Author(s): ZHAO, K., Institution: CHINA INSTITUTE OF SPORT SCIENCE, Country: CHINA, Abstract-ID: 469

INTRODUCTION:
Aerobic capacity can comprehensively reflect the bodys ability to uptake, transport, and utilize oxygen, providing an indication of the overall level of human health. However, the understanding of the limiting factors in the development of aerobic capacity in different age groups is not very clear. This study intends to investigate the limiting factors of aerobic capacity in male adolescents across different age groups from three aspects: oxygen uptake, oxygen transport, and oxygen utilization.
METHODS:
386 male adolescents aged 11-18 were selected as participants. They are grouped into three age categories based on their chronological age: 11-13 years old, 14-15 years old, and 16-18 years old. Their VO2peak was tested using a ramp-type incremental load exercise. Oxygen uptake indicators (pulmonary function indicators: FVC, FEV1, FEV1/FVC, PEF, FEF25, FEF50, FEF75, FEF25-75, IC, PIF), oxygen transportation indicators (cardiac structure and function indicators: IVSd, LVPWd, LVIDd, LVIDs, AoD, Las, E, DT, s’, e’, EDV, ESV, SV, LVM, EF, FS), and oxygen utilization indicators (muscle oxygen utilization capacity indicators: SmO2, tHb, BLA) were measured. Through factor analysis, principal components of indicators related to oxygen uptake, oxygen transport, and oxygen utilization capacity are extracted. Using the extracted principal components as independent variables and VO2peak as the dependent variable, a multiple regression analysis was conducted to explore the potential physiological mechanisms influencing aerobic capacity in male adolescents across different age groups.
RESULTS:
Found that the main limiting factors of aerobic capacity of 11-13 years old male adolescents are pulmonary function and cardiac structure. The adjusted R square is 0.520, among which pulmonary function index accounts for 83.06%, and cardiac structure index accounts for 16.94%. The main limiting factors of aerobic capacity of 14-15 years old male adolescents were cardiac structure and pulmonary function, with the adjusted R square of 0.603, among which pulmonary function index accounted for 69.26%, and cardiac structure index accounted for 30.74%. The main limiting factors of aerobic capacity of 16-18 years old male adolescents were pulmonary function, cardiac structure, cardiac function and muscle oxygen utilization ability, with the adjusted R square of 0.666, among which pulmonary function index accounted for 41.00%, cardiac structure and function index accounted for 23.54%, and muscle oxygen utilization ability index accounted for 18.36%.
CONCLUSION:
In the early stages of adolescence, the VO2peak of male adolescents is primarily influenced by pulmonary function and cardiac structure, with the impact of pulmonary function being particularly significant. With increasing age, the influence of cardiac structure, function, and muscle oxygen utilization capacity on VO2peak becomes more prominent, while the proportion of the impact of pulmonary function on VO2peak gradually decreases. This may be attributed to the delayed growth of the lungs compared to overall body growth.