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Sergio Estrada-Tenorio, José A. Julián, Alberto Aibar, José Martín-Albo and Javier Zaragoza

Background: School environment provides several intervention opportunities for physical activity. The aim of this study was to examine the relationship between objectively assessed moderate to vigorous physical activity (MVPA) and academic achievement in adolescents. Methods: Cross-sectional data were collected from 301 students aged between 13 and 15 years (46.51% boys), enrolled at 7 secondary schools in the city of Huesca (Spain). Participants wore accelerometers during a 7-day period, and their academic achievement was calculated from the average marks of all subjects. Structural equation modeling and quadratic regression analysis were performed to test both linear and nonlinear explanatory models. One-way analysis of variance was also performed to explore the effect of gender and the percentage of compliance with MVPA recommendations. Results: MVPA on weekdays and higher levels of body mass index were negatively associated with academic achievement. According to the curvilinear relationship, those students whose MVPA levels were closer to the daily recommendation were more likely to obtain higher academic achievement. However, a significant association was only shown in the case of boys. Conclusions: Adolescents who satisfy the international recommendations tend to obtain better academic achievement. Therefore, MVPA for adolescents should be prescribed within some beneficial time margins (50–70 min/d).

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Nickolai Martonick, Kimber Kober, Abigail Watkins, Amanda DiEnno, Carmen Perez, Ashlie Renfro, Songah Chae and Russell Baker

Clinical Scenario: Joint instability is a common condition that often stems from inadequate muscle activation and results in precarious movement patterns. When clinicians attempt to mechanically treat the unstable joint rather than attending to the underlying cause of the instability, patient outcomes may suffer. The use of kinesiology tape (KT) on an unstable joint has been proposed to aid in improving lower-extremity neuromuscular control. Clinical Question: Does KT improve factors of neuromuscular control in an athletic population when compared with no-tape or nonelastic taping techniques? Summary of Key Findings: The current literature was searched, and 5 randomized controlled studies were selected comparing the effects of KT with no-tape or nonelastic taping techniques on lower-extremity neuromuscular control in an athletic population. Primary findings suggest KT is not more effective than no-tape or nonelastic tape conditions at improving lower-extremity neuromuscular control in a healthy population. Clinical Bottom Line: The current evidence suggests that KT is ineffective for improving neuromuscular control at the ankle compared with nonelastic tape or no-tape conditions. KT was also found to be ineffective at improving hip and knee kinematics in healthy runners and cyclists. However, preliminary research has demonstrated improved neuromuscular control in a population displaying excessive knee valgus during a drop jump landing, after the application of KT. Clinicians should be cautious of these conflicting results and apply the best available evidence to their evaluation of the patient’s status. Strength of Recommendation: There is grade B evidence that the use of KT on an athletic population does not improve biomechanical measures of ankle stability. There is inconclusive, grade B evidence that KT improves neuromuscular control at the knee in symptomatic populations.

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Anderson Nascimento Guimarães, Herbert Ugrinowitsch, Juliana Bayeux Dascal, Alessandra Beggiato Porto and Victor Hugo Alves Okazaki

According to Bernstein, the central nervous system solution to the human body’s enormous variation in movement choice and control when directing movement—the problem of degrees of freedom (DF)—is to freeze the number of possibilities at the beginning of motor learning. However, different strategies of freezing DF are observed in literature, and the means of selection of the control strategy during learning is not totally clear. This review investigated the possible effects of the class and objectives of the skill practiced on DF control strategies. The results of this review suggest that freezing or releasing the DF at the beginning of learning does not depend on the class (e.g., discrete skill class: football kick, dart throwing; continuous skill class: athletic march, handwriting) or objective of the skill (e.g., balance, velocity, and accuracy), in isolation. However, an interaction between these two skill elements seems to exist and influences the selection of the DF control strategy.

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Justin L. Rush, Lindsey K. Lepley, Steven Davi and Adam S. Lepley

Context: Altered quadriceps activation is common following anterior cruciate ligament reconstruction (ACLR), and can persist for years after surgery. These neural deficits are due, in part, to chronic central nervous system alterations. Transcranial direct current stimulation (tDCS) is a noninvasive modality, that is, believed to immediately increase motor neuron activity by stimulating the primary motor cortex, making it a promising modality to use improve outcomes in the ACLR population. Objective: To determine if a single treatment of tDCS would result in increased quadriceps activity and decreased levels of self-reported pain and dysfunction during exercise. Design: Randomized crossover design. Setting: Controlled laboratory. Patients: Ten participants with a history of ACLR (5 males/5 females, 22.9 [4.23] y, 176.57 [12.01] cm, 80.87 [16.86] kg, 68.1 [39.37] mo since ACLR). Interventions: Active tDCS and Sham tDCS. Main Outcome Measures: Percentage of maximum electromyographic data of vastus medialis and lateralis, voluntary isometric strength, percentage of voluntary activation, and self-reported pain and symptom scores were measured. The 2 × 2 repeated-measures analysis of variance by limb were performed to explain the differences between time points (pre and post) and condition (tDCS and sham). Results: There was a significant time main effect for quadriceps percentage of maximum electromyographic of vastus medialis (F 9,1 = 11.931, P = .01) and vastus lateralis (F 9,1 = 9.132, P = .01), isometric strength (F 9,1 = 5.343, P = .046), and subjective scores for pain (F 9,1 = 15.499, P = .04) and symptoms (F 9,1 = 15.499, P = .04). Quadriceps percentage of maximum electromyographic, isometric strength, and voluntary activation showed an immediate decline from pre to post regardless of tDCS condition. Subjective scores improved slightly after each condition. Conclusions: One session of active tDCS did not have an immediate effect on quadriceps activity and subjective scores of pain and symptoms. To determine if tDCS is a valid modality for this patient population, a larger scale investigation with multiple treatments of active tDCS is warranted.

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Rachel McCormick, Alex Dreyer, Brian Dawson, Marc Sim, Leanne Lester, Carmel Goodman and Peter Peeling

The authors compared the effectiveness of daily (DAY) versus alternate day (ALT) oral iron supplementation in athletes with suboptimal iron. Endurance-trained runners (nine males and 22 females), with serum ferritin (sFer) concentrations <50 μg/L, supplemented with oral iron either DAY or ALT for 8 weeks. Serum ferritin was measured at baseline and at fortnightly intervals. Hemoglobin mass (Hbmass) was measured pre- and postintervention in a participant subset (n = 10). Linear mixed-effects models were used to assess the effectiveness of the two strategies on sFer and Hbmass. There were no sFer treatment (p = .928) or interaction (p = .877) effects; however, sFer did increase (19.7 μg/L; p < .001) over the 8-week intervention in both groups. In addition, sFer was 21.2 μg/L higher (p < .001) in males than females. No Hbmass treatment (p = .146) or interaction (p = .249) effects existed; however, a significant effect for sex indicated that Hbmass was 140.85 g higher (p = .004) in males compared with females. Training load (p = .001) and dietary iron intake (p = .015) also affected Hbmass. Finally, there were six complaints of severe gastrointestinal side effects in DAY, but only one in ALT. In summary, both supplement strategies increased sFer in athletes with suboptimal iron status; however, the ALT approach was associated with lower incidence of gastrointestinal upset.

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Rachel McCormick, Brian Dawson, Marc Sim, Leanne Lester, Carmel Goodman and Peter Peeling

The authors compared the effectiveness of two modes of daily iron supplementation in athletes with suboptimal iron stores: oral iron (PILL) versus transdermal iron (PATCH). Endurance-trained runners (nine males and 20 females), with serum ferritin concentrations <50 μg/L, supplemented with oral iron or iron patches for 8 weeks, in a parallel group study design. Serum ferritin was measured at baseline and fortnightly intervals. Hemoglobin mass and maximal oxygen consumption (V˙O2max) were measured preintervention and postintervention in PATCH. A linear mixed effects model was used to assess the effectiveness of each mode of supplementation on sFer. A repeated-measures analysis of variance was used to assess hemoglobin mass and V˙O2max outcomes in PATCH. There was a significant time effect (p < .001), sex effect (p = .013), and Time × Group interaction (p = .009) for sFer. At Week 6, PILL had significantly greater sFer compared with PATCH (15.27 μg/L greater in PILL; p = .019). Serum ferritin was 15.53 μg/L greater overall in males compared with females (p = .013). There were no significant differences in hemoglobin mass (p = .727) or V˙O2max (p = .929) preintervention to postintervention in PATCH. Finally, there were six complaints of severe gastrointestinal side effects in PILL and none in PATCH. Therefore, this study concluded that PILL effectively increased sFer in athletes with suboptimal iron stores, whereas PATCH showed no beneficial effects.

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Richard R. Suminski, Gregory M. Dominick, Philip Saponaro, Elizabeth M. Orsega-Smith, Eric Plautz and Matthew Saponaro

Today’s technology could contribute substantially to measuring physical activity. The current study evaluated traditional and novel approaches for assessing park use. The traditional approach involved a trained observer performing the System for Observing Play and Recreation in Communities (SOPARC) at 14 parks while wearing a point-of-view, wearable video device (WVD). The novel approach utilized computer vision to count park users in the WVD videos taken during in-person SOPARCs. Both approaches were compared to criterion counts from expert reviews of the WVD videos. In the 676 scans made during in-person SOPARCs, 293 individuals were observed while 341 were counted by experts in the corresponding WVD videos. When using scans/videos having individuals in them (84 scans/videos), intra-class correlations (ICC) indicated good-to-excellent reliability between in-person SOPARC and experts for counts of total women and men, within age groups (except seniors), of Blacks and Whites, and within intensity categories (ICCs > .87; p < 0.001). In a subsample of 42 scans/videos, 174 individuals were counted using computer vision and 213 by experts. When using 27 of the 42 WVD videos with individuals in them, ICCs indicated good reliability between computer vision and expert reviews (ICC = .83; p < 0.001). Bland-Altman analysis showed the concurrence of expert counts with both in-person SOPARC and computer vision counts decreased as the number of individuals in a scan/video increased. The results of this study support the use of a highly discrete method for obtaining point-of-view videos and the application of computer vision for automating the counting of park users in the videos.

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Susan Paudel, Alice J. Owen, Stephane Heritier and Ben J. Smith

Aim: To analyze the data from the World Health Organization Nepal STEPS survey 2013 to determine the prevalence of total and domain-specific physical activity (PA) and associated factors among Nepalese adults. Methods: A multistage cluster sampling technique was used to proportionately select participants from the 3 ecological zones (Mountain, Hill, and Terai) in Nepal. The Global PA Questionnaire was used to assess PA. The data were analyzed using quantile and ordinary least square regression. Results: Only 4% of the adults did not meet the World Health Organization PA guidelines. Age had a negative monotonic association with total PA and occupational PA, with the highest difference at the upper tails of the PA distribution. Lower total PA and occupational PA were associated with secondary or higher education, being retired or in unpaid employment, living in Terai or urban areas, and nonsmoking. Age, higher education, unpaid employment, and Terai or urban residence were negatively associated, while being currently married was positively associated with transport-related PA. Conclusion: Increasing age, higher education, unpaid employment, unemployment or retirement, and urban residence were associated with lower PA, with the stronger association at the upper tails of the distribution. The correlates had dissimilar associations across the quantiles of PA distribution.