Cardiorespiratory fitness and socioeconomic influences in Chilean schoolchildren: a cross-sectional study.

OBJECTIVE: To compare the cardiovascular risk and physical fitness, according to type of school in a national sample of Chilean school students. METHODS: A total of 7,218 students participated, who completed all the national tests of the National System for Measuring the Quality of Education, which included physical fitness and anthropometric tests. The results were compared according to the type of educational establishment and anthropometric indicators were considered. Physical fitness was measured by lower extremity strength, abdominal strength, upper extremity strength, trunk flexibility, exertional heart rate, and cardiorespiratory fitness. Body mass index, heart rate, and waist-to-height ratio were analyzed as predictors of cardiovascular risk. RESULTS: There were differences according to the type of establishment in the predictors of cardiovascular risk (p < 0.05). Differences were also found in the physical fitness tests evaluated (p < 0.01). Students in private schools (PSC) and subsidized schools (SC) had lower levels of cardiovascular risk and higher levels of physical fitness than public schools (PS) and schools with delegated administration (DA). CONCLUSIONS: In conclusion, students in educational establishments with a higher socioeconomic level have lower levels of cardiovascular risk and better physical fitness than students in public establishments. The authors suggest considering specific school interventions to mitigate cardiovascular risk and improve physical fitness among this vulnerable population. To this end, future studies should analyze the characteristics of physical activity and nutritional habits in schools to determine the factors that affect the results.

Effects of strength training on repeated sprint ability in team sports players: a systematic review.

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.

Land- and water-based aerobic exercise program on health-related outcomes in breast cancer survivors (WaterMama): study protocol for a randomized clinical trial.

BACKGROUND: Breast cancer is a prevalent form of cancer among women worldwide, often accompanied by physical and psychological side effects due to the disease and the treatment's aggressiveness. Regular physical exercise has emerged as a non-pharmacological approach to improve the quality of life of breast cancer survivors. We herein report the protocol of the WaterMama Study, which aims to evaluate the effects of land- or water-based aerobic exercise programs, compared to a health education program, on cancer-related fatigue and other health-related outcomes in breast cancer survivors. METHODS: The WaterMama trial is a randomized, single-blinded, three-arm, parallel, superiority trial. We aim to recruit 48 women ≥ 18 years of age who have completed primary treatment for stage I-III breast cancer. Participants are randomly allocated in a 1:1:1 ratio to 12-week interventions of aerobic exercise training programs either in the aquatic or land environment (two weekly 45-min sessions) plus health education (a weekly 45-min session), or an active-control group receiving health education alone (a weekly 45-min session). The primary outcome is cancer-related fatigue, and the secondary outcomes include cardiorespiratory fitness, muscular performance, muscle morphology, functional capacity, mental health, cognitive function, pain, and quality of life. Outcomes assessments are conducted before and after the 12-week intervention period. The analysis plan will employ an intention-to-treat approach and per protocol criteria. DISCUSSION: Our conceptual hypothesis is that both aerobic exercise programs will positively impact primary and secondary outcomes compared to the health education group alone. Additionally, due to its multi-component nature, we expect the aquatic exercise program promote more significant effects than the land exercise program on cancer-related fatigue, muscular outcomes, and pain. TRIAL REGISTRATION: The study was prospectively registered at ClinicalTrials.gov NCT05520515. Registered on August 26, 2022. https://clinicaltrials.gov/ct2/show/NCT05520515.

Perceptions of the mouthguard in basketball, rugby, and soccer players. Qualitative study at a public university in Colombia.

BACKGROUND/AIM: Orofacial and dental injuries in athletes, both amateur and professional, are highly prevalent. Mouthguards are devices to prevent this type of injury; however, athletes believe that the mouthguard limits their performance in the game and decreases their confidence. This study analyzed the perception that some basketball, rugby and soccer players from a public university in Colombia have about the use of mouthguards. MATERIAL AND METHODS: Comprehensive qualitative study with ethnographic approach. Twenty-nine players participated. Three data collection tools were used: semi-structured interviews, field diary and discussion groups. Content analysis was carried out using a categorical matrix and triangulation of sources. RESULTS: Participants perceive the mouthguard as a device to prevent orofacial and dental injuries, but unattractive to wear during competitions. Factors that determine the use or non-use of the mouthguard are player comfort and adaptability, communication and economic cost. CONCLUSIONS: Players' perception of mouthguards in soccer, basketball and rugby is multifactorial, and is mediated by the idea of contact risk during sports practice, prevention of orofacial injuries, influence on sports performance, comfort and adaptability to the mouthguard.

Physical Performance and Telomere Length in Older Adults.

BACKGROUND: The aging population prompts studying risk factors and markers to predict healthy aging. Telomere length is a promising candidate for assessing various age-related traits. AIM OF THE STUDY: To investigate the association between physical performance and telomere length. METHODS: We enrolled 323 older Mexican adults from the "Cohort of Obesity, Sarcopenia, and Frailty of Older Mexican Adults" affiliated with the Instituto Mexicano del Seguro Social and assessed their physical performance using the Short Physical Performance Battery, dividing participants into low (≤7) and high (>7) groups. Absolute telomere length was determined by qPCR, and individuals were classified into short (≤4.22 kb) and long (>4.22 kb) groups. We calculated the mean and adjusted mean, considering sex and age, among others, with 95% CI. We estimated the effect size between physical performance and telomere length using Cohen's d for unequal group sizes and calculated the odds ratio for physical performance based on telomere length. RESULTS: Participants with low physical performance had significantly shorter telomeres (mean 4.14.44.7 kb, adjusted mean 3.54.04.5 kb, p <0.001), while those with high physical performance exhibited longer telomeres (mean 5.55.75.9 kb, adjusted mean 4.75.35.8 kb, p <0.001), with a medium-to-high telomere length effect size (d = 0.762). The odds of low physical activity increased 2.13.66.1-fold per kb of telomere attrition (adjOR 1.73.36.3, p <0.001). CONCLUSION: Decreased physical function is associated with shorter telomere length. Absolute telomere length presents a promising biomarker for distinguishing between healthy and unhealthy aging, warranting further investigation.

Dual-task training is as effective as functional training on the functional fitness of older women: a randomized clinical trial.

BACKGROUND: The interest in approaches that improve older individuals' functional fitness and autonomy is increasing. However, the effects of dual-task training on older women's functional fitness and the comparison with the functional training approach are unclear. Therefore, we compared dual-task and functional training on the functional fitness of older women and the effects of three months of detraining. METHODS: Sixty-one women performed 16 weeks of dual-task training or functional training. The functional fitness was measured pre-, post-training, and post-detraining, based on the ability to put on and take off a t-shirt, evaluating the mobility of the upper limb, standing-up from the prone position measuring the global functionality, five times sit-to-stand test to assess the lower limbs muscle power, timed up and go to measure the dynamic balance and agility, gallon-jug shelf-transfer to evaluate the global functionality emphasizing the upper limbs and 10 m walk test to analyze the gait ability. RESULTS: Dual-task training and functional training generally provided significant small to moderate magnitude performance increases in the put on and take off a t-shirt (dual-task training: d = 0.35 / functional training: d = 0.49), five times sit-to-stand test (dual-task training: d = 0.41 / functional training: d = 0.77), timed up and go (dual-task training: d = 0.34 / functional training: d = 0.78), and gallon-jug shelf-transfer (dual-task training: d = 0.76 / functional training: d = 0.82). Only the functional training improved the 10 m walk test (d = 0.32; p = 0.013), and both groups did not change the standing-up from the prone position performance. After the detraining period, both groups kept the adaptations for the gallon-jug shelf-transfer and five times sit-to-stand test. At the same time, only the dual-task training maintained the adaptations for the put on and take off a t-shirt and the functional training for the timed up and go. CONCLUSION: Sixteen weeks of dual-task and functional training are similarly effective in improving older women's functional fitness, maintaining their benefits even after three months of detraining. TRIAL REGISTRATION: RBR-10ny848z ( https://ensaiosclinicos.gov.br/rg/RBR-10ny848z ).

The Mediating Role of Cardiorespiratory Fitness in the Association between a Negative Lifestyle and Poor Mental Health in Chilean Schoolchildren.

BACKGROUND: A negative lifestyle has a reported relationship with psychological problems and deteriorated well-being. However, there is little information regarding the mediating role of cardiorespiratory fitness (CRF) in this relationship. OBJECTIVES: The objectives of the present study are twofold: first, to investigate the association between negative lifestyle, physical self-concept (PSC), and depression, and second, to assess the potential mediating role of CRF in this complex relationship. METHODS: This cross-sectional study included 612 schoolchildren aged between 9 and 14 years from the Araucanía region (southern Chile). CRF was measured using the Leger test, and lifestyle, depression, and PSC were measured using validated questionnaires. RESULTS: A negative lifestyle reported an inverse association with PSC (p < 0.001) and a positive association with depression levels (p < 0.001). The mediation analysis showed that CRF was positively related to PSC (p < 0.001) and inversely related to depression (p = 0.001); besides, the indirect effect CRF acted as a partial mediator in the association between a negative lifestyle and PSC (indirect effect = -1.15; SE = 0.01; 95% CI, -1.87, -0.55) and depression levels (indirect effect = 0.22; SE = 0.08; 95% CI, 0.08, 0.38). CONCLUSION: In conclusion, CRF in schoolchildren played a potential mediating role in the association between a negative lifestyle and depression and PSC.

Effects of exercise, physical activity, and sports on physical fitness in adults with Down syndrome: A systematic review.

This systematic review aimed to analyze the effects of exercise, physical activity, and sports on physical fitness in adults with Down syndrome (DS). A literature search was conducted across four databases EBSCO, Scopus, Web of Science, and PubMed. The PRISMA guidelines were followed. The PEDro scale and the Cochrane risk of bias tool were used to assess the quality and risk of the studies, respectively. The protocol was registered in PROSPERO (code: CRD42023449627). Of the 423 records initially found, 13 were finally included in the systematic review, in which 349 adults with DS participated. 92% of the articles declared at least one significant difference post-intervention. The available evidence indicates that exercise, physical activity, and sports have a positive effect on some variables of physical fitness, especially strength, balance, body composition, cardiorespiratory fitness, flexibility, and functional capacity. Furthermore, it should be considered as an additional treatment or complementary therapy to improve the functionality and quality of life of adults with DS.

Plasticity in biomass allocation underlies tolerance to leaf damage in native and non-native populations of Datura stramonium.

An introduction to a novel habitat represents a challenge to plants because they likely would face new interactions and possibly different physical context. When plant populations arrive to a new region free from herbivores, we can expect an evolutionary change in their defense level, although this may be contingent on the type of defense, resistance or tolerance, and cost of defense. Here, we addressed questions on the evolution of tolerance to damage in non-native Spanish populations of Datura stramonium by means of two comparative greenhouse experiments. We found differences in seed production, specific leaf area, and biomass allocation to stems and roots between ranges. Compared to the Mexican native populations of this species, non-native populations produced less seeds despite damage and allocate more biomass to roots and less to stems, and had higher specific leaf area values. Plasticity to leaf damage was similar between populations and no difference in tolerance to damage between native and non-native populations was detected. Costs for tolerance were detected in both regions. Two plasticity traits of leaves were associated with tolerance and were similar between regions. These results suggest that tolerance remains beneficial to plants in the non-native region despite it incurs in fitness costs and that damage by herbivores is low in the non-native region. The study of the underlying traits of tolerance can improve our understanding on the evolution of tolerance in novel environments, free from plants' specialist herbivores.

Comparison between Measured and Predicted Resting Metabolic Rate Equations in Cross-Training Practitioners.

This study aimed to investigate the resting metabolic rate (RMR) in cross-training practitioners (advanced and novice) using indirect calorimetry (IC) and compare it with predictive equations proposed in the scientific literature. METHODS: A cross-sectional and comparative study analyzed 65 volunteers, both sexes, practicing cross-training (CT). Anthropometry and body composition were assessed, and RMR was measured by IC (FitMate PRO®), bioimpedance (BIA-InBody 570®), and six predictive equations. Data normality was tested by the Kolgomorov-Smirnov test and expressed as mean ± standard deviation with 95% confidence intervals (CI), chi-square test was performed to verify ergogenic resources, and a Bland-Altman plot (B&A) was made to quantify the agreement between two quantitative measurements. One-way ANOVA was applied to body composition parameters, two-way ANOVA with Bonferroni post hoc was used to compare the RMR between groups, and two-way ANCOVA was used to analyze the adjusted RMR for body and skeletal muscle mass. The effect size was determined using Cohen's d considering the values adjusted by ANCOVA. If a statistical difference was found, post hoc Bonferroni was applied. The significance level was p < 0.05 for all tests. RESULTS: The main results indicated that men showed a higher RMR than women, and the most discrepant equations were Cunningham, Tinsley (b), and Johnstone compared to IC. Tinsley's (a) equation indicated greater precision in measuring the RMR in CM overestimated it by only 1.9%, and BIA and the Harris-Benedict in CW overestimated RMR by only 0.1% and 3.4%, respectively. CONCLUSIONS: The BIA and Harris-Benedict equation could be used reliably to measure the RMR of females, while Tinsley (a) is the most reliable method to measure the RMR of males when measuring with IC is unavailable. By knowing which RMR equations are closest to the gold standard, these professionals can prescribe a more assertive diet, training, or ergogenic resources. An assertive prescription increases performance and can reduce possible deleterious effects, maximizing physical sports performance.

Load carriage does not reduce absolute mechanical power output but reduces agility in elite military police officers.

Objectives. The main objective of this study was to evaluate mean propulsive velocity (MPV), mean propulsive force (MPF) and mean propulsive power (MPP) in elite police officers under LOADED and UNLOADED conditions. The study also investigated the association of body composition and strength levels under the same load conditions. Methods. Twenty-one men from an elite unit in Brazil participated in the study, performing Smith machine half squats and an agility test. Dual energy X-ray absorptiometry measured body composition; a linear encoder measured MPV, MPF and MPP during the half squats; and a manual chronometer registered agility test performance. Results. The results showed that wearing and carrying occupational loads did not alter the squat exercise's MPP, MPV and MPF but reduced the performance of relative MPP and agility (p < 0.05). The results also showed that MPP had a higher association with force (i.e., MPF and one-repetition maximum [1RM]) than velocity (i.e., MPV and agility) under the LOADED condition (p < 0.05). Among the body composition variables, only lean body mass was associated with MPP under the LOADED condition (p < 0.05). Conclusion. These findings suggest that load carriage does not reduce absolute mechanical power output, but reduces the relative MPP and agility in military police officers.

Determinants of cardiorespiratory fitness measured by cardiopulmonary exercise testing in COVID-19 survivors: a systematic review with meta-analysis and meta­regression.

BACKGROUND: The relationship between cardiorespiratory fitness and its possible determinants in post-COVID-19 survivors has not been systematically assessed. OBJECTIVES: To identify and summarize studies comparing cardiorespiratory fitness measured by cardiopulmonary exercise testing in COVID-19 survivors versus non-COVID-19 controls, as well as to determine the influence of potential moderating factors. METHODS: We conducted a systematic search of MEDLINE/PubMed, Cochrane Library, EMBASE, Google Scholar, and SciELO since their inceptions until June 2022. Mean differences (MD), standard mean differences (SMD), and 95% confidence intervals (CI) were calculated. Subgroup and meta-regression analyses were used to evaluate potential moderating factors. RESULTS: 48 studies (3372 participants, mean age 42 years, and with a mean testing time of 4 months post-COVID-19) were included, comprising a total of 1823 COVID-19 survivors and 1549 non-COVID-19 controls. After data pooling, VO2 peak (SMD=1.0 95% CI: 0.5, 1.5; 17 studies; N = 1273) was impaired in COVID-19 survivors. In 15 studies that reported VO2 peak values in mL/min/kg, non-COVID-19 controls had higher peak VO2 values than COVID-19 survivors (MD=6.2, 95% CI: 3.5, 8.8; N = 905; I2=84%). In addition, VO2 peak was associated with age, time post-COVID-19, disease severity, presence of dyspnea, and reduced exercise capacity. CONCLUSION: This systematic review provides evidence that cardiorespiratory fitness may be impaired in COVID-19 survivors, especially for those with severe disease, presence of dyspnea, and reduced exercise capacity. Furthermore, the degree of reduction of VO2 peak is inversely associated with age and time post-COVID.

NaCl Modifies Biochemical Traits in Bacterial Endophytes Isolated from Halophytes: Towards Salinity Stress Mitigation Using Consortia.

Bacterial endophytes (120) were isolated from six halophytes (Distichlis spicata, Cynodon dactylon, Eragrostis obtusiflora, Suaeda torreyana, Kochia scoparia, and Baccharis salicifolia). These halophiles were molecularly identified and characterized with or without NaCl conditions. Characterization was based on tests such as indole acetic acid (IAA), exopolysaccharides (EPS), and siderophores (SID) production; solubilization of phosphate (P), potassium (K), zinc (Zn), and manganese (Mn); mineralization of phytate; enzymatic activity (acid and alkaline phosphatase, phytases, xylanases, and chitinases) and the mineralization/solubilization mechanisms involved (organic acids and sugars). Moreover, compatibility among bacteria was assessed. Eleven halophiles were characterized as highly tolerant to NaCl (2.5 M). The bacteria isolated were all different from each other. Two belonged to Bacillus velezensis and one to B. pumilus while the rest of bacteria were identified up to the genus level as belonging to Bacillus, Halobacillus, Halomonas, Pseudomonas, Nesterenkonia, and three strains of Oceanobacillus. The biochemical responses of nutrient solubilization and enzymatic activity were different between bacteria and were influenced by the presence of NaCl. Organic acids were involved in P mineralization and nutrient solubilization. Tartaric acid was common in the solubilization of P, Zn, and K. Maleic and vanillic acid were only detected in Zn and K solubilization, respectively. Furthermore, sugars appeared to be involved in the solubilization of nutrients; fructose was detected in the solubilization tests. Therefore, these biochemical bacterial characteristics should be corroborated in vivo and tested as a consortium to mitigate saline stress in glycophytes under a global climate change scheme that threatens to exacerbate soil salinity.

Effects of physical training on the metabolic profile of rats exposed to chronic restraint stress.

INTRODUCTION: Despite strong evidences supporting the protective role of exercise against stress-induced repercussions, the literature remains inconclusive regarding metabolic aspects. Therefore, this study aimed to evaluate the effect of Physical Training (PT) by swimming on the metabolic parameters of rats subjected to restraint stress. METHODS: Wistar rats (n = 40) were divided into four groups: Control (C), Trained (T), Stressed (S), and Trained/Stressed (TS). The restraint stress protocol involved confining the animals in PVC pipes for 60 minutes/day for 12 weeks. Concurrently, the swimming PT protocol was performed without additional load in entailed sessions of 60 minutes conducted five days a week for the same duration. The following parameters were analyzed: fitness progression assessed by the physical capacity test, body mass, serum level of glucose, triglyceride, cholesterol and corticosterone, as well as glycemic tolerance test, evaluated after glucose administration (2 g/kg, i.p.). RESULTS: Trained groups (T and TS) exhibited enhanced physical capacity (169 ± 21 and 162 ± 22% increase, respectively) compared to untrained groups (C: 9 ± 5 and S: 11 ± 13% increase). Corticosterone levels were significantly higher in the S group (335 ± 9 nmoL/L) compared to C (141 ± 3 nmoL/L), T (174 ± 3 nmoL/L) and TS (231 ± 7 nmoL/L), which did not differ from each other. There were no significant changes in serum glucose, cholesterol, and triglyceride levels among the groups. However, the glycemic curve after glucose loading revealed increased glycemia in the S group (area under curve 913 ± 30 AU) but the TS group exhibited values (673 ± 12 AU) similar to the groups C (644 ± 10 AU) and T (649 ± 9 AU). CONCLUSION: Swimming-based training attenuated stress-induced corticosterone release and prevented glucose intolerance in rats, reinforcing the importance of exercise as a potential strategy to mitigate the pathophysiological effects of stress.

Competitive fitness and stability of ammonium-excreting Azotobacter vinelandii strains in the soil.

Non-symbiotic N2-fixation would greatly increase the versatility of N-biofertilizers for sustainable agriculture. Genetic modification of diazotrophic bacteria has successfully enhanced NH4+ release. In this study, we compared the competitive fitness of A. vinelandii mutant strains, which allowed us to analyze the burden of NH4+ release under a broad dynamic range. Long-term competition assays under regular culture conditions confirmed a large burden for NH4+ release, exclusion by the wt strain, phenotypic instability, and loss of the ability to release NH4+. In contrast, co-inoculation in mild autoclaved soil showed a much longer co-existence with the wt strain and a stable NH4+ release phenotype. All genetically modified strains increased the N content and changed its chemical speciation in the soil. This study contributes one step forward towards bridging a knowledge gap between molecular biology laboratory research and the incorporation of N from the air into the soil in a molecular species suitable for plant nutrition, a crucial requirement for developing improved bacterial inoculants for economic and environmentally sustainable agriculture. KEY POINTS: • Genetic engineering for NH4+ excretion imposes a fitness burden on the culture medium • Large phenotypic instability for NH4+-excreting bacteria in culture medium • Lower fitness burden and phenotypic instability for NH4+-excreting bacteria in soil.

Effects of pilates exercises on strength, endurance and muscle power in older adults: Systematic review and meta-analysis.

INTRODUCTION: Pilates exercises have been used by the older adults and have shown potential to improve some components of physical fitness. OBJECTIVE: To verify the effects of Pilates on strength, endurance and muscle power in older adults. METHODS: The searches were performed in the databases: PubMed, EMBASE, CENTRAL, CINAHL, Web of Science, SPORTDiscus, LILACS and PEDro until September 2022, without filters that limited the date of publications or language. The studies included were: randomized clinical trials (RCTs); interventions that used Pilates; interventions with outcomes involving strength, endurance and/or muscle power; participants over 60 years old. RESULTS: 24 RCTs (1190 participants) were selected. There is low quality evidence that Pilates did not significantly improve muscle strength compared to the control group (Standardized Mean Difference (SMD) = 1.18 [95%CI -0.71, 3.08] I2 = 93%), and moderate quality compared to other exercises (SMD = 0.01 [CI95% -0.46, 0.48] I2 = 0%). Very low quality evidence shows that Pilates can improve muscular endurance of upper limbs compared to control group (Mean Difference (MD) = 4.87 [95%CI 2.38, 7.36] I2 = 88%) and lower limbs compared to other exercises (MD = 2.68 [CI95% 0.26, 5.10] I2 = 87%). It was not possible to perform muscle power analysis due to the reduced number of studies. CONCLUSION: Currently, it is not feasible to recommend Pilates exercises as a means to improve strength, endurance and muscle power in the older adults. More RCTs covering this topic are needed given the low quality of evidence available at this time.

Impact of aging on maximal oxygen uptake in female runners and sedentary controls.

The present study aimed to compare V̇O2max (absolute, adjusted to total body mass, and adjusted to lean mass) in recreational runners and sedentary women < and > 50 yr and verify the effect of aging and physical activity level on the three types of V̇O2 max expression. The study included 147 women:85 runners (45.7 ± 14.1 yr) and 62 sedentary controls (48.8 ± 9.8 yr). They were subjected to cardiopulmonary exercise testing for V̇O2 max measurement and a body composition test by dual-emission X-ray absorptiometry system. V̇O2max were expressed as absolute values (L/min), relative to total body mass values (mL/kg/min), and relative to lean mass values (mL/kgLM/min). The two-way analysis of variance revealed a significant interaction [F(2,131) = 4.43, p < 0.001] and effects of age group [F(2,131) = 32.79, p < 0.001] and physical activity group [F(2,131) = 55.64, p < 0.001] on V̇O2max (mL/min). V̇O2max (mL/kg/min) and V̇O2 max (mL/kgLM/min) were significantly influenced by age and physical activity levels. The multiple regression model explains 76.2 % of the dependent variable V̇O2max (mL/kg/min), age (ß = -0.335, t = -7.841, p < 0.001), and physical activity group (ß = -0.784, t = -18.351, p < 0.001). In conclusion, female runners had higher V̇O2 max values than sedentary women at all ages, even though aging has a greater impact on V̇O2 max in the runners group. In addition to cardiorespiratory fitness, women's metabolic lean mass function, as measured by V̇O2max adjusted by lean mass, is significantly influenced by aging. Finally, physical activity has a greater impact on V̇O2 max levels than aging.

Phase angle and its determinants among adolescents: influence of body composition and physical fitness level.

To examine the association between levels of physical fitness, parameters of body composition and phase angle (PhA) amongst adolescents. A total of 152 adolescents (84 girls) aged 11-16 years were included in this study. Weight and height were measured and the body mass index (BMI) was calculated. Bioelectrical impedance analysis (BIA) provided resistance and reactance parameters to calculate fat-free mass (FFM), PhA and fat mass (%FM). The following physical fitness variables were analysed: flexibility, abdominal muscular endurance, upper and lower limb explosive strength, agility, speed and cardiorespiratory fitness. Generalized Linear Models were applied to verify differences across sexes. Stepwise linear regression was used to establish an association between the variables studied. The study established an association between PhA and weight, FFM, BMI, FM, %FM and medicine ball throw (MBT) for girls. As for the boys, an association was verified between PhA and weight, FFM, BMI, standing long jump (SLJ), MBT and the three allometric VO2peak variables analyzed. An association was found between PhA and the boys' 4-m shuttle run test (4SRT) and 20-m sprint test (20SRT). Boys showed a greater phase angle than girls; In girls, BMI and %FM, were determinant of 32.4% (r = 0.57). PhA variability which is influenced by physical fitness, body composition and, therefore, the tissues electrical conductivity. Furthermore, boys' height, FFM, upper limb strength, and agility account for 58.4% (r = 0.76) PhA variability. There was a positive correlation between the physical fitness tests and the PhA.

Efectos del entrenamiento cluster sobre la hipertrofia muscular: una revisión sistemática / Effects of cluster training on muscle hypertrophy: a systematic review / Efeitos do treinamento em cluster na hipertrofia muscular: uma revisão sistemática

Resumen Objetivo: El objetivo de la presente revisión sistemática fue determinar los efectos del entrenamiento cluster sobre la hipertrofia muscular. Metodología: Se realizó una búsqueda bibliográfica en las bases de datos electrónicas Pubmed, Scopus y Web of Science, utilizando las siguientes palabras clave: 'cluster training', 'rest Interval', 'rest pause', 'hypertrophy', 'resistance training' y 'cross sectional area'. Se incluyeron ensayos clínicos que utilizaron el entrenamiento cluster como intervención en personas mayores de 18 años de ambos sexos. Resultados: La revisión sistemática obtenida durante la búsqueda de las bases de datos consultadas arrojó un total de 23 artículos, potencialmente elegibles, de los cuales se tomó una muestra de 9, con los que se podían obtener resultados que respondían al objetivo de esta revisión. La cantidad de participantes de los 9 artículos elegibles fue de 172 sujetos. Los entrenamientos cluster permiten aumentar el volumen de entrenamiento y la intensidad sin provocar elevados niveles de fatiga, favoreciendo así el desarrollo de la hipertrofia muscular. Conclusiones: Los resultados de esta revisión sistemática sugieren que los entrenamientos cluster pueden ser una herramienta eficaz para el desarrollo de la hipertrofia muscular.

Abstract Objective: The aim of this systematic review was to determine the effects of cluster training on muscle hypertrophy. Methodology: A literature search was performed in the electronic databases Pubmed, Scopus and Web of Science, using the following keywords: 'cluster training', 'rest interval', 'rest pause', 'hypertrophy', 'resistance training' and 'cross sectional area'. We included clinical trials that used cluster training as an intervention in people over 18 years of age of both sexes. Results: The systematic review obtained during the search of the databases consulted yielded a total of 23 potentially eligible articles, of which a sample of 9 was taken from which results could be obtained that responded to the objective of this review. The number of participants from the 9 eligible articles was 172 subjects. Cluster workouts allow for increased training volume and intensity without causing high levels of fatigue, thus favoring the development of muscle hypertrophy. Conclusions: The results of this systematic review suggest that cluster training can be an effective tool for the development of muscle hypertrophy.

Resumo Objetivo: O objetivo desta revisão sistemática foi determinar os efeitos do treinamento em cluster na hipertrofia muscular. Metodologia: Realizou-se uma busca na literatura nas bases de dados eletrônicas Pubmed, Scopus e Web of Science, utilizando as seguintes palavras-chave: 'cluster training', 'rest interval', 'rest pause', 'hypertrophy', 'resistance training' e 'cross sectional area'. Foram incluídos ensaios clínicos que utilizaram o treinamento em cluster como intervenção em pessoas com mais de 18 anos de ambos os sexos. Resultados: A revisão sistemática realizada durante a busca nas bases de dados consultadas resultou em um total de 23 artigos potencialmente elegíveis, dos quais uma amostra de 9 foi selecionada para obter resultados que respondessem ao objetivo desta revisão. O número de participantes nos 9 artigos elegíveis foi de 172 indivíduos. Os treinos em cluster permitem um aumento no volume e na intensidade do treinamento sem causar altos níveis de fadiga, favorecendo assim o desenvolvimento da hipertrofia muscular. Conclusões: Os resultados desta revisão sistemática sugerem que o treinamento em cluster pode ser uma ferramenta eficaz para o desenvolvimento da hipertrofia muscular.

Upper-Body Muscular Endurance and Its Association with Aerobic Capacity in University Students of Physical Culture, Sport, and Recreation / Fuerza resistencia de miembros superiores y su asociación con la capacidad aeróbica en universitarios de cultura física, deporte y recreación / Resistência Muscular do Corpo Superior e sua Associação com Capacidade Aeróbica em Estudantes Universitários de Cultura Física, Esporte e Recreação

Abstract Introduction: Upper-body muscular endurance (UBME) and aerobic capacity (AC) are essential components of physical fitness. Low levels of these components are related to cardiovascular disease. Purpose: To assess the association between UBME and AC levels in college students of physical culture. Methodology: Analytical cross-sectional study carried out in 192 students (169 men, 23 women; median age 20 years). Every participant of the study signed written consent. UMBE was the dependent variable assessed by the push-up test, and AC was the main independent variable assessed using the 20 m shuttle run test. To analyze differences by sex, and academic semester, Fischer exact, Student's T, and U Mann-Whitney tests were applied. Descriptive, as well as bivariate and multivariate analysis, were realized using logistic regression models. Results: 82.29 % of participants had healthy levels of UBME. Respecting the academic semester, students had a higher probability of having healthy levels of UBME as semesters increased (OR: 1.23, 95 % CI: 1.06 to 1.44, p = 0.007). Concerning AC, 58.33 % of participants registered healthy levels. After adjusting by sex, age, socioeconomic level, and academic semester, maximum oxygen consumption (VO2max), was associated with healthy levels of UBME (OR: 1.157, CI 95 %: 1.O71 - 1.249, p=<0.001). Conclusions: Students had a higher probability of presenting healthy levels of UBME as semesters of study increased, and those with a higheVO2max were more likely to have healthy levels of UBME.

Resumen Introducción: La fuerza resistencia de miembros superiores (FRMS) y la capacidad aeróbica (CA) son componentes esenciales de la condición física. Bajos niveles de estos componentes están relacionados con la enfermedad cardiovascular. Propósito: El objetivo de este estudio fue evaluar la asociación entre los niveles de FRMS y la CA en estudiantes universitarios de cultura física. Metodología: Estudio transversal analítico realizado en 192 estudiantes (169 hombres, 23 mujeres; mediana de edad, 20 años). Cada participante firmó el consentimiento informado. FRMS fue la variable dependiente y se valoró con la prueba de flexiones de brazo, y la CA fue la variable independiente y se evaluó usando la prueba de ida y vuelta de 20 m. Para analizar las diferencias por sexo y semestre académico, fueron utilizadas las pruebas exacta de Fischer, T de Student y U de Mann-Whitney. Se realizaron análisis descriptivos, bivariados y múltiples, usando modelos de regresión logística. Resultados: El 82.29 % de los participantes registraron niveles saludables de FRMS. Respecto al semestre académico, se evidenció una probabilidad más alta de tener niveles saludables de FRMS al incrementarse los semestres de estudio (OR: 1.23, 95 % CI: 1.06 to 1.44, p = 0.007). En lo concerniente a la CA, el 58.33 % de los participantes registro niveles saludables. Después de realizar ajustes por sexo, edad, nivel socioeconómico y semestre académico, el consumo máximo de oxígeno (VO2máx), estuvo asociado con niveles saludables de FRMS (OR: 1.157, CI 95 % 1.O71 - 1.249, p=<0.001). Conclusiones: Los participantes presentaron una mayor probabilidad de tener niveles saludables de FRMS, a medida que incrementaron los semestres de estudio, y aquellos con niveles de VO2máx más alto, fueron más proclives a tener niveles saludables de FRMS.

Resumo Introdução: A resistência muscular do corpo superior (UBME) e a capacidade aeróbica (AC) são componentes essenciais da aptidão física. Baixos níveis desses componentes estão relacionados a doenças cardiovasculares. Propósito: Avaliar a associação entre os níveis de UBME e AC em estudantes universitários de cultura física. Metodologia: Estudo transversal analítico realizado com 192 estudantes (169 homens, 23 mulheres; idade média 20 anos). Todos os participantes do estudo assinaram consentimento por escrito. UBME foi a variável dependente avaliada pelo teste de flexão de braço, e AC foi a principal variável independente avaliada pelo teste de corrida de vaivém de 20 m. Para analisar diferenças por sexo e semestre acadêmico, foram aplicados testes exatos de Fischer, t de Student e U de MannWhitney. Análises descritivas, bivariadas e multivariadas foram realizadas usando modelos de regressão logística. Resultados: 82,29 % dos participantes apresentaram níveis saudáveis de UBME. Respeitando o semestre acadêmico, os estudantes tiveram uma probabilidade maior de ter níveis saudáveis de UBME conforme os semestres aumentavam (OR: 1,23, IC 95 %: 1,06 a 1,44, p = 0,007). Em relação à AC, 58,33 % dos participantes registraram níveis saudáveis. Após ajuste por sexo, idade, nível socioeconômico e semestre acadêmico, o consumo máximo de oxigênio (VO2max) foi associado a níveis saudáveis de UBME (OR: 1,157, IC 95 %: 1,071 - 1,249, p <0,001). Conclusões: Os estudantes tiveram uma probabilidade maior de apresentar níveis saudáveis de UBME conforme os semestres de estudo aumentaram, e aqueles com um VO2max mais alto tiveram maior probabilidade de ter níveis saudáveis de UBME.