Background: Cardiac respiratory system plays an important role in individuals’ health, promotion of patients’ life quality, and professional athletes’ performance. It is of great importance to measure it for exchange of inhaled gases during sports stress tests as an efficient method to study the physiological efficacy of cardiac respiratory system and understand the active skeletal muscle metabolism in work measurement. Regarding the problems of measuring inhaled gases in sports maximal tests, using safe and simple methods with good validity in estimating the individuals’ cardiac respiratory preparedness becomes appropriate. Aims and Objectives: In this research, we aim to evaluate individual’s aerobic power with allometric equations through a simple mathematical formula. Materials and Methods: A total of 72 healthy youth boys with mean age (13.95 ± 1.84) years and weight (51.64 ± 13.15 kg) were divided into two groups of normal maturity (33 person) and non-normal (39 person) and participated in the maximal protocol of aerobics voluntarily. The practical capacity was measured directly by analyzer gas. Then, using regression analysis and harmonic graph of Bland Altman, we obtained the relationship between VO2max from the standard method (direct measurement) and estimated (design allometric equations). Results: Iranian-specific allometric equations (VO2max = 0.15 × lean body mass0.8, R = 0.73, SEE = 0.57) and (VO2max = 0.97 × body surface area1.89, R = 0.72, SEE = 0.58) were designed with greater validity and neutrality of maturity. Conclusions: We can with use of this allometric equations, the amount of youth boys’ aerobic power, preparation and assessed without any sports test.
