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Richard R. Suminski, Robert J. Robertson, Fredric L. Goss, Silva Arslanian, Jie Kang, Sergio DaSilva, Alan C. Utter and Kenneth F. Metz

Sixteen men completed four trials at random as follows: (Trial A) performance of a single bout of resistance exercise preceded by placebo ingestion (vitamin C); (Trial B) ingestion of 1,500 mg L-arginine and 1,500 mg L-lysine, immediately followed by exercise as in Trial A; (Trial C) ingestion of amino acids as in Trial B and no exercise; (Trial D) placebo ingestion and no exercise. Growth hormone (GH) concentrations were higher at 30,60, and 90 min during the exercise trials (A and B) compared with the resting trials (C and D) (p < .05). No differences were noted in [GH] between the exercise trials. [GH] was significantly elevated during resting conditions 60 min after amino acid ingestion compared with the placebo trial. It was concluded that ingestion of 1,500 mg arginine and 1,500 mg ly sine immediately before resistance exercise does not alter exercise-induced changes in [GH] in young men. However, when the same amino acid mixture is ingested under basal conditions, the acute secretion of GH is increased.

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Yara Fidelix, Mara C. Lofrano-Prado, Leonardo S. Fortes, James O. Hill, Ann E. Caldwell, João P. Botero and Wagner L. do Prado

Background: Physical activity may be as effective as some drugs for improving psychological outcomes; however, vigorous exercise may be needed for improving these outcomes in adolescents with obesity. The aim of this study is to examine the effects of low- and high-intensity training on self-esteem and symptoms of depression and anxiety in adolescents with obesity. Methods: A total of 62 pubertal adolescents with obesity (age 15 [1.5] y, body mass index 34.87 [4.22] kg/m2) were randomized into high-intensity group (HIG, n = 31) or low-intensity group (LIG, n = 31) for 24 weeks. All participants also received nutritional, psychological, and clinical counseling. Body composition and measures of depressive symptoms, anxiety, and self-esteem were assessed at baseline and after 24 weeks. Results: Depressive symptoms decreased significantly in both HIG (d = 1.16) and LIG (d = 0.45) (P ≤ .01). Trait anxiety decreased after 24 weeks for HIG (d = 0.81, P = .002) and LIG (d = 0.31, P = .002). No changes were observed in state anxiety or self-esteem. Conclusions: Results from the present study demonstrate that 24 weeks of multidisciplinary intervention improves depression and anxiety symptoms in adolescents with obesity; however, the magnitude of changes is higher in HIG compared with LIG.

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Mohammad Siahpush, Trish D. Levan, Minh N. Nguyen, Brandon L. Grimm, Athena K. Ramos, Tzeyu L. Michaud and Patrik L. Johansson

Background: The mortality benefits of meeting the US federal guidelines for physical activity, which includes recommendations for both aerobic and muscle-strengthening activities, have never been examined among smokers. Our aim was to investigate the association between reporting to meet the guidelines and all-cause, cancer, cardiovascular disease, and respiratory disease mortality among smokers. Methods: We pooled data from the 1998–2009 National Health Interview Survey, which were linked to records in the National Death Index (n = 68,706). Hazard ratios (HR) were computed to estimate the effect of meeting the physical activity guidelines on mortality. Results: Smokers who reported meeting the guidelines for physical activity had 29% lower risk of all-cause mortality (HR: 0.71; 95% confidence interval [CI], 0.62–0.81), 46% lower risk of mortality from cardiovascular disease (HR: 0.54; 95% CI, 0.39–0.76), and 26% lower risk of mortality from cancer (HR: 0.74; 95% CI, 0.59–0.93), compared with those who reported meeting neither the aerobic nor the muscle-strengthening recommendations of the guidelines. Meeting the aerobic recommendation of the guidelines was associated with a 42% decline in that risk (HR: 0.58; 95% CI, 0.44–0.77). Conclusion: Smokers who adhere to physical activity guidelines show a significant reduction in mortality.

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Kavita A. Gavand, Kelli L. Cain, Terry L. Conway, Brian E. Saelens, Lawrence D. Frank, Jacqueline Kerr, Karen Glanz and James F. Sallis

Background: To examine relations between parents’ perceived neighborhood recreation environments and multiple measures of adolescent physical activity (PA). Methods: Participants (N = 928; age 14.1 [1.4] y, 50.4% girls, and 33.4% nonwhite/Hispanic) and their parents were recruited. Teen moderate to vigorous PA (MVPA) was assessed with 7-day accelerometry. Self-reported total PA, PA near home, and PA at recreation locations were also assessed. Proximity of home to 8 types of recreation facilities was reported by parents. Mixed-model linear regressions relating environments to various measures of PA were adjusted for demographics and neighborhood clustering. Results: Perceiving more availability of recreation facilities around home was related to higher reports of days per week with 60+ minutes of PA (b = 0.153; P < .05), reported PA time near home (b = 0.152; P < .001), PA time at recreation facilities (b = 0.161; P < .001), accelerometer-measured total MVPA (b = 1.741; P < .05), and nonschool MVPA (b = 1.508; P < .01). Adolescents living in lowest quintile of recreation facility availability averaged 27.6 (3.2) minutes per day of total MVPA versus 49.8 (3.5) minutes per day for those living in highest quintile. Conclusions: Adolescents living in neighborhoods that parents reported having more availability of recreation facilities around homes had higher activity across 5 indicators of PA.

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Anne Sofie B. Malling, Bo M. Morberg, Lene Wermuth, Ole Gredal, Per Bech and Bente R. Jensen

The authors examined the associations between the performance of upper- and lower-extremity motor tasks across task complexity and motor symptom severity, overall disease severity, and the physical aspects of quality of life in persons with Parkinson’s disease. The performance was assessed for three lower-extremity tasks and two upper-extremity tasks of different levels of complexity. The motor symptoms and overall disease severity correlated significantly with all motor tasks with higher correlation coefficients in the complex tasks. Thus, the strength of the association between disease severity or severity of motor symptoms and motor performance is task-specific, with higher values in complex motor tasks than in simpler motor tasks. Mobility-related and activity-of-daily-living-related quality of life correlated with lower-extremity tasks of low and medium complexity and with the complex upper-extremity task, respectively; this suggests that Parkinson’s Disease Questionnaire-39 is capable of differentiating between the impact of gross and fine motor function on quality of life.

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Ryan D. Burns, Youngwon Kim, Wonwoo Byun and Timothy A. Brusseau

Background: To examine the relationships among school day sedentary times (SED), light physical activity (LPA), and moderate to vigorous physical activity (MVPA) with gross motor skills in children using Compositional Data Analysis. Methods: Participants were 409 children (mean age = 8.4 [1.8] y) recruited across 5 low-income schools. Gross motor skills were assessed using the test for gross motor development—third edition (TGMD-3), and physical activity was assessed using accelerometers. Isometric log-ratio coordinates were calculated by quantifying the relative proportion of percentage of the school day spent in SED, LPA, and MVPA. The associations of the isometric log-ratio coordinates with the TGMD-3 scores were estimated using general linear mixed-effects models adjusted for age, body mass index, estimated aerobic capacity, and school affiliation. Results: A higher proportion of the school day spent in %MVPA relative to %SED and %LPA was significantly associated with higher TGMD-3 total scores (γ MVPA = 14.44, P = .01). This relationship was also observed for the ball skills subtest scores (γ MVPA = 16.12, P = .003). Conclusions: Replacing %SED and %LPA with %MVPA during school hours may be an effective strategy for improving gross motor skills, specifically ball skills, in low-income elementary school-aged children.

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Stephanie L. Stockwell, Lindsey R. Smith, Hannah M. Weaver, Daniella J. Hankins and Daniel P. Bailey

Background: The objective of this study was to investigate the associations between sedentary behavior patterns and cardiometabolic risk in children using a monitor that accurately distinguishes between different postures. Methods: In this cross-sectional study, 118 children (67 girls) aged 11–12 years had adiposity, blood pressure, lipids, and glucose measured, and then they wore an activPAL device to record sitting, standing, and stepping for 7 consecutive days. Data were analyzed using multiple linear regression. Results: After adjustment for potential confounders and moderate to vigorous physical activity, the number of breaks in sitting was significantly negatively associated with adiposity (standardized β ≥ −0.546; P ≤ .001) and significantly positively associated with high-density lipoprotein cholesterol (β = 0.415; P ≤ .01). Time in prolonged sitting bouts was significantly negatively associated with adiposity (β ≥ −0.577; P ≤ .001) and significantly positively associated with high-density lipoprotein cholesterol (β = 0.432; P ≤ .05). Standing time was significantly negatively associated with adiposity (β ≥ −0.270; P ≤ .05) and significantly positively associated with high-density lipoprotein cholesterol (β = 0.312; P ≤ .05). Conclusions: This study suggests that increasing the number of breaks in sitting and increasing standing time are beneficially associated with cardiometabolic risk and should be considered in health promotion interventions in children.

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Janina M. Prado-Rico and Marcos Duarte

The goal of this work was to investigate body weight distribution during relaxed and quiet (constrained) standing tasks. Forty-one healthy, young adults performed relaxed and quiet standing tasks, and they stood with each leg on a separate force plate. The weight distribution asymmetry across time was computed as the difference between the right and left vertical force time series. The subjects presented a small average across time asymmetry during relaxed and quiet standing. However, during relaxed standing, the subjects alternated between postures, and, as a result, they were largely asymmetrical over time (instant by instant). Two unexpected results that the authors found for the relaxed standing task were that women were more asymmetrical over time than men and that there were two preferential modes of weight distribution.

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Manuel E. Hernandez, Erin O’Donnell, Gioella Chaparro, Roee Holtzer, Meltem Izzetoglu, Brian M. Sandroff and Robert W. Motl

Functional near-infrared spectroscopy was used to evaluate prefrontal cortex activation differences between older adults with multiple sclerosis (MS) and healthy older adults (HOA) during the performance of a balance- and attention-demanding motor task. Ten older adults with MS and 12 HOA underwent functional near-infrared spectroscopy recording while talking, virtual beam walking, or virtual beam walking while talking on a self-paced treadmill. The MS group demonstrated smaller increases in prefrontal cortex oxygenation levels than HOA during virtual beam walking while talking than talking tasks. These findings indicate a decreased ability to allocate additional attentional resources in challenging walking conditions among MS compared with HOA. This study is the first to investigate brain activation dynamics during the performance of balance- and attention-demanding motor tasks in persons with MS.

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Aaron England, Timothy Brusseau, Ryan Burns, Dirk Koester, Maria Newton, Matthew Thiese and Benjamin Chase

In adult performers, research suggests that mental representations (MRs) mediate performance of skilled movement. During adolescence, cortical brain areas responsible for generating MRs develop rapidly along with limb size, which, together, may affect movement and movement representations. The aim of this study was to examine the relationship between adolescent MRs and free-throw shooting expertise. Using structural dimensional analysis of MRs, skilled (n = 11) and less skilled (n = 11) participants sorted free-throw submovements according to their relatedness in movement execution. Data were analyzed using a hierarchical cluster analysis, factor analysis, and invariance test to examine between-group cluster comparisons. Cluster solutions for the skilled and less skilled participants were significantly variant (λ = 0.56). This method of measuring MRs distinguished expertise-related differences in MRs in an adolescent population. Findings may influence methods in which practitioners detect motor-planning faults, track development, and provide feedback to trainees.