer data. Supported by NHLBI.

PMID: 12574871;Abstract:

The purpose of this study was to determine the effects of 12 months of weight bearing and resistance exercise on bone mineral density (BMD) and bone remodeling (bone formation and bone resorption) in 2 groups of postmenopausal women either with or without hormone replacement therapy (HRT). Secondary aims were to characterize the changes in insulin-like growth factors-1 and -2 (IGF-1 and -2) and IGF binding protein 3 (IGFBP3) in response to exercise training. Women who were 3-10 years postmenopausal (aged 40-65 years) were included in the study. Women in the HRT and no HRT groups were randomized into the exercise intervention, resulting in four groups: (1) women not taking HRT, not exercising; (2) those taking HRT, not exercising; (3) those exercising, not taking HRT; and (4) women exercising, taking HRT. The number of subjects per group after 1 year was 27, 21, 25, and 17, respectively. HRT increased BMD at most sites whereas the combination of exercise and HRT produced increases in BMD greater than either treatment alone. Exercise training alone resulted in modest site-specific increases in BMD. Bone remodeling was suppressed in the groups taking HRT regardless of exercise status. The bone remodeling response to exercise training in women not taking HRT was not significantly different from those not exercising. However, the direction of change suggests an elevation in bone remodeling in response to exercise training, a phenomenon usually associated with bone loss. No training-induced differences in IGF-1, IGF-2, IGF-1:IGF-2 (IGF-1:IGF-2), and IGFBP3 were detected.

Abstract:

The aims of this study were to determine the effect of sample freezing on the susceptibility of LDL to oxidation and to determine mtra-assay and intra-subject variability. LDL oxidative susceptibility was determined by the analysis of thiobarbituric acid reactive substances (TBARSl generated during incubation of LDL with Cu²⁺. Blood was drawn from healthy postmenopausal subjects and separated into two fresh aliquots (FRIA and FR1B) which were immediately assayed for LDL oxidation susceptibility, while a third aliquot was frozen (FROZ) for 2-4 weeks at -30°C before analysis Subjects returned 2-4 weeks later for a second blood draw and LDL oxidation was measured the same day (FR2) LDL oxidation values were 28 4 ± 10 0. 27 6 ± 7 n. 32 0 ± 69 0 and 29.7 ± 03 {mean ± SD. n - 8) for FRIA, FRIB, FRO/ and FR2 respectively There were no significant differences among treatments. Significant correlations (P ' 0 03) were found between FRIA and FR1B (r = 0.97); the mean of FRIA and FRIB vs FR2 and FROZ (r = 0.71, r = 0.78 respectively) These results demonstrate that sample freezing had no effect on the susceptibility of LDL to oxidation and that there is no significant variation between samples taken at different time periods for the same individual.

PMID: 20019638;PMCID: PMC2892016;Abstract:

Purpose: The aim of this study was to examine the association of exercise frequency (ExFreq) and volume (total weight lifted by military press and squats (SQ)) with change in body composition among postmenopausal women participating in a progressive resistance training study. Methods: Previously, sedentary women (n = 122, age = 56.3 ± 4.3 yr) were followed for 6 yr. At 6 yr, there were women who had been randomly assigned to resistance training at baseline (n = 65) controls that were permitted to cross over to the exercise program at 1 yr (n = 32) and 25 true controls. Exercisers and crossovers directed to perform eight core exercises for two sets of eight repetitions at 70%-80% of one-repetition maximum, three times weekly, plus progressive weight bearing, stretching, and balance. Body weight and fat were measured at baseline and annually using anthropometry and dual-energy X-ray absorptiometry. Results: Average change in body weight and total body fat were 0.83 ± 5.39 and 0.64 ± 4.95 kg at 6 yr, respectively. In multiple linear regression, ExFreq, military press, and SQ were significantly inversely associated with change in body weight (standardized beta coefficient (SBC) =-0.22 to-0.28, P 0.01), fat (SBC =-0.25 to-0.33, P 0.01), and trunk fat (SBC =-0.20 to-0.31, P 0.03) after adjusting for age, years on hormone therapy, change in lean soft tissue, baseline body composition, and baseline habitual exercise. The lowest tertile of SQ (equivalent to 2.5% attendance) demonstrated significant gain in weight, fat, and trunk fat over 6 yr (P 0.004), whereas the highest tertile SQ (equivalent to 64% attendance) was able to maintain their weight, total, and regional fat. Conclusions: We conclude that resistance training is a viable long-term method to prevent weight gain and deleterious changes in body composition in postmenopausal women. Copyright © 2010 by the American College of Sports Medicine.