Highest oxygen consumption prediction: introducing variable theoretical proportional factors for different sports.

PURPOSE: The use of a fixed theoretical-proportional-factor (TPF15) is one of the indirect highest-oxygen-consumptions (HOC) assessment methods, but it may not accurately reflect the physiological differences across various sports (cycling-triathlon-running-football-multisport). The aim of this study is to evaluate the variability of TPF across different sports, proposing a series of sport-specific new TPF values for more accurate HOC estimation. METHODS: A sample of 340 adults (26.01 ± 7.18 years) performed a maximal-incremental-test using sport-specific-ergometers. HOC was considered for cycling  V ˙ O 2peak , whereas for the other investigated sports it was considered V ˙ O 2max . HOC was directly measured using a gas-analyzer, and TPF values were calculated using heart rate (HR): the ratio of HRmax/HRrest multiplied for the measured values of HOC. A one-way ANOVA was used to measure differences and Bland-Altman plots were constructed to compare predicted and actual  V ˙ O 2max / V ˙ O 2peak . RESULTS: Actual HOC was significantly greater than those predicted by the fixed TPF15 (P < 0.001). Sport-specific new TPF values ranged from 16.55 in multisport to 20.15 in cycling, consistently exceeding the old fixed TPF15, and predicting therefore better HOC. The new TPF exhibited a closer agreement with the directly measured V ˙ O 2max / V ˙ O 2peak  compared to the TPF15. Furthermore, the new TPF reduced the typical-measurement-error (14.94-17.78%) compared to TPF15 (15.63-24.13%). CONCLUSION: This study suggests that new TPF values predict V ˙ O 2max / V ˙ O 2peak  with higher accuracy compared to the traditional method. The use of HRmax and HRrest values allows to customize training programs for different athletes. Future research should focus on validating these findings across larger populations of athletes.

Muscle damage produced during a simulated badminton match in competitive male players.

The purpose of the study was to assess the occurrence of muscle damage after a simulated badminton match and its influence on physical and haematological parameters. Sixteen competitive male badminton players participated in the study. Before and just after a 45-min simulated badminton match, maximal isometric force and badminton-specific running/movement velocity were measured to assess muscle fatigue. Blood samples were also obtained before and after the match. The badminton match did not affect maximal isometric force or badminton-specific velocity. Blood volume and plasma volume were significantly reduced during the match and consequently haematite, leucocyte, and platelet counts significantly increased. Blood myoglobin and creatine kinase concentrations increased from 26.5 ± 11.6 to 197.3 ± 70.2 µg·L(-1) and from 258.6 ± 192.2 to 466.0 ± 296.5 U·L(-1), respectively. In conclusion, a simulated badminton match modified haematological parameters of whole blood and serum blood that indicate the occurrence of muscle fibre damage. However, the level of muscle damage did not produce decreased muscle performance.

Disadvantages of Automated Respiratory Gas Exchange Analyzers.

The use of automated gas exchange analysis systems in exercise studies is common throughout the industrialized world and are frequently used in sports medicine laboratories for the measurement of maximal oxygen uptake (VO2max), as an integrative parameter that allows the physical condition to be assessed, in spite of its limitations. Actually, the fundamental principles behind the measurement of respiratory gas exchange (RGE) have not changed for a century. It was used a manual Douglas bag method together with separate chemical analyses. The need for faster and more efficient techniques, has conditioned the traditional procedures and determined the emergence of automated systems. However, the validity and reliability of all these different systems is not well known. The common features associates with these systems, also have disadvantages that must be evaluated at the time of the acquisition of an automated equipment: (1) regular quality control checks, which entails other added economic costs, (2) the validity and reliability of the results, which it is necessary to verify, and (3) the user does not know the equations that determine the values of oxygen consumption and carbon dioxide production. This work aims to clarify the disadvantages of these automated systems. At maximum intensities, the variation of VO2max or VO2peak can be very significant in athletes and even more relevant in sick people undergoing a training program. Therefore, considerable care is needed when comparing RGE data with automated systems. NEW AND NOTEWORTHY: Actually, stress tests are more conveniently performed with automated systems. It is necessary to examine the validity and reliability of automated respiratory gas exchange systems. The algorithms incorporated in the software, apart from being a "mystery," show differences with respect to the data provided.

Determinación del área ventilatoria interumbral en individuos con diferentes capacidades de resistencia / Determining the ventilatory inter-threshold area in individuals with different endurance capacities

Existe un consenso general de que hay dos puntos de ruptura de la ventilación durante el ejercicio incremental, el umbral ventilatorio 1 (VT1) y el umbral ventilatorio 2 (VT2), que marcan los límites de la transición aeróbica-anaeróbica. El área interumbral se ha definido como un parámetro que relaciona los umbrales ventilatorios. El objetivo principal del presente estudio fue examinar el área entre los umbrales (ITA), es decir, el área entre VT1 y VT2 para la función ventilación/absorción de oxigeno. Seiscientos seis varones con diferentes estados de condición física, desarrollaron una prueba de esfuerzo incremental y se registraron los umbrales ventilatorios. EL ITA es un trapecio cuya área se calcula como la suma del área del triángulo y rectángulo que lo forman, tal como se muestra en la figura entre VT1 y VT2 y que permanecen por debajo de la función VO2/VE. La media de ITA para la función VO2-VE fue mayor en los ciclistas, como representantes de deportistas de resistencia, frente al área correspondiente a los estudiantes de educación física con menores niveles de resistencia (120±34 vs. 86±40L2/min2). Estos resultados sugieren que la determinación del ITA puede reflejar adecuadamente el estado metabólico durante el proceso de transición aeróbico-anaeróbico durante las pruebas de esfuerzo incrementales

There is a general consensus in the literature regarding the existence of two ventilation break points during incremental exercise, i.e., Ventilatory Threshold 1 (VT1) and Ventilatory Threshold 2 (VT2), which mark the boundaries of the aerobic-anaerobic transition. The Inter-Threshold Area (ITA) has been defined as a parameter that connects the ventilatory thresholds. The main aim of the present study was to examine the ITA i.e., the expressed area between VT1 and VT2 for the function: ventilation÷oxygen uptake (VE/VO2 in L2min2) in individuals with various endurance capacities. Six hundred and six men with different levels of endurance completed an incremental exercise test and their ventilatory thresholds were recorded. The ITA is a trapezoid whose area is calculated as the sum of the area of the triangle and rectangle that form it between VT1 and VT2 below the VO2/VE function. The mean ITA for the function VO2-VE was greater in cyclists, as the main representatives for endurance athletes, than the mean corresponding to physical education students, who averaged a lower endurance level (120±34 vs. 86±40L2/min2). The results suggest that the determination of the ITA can reflect metabolic status throughout the aerobic-anaerobic transition during maximal incremental exercise tests

Evolución de los parámetros ergoespirométricos con el entrenamiento en deportistas / Evolution of the ergospirometric parameters with the training in sportsmen

El objetivo de esta revisión es analizar la evolución de los parámetros más representativos de una prueba de esfuerzo a medio o largo plazo. Hemos realizado una búsqueda restringida en la base de datos medline y en la base de datos sobre tesis doctorales publicadas en España. Los parámetros ergoespirométricos analizados en los estudios consultados han sido el consumo máximo de oxígeno y la transición aeróbica anaeróbica. Las diferencias de VO2 máximo absoluto (l/min) han sido del 7% cuando se comparan resultados en diferentes momentos de una temporada e inferiores al 9% en unidades relativas (ml/Kg/min). La mayor parte de los estudios no han demostrado significación estadística, si bien en la mayor parte, los valores más altos correspondían al momento de mejor estado de entrenamiento. La transición aeróbica-anaeróbica experimenta una oscilación considerable entre diferentes estados de entrenamiento. El umbral ventilatorio 1 (VT1) estaba comprendido entre 0,5% y el 22% y el umbral ventilatorio2 (VT2) entre el 2,5 al 12,8%. El umbral láctico en los estudios consultados experimenta una variación del 0% al 36,8%. ¿Pueden explicar las diferencias encontradas la mejora del rendimiento deportivo a lo largo del proceso de entrenamiento? De no ser así, significaría que los procedimientos de análisis del volumen y composición del gas espirado son poco sensibles para determinar pequeñas variaciones que nos explique el mejor rendimiento. Por tanto, es de capital trascendencia ser extremadamente rigurosos en la calibración y control de la linealidad de los aparatos de ergoespirometría (AU)

The objective of this review is to analyze the evolution of the most representative ergospirometrics parameters in long term studies. We have carried out a search restricted in the medline database and in the doctoral thesis database published in Spain. The ergospirometrics parameters analyzed in advised studies have been the maximal oxygen uptake (VO2 max) and the aerobic-anaerobic transition. The differences of VO2 max (l/min) have been of 7% when results are compared in different moments of a season and inferior to 9% in relative units (ml/Kg/min). In most of the studies statistical significance has not been demonstrated, although in most the highest values corresponded to the moment of better training state. The ventilatory threshold 1 (VT1) oscillated between 0,5% and 22% in the different training states and the ventilatory threshold 2 (VT2)from 2,5 to 12,8%. The lactic threshold in the consulted studies experiences a variation from0% to 36,8%.Can be explain the differences of the improvement of sport performance along the training process? Of not being this way, would mean that the procedures of volume and composition analysis of the expired gas are not very sensitive to determines mall variations that explains to us the best performance. Therefore, it is of capital transcendency to be extremely rigorous in the calibration and control of lineality of the ergospirometrics divices (AU)