Characterizing the sprint threshold (25.2 km/h): a case study analysis on how soccer players reach sprint speeds and what relative intensity the threshold represents

Purpose This study investigated how soccer players reach sprint speeds (> 25.2 km & sdot;h-1) and what that fixed threshold represents to each player regarding their individual match peak speeds registered during competition. Methods Twenty professional players (n = 20) from a team competing in the Brazilian first division were monitored with a global navigation satellite system during six matches. All efforts with final speeds > 25.2 km & sdot;h(-1) were analyzed according to starting speed, and accelerations' duration and magnitude. Peak speeds for each player were also retrieved and compared to the sprint threshold. Results Most efforts > 25.2 km & sdot;h(-1) (> 91%) start with very short accelerations (< 0.5 s). Efforts started predominately from high starting speeds (20-25 and > 25 km & sdot;h-1) than low starting speeds (< 5 and 5-10 km & sdot;h(-1)) with huge effect sizes (p < 0.001). Most accelerations had magnitudes between 1 and 3 m & sdot;s(-2) (p < 0.05). The 25.2 km & sdot;h(-1) threshold represented an intensity of 71-91% of players' match peak speed. Conclusion The inclusion of accelerations and peak speeds associated to the sprinting events that occur > 25.2 km & sdot;h(-1) was shown to be useful for further characterization of soccer sprinting performance. In addition, the fixed threshold fails to individualize players' capabilities and performances, misleading load demands performed by players.