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PURPOSE: The long-term development of talent in endurance sports is a topic of interest. Among various factors, the importance of total hemoglobin mass (tHbmass) and the potential benefits of being an altitude-native athlete remain unclear, particularly in young categories. This study aimed to investigate the impact of altitude and training content on hematological characteristics by comparing young male cyclists age 15-16 and 17-18 years who were born and trained at a moderate altitude (ie, greater than or equal to 2500 m; MA) and cyclists who were born and trained at low altitude (below 1000 m; LA). METHODS: tHbmass (in grams and grams per kilogram), measured by using the optimized carbon monoxide rebreathing method during an incremental test on a cycle ergometer; hematocrit percentage, hemoglobin concentration; and erythrocyte, blood, and plasma volume were measured in youth male cyclists age 15-16 years and junior cyclists age 17-18 years who were born and trained at MA versus LA. All variables were analyzed with a 2-way (age [youth cyclist vs junior cyclist] × altitude level [MA vs LA]) analysis of variance with subsequent Tuckey post hoc test. RESULTS AND CONCLUSION: Some altitude-induced benefits were reported in cyclists at age 15-16 years in the MA group with higher values in hematocrit percentage, hemoglobin concentration, and tHbmass (grams per kilogram) (P < .05) than their LA counterparts. This was also observed at age 17-18 years (P < .001), except for tHbmass, wherein no significant difference was found between MA and LA groups. In contrast, plasma volume was lower in MA than LA junior cyclists. NEW FINDINGS: (1) The altitude of birth and residence could generate an advantage in tHbmass in young male cyclists age 15-16 and 17-18 years who train at MA compared with cyclists who are born and train at LA. (2) Altitude-induced benefits in physiological variables (hematocrit percentage, hemoglobin concentration, tHbmass in g·kg-1) were reported in cyclists at age 15-16 years and partially at age 17-18 years. In contrast, plasma volume was lower in MA than in LA junior cyclists. This may impact the strategies for identifying and developing talent in cycling.

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PURPOSE: This study investigated the impact of four weeks of age-dependent detraining on army soldiers' cardiorespiratory fitness and maximal and explosive strength. METHODS: Fourteen volunteer tactical athletes participated, divided into two age groups (20 to 29 and 30 to 40 years). Before and after the detraining period, we assessed their anthropometric measurements (weight, height, body mass index, fat mass, and fat-free mass), cardiorespiratory fitness (maximal oxygen uptake [VO2max] and ventilatory thresholds [VT1 and VT2]), and kinematic properties during a single-leg counter-moving jump (CMJ) test for both the dominant and non-dominant legs. Two-way ANOVA followed by the Holm-Sidak post hoc test was used. RESULTS: The anthropometric and cardiovascular variables did not show significant differences between the groups. However, both groups exhibited a significantly reduced maximum time and speed at the VO2max. Furthermore, the flight time and maximum height during the CMJ significantly decreased in the non-dominant leg for both age groups. Notably, the dominant leg's concentric impulse (CI) significantly reduced during the CMJ, but this effect was observed only in the 30-40 age group. There were significant differences between the two age groups. CONCLUSIONS: Our findings suggest that four weeks of detraining negatively impacts aerobic fitness and muscular strength, independently of age. However, the dominant leg may be more susceptible to detraining effects in army soldiers aged 30-40. Furthermore, as a perspective, our results strongly suggest that a detraining period could affect successful missions (aerobic performance deterioration), as well as promote a muscle imbalance between the legs, which could encourage muscle injuries and endanger combat missions.

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This study examines the relationship between physiological complexity, as measured by Approximate Entropy (ApEn) and Sample Entropy (SampEn), and fitness levels in female athletes. Our focus is on their association with maximal oxygen consumption (VO2,max). Our findings reveal a complex relationship between entropy metrics and fitness levels, indicating that higher fitness typically, though not invariably, correlates with greater entropy in physiological time series data; however, this is not consistent for all individuals. For Heart Rate (HR), entropy measures suggest stable patterns across fitness categories, while pulse oximetry (SpO2) data shows greater variability. For instance, the medium fitness group displayed an ApEn(HR) = 0.57±0.13 with a coefficient of variation (CV) of 22.17 and ApEn(SpO2) = 0.96±0.49 with a CV of 46.08%, compared to the excellent fitness group with ApEn(HR) = 0.60±0.09 with a CV of 15.19% and ApEn(SpO2) =0.85±0.42 with a CV of 49.46%, suggesting broader physiological responses among more fit individuals. The larger standard deviations and CVs for SpO2 entropy may indicate the body's proficient oxygen utilization at higher levels of physical demand. Our findings advocate for combining entropy metrics with wearable sensor technology for improved biomedical analysis and personalized healthcare.

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Introducción: La capacidad de resistencia física es uno de los indicadores del rendimiento profesional en el fútbol, no estando exceptos los profesionales del arbitraje, los cuales requieren entrenamientos especializados en función de sus aptitudes físicas; por lo cual, es útil conocer sus desempeños. Objetivo: determinar los parámetros reales de aptitud cardiorrespiratoria al esfuerzo máximo progresivo, de árbitros de fútbol de Pichincha. Métodos: se estudia a 25 árbitros hombres seleccionados intencionalmente, de la asociación de árbitros de fútbol profesional de Pichincha. Luego de un reconocimiento de salud previo, de realizó una prueba de esfuerzo progresivo sobre una banda sinfín, con un lector de consumo de oxígeno. Los árbitros tienen una experiencia media de 11 años, entrenan 3-4 días a la semana, y arbitran partidos oficiales 1-2 veces por semana. Resultados: el valor medio global de consumo máximo de oxígeno (VO2máx.) relativo de los árbitros evaluados en el presente estudio es: (= 52.00 ml·kg-1·min-1, similar al obtenido en otros estudios internacionales sobre la valoración de la capacidad física en árbitros, que describen unos valores relativos de vo2máx de 46-51 ml·kg-1·min-1 para hombres. Conclusiones: las competencias profesionales del arbitraje ecuatoriano son similares en la capacidad de resistencia que sus homólogos extranjeros. Se sugiere una implementación de contenidos del entrenamiento basados en mejorar la aptitud cardiorrespiratoria en el arbitraje, así como su control sistemático.

Introduction: Physical endurance capacity is one of the indicators of professional performance in soccer, not excepting referee professionals, who require specialized training based on their physical capabilities; Therefore, it is useful to know their performances. Objective: Determine the real parameters of cardiorespiratory fitness at maximum progressive effort, of soccer referees from Pichincha. Methods: 25 male referees intentionally selected from the Pichincha professional soccer referee association are studied. After a previous health examination, a progressive stress test was performed on a treadmill, with an oxygen consumption reader. Referees have an average experience of 11 years, train 3-4 days a week, and referee official matches 1-2 times a week. Results: The overall average value of relative maximum oxygen consumption (VO2max) of the referees evaluated in the present study is: (= 52.00 ml·kg-1·min-1, similar to that obtained in other international studies on the capacity physics assessment in referees, who describe relative vo2max values of 46-51 ml·kg-1·min-1 for men. Conclusions: the professional skills of Ecuadorian arbitration are similar in resistance capacity to their foreign counterparts. An implementation of training content based on improving cardiorespiratory fitness in refereeing, as well as its systematic control, is suggested.

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Las cualidades de la condición física como la flexibilidad, fuerza y VO2max en el deportista, se manifiestan en su totalidad en cualquier actividad deportiva. El objetivo de la investigación fue evaluar el nivel de flexibilidad y la relación existente con el nivel de fuerza explosiva y VO2max. Se seleccionaron 137 deportistas de la provincia de Imbabura en las disciplinas de fútbol, basquetbol, escalada, atletismo, ciclismo y taekwondo y se evaluaron mediante la prueba de sit and reach, salto vertical (VERT) y test de Queen College. Los resultados mostraron que el 81,8% fueron de etnia mestiza, el 56 % de la muestra de género masculino. Las disciplinas taekwondo y escalada fueron más flexibles (31 cm), la fuerza explosiva promedio que destacó fue la escalada (48cm) de capacidad de salto, seguido del basquetbol (45cm); el VO2max de los basquetbolistas fue excelente (57 ml*kg-1*min-1). El fútbol presentó un VO2max promedio (52,8 ml*kg-1*min), con diferencias significativas entre las medias (p=<0,05). La flexibilidad de las disciplinas deportivas tuvo una relación (p=<0,00) directa moderada con la fuerza e inversa moderada (p=<0,01/ rho =-0,4) con el VO2max. La flexibilidad fue directamente proporcional a la fuerza, es decir, si aumentó la flexibilidad también aumentó la fuerza; sin embargo, la flexibilidad fue inversamente proporcional a el VO2max, es decir, la flexibilidad disminuyó y el VO2 max aumentó.

As qualidades de aptidão física como flexibilidade, força e VO2max no atleta se manifestam em sua totalidade em qualquer atividade esportiva. O objetivo da pesquisa era avaliar o nível de flexibilidade e a relação existente com o nível de força explosiva e VO2max. Um total de 137 atletas foram selecionados da província de Imbabura nas disciplinas de futebol, basquete, escalada, atletismo, ciclismo e taekwondo e foram avaliados usando o teste sit and reach, salto vertical (VERT) e o teste Queen's College. Os resultados mostraram que 81,8% eram de etnia mista, 56% da amostra era masculina. As disciplinas de taekwondo e escalada eram mais flexíveis (31 cm), a força explosiva média que se destacava era a capacidade de saltar (48 cm), seguida do basquetebol (45 cm); o VO2max dos jogadores de basquetebol era excelente (57 ml*kg-1*min-1). O futebol tinha um VO2máx médio (52,8 ml*kg-1*min-1), com diferenças significativas entre os meios (p=<0,05). A flexibilidade das modalidades esportivas teve uma relação direta moderada (p=<0,00) com força e uma relação inversa moderada (p=<0,01/ rho =-0,4) com o VO2max. A flexibilidade foi diretamente proporcional à força, ou seja, se a flexibilidade aumentou, a força também aumentou; entretanto, a flexibilidade foi inversamente proporcional ao VO2máx, ou seja, a flexibilidade diminuiu e o VO2máx aumentou.

The qualities of the physical condition such as flexibility, strength and VO2max in the athlete, are fully manifested in any sporting activity. The objective of the research was to evaluate the level of flexibility and the existing relationship with the level of explosive strength and VO2max. One hundred thirty-seven athletes from the province of Imbabura were selected in the disciplines of soccer, basketball, climbing, athletics and taekwondo and were evaluated through the sit and reach test, vertical jump (VERT) and Queen College test. The results showed that 81.8 % were of mixed ethnicity, 56 % of the sample male. The taekwondo and climbing disciplines were more flexible (31 cm), the average explosive strength that stood out was climbing (48cm) of jumping capacity, followed by basketball (45cm); the VO2max of the basketball players was excellent (57 ml*kg-1*min-1). Soccer presented an average VO2max (52.8 ml*kg-1*min), with significant differences between the means (p=<0.05). The flexibility of the sports disciplines had a moderate direct relationship (p=<0.00) with strength and a moderate inverse relationship (p=<0.01/ rho =-0.4) with VO2max. Flexibility was directly proportional to strength, that is, if flexibility increased, strength also increased; however, flexibility was inversely proportional to VO2max, that is, flexibility decreased and VO2max increased.

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Introducción: El desacondicionamiento físico se asocia con disminución en la capacidad cardiorrespiratoria, aumento en el contenido de grasa corporal, e imbalances en respuesta inflamatoria, todos ellos factor de riesgo frente a la agresión de una intervención quirúrgica mayor. El valor de consumo de oxígeno (VO2max), el índice de masa corporal (IMC) y los valores plasmáticos de citoquinas de pacientes programados para una intervención quirúrgica mayor abdominal a menudo no se tienen en cuenta en la valoración prequirúrgica. Objetivo: Determinar la condición física e inflamatoria de pacientes que se trataron con una intervención quirúrgica mayor abdominal. Métodos: Investigación cuantitativa, descriptiva. Muestra por conveniencia de pacientes que se trataron con una intervención quirúrgica mayor abdominal en dos hospitales de Manizales (Colombia). Previo a la intervención, se midió VO2max, el IMC y valores de citoquinas. Resultados: Participaron en el estudio 6 hombres y 48 mujeres. Los valores promedio del VO2max se categorizaron como bajos. Se encontraron valores altos de IMC, del receptor antagonista de IL-1 (IL-1 Ra) y del factor neutrotrófico derivado del cerebro (BDNF). No se hallaron diferencias significativas en los valores promedio de VO2max, de IL-1Ra y de BDNF entre los grupos. Los pacientes programados para intervención quirúrgica ginecológica y gastrointestinal tuvieron sobrepeso y los programados para intervención quirúrgica bariátrica fueron obesos mórbidos. Conclusión: Pacientes programados para una intervención quirúrgica mayor abdominal presentan valores bajos de VO2max para la edad y altos de IMC. Se hallaron valores altos de IL-1Ra y de BDNF asociadas a obesidad y a posible antiinflamación(AU)

Introduction: Physical deconditioning is associated with, a decrease in cardiorespiratory capacity, an increase in body fat content and imbalances in the inflammatory response, all of which are risk factors for the aggression of a major surgical intervention. The oxygen consumption value (VO2max), body mass index (BMI), and plasma cytokine values of patients scheduled for major abdominal surgery are often not taken into account in the presurgical evaluation. Objective: To determine the physical and inflammatory condition of patients who were treated with a major abdominal surgery. Methods: Quantitative, descriptive research. Convenience sample of patients who underwent major abdominal surgery in two hospitals in Manizales (Colombia). Prior to the intervention, VO2max, BMI and cytokine values were measured. Results: 6 men and 48 women participated in the study. Average VO2max values were categorized as low. High values of BMI, IL-1 receptor antagonist (IL-1 Ra) and brain derived neutrotrophic factor (BDNF) were found. No significant differences were found in the mean VO2max, IL-1Ra and BDNF values between the groups. Patients scheduled for gynecological and gastrointestinal surgery were overweight and those scheduled for bariatric surgery were morbidly obese. Conclusion: Patients scheduled for major abdominal surgery have low VO2max values for age and high BMI. High IL-1Ra and BDNF values were found associated with obesity and possible anti-inflammation(AU)

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Background: The identification of variables obtained in the exercise test (ET) associated with increased risk of death is clinically relevant and would provide additional information for the management of Chagas disease (CD). The objective of the present study was to evaluate the association of ET variables with mortality in patients with chronic CD. Methods: This retrospective longitudinal observational study included 232 patients (median age 46.0 years; 50% women) with CD that were followed at the Evandro Chagas National Institute of Infectious Diseases (Rio de Janeiro, Brazil) and performed an ET between 1989 and 2000. The outcome of interest was all-cause mortality. Results: There were 103 deaths (44.4%) during a median follow-up of 21.5 years (IQR 25-75% 8.0-27.8), resulting in 24.5 per 1,000 patients/year incidence rate. The ET variables associated with mortality after adjustments for potential confounders were increased maximal (HR 1.02; 95% CI 1.00-1.03 per mmHg) and change (HR 1.03; 95% CI 1.01-1.06 per mmHg) of diastolic blood pressure (DBP) during ET, ventricular tachycardia at rest (HR 3.95; 95% CI 1.14-13.74), during exercise (HR 2.73; 95% CI 1.44-5.20), and recovery (HR 2.60; 95% CI 1.14-5.91), and premature ventricular complexes during recovery (HR 2.06; 1.33-3.21). Conclusion: Our findings suggest that ET provides important prognostic value for mortality risk assessment in patients with CD, with hemodynamic (increased DBP during exercise) and electrocardiographic (presence of ventricular arrhythmias) variables independently associated with an increased mortality risk in patients with CD. The identification of individuals at higher mortality risk can facilitate the development of intervention strategies (e.g., close follow-up) that may potentially have an impact on the longevity of patients with CD.

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Sex differences in triathlon performance have been decreasing in recent decades and little information is available to explain it. Thirty-nine male and eighteen female amateur triathletes were evaluated for fat mass, lean mass, maximal oxygen uptake (VO2 max), ventilatory threshold (VT), respiratory compensation point (RCP), and performance in a national Olympic triathlon race. Female athletes presented higher fat mass (p = 0.02, d = 0.84, power = 0.78) and lower lean mass (p < 0.01, d = 3.11, power = 0.99). VO2 max (p < 0.01, d = 1.46, power = 0.99), maximal aerobic velocity (MAV) (p < 0.01, d = 2.05, power = 0.99), velocities in VT (p < 0.01, d = 1.26, power = 0.97), and RCP (p < 0.01, d = 1.53, power = 0.99) were significantly worse in the female group. VT (%VO2 max) (p = 0.012, d = 0.73, power = 0.58) and RCP (%VO2 max) (p = 0.005, d = 0.85, power = 0.89) were higher in the female group. Female athletes presented lower VO2 max value, lower lean mass, and higher fat mass. However, females presented higher values of aerobic endurance (%VO2 max), which can attenuate sex differences in triathlon performance. Coaches and athletes should consider that female athletes can maintain a higher percentage of MAV values than males during the running split to prescribe individual training.

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La resistencia aérobica es la capacidad de realizar una actividad física en el mayor tiempo posible; esta es una capacidad determinante para muchos deportes y una necesidad para el personal militar activo, para lo cual se establecen estrategias especializadas en función de su potenciación como la aplicación del modelo interválico, considerado un entrenamiento basado en la repetición de periodos de trabajo de alta intensidad. En tal sentido, se planteó como objetivo de la investigación potenciar la resistencia aeróbica en soldados de la Escuela de Infantería del Ejército (EIE) a partir de un entrenamiento interválico HIIT. Se implementó una investigación descriptiva-correlacional. Se analizaron 75 soldados del curso de perfeccionamiento de la Escuela de Infantería del Ejército. Se evalúo su capacidad aeróbica e incluyó el índice de masa corporal antes y después de implementar un entrenamiento interválico durante ocho semanas. El promedio del índice de masa corporal fue de 23,91kg (normal; pretest), y de 23,38kg (normal; postest). Se muestreó significativamente diferente (p=0.000), mientras que el tiempo promedio en el test de dos millas fue de13´39min/s (pretest) y de 12´48min/s (postest), se mejora, para un -51s. El Vo2máx fue de 47,64 (ml/kg/min. pretest) y de 52,65ml/Kg/min (postest), un aumento de+5.01 ml/Kg/min, correspondiente a un 10,51 % de incremento del VO2máx. El entrenamiento interválico, se enfatiza en el extensivo-medio e intensivo-corto e incide positivamente en el desarrollo de la resistencia aeróbica a corto plazo, indica que es una alternativa para mejorar indicadores de resistencia aeróbica en soldados con un rango etario entre 23-28 años.

A resistência aeróbica é a capacidade de realizar uma atividade física no maior tempo possível; esta é uma capacidade determinante para muitos esportes e uma necessidade de pessoal militar ativo, para o qual são estabelecidas estratégias especializadas em termos de seu aperfeiçoamento, como a aplicação do modelo interválico, considerado um treinamento baseado na repetição de períodos de trabalho de alta intensidade. Neste sentido, o objetivo da pesquisa era melhorar a resistência aeróbica nos soldados da Escola de Infantaria do Exército (EIE) através do treinamento interválico HIIT. Uma pesquisa descritivo-correlacional foi implementada. Setenta e cinco soldados da Escola de Infantaria do Exército foram analisados no curso de treinamento avançado. Sua capacidade aeróbica foi avaliada e incluiu o índice de massa corporal antes e depois da implementação do treinamento interválico por oito semanas. O índice médio de massa corporal era de 23,91kg (normal; pré-teste), e 23,38kg (normal; pós-teste). A amostra foi significativamente diferente (p=0,000), enquanto o tempo médio no teste de duas milhas foi de 13'39min/s (pré-teste) e 12'48min/s (pós-teste), é melhorado, para um -51s. O Vo2max foi de 47,64 (ml/kg/min pré-teste) e 52,65ml/kg/min (pós-teste), um aumento de +5,01 ml/kg/min, correspondendo a um aumento de 10,51 % no VO2max. O treinamento interválico, enfatizado no intensivo-médio e intensivo-curto e tem um impacto positivo no desenvolvimento da resistência aeróbica de curto prazo, indica que é uma alternativa para melhorar os indicadores de resistência aeróbica em soldados com uma faixa etária entre 23-28 anos.

Aerobic resistance is the capacity to perform physical activity for as long as possible, being a determining capacity for many sports and a need for active military personnel, for which specialized strategies are established for its enhancement such as the interval model application, considered a training based on the repetition periods of high intensity load. In this sense, the research objective is to promote aerobic endurance in soldiers of the Escuela de Infantería del Ejército (EIE) from a HIIT interval training. A descriptive-co relational investigation is implemented, analyzing 75 soldiers from the improvement course of the Escuela de Infantería del Ejército, evaluating their aerobic capacity, including the Body Mass Index before and after implementing interval training for 8 weeks. The average body mass index was 23.91kg (Normal; Pretest), and 23.38kg (Normal; Posttest), being significantly different (p = 0.000), while the average time in the 2-mile test was 13'39min / s (Pretest) and 12'48 min / s (Posttest), improving -51s. The VoMax2 was 47.64 (ml / kg / min. Pretest) and 52.65 ml / Kg / min (Posttest), an increase of +5.01 ml / Kg / min, corresponding to a 10.51% increase of VO2max. Interval training, emphasizing the extensive-medium and intensive-short, positively affects the development of short-term aerobic endurance, being an alternative to improve aerobic endurance indicators in soldiers with an age range between 23-28 years.

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This paper investigated the effects over time of different forms of neuromuscular training on hemodynamic responses, the estimated VO2max, and walking performance. 105 older adults were randomly organized into three groups: RGA, RGB, and the Control Group (CG). RGA and RGB did 4 weeks of adaptation phase training and 12 weeks of intervention with different loads: moderate loads for RGB. and higher loads for RGA. A pre- and post-evaluation of the resting heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), double product (DP), estimated VO2max, and walking performance were assessed. Significant differences were observed for SBP, DBP, HR, and DP. For SBP, a post-evaluation reduction was observed only in RGA (p = 0.007) and when comparing RGA with the Control Group (p < 0.000). For the absolute VO2max, a significant improvement was seen in RGB compared to RGA (p = 0.037) and CG (p < 0.000). For the relative VO2max, RGB scored significantly higher than RGA (p < 0.000) and CG (p < 0.000), post-intervention. For the walk test, a significant reduction in completion times was observed for RGA (p = 0.027) and RGB (p < 0.000), and for RGB compared to RGA (p = 0.000) and CG (p < 0.000). Resistance training can be an excellent strategy for hemodynamic and cardiorespiratory improvement in the elderly.

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SUMMARY: Repeated sprint training in hypoxia (RSH) represents an innovative method in the process of development and improvement of physical performance among athletes. However, there is less scientific data on this topic. The purpose of this systematic review was to investigate the effect of RSH method on motor abilities and performance among athletes, obtain new information, and expand the already known conclusions. The data search was performed of 4 electronic databases for the years 2000-2021 May as follows: Google Scholar, PubMed, Web of Science, and ResearchGate. This search with English language restriction was made by using the following terms, individually/combination: "repeated sprint ability", "hypoxia", "effects", "physical performance", "VO2max" 844 studies were indentified, and 14 studies were selected (11 male studies, 1 female study, 2 both sexes). Results of this systematic review, a total sample size of 347 athletes (40 females and 307 males, aged 15.3 ± 0.5 - 35 ± 7 years), showed that RSH was an effective training method in improving all monitored variables (i.e. RSAmax, VO2max). However, it should be noted that major improvements were observed mainly in repeated sprint ability (RSA) tests, and less in aerobic tests (i.e. Wingate and Yo-Yo). In conclusion, based on current scientific studies, RSH is more effective method to improve the physical performance among athletes compared to repeated sprint training in normoxia (RSN). This study suggested that the RSH has a positive effect on the monitored variables in physical performance tests especially related to RSA.

RESUMEN: El entrenamiento de velocidad repetida en hipoxia (RSH) representa un método innovador en el proceso de desarrollo y mejora del rendimiento físico entre los deportistas. Sin embargo, existen pocos datos científicos sobre este tema. El propósito de esta revisión sistemática fue investigar el efecto del método RSH sobre las habilidades motoras y el rendimiento de los atletas, obtener nueva información y ampliar las conclusiones ya conocidas. La búsqueda de datos se realizó en 4 bases de datos electrónicas: Google Scholar, PubMed, Web of Science e Research Gate para los años 2000- a mayo de 2021. Esta búsqueda se realizó en artículos en idioma inglés mediante el uso de los siguientes términos, individualmente / combinación: "capacidad de sprint repetido", "hipoxia", "efectos", "rendimiento físico" y "VO2max" Se identificaron 844 estudios y se seleccionaron 14 de ellos (11 estudios realizados en hombres, un estudio realizado en mujeres y dos estudios realizados en am- bos sexos). Los resultados mostraron, un tamaño muestral total de 347 atletas (40 mujeres y 307 hombres, de 15,3 ± 0,5 - 35 ± 7 años). Se observó que la RSH fue un método de entrenamiento eficaz para mejorar todas las variables monitorizadas (es decir, RSAmax y VO2max). Sin embargo, se debe tener en consideración que se observaron mejoras importantes, principalmente, en las pruebas de capacidad de sprint repetido (RSA), y menos en las pruebas aeróbicas (es decir, Wingate y Yo-Yo). En conclusión, según los estudios científicos actuales, la RSH es un método más eficaz para mejorar el rendimiento físico entre los atletas en comparación con el entrenamiento de velocidad repetida en normoxia (RSN). Este estudio sugirió que la RSH tiene un efecto positivo sobre las variables monitoreadas en las pruebas de rendimiento físico especialmente relacionadas con RSA.

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This study aimed to examine the acute physiological effect of shuttle-run-based high-intensity intermittent exercise (HIIE) performed at the same relative speed (i. e., 100% PST-CAR) on sand (SAND) and grass (GRASS) in male junior soccer players. Seven Under-23 Brazilian national league ("Série A") soccer players completed four testing sessions in either SAND or GRASS surface condition. The first two testing sessions consisted of performing a maximal progressive shuttle-run field protocol until volitional exhaustion (Carminatti's test, T-CAR), whereas the third and fourth sessions comprised a HIIE session on each ground surface. The HIIE session consisted of three 5-min bouts [12 s shuttle-run (with a direction change every 6 s)/12 s of passive rest] performed at 100% of T-CAR peak speed (PST-CAR) with 3 min of passive recovery between sets. Measurements of oxygen uptake (VO2), heart rate (HR), blood lactate concentration ([La]), and rating of perceived exertion (RPE) were performed during all conditions. The SAND condition elicited significantly higher %VO2peak (94.58 ± 2.73 vs. 87.45 ± 3.31%, p < 0.001, d = 2.35), %HRpeak (93.89 ± 2.63 vs. 90.31 ± 2.87%, p < 0.001, d = 1.30), RPE (8.00 ± 0.91 vs. 4.95 ± 1.23 a.u., p < 0.001, d = 2.82), and [La] (10.76 ± 2.37 vs. 5.48 ± 1.13 mmol/L, p < 0.010, d = 2.84). This study showed that higher internal workloads are experienced by the players during a single HIIE session performed on a softer surface as SAND, even when the exercise intensity was individualized based on 100%PST-CAR.

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Nutrient consumption and body mass index (BMI) are closely related to the gut microbiota, and exercise effects on gut bacteria composition may be related to those variables. Thus, we aimed to investigate the effect of 10-week moderate aerobic exercise on the cardiorespiratory fitness and gut bacteria composition of non-obese men with the same nutritional profile. Twenty-four previously sedentary men (age 25.18 [SD 4.66] years, BMI 24.5 [SD 3.72] kg/m2) were randomly assigned into Control (CG; n = 12) or Exercise Groups (EG; n = 12). Body composition, cardiorespiratory parameters, blood markers, dietary habits and gut bacteria composition were evaluated. EG performed 150 min per week of supervised moderate (60-65% of VO2peak) aerobic exercise, while CG maintained their daily routine. The V4 16S rRNA gene was sequenced and treated using QIIME software. Only EG demonstrated marked improvements in cardiorespiratory fitness (VO2peak, p < 0.05; Effect Size = 0.971) without changes in other gut bacteria-affecting variables. Exercise did not promote clustering based on diversity indices (p > 0.05), although significant variations in an unclassified genus from Clostridiales order and in Streptococcus genus were observed (p < 0.05). Moreover, α-diversity was correlated with VO2peak (Pearson's R: 0.47; R2 0.23: 95%CI: 0.09 to 0.74, p = 0.02) and BMI (Pearson's R: -0.50; R2 0.25: 95%CI: -0.75 to -0.12, p = 0.01). Roseburia, Sutterella and Odoribacter genera were associated with VO2peak, while Desulfovibrio and Faecalibacterium genera were associated with body composition (p < 0.05). Our study indicates that aerobic exercise at moderate intensity improved VO2peak and affected gut bacteria composition of non-obese men who maintained a balanced consumption of nutrients.

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BACKGROUND: Minimum cardiorespiratory fitness (CRF) has been recommended for firefighters due to job requirements. Thus, it is important to identify accurate and readily available methods to assess CRF in this population. Non-exercise CRF estimates (NEx-CRF) have been proposed but this approach requires validation in this population. OBJECTIVE: To evaluate the accuracy of a NEx-CRF, as compared to a field maximum exercise test, among career military firefighters of both genders using a comprehensive agreement analysis. METHODS: We evaluated the accuracy of a NEx-CRF estimate compared to the Cooper 12 min running test among 702 males and 106 female firefighters. RESULTS: Cooper and NEx-CRF tests yielded similar CRF in both genders (differences <1.8±4.7 ml/kg-1.min-1; effect size <0.34). However, NEx-CRF underestimated Cooper-derived CRF among the fittest firefighters. NEx-CRF showed moderate to high sensitivity/specificity to detect fit or unfit firefighters (71.9% among men and 100% among women). Among men, the NEx-CRF method correctly identified most firefighters with less than 11 METs or greater than 13 METs, but showed lower precision to discriminate those with CRF between 11-13 METs. CONCLUSIONS: The NEx-CRF method to estimate firefighters' CRF may be considered as an alternative method when an exercise-based method is not available or may be used to identify those who require more traditional testing (CRF 11-13 METs).

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While performing aerobic exercise during chemotherapy has been proven feasible and safe, the efficacy of aerobic training on cardiorespiratory fitness (CRF) in women with breast cancer undergoing chemotherapy has not yet been systematically assessed. Therefore, the objective of this work was to determine (a) the efficacy of aerobic training to improve CRF; (b) the role of aerobic training intensity (moderate or vigorous) on CRF response; (c) the effect of the aerobic training mode (continuous or interval) on changes in CRF in women with breast cancer (BC) receiving chemotherapy. A systematic review and meta-analysis were conducted as per PRISMA guidelines, and randomized controlled trials comparing usual care (UC) and aerobic training in women with BC undergoing chemotherapy were eligible. The results suggest that increases in CRF are favored by (a) aerobic training when compared to usual care; (b) vigorous-intensity aerobic exercise (64-90% of maximal oxygen uptake, VO2max) when compared to moderate-intensity aerobic exercise (46-63% of VO2max); and (c) both continuous and interval aerobic training are effective at increasing the VO2max. Aerobic training improves CRF in women with BC undergoing chemotherapy. Notably, training intensity significantly impacts the VO2max response. Where appropriate, vigorous intensity aerobic training should be considered for women with BC receiving chemotherapy.

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PURPOSE: The aim of this study was to verify whether physiological components [vertical jumps (Squat Jump - SJ and Countermovement Jump - CMJ), eccentric utilization ratio (EUR) of vertical jumps, running economy (RE), metabolic cost (C MET ), first and second ventilatory threshold (VT1 and VT2) maximal oxygen uptake (VO2MAX)] can predict maximal endurance running performance. METHODS: Twenty male runners performed maximal vertical jumps, submaximal running at constant speeds, and maximal incremental running test. Before, we measured anthropometric parameters (body mass and height) and registered the training history and volume. SJ and CMJ tests were evaluated prior to running tests. Initially, the oxygen uptake (VO2) was collected at rest in the orthostatic position for 6 min. Soon after, a 10-min warm-up was performed on the treadmill at 10 km⋅h-1, followed by two 5-min treadmill rectangular tests at 12 and 16 km⋅h-1 monitored by a gas analyzer. After that, the runners performed a maximal incremental test, where the VT1, VT2, and VO2MAX were evaluated, as well as the maximum running speed (vVO2MAX). Thus, RE and C MET were calculated with data obtained during rectangular running tests. Multivariate stepwise regression analyses were conducted to measure the relationship between independent variables (height and power of SJ and CMJ, EUR; RE and C MET 12 and 16 km⋅h-1 ; VT1, VT2, and VO2MAX), as predictors of maximal running performance (vVO2MAX), with significance level at α = 0.05. RESULTS: We found that VO2MAX and RE at 16 km⋅h-1 predict 81% of performance (vVO2MAX) of endurance runners (p < 0.001). CONCLUSION: The main predictors of the maximal incremental running test performance were VO2MAX and RE.

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Perceived lack of time is one of the most often cited barriers to exercise participation. High intensity interval training has become a popular training modality that incorporates intervals of maximal and low-intensity exercise with a time commitment usually shorter than 30 min. The purpose of this study was to examine the effects of short-term run interval training (RIT) on body composition (BC) and cardiorespiratory responses in undergraduate college students. Nineteen males (21.5 ± 1.6 years) were randomly assigned to a non-exercise control (CON, n = 10) or RIT (n = 9). Baseline measurements of systolic and diastolic blood pressure, resting heart rate (HRrest), double product (DP) and BC were obtained from both groups. VO2max and running speed associated with VO2peak (sVO2peak) were then measured. RIT consisted of three running treadmill sessions per week over 4 weeks (intervals at 100% sVO2peak, recovery periods at 40% sVO2peak). There were no differences in post-training BC or VO2max between groups (p > 0.05). HRrest (p = 0.006) and DP (p ≤ 0.001) were lower in the RIT group compared to CON at completion of the study. RIT lowered HRrest and DP in the absence of appreciable BC and VO2max changes. Thereby, RIT could be an alternative model of training to diminish health-related risk factors in undergraduate college students.

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To evaluate the acute effects of ingestion of 500 mg of caffeine in addition to aerobic exercise on the optimization of cognitive attention tasks and simple reaction time. Twenty men were randomly divided into two groups, caffeine (CAF) and placebo (PLA), and underwent cardiopulmonary exercise testing and cognitive testing (D2SLK, D2GZ, D2F% and TRS). Then, both ingested 500 mg of caffeine or placebo (double blind), and after 60 min performed a 30-minute continuous exercise session at 70 % VO2Max. Cognitive tests were repeated immediately after exercise, and after 30 min. D2SLK, D2GZ, D2F% and TRS scores were compared by repeated measures ANOVA. The magnitude of the effect was established, and it was considered meaningful p = 0.05. CAF is able to alter D2SLK and also reduce D2F% (0.001 - moderate effect, 0.82) and improve the task after 30 min of exercise (p = 0.014 - moderate effect 0.95). The TRS showed significant gains for the CAF group compared to PLA (0.000 - high effect 1.76). Caffeine induces significant effects in attention and reaction time domains independent of the effect of aerobic exercise.

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Introducción: Existen beneficios en salud al realizar ejercicio físico, sin embargo, son pocas las investigaciones que reportan el rendimiento anaeróbico y su correlación con indicadores cardiorrespiratorios. Por tal motivo, el propósito de esta investigación fue determinar valores de rendimiento cardiorrespiratorio y aptitud anaeróbica después de un programa de ejercicio aeróbico en el cual se determinó la correlación entre ellos. Métodos: 22 hombres (20±2 años) conformaron dos grupos, G1-(entrenamiento), 6 semanas/tres días por semana, intensidad horaria de 45 minutos/día, G2-(Control). Antes y después realizaron un test de Wingate y una prueba de esfuerzo de predominancia aeróbica. Resultados: Aumentos significativos entre el pre-pos en G1 en VO2máx y vatios que mejoraron 7,6 % y 15,9 % respectivamente, diferencia significativa en la PP y en PM/kg con una mejora del 18,8 % y 18,9 %, respectivamente. Conclusión: Un programa de ejercicio aeróbico submáximo en bicicleta estática aumenta el rendimiento cardiorrespiratorio y rendimiento anaeróbico sin que exista una relación de dependencia entre las diferentes variables.

Introduction: There are health benefits when performing physical exercise, however, there are few investigations that report anaerobic performance and its correlation with cardiorespiratory indicators, for this reason, the purpose of this research was to determine the values of cardiorespiratory performance and anaerobic fitness after an aerobic exercise program determining the correlation between them. Method: 22 men (20 ± 2 years), were divided into two groups, G1 (training), 6 weeks, three days a week with an hourly intensity of 45 minutes per day, G2 (control). Before and after exercise they performed a Wingate test and a predominantly aerobic stress test. Results: Significant increases between pre-post in G1 in VO2Max and watts improving 7.6% and 15.9% respectively, a significant difference in PP and PM/kg improving 18.8% and 18.9% respectively. Conclusion: A submaximal aerobic exercise program on a stationary bike increases cardiorespiratory performance and anaerobic performance without a dependency relationship between the different variables.

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INTRODUCTION: To associate food consumption according to the groups that make up the food pyramid with the aerobic and anaerobic performance of Brazilian athletes. A cross-sectional study of 168 athletes with a mean age and BMI of 20.84 ± 7.74 years and 22.88 ± 3.1 kg/m², respectively. Maximum power output was significantly associated with the meat and eggs groups (ß = 0.31; p < 0.05). VO2max exhibited a positive relationship with the fruit group (ß = 0.29; p < 0.05). A significant inverse relation between VO2max and the legumes group was observed (ß = -0.76; p < 0.05). The meat and eggs group and the dairy products group had an inverse and significant association with VO2max (ß = -0.43; p < 0.01). Consumption of meat and eggs showed a positive association with anaerobic performance, whereas the same group and the dairy products group had a negative association with aerobic performance.

INTRODUCCIÓN: Asociar el consumo de alimentos según los grupos que componen la pirámide de alimentos con el rendimiento aeróbico y anaeróbico de deportistas brasileños. Estudio transversal de 168 deportistas con una media de edad e IMC de 20,84 ± 7,74 años y 22,88 ± 3,1 kg/m², respectivamente. La potencia máxima se asoció significativamente con el consumo de los grupos de carne y huevos (ß = 0,31; p < 0,05). El VO2max mostró una relación positiva con el grupo de la fruta (ß = 0,29; p < 0,05). Se observó una relación inversa significativa entre el VO2max y el grupo de las leguminosas (ß = −0,76; p < 0,05). El grupo de carnes y huevos y el grupo de productos lácteos tuvieron una asociación inversa y significativa con el VO2max (ß = −0,43; p < 0,01). El consumo de carne y huevos mostró una asociación positiva con el rendimiento anaeróbico, mientras que el mismo grupo y los productos lácteos se asociaron de forma negativa al rendimiento aeróbico.

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