Correspondence Information Copyright© Asian Exercise & Sport Science Association (AESA). www.aesasport.com International Journal of Applied Exercise Physiology 2322-3537 www.ijaep.com Vol.6 No.1 Received: December 2016, Accepted: March 2017, Available online: April 2017 Evaluation of pulmonary function for estimation of peak oxygen consumption through the respiratory gas analysis and allometric equation in boy student Seyyed Reza Attarzadeh Hosseini 1* , Keyvan Hejazi 2 1 Department of Physical Education and Sports Sciences, Professor in Sport Physiology, Ferdowsi University of Mashhad, Mashhad, Iran, E-mail: attarzadeh@um.ac.ir (Corresponding Author). 2 Department of Physical Education and Sports Sciences, PhD student of Physical Education and Sport Sciences, Ferdowsi University of Mashhad, Mashhad, Iran. E-mail: keyvanhejazi@gmail.com ABSTRACT: Purpose: Allometry is a method of expressing the relationship between physiological and anatomical variables, which can be used in order to measure the vital capacity through mathematical equations. This study investigated the evaluating lung function indices in order to estimate the maximal aerobic power by respiratory gas analysis device and the allometric equation. Methods: This study is a descriptive from correlation type, 80 subjects were chosen by convenience sampling. Anthropometric characteristics and dimensions of chest circumference (diameter and depth of the chest) were measured, and Bruce Test was used in order to measure maximal aerobic power. Pearson correlation coefficient and multivariate regression analysis were performed using SPSS version 16. Results: There is a positive significant relationship between vital capacity and maximal aerobic power (r=0.229 and P=0.041) and between the amounts of the device vital capacity and formula vital capacity(r=1.00 and P=0.00). Accordingly, the following model was developed (chest circumference × 0.284) + (age × 0.319) + (vital capacity × 1.761) + incline = Maximal Oxygen Consumption. Conclusion: According to the results of this study, there is a significant correlation between device vital capacity and formula vital capacity. Thus, it can be concluded that in order to gain predict of the maximal oxygen consumption, in the absence of accessibility to other experimental methods, allometric equation can be used. KEY WORDS: Pulmonary Function, Peak Oxygen Consumption, Allometric Equation INTRODUCTION Increasing the frequency and depth of breathing are among the physiological changes in the body which happen at the beginning of sporting activities in a way that at the start of sporting activities, these two factors are used in order to provide the body's supply of oxygen needed by active muscles and to minimize lack of oxygen. Ventilation rate should increase parallel to the cardiac output in order that the volume of air in the lungs reach to the extent that oxygen is delivered to the blood and carbon dioxide is excreted from it [1]. In order to do so, while doing physical activities and sport, the amount of oxygen consumption in different organs of the body increases, and the volume and velocity (speed) of blood flow also increase in order to deliver nutrients and oxygen to various organs and tissues [2]. Therefore, participating in aerobic activity increases the number of breaths and heart beats and put a considerable strain on the cardio-respiratory system; therefore, its effect on lung capacity and volumes not