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Abstract Cardiorespiratory fitness is the most important variable related to health and a strong predictor of mortality. However, it is rarely used in clinics due to costs, specialized equipment, space needs, and the requirements of expert staff such as an exercise physiologist, physician, or other health professional. This work aims to validate and test the reliability of a submaximal step test to estimate VO2max of 8-to 16-year-old pediatric populations as a simple and low-cost tool for clinical practice. A cross-sectional study included 242 children and adolescents (42.1% girls) aged 8–16. Cardiorespiratory fitness was determined by a maximal incremental test on a treadmill until exhaustion. The step test entailed maintaining a steady pace of 22 steps per minute for 3 min (60 bpm), with the heart rate being recorded at the end of the test. Nutritional status was computed through BMI z-score. A multiple linear regression model validated the step test and developed a new equation to predict VO2max, including the third-minute heart rate, weight, and height. The reliability among predicted and measured VO2max was assessed by Bland-Altman analysis. The mean age was 12.5 ± 2.6; 51.6% were overweight or obese. The cardiorespiratory fitness measured as VO2max was 35.01 ± 0.58 ml·min-1·kg−1. A robust correlation was observed between the predicted VO2max from the step test and the measured VO2max (r = 0.86, p

Aunque las investigaciones actuales indican que el modo activo de desplazamiento influye en la salud de los escolares, lo que se sabe sobre la relación entre la condición física autoinformada y su relación con la forma de desplazarse activamente hacia y desde la escuela (ACS, por sus siglas en inglés) se sabe menos. Los objetivos de este estudio fueron a) analizar la aptitud física autoinformada y la ACS, y b) determinar la asociación entre la aptitud física autoinformada con ACS a través de una encuesta realizada en el sur de Chile. Se realizó un diseño analítico transversal. La muestra estuvo compuesta por 733 escolares (de 10 a 16 años, 46,1% niñas) de colegios públicos chilenos. Se utilizó la International Fitness Scale (IFIS) para determinar la aptitud física autoinformada. Se evaluaron los modos de desplazamiento de los estudiantes a la escuela mediante preguntas separadas sobre ACS. Los principales resultados mostraron que los niños presentaron una mejor aptitud física autoinformada que las niñas, excepto en la autopercepción de flexibilidad (p= 0,041). Además, se observó asociación entre el tipo de ACS y la flexibilidad autoinformada (OR:1,53, p=0,022; OR:1,47, p= 0,036), asociación que se mantuvo al ajustar por sexo y la edad (OR:1,55, p=0,020; OR:1,50, p= 0,030), la velocidad y la agilidad autoinformada se asociaron sólo con el desplazamiento activo desde la escuela (OR:1,60, p=0,005), también después del modelo ajustado (OR:1,81, p=0,024). En conclusión, este estudio proporciona evidencia sobre la relación entre la aptitud física autoinformada y las formas de ACS. Para promover la salud en los escolares se deben buscar estrategias que favorezcan los ACS.

El uso de escalas de tasa de esfuerzo percibido (RPE) basadas en repeticiones de reserva (RIR) puede ser un complemento a los métodos absolutos, como 1 repetición máxima (1RM), la variable porcentual con respecto a 1RM (xRM) y la velocidad concéntrica media (VCM), optimizando el control de la intensidad del entrenamiento. El objetivo de este estudio fue evaluar la validez del uso de la escala de esfuerzo subjetiva RPE-RIR como herramienta de autorregulación con respecto a los métodos de cuantificación de la intensidad de la carga de entrenamiento. Realizamos una búsqueda sistemática en las bases de datos PubMed, WOS y Scopus. Se revisaron un total de 2.271 artículos, de los cuales 7 cumplieron con los criterios de elegibilidad. En estos estudios participaron 147 sujetos entrenados en fuerza (novatos, experimentados, profesionales, levantadores de pesas), que respondieron a la implementación de protocolos que cuantifican la intensidad de carga subjetiva y objetiva (relación RPE-RIR e intensidad de carga objetiva, velocidad concéntrica media - 1RM/xRM). Se encontraron fuertes correlaciones entre las variables del estudio RPE-RIR/ Velocidad concéntrica media (r = 0,90 - 0,92; r = -0,98 a -1,00; EL: r = 0,85/ r = -0,88, NL: r = 0,85/ r = -0,77), RPE-RIR/1RM (r = 0,88 a 0,91). Las principales conclusiones de esta revisión sistemática en relación con los métodos y medios para cuantificar la intensidad objetiva y subjetiva de la carga de entrenamiento indican una fuerte correlación entre el RPE-RIR (como método subjetivo) y el VCM y 1RM/xRM (como método objetivo), especialmente en poblaciones inexpertas. Sin embargo, estas conclusiones deben considerarse individualmente, dadas las diferencias entre protocolos y movimientos analizados y el análisis limitado de poblaciones noveles. Palabras clave: Esfuerzo subjetivo, carga de entrenamiento, metodologías de ejercicio. Abstract. The use of rate of perceived effort scales (RPE) based on reserve repetitions (RIR) can be a complement to absolute methods, such as 1 maximum repetition (1RM), the percentage variable with respect to 1RM (xRM), and the average concentric velocity (ACV), optimizing control of training intensity. This study aimed to evaluate the validity of using a subjective RPE-RIR effort scale as a self-regulation tool with respect to quantifying the intensity of the training load. We perform a systematic search in PubMed, WOS, and Scopus databases. 2,271 articles were reviewed, of which 7 met the eligibility criteria. These studies involved 147 subjects trained in strength (novices, experienced professionals, and powerlifters), who responded to the implementation of protocols that quantify the subjective and objective load intensity (RPE-RIR relationship and objective load intensity, mean speed - 1RM/xRM). There are strong correlations between the variables in the RPE-RIR study/ Average concentric velocity (r = 0.90 - 0.92; r = -0,98 to -1,00; EL: r = 0.85/ r = -0.88, NL: r = 0.85/ r = -0.77), RPE-RIR/1RM (r = 0.88 to 0.91). The main conclusions of this systematic review regarding methods and means of quantifying objective and subjective intensity of training load indicate a strong correlation between RPE-RIR (as a subjective method) and ACV and 1RM/xRM (as an objective method), especially in inexperienced populations. However, these findings should be considered individually, given the differences between protocols and movements analyzed and the limited analysis of novice populations. Keywords: Subjective Effort, Training Load, Exercise Methodologies.

Whey protein (WP) supplements have grown in popularity for exercising populations to enhance muscle protein synthesis and promote recovery. The purpose of this investigation was to examine the macronutrient profile, especially protein, of commonly sold protein powder brands in the Colombian (South America) sports supplement market. Eleven popular whey proteins supplements made and sold on the Colombian market were sampled and determined the humidity, ash, total carbohydrates, fat, proteins, and calories (kcal). The mean calorie content declared by product labeling was significantly lower (p

Introducción. El estudio de variables antropométricas y genéticas son fundamentales como determinantes del rendimiento deportivo. Objetivo. El objetivo del estudio fue determinar el somatotipo y la frecuencia de genotipo y alelo de 𝜶-actinina 3 (ACTN3) R577X y enzima convertidora de angiotensina (ECA) I/D polimorfismo de jugadores de tenis de mesa chilenos. Método. Se estudiaron 24 tenimesistas varones (edad 22,1 ± 5,4) del ranking nacional de Chile. La obtención de ACTN3 y ECA se recogió por muestra la saliva y se analizaron mediante reacción cadena de la polimerasa convencional. La estructura corporal se caracterizó a través del método del somatotipo propuesto por Carter. A partir de estadísticas descriptiva, se analizaron los valores medios de somatotipo, frecuencia de clasificación y ubicación de somato carta, además, de valores de frecuencia de genotipo y alelo de ACTN3 R/X y ECA I/D polimorfismo de acuerdo con número de aparición y porcentaje.Resultados. Se evidenció un predominio de clasificación mesoendomórfica y endomesomórfica, una mayor frecuencia fenotípica XX con predominio de alelo X para el gen ACTN3 y mayor frecuencia DI con predominio de alelo D para ECA. Conclusión. El somatotipo de tenimesistas chilenos tiene una orientación hacia mesoendomorfía y un predominio XX y alelo X del gen ACTN3 y, predominio del genotipo DI y alelo D del gen ECA, estas características podrían ofrecer una ventaja genética en cuanto a niveles de fuerza y potencia muscular, posiblemente facilitando la práctica y el éxito competitivo en estos tenimesistas chilenos. Abstract. Introduction. The study of anthropometric and genetic variables are essential as determinants of sports performance. Objective. The objective of the study was to determine the somatotype and the frequency of genotype and allele of 𝜶-actinin 3 (ACTN3) R577X and angiotensin converting enzyme (RCT) I / D polymorphism of Chilean table tennis players. Method. 24 male table tennis players (age 22.1 x 5.4) of Chile's national rankings were studied. Obtaining ACTN3 and ACE was collected by sample of saliva and analyzed by polymerase chain in real time. The body structure was characterized through the somatotype method proposed by Carter. From descriptive statistics, the mean values of somatotype, frequency of classification and location of somato letter were analyzed, in addition, of genotype frequency values and allele of ACTN3 R/X and ECA I/D polymorphism according to number of occurrence and percentage. Results. It demonstrated a predominance of mesoendomorphy and endomorphy classification, a higher phenotypic frequency XX with predominance of allele X for the ACTN3 gene and higher frequency of DI allele with predomina D for ACE. Conclusion. The somatotype of Chilean tenimestists has an orientation towards mesoendomorphy and a predominance of the genotype XX and allele X of the ACTN3 gene and, predominance of the DI genotype and allele D of the ACE gene, these characteristics could offer a genetic advantage in terms of strength levels and muscle potency, possibly facilitating practice and competitive success in these Chilean tenimists.

Caffeine is a popular ergogenic aid that has a plethora of evidence highlighting its positive effects. A Google Scholar search using the keywords “caffeine” and “exercise” yields over 200,000 results, emphasizing the extensive research on this topic. However, despite the vast amount of available data, it is intriguing that uncertainties persist regarding the effectiveness and safety of caffeine. These include but are not limited to: 1. Does caffeine dehydrate you at rest? 2. Does caffeine dehydrate you during exercise? 3. Does caffeine promote the loss of body fat? 4. Does habitual caffeine consumption influence the performance response to acute caffeine supplementation? 5. Does caffeine affect upper vs. lower body performance/strength differently? 6. Is there a relationship between caffeine and depression? 7. Can too much caffeine kill you? 8. Are there sex differences regarding caffeine’s effects? 9. Does caffeine work for everyone? 10. Does caffeine cause heart problems? 11. Does caffeine promote the loss of bone mineral? 12. Should pregnant women avoid caffeine? 13. Is caffeine addictive? 14. Does waiting 1.5–2.0 hours after waking to consume caffeine help you avoid the afternoon “crash?” To answer these questions, we performed an evidence-based scientific evaluation of the literature regarding caffeine supplementation.

This study aimed to automatically classify physical fitness and cardiometabolic risk in a Chilean adolescent using self-organizing maps. This cross-sectional study analysed a nationally representative database from the Physical Education Quality Measurement System (n = 7197). Physical fitness and cardiometabolic risk variables were derived from anthropometric indicators. Self-Organizing maps (SOM) were employed to identify participant profiles based on an unsupervised predictive model. After implementing and training the SOM, a detailed analysis of the generated maps was conducted to interpret the revealed relationships and clusters. The analysis resulted in three classification groups, categorizing the sample into low, moderate, and high-risk levels. Students with better physical fitness exhibited lower cardiometabolic risk levels and a lower body mass index. SOM, through an unsupervised model, is a reliable tool for classifying cardiometabolic risk and physical fitness in adolescents.

Objective This systematic review was conducted to analyze the existing evidence on the effects of strength training (ST) and complex/contrast training (CCT) on repeated sprint ability (RSA) in team sports players. Methods A systematic review of the literature was performed following the PRISMA statement. PubMed, Web of Science, and Scopus databases were used. Original full-text articles were analyzed, without date restriction until May 26, 2024, written in English, peer-reviewed, and for eligibility must have included (1) male or female team sports players, amateur or professional category, without age restriction (2) lower extremity ST and/or CCT program (3) active control group (4) running RSA test (e.g., repeated shuttle sprint ability test or straight-line repeated sprint ability test) before and after the intervention period (5) controlled trial. Results A total of 3,376 studies were identified and screened. Finally, 10 articles were included based on the inclusion and exclusion criteria, all with moderate methodological quality according to the PEDro scale. The best time, mean time, and total time presented significant pre and post-test changes, using ST in 3, 2, and 1 experimental groups, respectively, and using CCT in 1, 1, and 1 experimental groups, respectively, with almost no differences in the percentage decrement most commonly reported in RSA tests. There were no changes in the control groups. Conclusion Together, ST performed in a range of maximal power provides benefits in the best time and mean time and performed between 80 to 95% of 1 repetition maximum (RM) provides benefits in the best time, mean time, and total time in RSA tests. CCT performed between 75 to 90% of 1 RM combined with jumps and sprints provides benefits in the best time, mean time, and total time in RSA test, but no unaltered percentage decrement in ST and CCT in elite and semi-professional team sport players.

This study evaluated the influence of acute fatigue on heart rate variability (HRV) and muscle oxygen saturation (SmO2) at rest, as well as the reliability of SmO2 data measured using near-infrared spectroscopy (NIRS) during a vascular occlusion test (VOT). Twelve physically active subjects participated. Measurements included perceived muscle soreness using the visual analog scale (VAS pain), HRV parameters, variables of resting SmO2 (desaturation and resaturation), and reoxygenation kinetics (mean response time, MRT) through a VOT-NIRS located in the vastus lateralis (VL). Measurements were taken at three points: 24 h before, before exhaustive exercise, and 30 min after exhaustive exercise. The results indicated that acute fatigue increased resting muscle oxygen consumption in desaturation (+22 SmO2) and resaturation (+18 SmO2), improved MRT (−15 s), and elevated sympathetic nervous system (SNS) activity, as observed in the R-R interval (−262 ms) and SNS index (+0.5). HRV significantly influenced desaturation (r2 = 0.69), resaturation (r2 = 0.60), and MRT (r2 = 0.54). Reliability was established with an ICC of 0.49 and 0.63 for desaturation and resaturation, respectively. Real changes in desaturation and resaturation should be considered ≥ 7% SmO2 at rest and ≥ 11% SmO2 to avoid daily fatigue interference. In conclusion, acute fatigue increases resting SmO2 consumption and is associated with higher SNS activity and increased VAS pain.

Non-communicable diseases (NCDs) account for 71% of all annual deaths, totaling 41 million people worldwide. The development and progression of these diseases are highly related to the environment and lifestyle choices, among which physical inactivity and excess malnutrition stand out. Currently, in Chile, there is no evidence at the regional and local level on the impact of physical activity and healthy nutrition plans and interventions on health promotion, prevention, and timely treatment of NCDs. The following protocol delineates the URO/FOCOS (Universidad Regional de O’Higgins/FOrtaleciendo COmunidades Saludables- Regional University of O’Higgins/Strengthening Healthy Communities) study, which will assess pilot community intervention strategies using a participatory action research approach by identifying barriers and facilitators on the practice of physical activity and healthy eating habits. In this project, the community from the O’Higgins region will be involved throughout the entire research process to develop strategies that promote regular physical activity and healthy eating practices. We propose three interrelated strategies: (1) Participatory Action Research, (2) Community interventions for promoting physical activity and healthy nutrition practices, and (3) health education. The URO/FOCOS study offers a unique opportunity in the O’Higgins region to develop participatory strategies and interventions based on the community’s needs and motivations with regard to physical activity and healthy eating habits. We believe these strategies will help to improve the community’s overall health through effective changes in their decision and preferences toward a more active lifestyle and healthier nutrition practices.

Abstract The endocannabinoid system (ECS) regulates energy metabolism, has been implicated in the pathogenesis of metabolic diseases and exerts its actions mainly through the type 1 cannabinoid receptor (CB1). Likewise, autophagy is involved in several cellular processes. It is required for the normal development of muscle mass and metabolism, and its deregulation is associated with diseases. It is known that the CB1 regulates signaling pathways that control autophagy, however, it is currently unknown whether the ECS could regulate autophagy in the skeletal muscle of obese mice. This study aimed to investigate the role of the CB1 in regulating autophagy in skeletal muscle. We found concomitant deregulation in the ECS and autophagy markers in high-fat diet-induced obesity. In obese CB1-KO mice, the autophagy-associated protein LC3 II does not accumulate when mTOR and AMPK phosphorylation levels do not change. Acute inhibition of the CB1 with JD-5037 decreased LC3 II protein accumulation and autophagic flux. Our results suggest that the CB1 regulates autophagy in the tibialis anterior skeletal muscle in both lean and obese mice.

Physical inactivity is a major health concern, associated with the development of several non-communicable diseases and with an increased mortality rate. Therefore, promoting active lifestyles has become a crucial public health necessity for enhancing overall health and quality of life. The WHO guidelines for physical activity (PA) present valuable contributions in this respect; however, we believe that greater specificity should be added or complemented towards physical exercise (PE) testing, prescription and programming in future recommendations. In this review article, we suggest simple and practical tools accessible to the entire population to improve the specificity of this approach, highlighting aspects of PE programming used by trained subjects. By adopting these suggestions, exercise professionals, clinicians and physical trainers can optimise the current general PA recommendations towards PE prescription to improve fitness status and encourage PE adherence in the general population.

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.

The hypocaloric Mediterranean diet (MD) mainly reduces fat mass but inevitably causes a loss of skeletal muscle mass. High-intensity interval training (HIIT) seems to have advantages in preserving muscle mass during a hypocaloric regime. Our study compares body composition and metabolic changes in overweight and obese Chilean women and men after 3 months of weight loss treatment with a Mediterranean-type hypocaloric diet, HIIT, or a combination of both. The study included 83 overweight or obese women and men between the ages of 25 and 50. The subjects were randomly assigned to one of the three intervention groups: (1) MD, (2) EX, and (3) MD + EX. Baseline and post-intervention measurements included: (a) body composition by dual-beam densitometry, muscle, and fat measurements by thigh ultrasound and computed tomography; (b) handgrip and quadriceps muscle strength; (c) exercise performance by peak oxygen consumption, peak load, work efficiency, and exercise energy expenditure; and (d) metabolic parameters. Out of 83 participants, the retention rate was 49% due to low compliance with the interventions. As expected, the MD group resulted in significantly greater weight loss (MD −7%, EX −0.6% and MD + EX −5.3%) and appendicular fat mass loss (MD −11.1%, EX −2.9, MD + EX −10.2%) but was associated with significant lean tissue loss (2.8%), which was prevented by HIIT (EX −0.1 and MD + EX −0.6%). Metabolic and glycoxidative parameters remained unchanged, irrespective of changes in body composition. Hypocaloric diets remain the most effective means to lose weight and body fat. However, it induces a loss of lean body mass when not accompanied by exercise training. This study shows that HIIT prevents the loss of muscle mass caused by a hypocaloric Mediterranean diet.

La actividad física y ejercicio físico durante la gestación entregan beneficios tanto para la madre, al disminuir el riesgo de desarrollar condiciones como preeclampsia y diabetes gestacional, como para el feto, disminuyendo condiciones como la macrosomía y morbilidad respiratoria llevando a mejorar el resultado perinatal. Del mismo modo, una mejor condición física se asocia a resultados perinatales favorables. A nivel mundial, existen una serie de recomendaciones sobre los niveles de actividad física necesarios para obtener estos beneficios. La mayoría coincide en que se deben alcanzar al menos 150 minutos de actividad física moderada a la semana. A pesar de esto, la actividad física, el ejercicio y la condición física durante la gestación han sido poco explorados en Chile, existiendo una brecha en el conocimiento respecto a este tema. El objetivo de esta revisión es recopilar la evidencia disponible en Chile sobre actividad física, ejercicio y condición física durante la gestación, identificando las principales brechas de conocimiento respecto a este tema. Palabras clave: Actividad física, gestación, condición física. Abstract. Physical activity and exercise during pregnancy are beneficial for the mother, reducing the risk of developing conditions such as preeclampsia and gestational diabetes, as well as for the fetus by decreasing complications such as fetal macrosomia and respiratory outcomes, leading to an improved perinatal outcome. In the same way, a better physical fitness is associated to better perinatal outcomes. Worldwide, there are several recommendations regarding the appropriate physical activity levels necessary to obtain these benefits. Most agree that at least 150 minutes of moderate physical activity per week should be achieved. Despite this, physical activity, exercise, and physical fitness during pregnancy have been poorly explored in Chile, and thus there is a gap in knowledge on this subject. This review aims to compile the evidence available in Chile on physical activity, exercise, and physical fitness during pregnancy, identifying the main knowledge gaps on this topic. Keywords: Physical activity, pregnancy, fitness.

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; β = 0.678: p = 0.002; β = 0.751), and that the total and segmented skeletal muscle mass are associated with higher reoxygenation velocities during hyperemia (p = 0.020; β = −0.614: p = 0.027; β = −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; β = 0.692: p = 0.037; β = 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; β = −0.703: p = 0.017; β = −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.

The non-responders (NRs) after exercise training have been poorly studied in populations with morbid obesity. The purpose of this study was to determine the NR prevalence after 20 weeks of concurrent training of morbidly obese women with a high or low number of metabolic syndrome (MetS) risk factors. Twenty-eight women with morbid obesity participated in an exercise training intervention and were allocated into two groups distributed based on a high (≥3, n = 11) or low number (

La capacidad de generar máxima potencia neuromuscular es el factor más importante y determinante en el rendimiento atlético. Debido a esto, el entrenamiento con movimientos de Halterofilia (EMH) y sus derivados es uno de los métodos más usados, ya que la evidencia muestra que genera adaptaciones de fuerza-potencia superiores comparadas con el entrenamiento de fuerza tradicional, de salto y de kettlebells. Objetivo: Identificar los efectos del EMH en la capacidad de salto, esprint y cambio de dirección (COD) en población deportista. Método: Se realizó una búsqueda exhaustiva en diferentes bases de datos, como PUBMED, Sportdiscus (EBSCO), Scopus y Web of Science (WOS) bajo modelo PRISMA. Los trabajos revisados fueron experimentales con y sin grupo de control, entre los años 2000 y 2020. Resultados: El EMH produce mejoras significativas en las capacidades de salto, de esprint y de COD en población deportista. Conclusión: El EMH genera mejoras significativas en el rendimiento de salto, carreras y cambio de dirección bajo distintos protocolos. Existe evidencia que sustenta la aplicación de EMH, recomendando sus derivados centrados en el segundo tirón y aquellos que utilicen el ciclo de estiramiento-acortamiento en sus variantes colgantes. Abstract: The ability to generate maximum power is the most important and determining neuromuscular function in sports performance. Therefore, weightlifting training (WT) and its derivatives is one of the most widely used methods, generating superior strength-power adaptations compared to traditional strength training, jumping and kettlebell training. Objective: To identify the effects of WT on the ability to jump, sprint and change of direction (COD) in athletes. Method: An exhaustive search was carried out in different databases, such as PUBMED, Sportdiscus (EBSCO), Scopus and Web of Science (WOS) under the PRISMA model. The reviewed papers were experimental with and without a control group, between the years 2000 and 2020. Results: The WT produces significant improvements in jump, sprint and in change of direction capacities in the sport population. Conclusion: WT generates significant improvements in jumping, running and change of direction performance under different protocols. There is evidence supporting the use of WT, suggesting its derivatives focused on the second pull and those that use the stretch-shortening cycle in their hanging variants.

Olympic combat sports are unconventional physical activity strategies to train middle-aged and older people with and without health problems. This systematic review aimed to assess the available body of published peer-reviewed articles related to the effects of Olympic combat sports interventions (boxing, fencing, judo, karate, taekwondo, wrestling) on health-related quality of life in adults aged 45 and older. The search was carried out in five generic databases until July 2021 and the protocol was registered in PROSPERO (code: CRD42021244161). The PRISMA guidelines were followed and the Downs and Black checklist was used to assessed the methodological quality of the studies. After reviewing 1,151 records, only seven studies met the inclusion criteria, adding 212 participants (43.4% female) with a mean age of 63.7 years. Six studies (two with middle-aged participants and four with older people) provided data to calculate the effect size (ES) in the Olympic combat sports groups (No research that used taekwondo or wrestling as an intervention modality was found). Three studies reported beneficial changes with a small ES for the total score (d < 0.40) of the health-related quality of life. Two studies reported a beneficial change with a small ES (d = 0.49) and strong ES (d = 4.45) for physical health. One study reported improvements with a small ES for emotional (d = 0.23) and functional (d = 0.26) well-being. In conclusion, interventions based on Olympic combat sports produce beneficial effects with a small and moderate ES on health-related quality of life in male and female aged 45 and older who are healthy participants, participants with Parkinson's disease, and participants with breast cancer.Systematic Review Registration:https://www.crd.york.ac.uk/prospero/, PROSPERO: CRD42021244161.

We sought to assess the residual effects (post 72-h training cessation) on fasting plasma glucose (FPG) and fasting insulin (FI) after 12-weeks of high-intensity interval training (HIIT), resistance training (RT), or concurrent training (CT) in women with insulin resistance (IR). We also aimed to determine the training-induced, post-training residual impact of CT. A total of adult 45 women (age 38.5±9.2years) were included in the final analysis and were assigned to a control (CG; n=13, BMI 28.3±3.6kg/m2), HIIT [n=14, BMI 28.6±3.6kg/m2, three sessions/wk., 80–100% of the maximum heart rate (HRmax)], RT [n=8, BMI 29.4±5.5kg/m2, two sessions/wk., 8–10 points of the modified Borg, corresponding to 20 to 50% range of one maximum repetition test (1RM)], or CT group (n=10, BMI 29.1±3.0kg/m2, three sessions/wk., 80–100% of HRmax, and 8–10 Borg, or 20 to 50% range of 1RM, to each HIIT and RT compounds), with the latter including both HIIT and RT regimens. Training interventions lasted 12-weeks. The main outcomes were FPG and FI measured at pre- and 24-h and 72-h post-training (FPG24h, FI24h, and FPG72h, FI72h, respectively). Secondary endpoints were body composition/anthropometry and the adiposity markers waist circumference (WC) and tricípital skinfold (TSF). The residual effects 72-h post-training [delta (∆)] were significantly poorer (all p

Overweightness and obesity can negatively influence many activities, including postural balance and locomotion, increasing predisposition to injury and risk of falls due to limitations on the biomechanics of daily living. The present study aimed to determine the influence of the anthropometric profile and physical activity level (PAL) on the postural balance of overweight and obese children. The sample included 387 schoolchildren (216 boys and 171 girls). The variables of the anthropometric profile studied were body mass, biped height, BMI, waist circumference, waist-to-hip ratio (WHR), summation of folds, body composition, and somatotype. PAL was measured using the PAQ-C questionnaire. Static and dynamic postural balance were measured through an open-eye (OE) and closed-eye (CE) posturographic test and the SEBTm, respectively. For static balance, the significant models were for mediolateral velocity (R2 = 0.42 in OA; R2 = 0.24 in OC), anteroposterior velocity (R2 = 0.21 in OA; R2 = 0.27 in OC), and mean velocity (R2 = 0.27 in OA; R2 = 0.46 in OC), where the predictors of low performance were younger age, male sex, overweight/obese nutritional status, greater thickness of skin folds, less tendency to mesomorphy, and greater fat mass. On the other hand, for dynamic postural balance, the significant models were observed in the previous direction (R2 = 0.39), posteromedial (R2 = 0.57), and posterolateral (R2 = 0.56), where the variables that predict a low performance were low PAL, overweight/obese nutritional status, and high WHR. Overweight and obese children presented a deficit in static and dynamic postural balance, enhanced by variables such as gender, age, PAL, and anthropometric characteristics related to adiposity.

Context: High-intensity interval training (HIIT) is considered a time-efficient strategy to improve cardiometabolic health markers in children and adolescents. However, the evidence regarding the characterization of each intervention and the quantification of their health effects within the school environment is required. Objectives: To systematically review the characteristics of HIIT-based interventions during school time and quantify their effects on the health of children and adolescents. Data Sources: Recommendation of PRISMA for systematic review was applied. The protocol was registered in the PROSPERO repository 2018 CRD42018089017. A search of the literature (2008 - 2018) on the databases PubMed,Web of Science, CINHAL and PsycINFo was carried out. Study Selection: Twelve publications using HIIT on children and adolescents in a school-based environment were selected. The inclusion criteria were: (1) HIIT; (2) intervention and, (3) type of study. Data Extraction: The inclusion criteria to the titles and abstracts, or three independent researchers analyzed the articles. PRISMA’s recommendation for systematic reviews, Cochrane tool and ROBINS for randomized and non-randomized studies were used. Results: We identified 12 studies that included a total of 917 children and adolescents; 83% of the interventions were performed during physical education classes. The average duration and intensity of the interventions were 8 weeks and > 90% HR, respectively. The most important variables evaluated and impacted by HIIT were cardiovascular fitness, nutritional status, and physiological wellbeing. Conclusions: HIIT seems to be a reliable and time-efficient approach to impact especially cardiovascular fitness of children and adolescents during school time. The focus on class intensity and the number of repetitions needs further investigation to find interventions based on each school due to individual differences regarding time and implementation constraints to impact health parameters.

A growing body of research indicates that cortisol, the glucocorticoid product of the activation of the hypothalamic-pituitary-adrenal axis, plays a role in the pathophysiology of metabolic syndrome. In this regard, chronic exposure to cortisol is associated with risk factors related to metabolic syndrome like weight gain, type 2 diabetes, hypertension, among others. Mifepristone is the only FDA-approved drug with antiglucocorticoids properties for improved the glycemic control in patients with type 2 patients secondary to endogenous Cushing’s syndrome. Mifepristone also have been shown positive effects in rodents models of diabetes and patients with obesity due to antipsychotic treatment. However, the underlying molecular mechanisms are not fully understood. In this perspective, we summarized the literature regarding the beneficial effects of mifepristone in metabolic syndrome from animal studies to clinical research. Also, we propose a potential mechanism for the beneficial effects in insulin sensitivity which involved the regulation of mitochondrial function in muscle cells.

Background Hydration status affects endurance performance. Pre-exercise hydration recommendations target the consumption of high carbohydrate and sodium beverages. Milk, due to its carbohydrate and sodium content, may be considered an effective pre-exercise hydration beverage. Purpose In a randomized cross-over trial, we compared the effects of an isotonic sport drink (SPD) with skim milk (SM) consumption before a race, on fluid homeostasis and time-trial performance in road cyclists. Methods Male road cyclists (n = 9; age, 26.8 ± 4.78 years) with 10.8 ± 8.56 years of experience in national competitions, consumed either SPD or SM in doses of 350 mL at 3 h and 350 mL at 1.5 h before a 18.6 km time-trial race. Measurements of body mass, urine specific gravity (USG), urine color and time-trial were compared between drinks (group; g) before and after the race (time; t). Results The two-way ANOVA showed no differences between SPD and SM in body mass (t, p