Acceleration and Acceleration-Initial Speed Running are important factors in soccer performance. The aims of the study were (a) analyze by playing position the acceleration-initial speed (AS₀) profile and (b) analyze the relevance of the number of accelerations > 3 m·s⁻² according to final league position. The subjects (n = 309) from the Spanish First Division during the 2021–2022 and 2022–2023 seasons were classified in six positions: Central Defenders (CD), Full Backs (FB), Central Midfielders (CM), Offensive Midfielders (OF), Wingers (W), and Forwards (F). A total of 6180 match observations were recorded using the Mediacoach System. The parameters analyzed were accelerations > 3 m·s⁻² and AS₀ profile variables, maximal theoretical acceleration (A_0Int), and maximal theoretical initial running speed (S_0Int). The AS₀ profile was calculated using a linear regression model. Welch’s analysis of variance (ANOVA) revealed a consistent relationship between the A_0Int variable of the AS₀ profile and team success in CM, FB, and W positions. Moreover, the successful teams for CD, CM, FB, OM, and W positions showed a statistically higher number of accelerations > 3 m·s⁻² than unsuccessful teams. In conclusion, these findings suggest the importance of enhancing acceleration abilities, particularly for lower-performing teams, to achieve the physical standards of successful teams.

The aims of the present study were to (a) analyze the relationship between acceleration capacity at low and high initial running speeds and the player’s ability to cover high-intensity running distances and perform high-intensity accelerations during competition and (b) examine whether these differences also occur across playing positions in professional soccer players. A total of 222 professional male soccer players from LALIGA participated in the study during the 2021–2022 and 2022–2023 seasons. Players were classified in six positions: central defender (CD), full back (FB), central midfielder (CM), offensive midfielder (OM), winger (W) and forward (F). K-means clustering was applied to classify players based on the maximal theoretical acceleration (A_0Int) capacity and the maximal theoretical initial running speed (S_0Int). Mixed models were used to examine the accelerations performed above 75% of the acceleration–speed profile (Mean₇₅AS₀) according to IntS; distance covered at high speeds (21–24 km·h⁻¹, >24 km·h⁻¹, >28 km·h⁻¹); and maximum speed across playing positions, cluster groups and contextual variables. C1 (high A_0Int and S_0Int) showed a significantly greater distance covered during high-intensity running and accelerations than C2 (low A_0Int and S_0Int) across all IntS thresholds. C3 (high A_0Int and low S_0Int) achieved higher accelerations at a low IntS. In conclusion, offensive positions displayed greater distance covered during high-intensity running and acceleration across all IntS categories, while CD produced lower values. In conclusion, this study highlights how the accelerations quantified in relation to the IntS vary according to the relationship between A_0Int and S_0Int during competition and the positional role of the player.