<p>This study aimed to develop regression equations to estimate running velocity of maximal oxygen uptake (vVO₂max) and onset of blood lactate accumulation (vOBLA) from a 3200-m run time using a soccer pitch. Forty-four Japanese male junior youth soccer players from a team in the Japan Professional Football League First Division (J1 League) participated in this experiment. In the laboratory, vVO₂max and vOBLA were measured using an incremental load test, while the 3200-m run time was measured on the soccer pitch. Structural equation modeling was applied to analyze the sequential causal structure and latent growth curve models of aerobic running capability development during soccer training. A regression equation (1) utilized the 3200-m run time (s) as the independent variable (x) and vVO₂max (km/h) as the dependent variable (y), resulting in the equation y=-0.02461x+36.60 (r²=0.564). The regression equation (2) utilized the 3200-m run time (s) as the independent variable (x) and vOBLA (km/h) as the dependent variable (y), resulting in the equation y=-0.01833x+29.30 (r²=0.541). The coefficient of determination (r²) for the regression equations exceeded 0.5. We successfully developed to estimate vVO₂max and vOBLA from a 3200-m run time in Japanese male junior youth soccer players.</p>