Different Signatures of High Cardiorespiratory Capacity Revealed With Metabolomic Profiling in Elite Athletes.

PURPOSE: High cardiorespiratory capacity is a key determinant of human performance and life expectancy; however, the underlying mechanisms are not fully understood. The objective of this pilot study was to investigate biochemical signatures of endurance-performance athletes using high-resolution nontargeted metabolomics. METHODS: Elite long-distance runners with similar training and anthropometrical records were studied. After athletes' maximal oxygen consumption (V˙O2max) was measured, they were divided into 2 groups: low V˙O2max (<65 mL·kg-1·min-1, n = 7) and high V˙O2max (>75 mL·kg-1·min-1, n = 7). Plasma was collected under basal conditions after 12 hours of fasting and after a maximal exercise test (nonfasted) and analyzed by high-resolution LC-MS. Multivariate and univariate statistics were applied. RESULTS: A total of 167 compounds were putatively identified with an LC-MS-based metabolomics pipeline. Partial least-squares discriminant analysis showed a clear separation between groups. Significant variations in metabolites highlighted group differences in diverse metabolic pathways, including lipids, vitamins, amino acids, purine, histidine, xenobiotics, and others, either under basal condition or after the maximal exercise test. CONCLUSIONS: Taken together, the metabolic alterations revealed in the study affect cellular energy use and availability, oxidative stress management, muscle damage, central nervous system signaling metabolites, nutrients, and compound bioavailability, providing new insights into metabolic alterations associated with exercise and cardiorespiratory fitness levels in trained athletes.

Validation of Maximal, Submaximal, and Nonexercise Indirect [Formula: see text]O2max Estimations at 2600 m Altitude.

Aim: To study the criterion validity of three indirect maximal oxygen uptake ([Formula: see text]O2max) assessment equations at altitude. Methods: We studied 64 young adults (53% men) at Bogota, Colombia (2600 m altitude). Direct [Formula: see text]O2max was measured by indirect calorimetry using a maximal incremental treadmill protocol. Indirect [Formula: see text]O2max was estimated by two exercise field tests (the 20-m shuttle-run test [20-MST] and the 2-km walking test (UKK)) and one nonexercise method (the perceived functional ability-physical activity rating questionnaire [PFA-PAR]). Altitude-adjusted PFA-PAR was estimated as a 13% linear reduction in PFA-PAR. We calculated Lin concordance coefficients (LCC) and standard error of the estimates (SEEs), and we performed Bland-Altman analyses for each indirect method. Results: Mean [Formula: see text]O2max was 41.2 ± 5.8 mL/kg/min in men and 32.2 ± 3.6 mL/kg/min in women. We found the highest agreement with direct [Formula: see text]O2max for the 20-MST (LCC = 0.79, SEE = 3.91 mL/kg/min), followed in order by the altitude-adjusted PFA-PAR (LCC = 0.71, SEE = 4.12 mL/kg/min), the UKK (LCC = 0.67, SEE = 5.48 mL/kg/min), and the unadjusted PFA-PAR (LCC = 0.57, SEE = 4.75 mL/kg/min). The unadjusted PFA-PAR tended to overestimate [Formula: see text]O2max, but Bland-Altman analysis showed that this bias disappeared after altitude adjustment. Conclusion: Several maximal, submaximal, and nonexercise methods provide estimates of [Formula: see text]O2max with acceptable validity for use in epidemiological studies of populations living at moderate altitude.

Simplified method for determination of the Oxygen Dissociation Curve (ODC) / Método simplificado para determinar la curva de disociación de oxígeno (cdo)

RESUMEN La afinidad de la hemoglobina (Hb) por oxigeno (O2) es un factor importante que influye en el transporte de este gas, especialmente en hipoxia y en diferentes enfermedades como anemia o fibrosis quística. En la medición de la afinidad se usa la determinación de la curva de disociación Hb:O2. El método presentado para establecer la curva de disociación Hb:O2 (CDO) simplifica los protocolos normalmente utilizados, ya que elimina el requerimiento del equipo específico para equilibrar la sangre con oxígeno en niveles fijos de presión parcial (PO2). Mediante el uso de ecuaciones matemáticas es posible establecer la cinética de saturación de la hemoglobina (SO2) a valores crecientes de PO2. De igual forma, mediante el método se determinan aspectos típicos de la unión Hb: O2 como la dependencia del pH (coeficiente de Bohr) y el tipo de asociación de la proteína con su ligando mediante el diagrama de Hill. En virtud de la simplificación realizada, el método es aplicable en prácticas de laboratorio en población humana y animal, así como en la investigación de diferentes condiciones experimentales.

ABSTRACT The affinity of hemoglobin (Hb) for oxygen (O2) is an important factor influencing the transport of this gas especially in hypoxia and in different diseases such as anemia or cystic fibrosis. By the affinity measurement, the determination of the Hb: O2 dissociation curve is used. The presented method to establish the Hb: O2 oxygen dissociation curve (CDO) simplifies the protocols normally used, since it eliminates the requirement of specific equipment to equilibrate blood with oxygen at fixed levels of oxygen pressure (PO2). By using mathematical equations, it is possible to establish the saturation change of hemoglobin (SO2) at increasing oxygen partial pressure. Similarly, the method determines typical aspects of the Hb: O2 binding as the pH dependence (Bohr coefficient) and the association type of protein with its ligand by the Hill diagram. By this simplification, the method is applicable in laboratory practices in human and animal population, as well as in the investigation of different experimental conditions.

A Multidimensional Approach to Assessing Anthropometric and Aerobic Fitness Profiles of Elite Brazilian Endurance Athletes and Military Personnel.

INTRODUCTION: Military personnel must remain physically active to meet operational requirements. Military physical training not only provides the performance capabilities required for performing occupational tasks but also fosters the development of sport. Thus, Armed Forces across the world have historically invested in developing elite- and Olympic-level athletes. This study aimed to assess the anthropometric and physiological differences among groups of Brazilian military athletes (MA), non-military athletes (A), and military non-athletes (M). MATERIALS AND METHODS: Seventy-five individuals participated in the study: 17 MA (23.7 ± 4.8 years), 27 A (24.7 ± 5.3 years), and 31 M (26.9 ± 3.3 years). MA and A individuals specialized in endurance sports, and had a mean weekly training volume of (100.0 ± 34.8 and 106.3 ± 40.5 Km; F = 0.894, p = 0.6), respectively. Anthropometric measures and maximal oxygen uptake (V̇O2máx) were assessed in all participants. Ergospirometry and anthropometry variables were analyzed with one-way analysis of variance (ANOVA) for independent measures. Comparisons of weekly training volume (km) and training experience (years) were performed only between the A and MA using the Student's t-test for independent samples. For a multidimensional approach, Partial least squares discriminant analysis (PLS-DA) was performed for all variables using the online tool MetaboAnalyst. RESULTS: We found no differences in anthropometric and physiological profiles between A and MA, but significant differences between M and MA/A in body mass index (kg/m2) (BMI), body fat percentage, fat mass (kg), waist circumference (cm) (WC), somatotype, and V̇O2máx (mL min-1 kg-1). CONCLUSION: In conclusion, military endurance athletes have similar anthropometric and physiological profiles to non-military athletes and superior levels to non-athlete military. These findings indicate that the Brazilian Armed Forces scouting system has been successful in identifying endurance athletic talent in line with their historic role of developing sport in Brazil.

Comportamiento de la concentración de hemoglobina, el hematocrito y la saturación de oxígeno en una población universitaria en Colombia a diferentes alturas / Behavior of hemoglobin concentration, hematocrit and oxygen saturation in colombian university population at different altitudes

Introducción: el desarrollo de la presente investigación se basa en el creciente interés por comprender las adaptaciones a la hipoxia crónica, principalmente en el rango altitudinal denominado de alturas intermedias (1.500- 3.000 m.s.n.m), con la necesidad de establecer parámetros de normalidad en las variables [Hb], Hct y SO2 con fines diagnósticos y de caracterización de la población. Objetivos: analizar el comportamiento de la [Hb], el Hct y la SaO2 a diferentes alturas intermedias (970 m.s.n.m, 1.520 m.s.n.m, 1.728 m.s.n.m, 1.923 m.s.n.m, 2.180 m.s.n.m y 2.600 m.s.n.m) con el fin de aportar conocimiento sobre la fisiología de la altura y al campo clínico para apoyar el diagnóstico de anemia. Métodos: sujetos clínicamente sanos, con nivel bajo de actividad física y reporte de consumo de alimentos con contenido de hierro. Total de 264 participantes de ambos géneros entre 18 y 30 años. Las muestras se obtuvieron de sangre de la vena antecubital y del lóbulo de la oreja y fueron analizadas en un radiómetro. Se realizó un análisis estadístico no paramétrico. Resultados: con el incremento de la altitud los valores de [Hb] y Hct se incrementaron, mientras la SO2 descendió. Los hombres presentaron valores más altos que las mujeres en [Hb] y Hct, relacionado con valores más bajo de SO2 que las mujeres. Discusión: no se evidenció un umbral de las variables, quizás por la pequeña distancia entre las alturas. Los valores reportados fueron similares pero no iguales a otros estudios, lo que podría deberse a la diversidad genética entre poblaciones. Conclusiones: este estudio permite obtener los primeros valores de caracterización de la población estudiada. Todas las alturas estuvieron por encima del punto de corte para el diagnóstico de anemia ([Hb] 12 g/dl) (AU)

Introduction: the development of this research is base on the growing interest in understanding the adaptations to chronic hipoxia mainly in the range of intermediate altitudes (1 500-3 000 m.s.n.m) and the need to establish parameters of normality in the variables [Hb], Hct and SO2 for diagnostic and characterization of the population purposes. Objective: to analyze the behavior of the [Hb], Hct and SaO2 at different intermediate altitudes (970 m.s.n.m, 1520 m.s.n.m, 1 728 m.s.n.m, 1 923 m.s.n.m, 2 180 m.s.n.m and 2600 m.s.n.m) in order to contribute to the knowledge of the high altitude physiology and the clinical field to support the diagnosis of anemia. Methods: clinically healthy subjects with low levels of physical activity and food consumption report containing iron. Total of 264 participants of both genders between 18 and 30 years. The blood samples were collected from the antecubital vein and the earlobe and analyzed in a radiometer. A non-parametric statistical analysis was performed. Results: with increasing of altitude, [Hb] and Hct values were increased while the SO2 decreased. Men showed higher values than women in [Hb] and Hct, related to lower values of SO2 than women. Discussion: a threshold variable was not found, perhaps because of the small distance between the altitudes. The values reported were similar but not identical to other studies. This difference could be explained by genetic diversity among populations. Conclusions: this study allows for the first values of characterization of the study population. All altitudes were above the cutoff for the diagnosis of anemia ([Hb] 12 g/dl) (AU)

Built environment attributes and walking patterns among the elderly population in Bogotá.

BACKGROUND: There is increasing evidence that the built environment has an influence on physical activity; however, little is known about this relationship in developing countries. PURPOSE: This study examined the associations between attributes of the built environment and walking patterns among the elderly. METHODS: A multilevel cross-sectional study was conducted in 2007. Fifty neighborhoods were selected and 1966 participants aged > or =60 years were surveyed. Objective built environment measures were obtained in a buffer of 500 m using GIS. Environmental perceptions were assessed via questionnaire. RESULTS: People who lived in areas with middle park area (4.53%-7.98% of land) were more likely to walk for at least 60 minutes during a usual week (prevalence OR [POR]=1.42, 95% CI=1.02, 1.98). Those who lived in areas with the highest connectivity index (1.81-1.99) were less likely to report walking for at least 60 minutes (POR=0.64, 95% CI=0.44, 0.93). Participants who reported feeling safe or very safe from traffic were more likely to report walking for at least 60 minutes (POR=1.50, 95% CI=1.11, 2.03). The presence of Ciclovía (recreational program) was marginally associated with having walked at least 150 minutes in a usual week (POR=1.29, 95% CI=0.97, 1.73). CONCLUSIONS: This study showed that certain built and perceived environment characteristics were associated with walking among older adults living in Bogotá. Further studies should be conducted to better understand the potential influence of the built environment on physical activity among the elderly population in the context of Latin American cities.

Arterial oxygen saturation and hemoglobin mass in postmenopausal untrained and trained altitude residents.

Because of lacking ventilatory stimulation by sex hormones in postmenopausal women (PW), one might expect a lowered arterial oxygen saturation (S(O(2))) in hypoxia and therefore a stronger erythropoietic reaction than in young women (YW). Nine untrained (UTRPW) and 11 trained (TRPW) postmenopausal altitude residents (2600 m) were compared to 16 untrained (UTRYW) and 16 trained young women (TRYW) to check this hypothesis and to study the combined response to hypoxia and training. S(O(2)) was decreased in PW (89.2% +/- 2.2 vs. 93.6 +/- 0.7% in YW, p < 0.01). Hb mass, however, was similar in UT (UTRYW: 9.2 +/- 0.9 g/kg(1), UTRPW: 8.7 +/- 1.0 g/kg). But if body fat rise with age was excluded by relation to fat-free mass, Hb mass was increased in UTRPW (+1.2 g/kg, p < 0.05) compared to UTRYW. Training caused a similar rise of Hb mass in PW and YW (0.3 g/kg per mL/kg x min(1) rise in V(O(2peak))). There was no difference in erythropoietin among the groups. Ferritin was higher in PW than YW. The results show that female hormones and fitness level have to be considered in studies on erythropoiesis at altitude. The role of erythropoietin during chronic hypoxia still has to be clarified.

Blood volume and hemoglobin mass in endurance athletes from moderate altitude.

PURPOSE: To determine whether total hemoglobin (tHb) mass and total blood volume (BV) are influenced by training, by chronic altitude exposure, and possibly by the combination of both conditions. METHODS: Four groups (N = 12, each) either from locations at sea level or at moderate altitude (2600 m) were investigated: 1) sea-level control group (UT-0 m), 2) altitude control group (UT-2600 m), 3) professional cyclists from sea level (C-0 m), and 4) professional cyclists from altitude (C-2600 m). All subjects from altitude were born at about 2600 m and lived all their lives (except during competitions at lower levels) at this altitude. tHb and BV were determined by the CO-rebreathing method. RESULTS: VO2max (mL x kg(-1) x min(-1)) was significantly higher in UT-0 m (45.3 +/- 3.2) than in UT-2600 m (39.6 +/- 4.0) but did not differ between C-0 m (68.2 +/- 2.7) and C-2600 m (69.9 +/- 4.4). tHb (g x kg(-1)) was affected by training (UT-0 m: 11.0 +/- 1.1, C-0 m: 15.4 +/- 1.3) and by altitude (UT-2600 m: 13.4 +/- 0.9) and showed both effects in C-2600 m (17.1 +/- 1.4). Because red cell volume showed a behavior similar to tHb and because plasma volume was not affected by altitude but by training, BV (mL x kg(-1)) was increased in C-0 m (UT-0 m: 78.3 +/- 7.9; C-0 m: 107.0 +/- 6.2) and in UT-2600 m (88.2 +/- 4.8), showing highest values in the C-2600 m group (116.5 +/- 11.4). CONCLUSION: In endurance athletes who are native to moderate altitude, tHb and BV were synergistically influenced by training and by altitude exposure, which is probably one important reason for their high performance.