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 Gut Barrier, Intestinal Microbiota, and Liver Disease: Molecular Mechanisms and Strategies to Manage.

Liver disease encompasses pathologies as non-alcoholic fatty liver disease, non-alcoholic steatohepatitis, alcohol liver disease, hepatocellular carcinoma, viral hepatitis, and autoimmune hepatitis. Nowadays, underlying mechanisms associating gut permeability and liver disease development are not well understood, although evidence points to the involvement of intestinal microbiota and their metabolites. Animal studies have shown alterations in Toll-like receptor signaling related to the leaky gut syndrome by the action of bacterial lipopolysaccharide. In humans, modifications of the intestinal microbiota in intestinal permeability have also been related to liver disease. Some of these changes were observed in bacterial species belonging Roseburia, Streptococcus, and Rothia. Currently, numerous strategies to treat liver disease are being assessed. This review summarizes and discusses studies addressed to determine mechanisms associated with the microbiota able to alter the intestinal barrier complementing the progress and advancement of liver disease, as well as the main strategies under development to manage these pathologies. We highlight those approaches that have shown improvement in intestinal microbiota and barrier function, namely lifestyle changes (diet and physical activity) and probiotics intervention. Nevertheless, knowledge about how such modifications are beneficial is still limited and specific mechanisms involved are not clear. Thus, further in-vitro, animal, and human studies are needed.

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 Modified Invasion Games on Motor Competence and Self-Assessed Physical Condition in Elementary School Students in the Physical Education Classroom.

Modified invasion games promote the development of real and perceived motor competence. Children with higher motor competence are more likely to participate in physical activity practice and to remain in it, both in adolescence and adulthood. (1) Background: The purpose of this study is to determine the effect of modified invasion games on the real motor competence and self-assessment of the physical condition fifth-grade students from a private school in Viña del Mar, Chile. (2) Methods: 40 girls and boys with an average age of 11.47 years (SD = 0.554) participated in this study during a 12-week intervention. The MOBAK 5-6 battery was used to assess actual motor competence, the SEMOK questionnaire was used to determine perceived motor competence, the International Fitness Scale (IFIS) self-assessment questionnaire was used to assess perceived physical fitness, and the weight/size ratio was used to determine BMI. A Friedman's nonparametric ANOVA analysis was applied to determine the effect of the intervention, in addition to an analysis of covariance (ANCOVA) to identify the influence of the covariates on motor competence. (3) Results: No statistically significant differences were established between weight, BMI, and waist circumference. There was a statistically significant difference after the intervention in the actual motor competence of object control (p = 0.005) and perceived motor competence of object control (p ≤ 0.001) (4) Conclusions: An intervention based on modified invasion games is effective for the improvement of actual and perceived motor competence of object control. It was not possible to identify a positive effect on the self-assessment of muscle strength after the intervention.

Muscle Oxygen Extraction during Vascular Occlusion Test in Physically Very Active versus Inactive Healthy Men: A Comparative Study.

An increase in the delivery and use of oxygen to the musculature in physically active subjects are determinants of improving health-related aerobic capacity. Additional health benefits, such as an increase in the muscle mass and a decrease in fat mass, principally in the legs, could be achieved with weekly global physical activity levels of more than 300 min. The objective was to compare the muscle vascular and metabolic profiles of physically very active and inactive subjects. Twenty healthy men participated in the study; ten were assigned to the physically very active group (25.5 ± 4.2 years; 72.7 ± 8.1 kg; 173.7 ± 7.6 cm) and ten to the physically inactive group (30.0 ± 7.4 years; 74.9 ± 11.8 kg; 173.0 ± 6.4 cm). The level of physical activity was determined by the Global Physical Activity Questionnaire (GPAQ). A resting vascular occlusion test (5 min of an ischemic phase and 3 min of a reperfusion phase) was used, whereas a near-field infrared spectroscopy (NIRS) device was used to evaluate the muscle oxygenation in the right vastus lateralis of the quadriceps muscle. The area under the curve of the deoxyhemoglobin (HHb) during the ischemic phase and above the curve of the tissue saturation index (TSI) during the reperfusion phase were obtained to determine muscle metabolic and vascular responses, respectively. Physically very active group showed a higher absolute HHb (3331.9 ± 995.7 vs. 6182.7 ± 1632.5 mmol/s) and lower TSI (7615.0 ± 1111.9 vs. 5420.0 ± 781.4 %/s) and relative to body weight (46.3 ± 14.6 vs. 84.4 ± 27.1 mmol/s/kg and 106.0 ± 20.6 vs. 73.6 ± 13.8 %/s/kg, respectively), muscle mass (369.9 ± 122.2 vs. 707.5 ± 225.8 mmol/kg and 829.7 ± 163.4 vs. 611.9 ± 154.2 %/s/kg) and fat mass (1760.8 ± 522.9 vs. 2981.0 ± 1239.9 mmol/s/kg and 4160.0 ± 1257.3 vs. ±2638.4 ± 994.3 %/s/kg, respectively) than physically inactive subjects. A negative correlation was observed between HHb levels and TSI (r = -0.6; p < 0.05). Physically very active men (>300 min/week) present better muscle oxidative metabolism and perfusion and perform significantly more physical activity than physically inactive subjects. Extra benefits for vascular health and muscle oxidative metabolism are achieved when a subject becomes physically very active, as recommended by the World Health Organization. In addition, a higher level of physical activity determined by GPAQ is related to better vascular function and oxidative metabolism of the main locomotor musculature, i.e., the quadriceps.

Calculating Load and Intensity Using Muscle Oxygen Saturation Data.

The study aimed to calculate training intensity and load using muscle oxygen saturation (SmO2) during two differentiated physical tasks. 29 university athletes participated in a 40-m Maximal Shuttle Run Test (MST, 10 × 40-m with 30 s recovery between sprints) and a 3000-m time trial run. Distance and time were used to calculate external load (EL). Internal load indicators were calculated based on percentage of maximum heart rate (%HRMAX) and SmO2 variables: muscle oxygen extraction (∇%SmO2) and the cardio-muscle oxygen index (CMOI) was also provided by relating ∇%SmO2 ÷ %HRMAX, and the training load were calculated as the product of speed (m/min × IL) and the efficiency index [Effindex (m/min ÷ IL)]. A student t test was applied based on Bayesian factor analysis. As expected, EL differed in the 40-m MST (331 ± 22.8) vs. 3000-m trials (222 ± 56.8) [BF10 = 6.25e+6; p = <0.001]. Likewise, IL showed higher values in 40-m MST (39.20 ± 15.44) vs. 3000-m (30.51 ± 8.67) in CMOI: [BF10 = 1.70; p = 0.039]. Training load was greater in 40-m MST (85.77 ± 27.40) vs. 3000-m (15.55 ± 6.77) [(m/min × ∇%SmO2): BF10 = 12.5; p = 0.003] and 40-m MST (129.27 ± 49.44) vs. 3000-m (70.63 ± 32.98) [(m/min × CMOI): BF10 = 169.6; p = <0.001]. Also, the Effindex was higher in 40-m MST (10.19 ± 4.17) vs. 3000-m (6.06 ± 2.21) [(m/min × ∇%SmO2): BF10 = 137.03; p = <0.001] and 40-m MST (9.69 ± 4.11) vs. 3000-m (7.55 ± 1.87) [(m/min × CMOI): BF10 = 1.86; p = 0.035]. This study demonstrates calculations of training intensity and load based on SmO2 as an internal load indicator along with speed as an external load indicator during two differentiated exercises.

Development of Basic Motor Skills from 3 to 10 Years of Age: Comparison by Sex and Age Range in Chilean Children.

Basic motor skills are recognized as fundamental movements that allow children to interact with their environment and are identified as the basic structure on which more complex movements are built. OBJECTIVE: to identify the level of motor development of children from 3 to 10 years of age according to sex and age group. METHODOLOGY: We studied a sample with a total of 328 participants (girls = 170; boys = 158) at preschool (n = 154) and school levels (n = 174). The ages of the students ranged from 3 to 10 years, with a mean of 5.94 years (±2.53). TGMD2 was applied to identify motor development. RESULTS: boys and girls present low levels of physical activity, with most of them in the very poor, poor, and low-average categories (n = 182, 55.5%). Levels of motor development in locomotion, manipulation, and general development by age show significant differences (p = 0.000). However, levels of development by sex are not significant in manipulation, locomotion, and gross motor skills tests, respectively (p = 0.150, p = 0.208, and p = 0.210), and in relation to chronological age and motor development age show significant differences (p = 0.000).

[Profile and indicators of long-stay establishments for older adults in Chile]. / Perfil e indicadores de los establecimientos de larga estancia para adulto mayor en Chile.

BACKGROUND AND OBJECTIVE: In this article we sought to characterize the Long Stay Establishments for the Elderly in Chile, besides presenting the services offered in the public and private. MATERIAL AND METHODS: It is a quantitative, cross-sectional descriptive study, with secondary information source. We analyze all establishments in the country registered with the National Service of the Elderly. As of November 2015, a total of 724 establishments were registered and distributed in 169 neighborhoods throughout the country in which 16,985 adults aged 60 and over were institutionalized. RESULTS: Most of the establishments (65.9% [n=246/724]) are private, 47.5% of them (n=344/724) are located in the metropolitan region of Santiago. Of the residents' health, only 26.5% are considered functional brave, 28.3% are physically handicapped and 8.8% are mentally handicapped. Most establishments offer manual activities, physical exercises, memory classes, cultural classes and recreational or touristic tours. Proportionally of the activities offered were mostly private ones. CONCLUSIONS: In Chile, most of the establishments are private, located in the metropolitan region where there is the largest supply deficit of this type of service, with an occupancy rate of 90.7%, with 72.4% women and almost half 47.7% with some physical or psychic dependence.

Association between Fractional Oxygen Extraction from Resting Quadriceps Muscle and Body Composition in Healthy Men.

This study aimed to associate body composition with fractional oxygen extraction at rest in healthy adult men. Fourteen healthy adults (26.93 ± 2.49 years) from Chile participated. Body composition was assessed with octopole bioimpedance, and resting muscle oxygenation was evaluated in the vastus lateralis quadriceps with near-infrared spectroscopy (NIRS) during a vascular occlusion test, analyzing the muscleVO2, resaturation velocity during reactive hyperemia via the muscle saturation index (%TSI), and the area above the curve of HHb (AACrep). It was observed that the total and segmented fat mass are associated with lower reoxygenation velocities during hyperemia (p = 0.008; ß = 0.678: p = 0.002; ß = 0.751), and that the total and segmented skeletal muscle mass are associated with higher reoxygenation velocities during hyperemia (p = 0.020; ß = -0.614: p = 0.027; ß = -0.587). It was also observed that the total and segmented fat mass were associated with a higher area above the curve of HHb (AACrep) during hyperemia (p = 0.007; ß = 0.692: p = 0.037; ß = 0.564), and that total and segmented skeletal muscle mass was associated with a lower area above the curve of HHb (AACrep) during hyperemia (p = 0.007; ß = -0.703: p = 0.017; ß = -0.632). We concluded that fat mass is associated with lower resaturation rates and lower resting fractional O2 extraction levels. In contrast, skeletal muscle mass is associated with higher resaturation rates and fractional O2 extraction during reactive hyperemia. The AACrep may be relevant in the evaluation of vascular adaptations to exercise and metabolic health.

Physical fitness mediates the inverse association between fatness indicators and academic achievement, despite the school vulnerability of adolescents-The Cogni-Action Project.

Objective: This study aims to determine the mediating role of physical fitness in the relationship between fatness indicators and academic achievement, exploring the influence of school vulnerability. Methods: A total of 1,296 Chilean adolescents (aged 10 to 14 years; 50% girls) participated in this study. The global fitness score (GFS) was obtained by adding the three main components of the ALPHA fitness test: cardiorespiratory fitness (CRF), muscular fitness (MF), and speed/agility fitness (SAF). CRF was evaluated through the 20 m shuttle run test; MF by upper and lower limb strength tests; and SAF by the 4 × 10 shuttle run test. BMIz and WHtR were evaluated as general (unspecific) and central (specific) fatness indicators. Academic achievement was established through grades in math, language, and science and their average scores. Multiple mediation analyses were performed according to two models, adjusted for sex, maturity, and schools (model 1), and in model 2, the school vulnerability index (SVI) was added. The SVI is an important proxy of socioeconomic status at the school level, and it was categorized as high-, mid-, or low-SVI. Mediation percentages were calculated, and confidence intervals (bootstrapping) were used to establish significant findings. Results: CRF, SAF, and GFS mediate the relationship between fatness indicators and academic achievement, both partially and totally (ranging from 12.7 to 59.2%). However, MF did not show any mediation effect. After controlling for SVI, CRF, and GFS, mediation changed from partial to total in the associations between math and science with WHtR. Although SAF contributed to GFS mediation, CRF seems to have the most significant mediation role for all academic achievements, regardless of SVI and the fat indicator studied. Conclusion: A higher level of general physical fitness, especially CRF, significantly mediates the detrimental influence of fatness on the academic achievement of schoolchildren. This study suggests that physical fitness plays a relevant role in academic and public health, considering the high prevalence and detrimental influence of obesity and school vulnerability in children and adolescents.

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.

Insights into the Impact of Microbiota in the Treatment of NAFLD/NASH and Its Potential as a Biomarker for Prognosis and Diagnosis.

Non-alcoholic fatty liver disease (NAFLD) is an increasing cause of chronic liver illness associated with obesity and metabolic disorders, such as hypertension, dyslipidemia, or type 2 diabetes mellitus. A more severe type of NAFLD, non-alcoholic steatohepatitis (NASH), is considered an ongoing global health threat and dramatically increases the risks of cirrhosis, liver failure, and hepatocellular carcinoma. Several reports have demonstrated that liver steatosis is associated with the elevation of certain clinical and biochemical markers but with low predictive potential. In addition, current imaging methods are inaccurate and inadequate for quantification of liver steatosis and do not distinguish clearly between the microvesicular and the macrovesicular types. On the other hand, an unhealthy status usually presents an altered gut microbiota, associated with the loss of its functions. Indeed, NAFLD pathophysiology has been linked to lower microbial diversity and a weakened intestinal barrier, exposing the host to bacterial components and stimulating pathways of immune defense and inflammation via toll-like receptor signaling. Moreover, this activation of inflammation in hepatocytes induces progression from simple steatosis to NASH. In the present review, we aim to: (a) summarize studies on both human and animals addressed to determine the impact of alterations in gut microbiota in NASH; (b) evaluate the potential role of such alterations as biomarkers for prognosis and diagnosis of this disorder; and (c) discuss the involvement of microbiota in the current treatment for NAFLD/NASH (i.e., bariatric surgery, physical exercise and lifestyle, diet, probiotics and prebiotics, and fecal microbiota transplantation).

Impact of Exercise on Gut Microbiota in Obesity.

Physical activity, exercise, or physical fitness are being studied as helpful nonpharmacological therapies to reduce signaling pathways related to inflammation. Studies describing changes in intestinal microbiota have stated that physical activity could increase the microbial variance and enhance the ratio of Firmicutes/Bacteroidetes, and both actions could neutralize the obesity progression and diminish body weight. The aim of this review is to provide an overview of the literature describing the relationship between physical activity profiles and gut microbiota and in obesity and some associated comorbidities. Promoting physical activity could support as a treatment to maintain the gut microbiota composition or to restore the balance toward an improvement of dysbiosis in obesity; however, these mechanisms need to be studied in more detail. The opportunity to control the microbiota by physical activity to improve health results and decrease obesity and related comorbidities is very attractive. Nevertheless, several incompletely answered questions need to be addressed before this strategy can be implemented.

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.

Anthropometric Characteristics, Training Intensity Distribution, Physiological Profile and Performance of an Elite Trail Runner: A Longitudinal Case Study

SUMMARY: Trail running (TR), an extreme endurance sport, presents unique challenges due to the variety of terrain and distances, where physiological capacity and body composition have been considered better predictors of performance. This longitudinal case study examines the impact of training intensity distribution (TID) on an elite trail runner's physiological profile and performance over four years. Two TID models were implemented: polarized (POL) and pyramidal (PYR). Physiological assessments included maximal oxygen consumption (VO2max), lactate thresholds (LT1 and LT2), and anthropometric characteristics. The training was classified according to the 3-zone intensity model (zone 1: below the first lactate threshold; zone 2: between the first and second lactate threshold; zone 3: above the second lactate threshold). During the four years, the average TID distribution was 75 % zone 1, 18 % zone 2, and 7 % zone 3. Physiological capacity increased by 7.14 % (14 to 15 km/h) for velocity at LT1 (vLT1) and 8.13 % (16 to 17.3 km/h) for velocity at LT2 (vLT2). The most significant increases were observed during the second year when the percentage of training time in zone 1 was lower (65 %) and in zone 2 greater (30 %) than those reported in other years. Consequently, vLT1 and vLT2 increased by 3.5 % (from 14.1 to 14.6 km/h) and 3.6 % (from 16.5 to 17.1 km/h), respectively. In conclusion, this case study revealed that emphasizing training in zone 2 (moderate intensity) and increasing the training load significantly improved performance at lactate thresholds. Despite modifying body composition, no influence on improving endurance performance was observed. These findings underscore the importance of TID in elite trail runners and highlight the potential to optimize physiological adaptations and performance outcomes.

Trail running (TR), un deporte de resistencia extrema, presenta desafíos únicos debido a la variedad de terrenos y distancias, donde la capacidad fisiológica y la composición corporal se han considerado mejores predictores del rendimiento. Este estudio de caso longitudinal examina el impacto de la distribución de la intensidad del entrenamiento (TID) en el perfil fisiológico y el rendimiento de un corredor de montaña de élite durante cuatro años. Se implementaron dos modelos TID: polarizado (POL) y piramidal (PYR). Las evaluaciones fisiológicas incluyeron el consumo máximo de oxígeno (VO2max), los umbrales de lactato (LT1 y LT2) y las características antropométricas. El entrenamiento se clasificó según el modelo de intensidad de 3 zonas (zona 1: por debajo del primer umbral de lactato; zona 2: entre el primer y segundo umbral de lactato; zona 3: por encima del segundo umbral de lactato). Durante los cuatro años, la distribución TID promedio fue 75 % zona 1, 18 % zona 2 y 7 % zona 3. La capacidad fisiológica aumentó un 7,14 % (14 a 15 km/h) para la velocidad en LT1 (vLT1) y un 8,13 % (16 a 17,3 km/h) para velocidad en LT2 (vLT2). Los incrementos más significativos se observaron durante el segundo año cuando el porcentaje de tiempo de entrenamiento en la zona 1 fue menor (65 %) y en la zona 2 mayor (30 %) que los reportados en otros años. En consecuencia, vLT1 y vLT2 aumentaron un 3,5 % (de 14,1 a 14,6 km/h) y un 3,6 % (de 16,5 a 17,1 km/h), respectivamente. En conclusión, este estudio reveló que enfatizar el entrenamiento en la zona 2 (intensidad moderada) y aumentar la carga de entrenamiento mejoró significativamente el rendimiento en los umbrales de lactato. A pesar de modificar la composición corporal, no se observó influencia en la mejora del rendimiento de resistencia. Estos hallazgos subrayan la importancia del TID en los corredores de trail de élite y resaltan el potencial para optimizar las adaptaciones fisiológicas y los resultados de rendimiento.

Capacidades Físicas y Composición Corporal de los Practicantes Recreativos de Tang Soo Do y de Karate: Una Revisión Sistemática / Physical Abilities and Body Composition of Recreational Practitioners of Tang Soo Do and Karate: A Systematic Review

El Tang Soo Do es un arte marcial versátil que destaca por el uso de la cadera para sus gestos técnicos. El karate es una de las artes marciales más atractivas alrededor del mundo. Tanto karate como Tang Soo Do comparten un estilo firme en sus técnicas y combate. Sin embargo, algunas de las formas en Tang Soo Do poseen un estilo suave similar al kung fu y al tai chi. Por ello, es interesante describir y comparar las capacidades físicas y la composición corporal de los practicantes de Tang Soo Do y karate a nivel recreativo. Para ello, se realizó una búsqueda en Medline® y Web of Science® durante enero de 2021. Se escogieron 10 estudios, organizando sus datos según composición corporal, fuerza muscular, resistencia muscular, flexibilidad y VO2max. Se encontraron 2 estudios en practicantes recreativos de Tang Soo Do y 8 en karate a nivel mundial, por lo que no existen suficientes estudios que permitan describir y comparar adecuadamente las capacidades físicas y la composición corporal entre sus practicantes a nivel recreativo; sin embargo, los resultados encontrados indican que es importante realizar más investigaciones que midan estas variables, con la finalidad de considerar en base a la evidencia alTang Soo Do como una importante opción para el bienestar físico y mental de sus practicantes. Las investigaciones futuras pueden evaluar estos datos en distintos grupos etarios, localización, tiempo de entrenamiento o tipos de competiciones según formas, combate o mixto. Además, se pueden realizar estudios comparativos en los practicantes de Tang Soo Do que permita a este arte marcial ser desde la evidencia una importante opción de práctica en colegios y universidades, así como un estilo de vida para sus practicantes.

SUMMARY: Tang Soo Do is a versatile martial art that stands out for the use of the hip for its technical gestures. Karate is one of the most attractive martial arts around the world. Both karate and Tang Soo Do share a firm style in their techniques and combat. However, some of the forms in Tang Soo Do possess a gentle style similar to Kung Fu and Tai Chi. Therefore, it is interesting to describe and compare the physical abilities and body composition of recreational Tang Soo Do and karate practitioners. A search was carried out in Medline® and Web of Science® during January 2021. Following the search 10 studies were chosen, organizing their data according to body composition, muscular strength, muscular resistance, flexibility and VO2max. Two studies were found on recreational Tang Soo Do practitioners and eight on karate worldwide, hence, there are not enough studies to adequately describe and compare physical abilities and body composition among recreational practitioners; However, the results found, indicate that it is important to conduct further research to measures these variables, in order to consider Tang Soo Do as an important option for the physical and mental well-being of its practitioners. Future research can evaluate these data can be evaluated in different age groups, location, training time or types of competitions according to forms, combat or mixed. In addition, comparative studies can be carried out on Tang Soo Do practitioners that allow this martial art to become an important option for practice in schools and universities, as well as a lifestyle for its practitioners.

Análisis de Datos Antropométricos y Madurativos para la Selección de Talentos en Voleibol / Analysis of Anthropometric and Maturational Data for Talents Selection in Volleyball

El proceso madurativo tiene una gran influencia sobre los factores antropométricos y las capacidades físicas del atleta, y por tanto, sobre el proceso de selección de talentos deportivos. El objetivo de este trabajo fue analizar el estado madurativo y las características antropométricas junto con la comparación de estos datos por sexo en una muestra de 39 jugadores jóvenes de voleibol dentro de un proceso de selección de talentos (19 damas de 14,88±1,05 años y 13 varones de 15,1 años). Se obtuvieron datos de edad cronológica, altura, peso, altura sentado, altura de la madre y padre, la edad pico de crecimiento, el "timing" o periodo de tiempo por encima o por debajo de la edad pico, altura al final del proceso madurativo, el porcentaje actual de altura máxima, los centímetros restantes y el estado madurativo (pre-púber, púber o pos-púber). Los jugadores mostraron una mayor altura en el momento de las mediciones (179,92±6,87 vs 171,05±4,80; p<0,001), así como una mayor altura final calculada (189,46±3,73 vs 178,52±5,17; p<0,001), en comparación a las jugadoras. El pico en la velocidad de crecimiento también fue superior en los jugadores (14,56±0,44 vs 12,60±0,57; p<0,001), aunque su timing era inferior al de las jugadoras (0,531±1,19 vs 2,27±0,64; p<0,001). Esto se debió a un mayor porcentaje de jugadores masculinos en estados puberales, incluyendo un jugador en estadio pre-puberal, mientras que fue abundante la presencia de jugadoras en estado pospuberal. Estos datos reflejan la gran cantidad de jugadores que tienden a estar en periodos avanzados de maduración en procesos de selección de talentos. Por tanto, entrenadores y seleccionadores deben contemplar estas variables para evitar sesgos en el proceso de identificación del talento deportivo.

SUMMARY: The maturation process has a great influence on the anthropometric factors and physical capabilities of the athlete, and therefore, on the selection process of sporting talents. The objective of this work was to analyze the maturational state and anthropometric characteristics together with the comparison of these data by sex in a sample of 39 young volleyball players within a talent selection process (19 ladies of 14.88±1. 05 years old and 13 males aged 15.1 years). Data were obtained on chronological age, height, weight, sitting height, height of the mother and father, peak age of growth, timing or period of time above or below the peak age, height at the end of the process. maturation, the current percentage of maximum height, the remaining centimeters and the maturation status (pre-pubertal, pubertal or post-pubertal). The players showed a greater height at the time of the measurements (179.92±6.87 vs. 171.05±4.80; p<0.001), as well as a greater final calculated height (189.46±3.73 vs. 178.52±5.17; p<0.001), compared to the female players. The peak in growth speed was also higher in male players (14.56±0.44 vs 12.60±0.57; p<0.001), although their timing was lower than that of female players (0.531±1.19 vs 2.27±0.64; p<0.001). This was due to a higher percentage of male players in pubertal states, including one player in a pre-pubertal stage, while the presence of female players in a post-pubertal stage was abundant. These data reflect the large number of players who tend to be in advanced periods of maturation in talent selection processes. Therefore, coaches and selectors must consider these variables to avoid biases in the process of identifying sporting talent.

Relación entre la Composición Corporal, Condición Física y Capacidad Operativa en Militares Chilenos / Relationship Between Body Composition, Physical Condition and Operational Capacity in Chilean Military

La composición corporal engloba una serie de variables relacionadas con la salud e influye en la condición física. A pesar de ello, existe poca evidencia sobre sus efectos en la capacidad operativa en militares. El objetivo de este estudio fue relacionar la composición corporal, la condición física y la capacidad operativa de militares chilenos. Participaron 57 militares chilenos (26,9 ± 4,8 años), con especialización operativa en infantería. La composición corporal fue evaluada con bioimpedancia octopolar estimando masa libre de grasa, tejido muscular y tejido adiposo, entre otras variables. También se realizaron las siguientes pruebas de condición física: 5000 m planos, dominadas, abdominales y flexibilidad, así como cuatro pruebas específicas de actividades operativas militares específicas (situación de combate simulado). Los resultados mostraron un porcentaje de tejido muscular de 45,4 ± 2,9 % (IC95%: 44,6 - 46,2), mientras que el porcentaje de tejido adiposo fue de 20,3 ± 4,9 % (IC95%: 14,7 - 17,3). Se encontraron correlaciones negativas de pequeña magnitud entre el tiempo de carrera (5000 m) y el tejido muscular (%) (r = -0,275) y positiva con el tejido adiposo (%) (r = 0,294). Sin embargo, se observaron correlaciones de alta magnitud entre dominadas y tejido muscular (%) (r = 0,517) y tejido adiposo (%) (r = -0,558). El tejido adiposo se relacionó negativamente con la capacidad aeróbica, fuerza de brazos(??) y fuerza resistencia abdominal, mientras que el tejido muscular se relacionó positivamente con estas mismas variables. No se apreciaron correlaciones entre la composición corporal y la capacidad operativa militar (p<0,05). Se concluye que la composición corporal y la condición física no se relacionan con la capacidad operativa militar en situación de combate en especialistas en infantería, pero si la composición corporal se relaciona con la fuerza y la capacidad cardiorrespiratoria.

SUMMARY: Body composition encompasses a series of variables that are health-related and influence physical condition. Nevertheless, there is little evidence on its effects on the operational capacity of the military. The objective of this study was to relate the body composition, the physical condition and the operational capacity of the Chilean military. Fifty-seven Chilean soldiers (26.9 ± 4.8 years) participated, with operational specialization in infantry. Body composition was evaluated with octopolar bioimpedance, estimating fat- free mass, muscle tissue, and adipose tissue, among other variables. The following physical condition tests were also carried out: 5000 m flat, pull-ups, abdominals and flexibility, as well as four specific tests of specific military operational activities (simulated combat situation). The results showed a percentage of muscle tissue of 45.4 ± 2.9 % (95%CI: 44.6 - 46.2), while the percentage of adipose tissue was 20.3 ± 4.9 % (95%CI). : 14.7-17.3). Negative correlations of small magnitude were found between race time (5000 m) and muscle tissue (%) (r = -0.275) and positive with adipose tissue (%) (r = 0.294). However, high magnitude correlations were observed between pull-ups and muscle tissue (%) (r = 0.517) and adipose tissue (%) (r = -0.558). Adipose tissue was negatively related to aerobic capacity, arm strength, and abdominal endurance strength, while muscle tissue was positively related to these same variables. No correlations were found between body composition and military operational capacity (p<0.05). It is concluded that body composition and physical condition are not related to military operational capacity in combat situations in infantry specialists, but body composition is related to strength and cardiorespiratory capacity.

Perfil de composición corporal en militares élite chilenos / Body composition profile of elite Chilean military

RESUMEN: La Bioimpedancia Eléctrica (BIA), al ser una técnica no invasiva pero de elevada precisión, se ha convertido en la actualidad en una herramienta valiosa para determinar la composición corporal en militares, facilitado el control de las distintas variables que se asocian a cada especialidad. El objetivo del presente estudio fue describir el perfil de composición corporal en militares de elite al momento de finalizar un curso de especialización. Participaron 11 militares con un rango de edad entre 22 y 29 años. Se evalúo la composición corporal a través de BIA, inmediatamente después de finalizado un curso de especialización para militares de élite. Las evaluaciones en los militares sobre las variables de la composición corporal a través de BIA mostraron: peso corporal de 84,3 ± 4,52 kg, talla 1,78 ± 0,06 m, índice de masa corporal (IMC) 26,5 ± 1,09, tejido adiposo de 13,7 ± 3,65 %, tejido muscular 49,5 ± 2,34 %, masa libre de grasa 72,7 ± 5,23 kg y 53,2 ± 3,78 l de agua corporal total. Conclusiones: Los militares de elite presentaron elevados niveles de masa libre de grasa, tejido muscular y bajos niveles de tejido adiposo lo que favorece el desarrollo de las actividades militares especializadas y disminuye el riesgo de lesiones. Los datos aquí recogidos sirven como marco de referencia para futuros estudios.

SUMMARY: Electrical bioimpedance (BIA), being a non- invasive technique but with high precision, has become a valuable tool for determining body composition in the military, facilitating the control of the different variables associated with each specialty. The aim of the present study was to describe the body composition profile of elite military personnel at the end of a specialization course. Eleven military personnel between 22 and 29 years of age participated in the study. Body composition was assessed by BIA immediately after completion of a specialization course for elite military personnel. Assessments in the military on body composition variables through BIA showed: body weight of 84.3 ± 4.52 kg, height 1.78 ± 0.06 m, body mass index (BMI) 26.5 ± 1.09, adipose tissue of 13.7 ± 3.65 %, muscle tissue 49.5 ± 2.34 %, fat free mass 72.7 ± 5.23 kg and 53.2 ± 3.78 l of total body water. Conclusions: Elite military personnel presented high levels of fat free mass, muscle tissue and low levels of adipose tissue which favors the development of specialized military activities and decreases the risk of injury. The data collected here serve as a frame of reference for future studies.