Background: The purpose of this study was to examine the effect of a Comprehensive School Physical Activity Program (CSPAP) on physical activity and health-related fitness (HRF) in children from low-income families.Methods: Participants included 1390 children recruited from kindergarten through sixth grade (mean age = 8.4 ± 1.8 years). Physical activity measures were collected at baseline and at 6 weeks and 12 weeks after program implementation, and HRF measures were collected at baseline and at 12 weeks after program implementation.Results: There were significant but weak-to-moderate increases in step counts (mean difference = 603.1 steps, P < .001, d = 0.39) and moderate-to-vigorous physical activity (mean difference = 4.9 minutes, P < .001, d = 0.39) at 12 weeks compared with baseline. There were also significant but moderate increases in Progressive Aerobic Cardiovascular Endurance Run laps (mean difference = 6.5 laps, P < .001, d = 0.47) at 12 weeks compared with baseline. Generalized mixed models respectively yielded 3.02 and 2.34 greater odds that a child would achieve step count and moderate-to-vigorous physical activity standards and 2.26 greater odds that a child would achieve aerobic fitness standards at 12 weeks compared with baseline (P < .001).Conclusions: The 12-week CSPAP improved physical activity and HRF in children from low-income families; however, the magnitude of the effects was weak to moderate.

The purpose of this study was to examine the effect of a 12-week resistance training programme on fat-free mass (FFM), muscle cross-sectional area, muscular strength and muscle quality in women who underwent Roux-en-Y gastric bypass surgery. Participants were 16 women (mean age = 44.9 ± 10.2 years) from bariatric surgical groups who were randomly assigned into either a control or an intervention group. Air displacement plethysmography measured FFM and magnetic resonance imaging measured quadriceps muscle cross-sectional area and whole thigh muscle cross-sectional area. Muscular strength and quality was assessed using an estimated 1-Repetition Maximum assessment. All measurements were collected twice, at baseline and at a 12-week follow-up. There were significantly greater improvements in leg press strength (mean differences = 55.4%, P < 0.001, Cohen’s d = 2.4), leg extension strength (mean differences = 18.0%, P = 0.014, Cohen’s d = 0.86) and leg press muscle quality (mean differences = 54.5%, P < 0.001, Cohen’s d = 1.9) in the intervention group compared to the control group following the resistance training programme. The resistance training intervention significantly improved muscular strength and quality; however, it did not illicit changes in FFM or muscle cross-sectional area in women who underwent Roux-en-Y gastric bypass surgery.

Trunk and core muscular development has been advocated to increase athletic performance and for maintenance of musculoskeletal health, especially related to the prevention of low back pain (LBP). The purpose of this study was to examine the effects of a simple core conditioning routine on tests of trunk and core muscular endurance in school-aged children. Participants included 164 students (86 girls, 78 boys; mean age, 11.5 ± 2.5 years) recruited from a grade school in a metropolitan area located in the southwestern United States. Students performed an equipment-free, moderate-to-high intensity, dynamic core conditioning warm-up routine once a week for a period of 6 weeks during the start of their physical education classes. The intervention consisted of 10 different dynamic core conditioning exercises performed at a 30-second duration per exercise totaling 5 minutes per session. Pre- and post-assessments of muscular endurance consisted of 5 different trunk and core muscular endurance tests: Parallel Roman Chair Dynamic Back Extension, Prone Plank, Lateral Plank, Dynamic Curl-Up, and Static Curl-up. A generalized estimation equation was used to analyze differences in pre- and post-intervention muscular fitness assessments controlling for gender and grade level. Analysis of the data revealed significant increases in muscular fitness test performance for each of the 5 measured outcomes (p < 0.001). Because risk factors of LBP are thought to commence during childhood, results of this study suggest that it may be desirable for children and adolescents to perform moderate-to-high intensity dynamic core exercises during physical education warm-up to improve trunk and core muscular endurance.