Higher VO2max Delays Substrate Switching and Shifts the Crossover Point to Greater Oxygen Uptake During Incremental Exercise

Author : Elvn Onarici Gngr

Abstract : This study investigated the relationship between maximal oxygen uptake (VO₂max) and substrate crossover point during incremental exercise. The objectives of this study were to examine whether VO₂max is associated with the time to reach the crossover point and the oxygen uptake (VO₂) at crossover point. A total of 25 Physical Education students, 22 ± 2 years of age, were performed an incremental exercise test to assess VO₂, VCO₂ and substrate utilization patterns. The crossover point was identified based on the respiratory exchange ratio. The relationships between VO₂max and time to reach the crossover point, %VO₂max at the crossover point, VO₂ at the crossover point and heart rate at the crossover point were evaluated using Pearson correlation analysis. Linear regression analysis revealed a positive association between VO₂max and time to crossover point. Linear regression analysis revealed a negative association between VO₂max and %VO₂max at the crossover point. No significant correlation was observed between VO₂max and heart rate at the crossover point. Results demonstrated that higher VO₂max was positively associated with a delayed time to the crossover point and with higher oxygen uptake at the point of metabolic transition. These findings indicate that individuals with greater aerobic capacity maintain lipid oxidation for a longer duration and exhibit a rightward shift in substrate switching during incremental exercise. This suggests that VO₂max plays an important role in determining metabolic flexibility and the regulation of substrate utilization under increasing exercise intensity. Overall, the present study provides evidence that aerobic capacity is a key determinant of both the timing and intensity of the substrate crossover phenomenon during exercise.

Keywords : VO₂max, Substrate Crossover, Aerobic Capacity, Exercise Metabolism, Fat Oxidation

Conference Name : International Conference on Functional Training Strategies for Elite Athletes (ICFTSEA-26)

Conference Place : Milan, Italy

Conference Date : 21st Jul 2026