Introduction:
Player on-field performance is often dictated by tactical constraints such as positional demands, playing formation and match scoreline. However, the relationship between how fast players run during an actual match compared to how fast they are able to run under controlled testing conditions is not well established.

Aim of the study:
The present study sought to investigate the effect of maximal sprinting speed (MSS) on match very high-speed running distance (VHSR), sprinting distance (SpD) and peak sprinting speed (PSS) in professional football players.

Material and methods:
Sixteen players were monitored though an entire in-season phase (26 matches, n = 170 individual observations). Global positioning system samplings at 10 Hz were used to measure VHSR, SpD and PSS. MSS was recorded as the highest speed achieved throughout the season during top-speed training sessions and/ or large-sided games. Linear mixed effects model was used to quantify the effect of MSS after adjusting for seasonal trends of the response variables as well as the within-player, betweenplayer and between-game sources of variability. Effects were evaluated using non-clinical magnitude-based decisions.

Results:
Our results indicated that faster players covered on average very likely substantially more SpD (48.2 m [90% CI: 26.0 to 70.2], 41.0% [90% CI: 15.1 to 72.1]), and reached on average very likely substantially higher PSS than their slower counterparts (1.1 km·h–1 [90% CI: 0.8 to 1.4], 3.6% [90% CI: 2.5 to 4.6]). In addition, PSS showed on average a very likely substantial seasonal reduction (–1.2 km·h–1 [90% CI: –1.9 to –0.4], –3.7% [90% CI: –5.9 to –1.4]).

Conclusions:
Higher MSS is beneficial for SpD and PSS in professional soccer players; however, substantial seasonal reductions in PSS affect all players irrespective of their MSS. Future studies could examine whether these trends are also evident with relative speed thresholds.