Scott B Going

PMID: 23698240;PMCID: PMC3833884;Abstract:

INTRODUCTION: Poor muscle quality and sedentary behavior are risk factors for metabolic dysfunction in children and adolescents. However, because longitudinal data are scarce, relatively little is known about how changes in muscle quality and physical activity influence bone development. PURPOSE: In a 2-yr longitudinal study, we examined the effects of physical activity and changes in muscle quality on bone parameters in young girls. METHODS: The sample included 248 healthy girls age 9-12 yr at baseline. Peripheral quantitative computed tomography was used to measure calf and thigh muscle density, an indicator of skeletal muscle fat content or muscle quality, as well as bone parameters at diaphyseal and metaphyseal sites of the femur and tibia. Physical activity was assessed using a validated questionnaire specific for youth. RESULTS: After controlling for covariates in multiple regression models, increased calf muscle density was independently associated with greater gains in cortical (β = 0.13, P 0.01) and trabecular (β = 0.25, P 0.001) volumetric bone mineral density and the bone strength index (β = 0.25, P 0.001) of the tibia. Importantly, these relationships were generalized, as similar changes were present at the femur. Associations between physical activity and changes in bone parameters were weaker than those observed for muscle density. Nevertheless, physical activity was significantly (all P 0.05) associated with greater gains in trabecular volumetric bone mineral density and the bone strength index of the distal femur. CONCLUSIONS: These findings suggest that poor muscle quality may put girls at risk for suboptimal bone development. Physical activity is associated with more optimal gains in weight-bearing bone density and strength in girls, but to a lesser extent than changes in muscle quality. Copyright © 2013 by the American College of Sports Medicine.

PMID: 12885714;Abstract:

Background: Nationwide data on obesity prevalence in American Indian communities are limited. Objective: We describe the body composition and anthropometric characteristics of schoolchildren from 7 American Indian communities enrolled in the Pathways study, a randomized field trial evaluating a program for the primary prevention of obesity. Design: A total of 1704 children in 41 schools were enrolled in the study. Basic anthropometric measurements included weight, height, and triceps and subscapular skinfold thicknesses. Percentage body fat was estimated from bioelectrical impedance and anthropometric variables with the use of an equation developed and validated for this population. Results: The children's mean (± SD) age was 7.6 ± 0.6 y, and their mean weight and height were 32.1 ± 8.9 kg and 129.8 ± 6.3 cm, respectively. Mean body mass index (BMI; in kg/m ²) was 18.8 ± 3.9, and mean percentage body fat was 32.6 ± 6.8%. With the use of current Centers for Disease Control and Prevention reference values, 30.5% of girls and 26.8% of boys were above the 95th percentiles for BMI-for-age, and 21% of girls and 19.6% of boys were between the 85th and 95th percentiles. Although there was a wide range in BMI across study sites and for both sexes, the percentage of children with a BMI above the 95th percentile was consistently higher than the national averages in all communities studied and in both girls and boys. Conclusions: Overweight can be documented in a substantial number of American Indian children by the time they reach elementary school. Despite differences in the prevalence of overweight observed among communities, rates are uniformly high relative to national all-race averages.

Abstract:

The Pathways physical activity intervention is a school-based activity program that promotes children's enjoyment and participation in regular, moderate-to-vigorous physical activity with a long range goal of encouraging lifelong activity to prevent obesity. Recess and physical education (PE) are emphasized. After reviewing existing curricula. Pathways PE was developed from SPARK PE, which was shown to increase activity during PE in other populations. Healthrelated physical activity goals are emphasized while also developing sports-related skills. This approach was taken since adequate skill development contributes to lifelong enjoyment in a variety of physical activities. Cultural relevance was enhanced by adding American Indian games. Recess activity is increased through age-appropriate activity challenges. Two PE classes and three recess sessions per week were set as minimum goals. Pilot studies showed the program was feasible in four Indian communities. Moreover, with adequate training and support, the program may be delivered by either classroom teachers or PE specialists.

PMID: 20191490;PMCID: PMC2831227;Abstract:

Objective. To assess the relative effectiveness of combining self-management and strength training for improving functional outcomes in patients with early knee osteoarthritis. Methods. We conducted a randomized intervention trial lasting 24 months at an academic medical center. Community-dwelling middle-aged adults (n = 273) ages 35-64 years with knee osteoarthritis, pain, and self-reported physical disability completed a strength training program, a self-management program, or a combined program. Outcomes included 5 physical function tests (leg press, range of motion, work capacity, balance, and stair climbing) and 2 self-reported measures of pain and disability. Results. A total of 201 participants (73.6%) completed the 2-year trial. Overall, compliance was modest for the strength training (55.8%), self-management (69.1%), and combined (59.6%) programs. The 3 groups showed a significant and large increase from pre- to posttreatment in all of the physical functioning measures, including leg press (d = 0.85), range of motion (d = 1.00), work capacity (d = 0.60), balance (d = 0.59), and stair climbing (d = 0.59). Additionally, all 3 groups showed decreased self-reported pain (d= -0.51) and disability (d= -0.55). There were no significant differences among the groups. Conclusion. Middle-aged, sedentary persons with mild early knee osteoarthritis benefited from strength training, self-management, and the combination program. These results suggest that both strength training and self-management are suitable treatments for the early onset of knee osteoarthritis in middle-aged adults. Self-management alone may offer the least burdensome treatment for early osteoarthritis. © 2010, American College of Rheumatology.