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Lepidium meyenii Walp (LmW) or Maca, including its bioactive components such as macamides, among others, has demonstrated antioxidant effects. However, the effect size (ES) of LmW on oxidative stress has not been qualitatively described and calculated. The primary objective of this systematic review and meta-analysis was to review and qualitatively describe the studies published up to 2023 that supplemented LmW to control cellular oxidative stress; the secondary objective was to calculate the ES of the different interventions. The search was designed following the PRISMA® guidelines for systematic reviews and meta-analyses and performed in the Web of Science, Scopus, SPORTDiscus, PubMed, and MEDLINE until 2023. The selection of studies included randomized controlled trials, with tests and post-tests, both in vitro and in vivo in animals and humans. The methodological quality and risk of bias were evaluated with the CAMARADES tool. The main variables were reduced glutathione, glutathione peroxidase, superoxide dismutase, and malondialdehyde. The analysis was conducted with a pooled standardized mean difference (SMD) through Hedges' g test (95% CI). Eleven studies were included in the systematic review and eight in the meta-analysis. They revealed a small effect for reduced glutathione (SMD = 0.89), a large effect for glutathione peroxidase (SMD = 0.96), a moderate effect for superoxide dismutase (SMD = 0.68), and a moderate effect for malondialdehyde (SMD = -0.53). According to the results, the phytochemical compounds of LmW effectively controlled cellular oxidative stress, mainly macamides. It was also determined that a higher dose of LmW generated a greater antioxidant effect. However, information concerning humans is scarce.

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The use of creatine monohydrate (Cr) in professional soccer is widely documented. However, the effect of low doses of Cr on the physical performance of young soccer players is unknown. This study determined the effect of a low dose of orally administered Cr on muscle power after acute intra-session fatigue in young soccer players. Twenty-eight young soccer players (mean age = 17.1 ± 0.9 years) were randomly assigned to either a Cr (n = 14, 0.3 g·kg-1·day-1 for 14 days) or placebo group (n = 14), using a two-group matched, double-blind, placebo-controlled design. Before and after supplementation, participants performed 21 repetitions of 30 m (fatigue induction), and then, to measure muscle power, they performed four repetitions in half back squat (HBS) at 65% of 1RM. Statistical analysis included a two-factor ANOVA (p ˂ 0.05). Bar velocity at HBS, time: p = 0.0006, ŋp2 = 0.22; group: p = 0.0431, ŋp2 = 0.12, time × group p = 0.0744, ŋp2 = 0.02. Power at HBS, time: p = 0.0006, ŋp2 = 0.12; group: p = 0.16, ŋp2 = 0.06, time × group: p = 0.17, ŋp2 = 0.009. At the end of the study, it was found that, after the induction of acute intra-session fatigue, a low dose of Cr administered orally increases muscle power in young soccer players.

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Functional autonomy (FA) is a critical factor in determining the quality of life of older adults (OA), especially in the case of older women (OW), as they face a decline in FA in their later years of life. FA should be assessed early, using valid, reliable, and low-cost tests. This study evaluated the test-retest reliability of GDLAM and GDLAM autonomy index (GI) in OW. Thirty-nine OW (71.2 ± 6.50 years) participated in the study. A repeated measures design was used to compare the interday test-retest reliability of the five GDLAM tests (seconds) and the GI (points). The five tests represent activities of daily living, such as dressing or wandering around the house, while the GI provides a weighting of the results of the five tests. The analysis consisted of the intraclass correlation coefficient (ICC), standard error of measurement (SEM), and coefficient of variation (CV). A CV ≤ 10% and an ICC ≥ 0.80 were considered acceptable reliability, whereas a CV ≤ 5% and an ICC ≥ 0.90 were considered high reliability. The outcome of the five tests, represented by the GI, showed high interday test-retest reliability (CV = 6.00% and ICC = 0.91). The results of this study demonstrate that the five tests of the GDLAM protocol and the GI have high interday test-retest reliability and good interday reproducibility. From a practical point of view, the GDLAM protocol allows the assessment of FA of community-dwelling OW, providing background for early diagnosis and, with it, the possibility of developing an individualized physical exercise prescription.

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Background and Aims: Due to increased urbanization and industry, environmental pollution is a serious public health concern. Globally, the quality of life is particularly lowered by exposure to high amounts of particulate matter (PM). Chile has five industrial zones with high pollution levels, called "sacrifice zones." However, the effect of polluted air on the quality of life and functional autonomy (FA) of older people living in industrial zones with high pollution levels is unknown. Therefore, this study aimed to determine the quality of life and FA differences between Chilean older women (OW) living in areas with lower and higher PM levels. Materials and Methods: Seventy-two OW volunteered for this study. The sample was divided into Zone 1 (PM2.5 ≤ 15 µg/m3, n = 36) and Zone 2 (PM2.5 > 15 µg/m3, n = 36). The variables were quality of life-assessed through the SF-36v2.0 questionnaire, and FA-assessed through the GDLAM protocols. Differences between zones were tested by Student's t-test and Mann-Whitney test, both for independent samples (p < 0.05). Results: All eight dimensions of quality of life were lower in Zone 2, of which the role emotional (RE) showed significant differences between zones (p < 0.05). Performance on the GDLAM protocols and the FA index were lower in Zone 2 (p ˃ 0.05). Conclusion: OW in Zone 2 showed lower quality of life and FA. PM could affect the older population's physical and mental health and, therefore, the quality of life.

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A good muscle quality index (MQI) may have an inverse relationship with psychosocial variables of depression, anxiety, and stress in adolescents. Unfortunately, little scientific evidence has related MQI to psychosocial variables in this population. Therefore, this research aimed to determine the relationship between the MQI and psychosocial variables of depression, anxiety, and stress in Chilean adolescents. In this quantitative correlational design study, sixty adolescents participated voluntarily (mean ± standard deviation [SD]: age 15.11 ± 1.78 years). Anthropometric parameters, prehensile strength, MQI, and psychosocial variables were evaluated. The results showed that adolescents with high levels of MQI presented lower levels of depression (7.50 ± 6.06 vs. 10.97 ± 5.94), anxiety (5.64 ± 4.81 vs. 9.66 ± 5.12), and stress (6.79 ± 5.09 vs. 10 ± 5.58), in addition to reported lower abdominal obesity (WtHR, 0.47 ± 0.07 vs. 0.52 ± 0.07) than those with low levels of MQI. The group with high levels of MQI reported a higher prevalence of nonanxiety (81.3%, p = 0.031) and a lower prevalence of abdominal obesity (55.8%, p = 0.023). Likewise, a significant inverse association was evidenced between MQI and depression (ß; -6.18, 95% CI; -10.11: -2.25, p = 0.003), anxiety (ß; -6.61, 95% CI; -9.83: -3.39, p < 0.001) and stress (ß; -4.90, 95% CI; -8.49: -1.32 p = 0.008). In conclusion, the results suggest that high levels of MQI are associated with a higher prevalence of nonanxiety in adolescents and a significant inverse association between MQI and levels of depression, anxiety, and stress.

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Background: Mental health among university students is a public health problem in Chile, understanding that this population is susceptible to mental disorders. Objective: The present study aimed to determine the prevalence and variables influencing depression, anxiety, and stress in Chilean university students. Method: A representative sample (n = 1,062) of Chilean university students and a cross-sectional study design were used. Bivariate analysis and multiple logistic regression were performed to identify risk factors associated with symptomatology. They were analyzed using descriptive statistics. A questionnaire with sociodemographic variables was applied in November 2022, in addition to the depression anxiety stress scale (DASS-21), instruments with excellent reliability in this population (α = 0.955; ω = 0.956). On the other hand, the Questionnaire of Problematic Alcohol and Drug Consumption (DEP-ADO) was applied. A descriptive analysis was performed, followed by bivariate analysis and multiple logistic regression using SPSS version 25. The variables showed a value of p <0.05; they were declared statistically significant in the final model. Odds ratios (OR) were adjusted to a 95% confidence interval (95% CI), which was used to determine the independent predictors. Results: The prevalence of mental health problems in this population was high, with depressive symptoms in 63.1% of the sample; 69.2% with anxiety; 57% with stress; 27.4% with problematic alcohol consumption; and 14.9% with inappropriate marijuana consumption. Some 10.1% of the sample reported daily medication with antidepressants and/or anxiolytics. Concerning significant variables for depression, these were: being female, belonging to sexual, not having children, having problematic marijuana use, and using prescription drugs. Concerning anxiety, the significant variables were being a woman, belonging to sexual minorities, being an adolescent, and consuming prescription medication. Finally, concerning stress, the significant variables were being a woman, belonging to sexual minorities, being a student dedicated exclusively to academic activities, and taking prescription medication. Conclusion: Chilean university students presented a high prevalence of anxiety, depression, and stress, where being female and belonging to sexual minorities seem to be the variables that have the greatest impact on susceptibility to mental health problems. These results should call the attention of political and university authorities in Chile to improve this population's mental health and quality of life since they are the following professional generation of our country.

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Variable resistance (VR) is a methodology that has shown good results in developing muscular strength and power. However, no updated information relates to the use of VR as an activation to trigger post-activation performance enhancement (PAPE). The primary objective of this systematic review and meta-analysis was to review and qualitatively describe studies published between 2012 and 2022 that used VR to generate PAPE in muscle power-dominant sports. The secondary objective was to calculate the effect size of the different power outcomes reported in the selected studies. The search was designed following the PRISMA® guidelines for systematic reviews and meta-analyses and performed in the Web of Science (WOS), Scopus, SPORTDiscus, PubMed, and MEDLINE between 2012 and 2022. The methodological quality and risk of bias were evaluated with the Cochrane Collaboration tool. The main variables were the throwing speed, time in sprint tests, and jump height. The analysis was conducted with a pooled standardized mean difference (SMD) through a Hedges' g test (95% CI). Twenty-two studies were included in the systematic review and ten in the meta-analysis, revealing a trivial effect for throwing speed (SMD = 0.06; CI = 95%: -0.23-0.35; p = 0.69), a small effect for the time in sprint tests (SMD = -0.37; CI = 95%: -0.72--0.02; p = 0.04), and a moderate effect for jump height (SMD = 0.55; CI = 95%: 0.29-0.81; p ˂ 0.0001). All forms of VR used for neuromuscular activation effectively triggered PAPE. Specifically, the results showed that activation with VR generates performance increases in time, in sprint tests and jump height, and a trivial effect in throwing tests (speed and distance).

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The objectives of this study were: (a) to determine asymmetries, both lower limb (LL) and upper limb (UL), in Chilean older adults, and (b) to relate asymmetries to FA in both LL and UL. Forty-one older adults voluntarily participated in this study (mean ± standard deviation [SD]: age 72.0 ± 8.0 years, LL asymmetries 13.78 ± 14.87%, UL asymmetries 10.70 ± 8.85%, FA 40.35 ± 16.26 points). The variables were: (1) asymmetries of LL and UL, assessed through a force platform and handgrip, respectively; (2) FA, assessed through the Latin American Group for Maturity (GDLAM) and the GDLAM index of autonomy (GI) protocol. The relationship between the variables was performed through Spearman's correlation. The analysis showed that 39% of the participants presented asymmetries above 15% in the LL. Likewise, this 39% of older adults presented a lower FA than their peers with asymmetries below 15% in the LL (≤15%: 35.64 ± 12.26 points vs. >15%: 47.69 ± 19.23 points, p = 0.003). The analysis showed a small correlation between LL and GI asymmetries (r = 0.27, p = 0.07) and a small but negative correlation between UL and GI (r = -0.21). The mean values of asymmetries of both LL and UL are within 'normal' parameters. However, several older adults were identified as being at risk. In parallel, older adults who presented a higher level of asymmetries in LL showed a lower level of FA.

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Some experiences demonstrate a direct correlation between attention capacity and reaction capacity. However, the evidence from adolescents enrolled in the Chilean school system is scarce. The purpose of this study was to determine the relationship between attention capacity and hand-eye reaction time (RT) in adolescents between 15 and 18 years of age. Thirty-one adolescents participated voluntarily in this study. The variables were: attention capacity, evaluated through the Evalúa-10 battery (item 1.1), and hand-eye RT, assessed through a simple RT test (SRT) and complex RT (CRT). The relationship between the variables was performed through Pearson's correlation. Comparisons between males and females were performed with the t-test for independent samples (p ˂ 0.05). There was a moderate correlation between attention and CRT (r = -0.43), a very high correlation between attention and SRT in males (r = -0.73), and between attention and CRT in females (r = -0.73). Between males and females, there was no difference in attention (p ˃ 0.05), while males showed better RT in all tests (p ˂ 0.05). Attention positively influences hand-eye RT in both males and females. Likewise, male adolescents present better hand-eye RT than their female peers.

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Background: Standardized tests are currently available to assess power output in elite rowers. However, there are no valid and reliable tests to assess power output in amateur rowers. Objective: This study aimed to determine the validity and reliability of a 6-min rowing ergometer test (6-minRT) as a predictor of power output (PO) in amateur male rowers. Methods: Twelve male amateur rowers were part of the study. All participants were instructed to perform an incremental test (IT), a 6-minRT test, and a retest. The validity of the 6-minRT was determined by comparing maximum oxygen uptake (VO2max) and power output (PO) between the IT and 6-minRT. Reliability included the coefficient of variation (CV), intra-class correlation coefficient (ICC), and mean standard error between the 6-minRT test and retest. The significance level was p < 0.05. Results: There was no significant difference in VO2max in both IT and 6-minRT (p = 0.18), while the mean power output (Pmean) generated in the 6-minRT equaled 91.96% of the maximal aerobic power (MAP) generated in the IT (p = 0.004). Reliability analysis for the 6-minRT showed a CV = 0.50% and ICC = 0.97 for distance, a CV = 1.85% and ICC = 0.96 for Pmean. Conclusion: From a ventilatory and mechanical point of view, the 6-minRT is a maximally valid test for establishing MAP in amateur rowers. Also, the 6-minRT evidences a high degree of agreement between days. Therefore, the 6-minRT is a valid and reliable test for assessing PO in amateur male rowers.

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Introduction: Affectivity has a fundamental role in educational systems' training process. However, there are no updated studies that show the different socio-affective agents used in the creation of physical habits in the child and adolescent population in school systems. Objective: To review and analyze previously published research that studied the influence of affectivity on children and adolescents' physical habits in school systems. Materials and methods: A systematic review was conducted with articles published between 2010 and 2020, which connected affectivity and physical habits. The electronic search was performed through Web of Science, Scopus, and Scielo databases. All articles that studied the influence of affectivity on the population's physical habits were included. Results: Three studies that analyzed the influence of affectivity on children and adolescents' physical habits were found. Conclusions: At the end of the systematic review, it was demonstrated that there is a significant relationship between affectivity and the physical habits in child and adolescent populations. It was also possible to observe that this influence, positive or negative, determines the child and adolescent population's interest in physical activity and sports in adult life.

Introducción: La afectividad tiene un papel fundamental dentro del proceso de formación en los sistemas educativos. Sin embargo, no existen estudios actualizados que evidencien los diversos agentes socioafectivos utilizados en la creación de hábitos físicos en la población infantil y adolescente de los sistemas escolares. Objetivo: Analizar investigaciones previamente publicadas que estudiaron la influencia de la afectividad en los hábitos físicos de niños y adolescente de los sistemas escolares. Materiales y métodos: El estudio corresponde a una revisión sistemática. Se evaluaron artículos publicados entre 2010 y 2020 que relacionaron afectividad y hábitos físicos. La búsqueda electrónica se realizó a través de las bases Web of Science, Scopus y Scielo. Se incluyeron todos los artículos que utilizaron la afectividad sobre los hábitos físicos de la población. Resultados: Se encontraron tres artículos que utilizaron la afectividad sobre los hábitos físicos de niños y adolescentes. Conclusiones: Al término de la revisión sistemática, se demostró que existe una tremenda influencia entre la afectividad y los hábitos físicos de la población infantil y adolescente. También se pudo observar que esta influencia, positiva o negativa, condiciona el interés de la población infantil y juvenil por la actividad física y el deporte en la vida adulta.

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The assessment of the strength and muscle mass of the hand-finger segment are reliable indicators of health and predictors of cardiometabolic risk in the adult population. However, there are no valid and reliable tests to assess the muscle power of this segment in healthy adolescents. The objective of this study was to determine the validity and inter-day reliability of a grip power test (GripW test) in healthy adolescents. Twenty-one adolescents (15.61 ± 2.20 years old) were part of the study. All participants were instructed to perform a grip with incremental load sets from 1-10 kg as fast as possible. The validity of the GripW test was determined with the load-power curve and linear regression equation. Inter-day reliability considered the coefficient of variation (CV), intra-class correlation coefficient (ICC), and standard error of the mean (SEM). The significance level for all statistical analyses was p < 0.05. The parabola in the load-power curve for both hands showed normality for the GripW test. In addition, the analysis showed a CV = 4.63% and ICC = 1.00 for the right hand, while the left hand showed a CV = 3.23% and ICC = 1.00. The GripW test proved to be valid and reliable for assessing gripping muscle power functionally and unilaterally in healthy adolescents.

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Recent research has shown that good sleep quality has a positive effect on physical performance. However, sleep quality in Chilean professional soccer players is unknown. The purpose of this study was to determine sleep quality in Chilean professional soccer players. It was a cross-sectional, explanatory study with observable variables. The sample consisted of 94 Chilean male soccer players belonging to four professional clubs. The main variable was the Sleep Quality Index, evaluated through the Pittsburgh questionnaire (Spanish version). After estimating sleep quality individually, the four professional soccer clubs' comparison was performed through a one-factor ANOVA. The Pearson test was used to relate the questionnaire variables; the significance level was p < 0.05. In the global analysis of the Pittsburgh Sleep Quality Index, a value of 4.75 ± 2.29 on a scale of 0-21 was observed, with no significant differences between the clubs evaluated (p > 0.05). Based on the results obtained, Chilean male professional soccer players present good sleep quality. However, the high values of "sleep latency" and "sleep disturbances" are indicators that should be worked on by the multidisciplinary team of each professional club. They should develop strategies to improve sleep hygiene, encourage good sleep, and fall asleep efficiently.

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