Vertical and horizontal force-velocity profiles show limited association and distinct relationships with sprint performance in U23 football players

Background Force-velocity (F-V) profiling is increasingly employed in football to characterise neuromuscular performance and to guide individualised training. However, the extent to which vertical and horizontal F-V profiles reflect comparable mechanical qualities remains unclear, particularly among semi-professional players. Methods Eighteen semi-professional Moroccan U23 male football players (age: 20.39 ± 1.82 years; height: 176.94 ± 9.69 cm; body mass: 65.39 ± 8.53 kg) underwent vertical F-V profiling through countermovement jump (CMJ) assessment and horizontal F-V profiling through 30-m sprint testing. Mechanical variables included theoretical maximal force (F0), theoretical maximal velocity (V0), maximal power output (Pmax), slope of the F-V relationship, peak ratio of horizontal force (RFmax), and rate of decrease in the force ratio (DRF). Correlation analyses, and tests for differences in profile distribution were performed. Results Weak and mostly non-significant associations were observed between vertical and horizontal F-V variables, indicating limited transferability of mechanical qualities across tasks. A moderate inverse, non-significant relationship was found between F0_vert and F0_horiz (r = –0.412, p = 0.089), whereas trivial associations were observed for V0 and Pmax across tasks. Profile distribution differed significantly between vertical and horizontal assessments (χ2 = 8.667, p = 0.034), with a predominance of velocity-oriented profiles in the vertical assessment and a more balanced distribution in the horizontal assessment. Substantial inter-individual variability was also observed across both profiling approaches. Conclusions Vertical and horizontal F-V profiles were only weakly associated, suggesting that these assessments may reflect task-specific mechanical characteristics rather than interchangeable expressions of explosive performance. Combining both profiling approaches may, therefore, provide a more comprehensive basis for individualised performance assessment and training prescription in football.