Which one? A comparative study of traditional and sports uniforms on academic achievement, cognitive performance, playtime, bullying, and discrimination in adolescents: The Cogni-Action Project

Objective

The aim of this study was to compare academic achievement, cognitive performance, playtime, bullying, and discrimination in adolescents according to traditional uniforms (TUs) and sports uniforms (SUs) worn at school, while simultaneously exploring the influence of the school vulnerability index.

Methods

A total of 988 Chilean adolescents (52.6% boys) aged 10-14 years participated in this cross-sectional study. Academic achievement was evaluated by the average grade in maths, language, and science grades, while cognitive performance was assessed through eight cognitive tasks. TUs affecting physical activity, playtime, bullying, and discrimination were queried. Mixed model analyses were performed.

Results

No differences were observed in academic achievement (TU: 5.4 ± 0.1 vs. SU: 5.5 ± 0.2, p = 0.785) or in cognitive performance (TU: 99.6 ± 0.8 vs. SU: 98.9 ± 1.8, p= 0.754) according to the school uniformtype. Moreover, 64.1 % of participants declared that wearing TU affects their physical activity (traditional uniforms: + 8 min and sports uniforms: + 20 min), and those who believed so spent more time playing than those who answered negatively (14.5 min, p = 0.012). Finally, adolescents wearing SU displayed a lower feeling of bullying and discrimination; this finding depended mainly on the school's vulnerability.

Conclusion

It is concluded that wearing TU does not show an educational advantage at an academic and cognitive level that justifies its obligation. In addition, it could be suggested that schools consider adolescents' opinions in adopting a more comfortable uniform, such as the SU. This feasible and low-cost measure would help to increase adolescents' physical activity during the school day, and, contrary to belief, it would not be related to increased feelings of bullying and discrimination.

Mediation Role of Physical Fitness and Its Components on the Association Between Distribution-Related Fat Indicators and Adolescents' Cognitive Performance: Exploring the Influence of School Vulnerability. The Cogni-Action Project

Background: Physical fitness and fatness converge simultaneously modulating cognitive skills, which in turn, are associated with children and adolescents’ socioeconomic background. However, both fitness components and fat mass localization are crucial for understanding its implication at the cognitive level.

Objective: This study aimed to determine the mediation role of a global physical fitness score and its components on the association between different fatness indicators related to fat distribution and adolescents’ cognitive performance, and simultaneously explore the influence of school vulnerability.

Methods: In this study, 1,196 Chilean adolescents participated (aged 10–14; 50.7% boys). Cardiorespiratory fitness (CRF), muscular fitness (MF), and speed-agility fitness (SAF) were evaluated, and a global fitness score (GFS) was computed adjusted for age and sex (CRF + MF + SAF z-scores). Body mass index z-score (BMIz), sum-of-4-skinfolds (4SKF), and waist-to-height ratio (WHtR) were used as non-specific, peripheral, and central adiposity indicators, respectively. A global cognitive score was computed based on eight tasks, and the school vulnerability index (SVI) was registered as high, mid or low. A total of 24 mediation analyses were performed according to two models, adjusted for sex and peak high velocity (Model 1), and adding the school vulnerability index (SVI) in Model 2. The significance level was set at p < 0.05.

Results: The fitness mediation role was different concerning the fatness indicators related to fat distribution analyzed. Even after controlling for SVI, CRF (22%), and SAF (29%), but not MF, mediated the association between BMIz and cognitive performance. Likewise, CRF, SAF and GFS, but not MF, mediated the association between WHtR and cognitive performance (38.6%, 31.9%, and 54.8%, respectively). No mediations were observed for 4SKF.

Conclusion: The negative association between fatness and cognitive performance is mitigated by the level of adolescents’ physical fitness, mainly CRF and SAF. This mediation role seems to be more consistent with a central fat indicator even in the presence of school vulnerability. Strategies promoting physical fitness would reduce the cognitive gap in children and adolescents related to obesity and school vulnerability.

Injury Profile Among Street Workout Practitioners

Background:

Street workout (SW) is an urban sport based on calisthenic exercises. Injury profiles and risk factors are widely explored in various sport disciplines. However, because of the lack of research in SW, injury profiles have not yet been established.

Purpose:

To investigate the characteristics and prevalence of injuries and variables that may increase these odds in SW practitioners.

Study Design:

Case-control study; Level of evidence, 4.

Methods:

An electronic survey was conducted between September 2018 and March 2019 in order to obtain practitioner information, physical activity level, training characteristics, and injury information of SW practitioners. Responses from 93 practitioners were eligible for analysis. Univariate and multivariate binary logistic regression analyses were used to examine the association among several variables and the presence of injury in the past 12 months based on odds ratios (ORs).

Results:

Overall, 62.4% of the 93 participants reported an injury in the previous 12 months, and tendinopathy was the most reported diagnosis (31.0% of injured practitioners). High injury frequency was reported in the shoulder (23.0%) and back (upper and mid) (18.4%). Overtraining was the most reported perception of cause of injury (56.9%). Most injured practitioners (20.7%) performed freestyle exercises before the injury, followed by upper body exercises. A history of previous injuries (OR, 4.078; P = .005) and the middle and higher tertiles of vigorous physical activity (OR, 4.370; P = .015 and OR, 5.634; P = .003, respectively) were associated with a higher odds of injury.

Conclusion:

In SW, the shoulder and back (upper and mid) were the most injured body parts, with tendinopathy being the most frequent diagnosis. Overtraining was typically reported as the perceived cause of injury, with freestyle and upper limb exercises the most performed exercises when injured. A history of previous injuries, along with vigorous physical activity, was found to augment the odds of injury. More research is needed to corroborate our findings, along with increased knowledge about SW practice and injuries.

Physical fitness and its association with cognitive performance in Chilean schoolchildren: The Cogni-Action Project

This study aimed to establish the association and differences in a diversity of cognitive domains according to cardiorespiratory fitness (CRF), muscular fitness (MF), and speed-agility fitness (S-AF) level in a large sample of Chilean schoolchildren. 1171 Chilean schoolchildren aged 10-14 years participated. CRF, MF, and S-AF were assessed through the ALPHA-fitness test battery. Cognition was evaluated through the NeuroCognitive Performance Test, which involved eight tests related to four main domains: cognitive flexibility (CF), working memory (WM), inhibitory control (IC), and intelligence (IN). Both global (multivariate) and individual (univariate) analyses were performed to determine the differences in cognitive functioning according to low-, middle-, and high-fitness level. The global analyses showed a significant main effect for CRF, F_(16,940)  = 3.08, p ≤ .001 and MF groups, F_(16,953)  = 2.30, p = .002, but not for S-AF, F_(16,948)  = 1.37, p = .105. CRF shows a significant main effect in seven of eight tests, involving CF, WM, IC, and IN domains, whereas MF shows a significant main effect in five of eight tests without association with IN. SA-F shows a significant main effect only with IC. Statistical differences were found between the low- and middle/high-fitness groups but not between the middle- and high-fitness groups. At a global level, both CRF and MF seem to be associated with a higher cognitive profile in scholars; however, at an individual level, all fitness components show a favorable relationship to some cognitive domine. Then, future cognitive developing strategies should consider all fitness components, prioritizing those low-fitness schoolchildren.

The Mediation Effect of Self-Report Physical Activity Patterns in the Relationship between Educational Level and Cognitive Impairment in Elderly: A Cross-Sectional Analysis of Chilean Health National Survey 2016-2017

The aims of this cross-sectional study were (i) to determine the association of educational level attained with cognitive impairment and (ii) to investigate the mediating effect of different self-report physical activity (PA) patterns in a large sample of older Chileans. A sample of 1571 older adults from the National Chilean Survey (2016-2017) was included. The educational level attained, PA levels, mode of commuting, sedentary time, and leisure-time PA were self-reported through validated questionnaires. Cognitive impairment was determined by Mini-Mental State Examination (modified version). Association between educational level attained and cognitive impairment was examined using logistic regression models. Counterfactual mediation models were used to test the mediating effect of self-reported PA patterns. A lower educational level was consistently associated with higher odds of cognitive impairment (OR range 2.846 to 2.266, all p < 0.001), while leisure-time PA was the only PA pattern that partially mediated this association (proportion mediated 8.0%). In conclusion, leisure-time PA was the solely PA pattern that partially mediated the association between the educational level and cognitive impairment. The rest self-reported PA patterns did not modify this association.

Study protocol and rationale of the "Cogni-action project" a cross-sectional and randomized controlled trial about physical activity, brain health, cognition, and educational achievement in schoolchildren

BACKGROUND

Education and health are crucial topics for public policies as both largely determine the future wellbeing of the society. Currently, several studies recognize that physical activity (PA) benefits brain health in children. However, most of these studies have not been carried out in developing countries or lack the transference into the education field. The Cogni-Action Project is divided into two stages, a cross-sectional study and a crossover-randomized trial. The aim of the first part is to establish the associations of PA, sedentarism, and physical fitness with brain structure and function, cognitive performance and academic achievement in Chilean schoolchildren (10-13 years-old). The aim of the second part is to determinate the acute effects of three PA protocols on neuroelectric indices during a working memory and a reading task.

METHODS

PA and sedentarism will be self-reported and objectively-assessed with accelerometers in a representative subsample, whilst physical fitness will be evaluated through the ALPHA fitness test battery. Brain structure and function will be assessed by magnetic resonance imaging (MRI) in a randomized subsample. Cognitive performance will be assessed through the NeuroCognitive Performance Test, and academic achievement by school grades. In the second part 32 adolescents (12-13 year-old) will be cross-over randomized to these condition (i) "Moderate-Intensity Continuous Training" (MICT), (ii) "Cooperative High-Intensity Interval Training" (C-HIIT), and (iii) Sedentary condition. Neuroelectric indices will be measures by electroencephalogram (EEG) and eye-tracking, working memory by n-back task and reading comprehension by a reading task.

DISCUSSION

The main strength of this project is that, to our knowledge, this is the first study analysing the potential association of PA, sedentarism, and physical fitness on brain structure and function, cognitive performance, and academic achievement in a developing country, which presents an important sociocultural gap. For this purpose, this project will use advanced technologies in neuroimaging (MRI), electrophysiology (EEG), and eye-tracking, as well as objective and quality measurements of several physical and cognitive health outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03894241 Date of register: March 28, 2019. Retrospectively Registered.

Effects of beta-hydroxy-beta-methylbutyrate supplementation on strength and body composition in trained and competitive athletes: A meta-analysis of randomized controlled trials

OBJECTIVES

The aim of this meta-analysis was to examine the evidence for the effectiveness of beta-hydroxy-beta-methylbutyrate supplementation interventions on modification in strength and body composition in trained and competitive athletes.

DESIGN

Systematic review and meta-analysis.

METHODS

A systematic search was performed using three databases: MEDLINE, EBSCO and Web of Science. The analysis was restricted to randomized controlled trials that examined the effect of HMB supplementation interventions on modification in bench and leg press strength, body mass, fat-free mass and fat mass. Effect sizes (ES) and 95% confidence intervals (CIs) were calculated using a fixed effect meta-analysis due to low value of the heterogeneity. The Egger test was used to determine the presence of publication bias, and the Q and I² statistics were used to assess heterogeneity among studies. Significance was set at p<0.05.

RESULTS

Six studies were selected for meta-analysis, as they fulfilled the inclusion criteria (n=193 participants). HMB supplementation interventions present a trivial non-significant ES in all variables studied (bench press ES=0.00, leg press ES=0.09, body mass ES=-0.01, fat-free mass ES=0.16, and fat mass ES=-0.20; all cases p>0.05, and null heterogeneity I²=0.0% p>0.05). These results remained constant even analyzing by subgroups (HMB doses, duration of intervention, training level and diet co-intervention).

CONCLUSIONS

This meta-analysis found no effect of HMB supplementation on strength and body composition in trained and competitive athletes.

A new thienodiazepine, brotizolam, for the treatment of insomnia

A double-blind crossover study was carried out in twenty hospitalized inpatients who, apart from their primary diagnosis, suffered from non-psychiatric chronic insomnia. The patients received 0·5 mg brotizolam or 30 mg flurazepam for a 2-week period. Both drugs improved the induction and continuity of sleep, and increased the total sleep time, although better results were observed with brotizolam in all the parameters studied.