Purpose: This manuscript is devoted to discuss the interplay between velocity and acceleration in setting metabolic and mechanical power in team sports. Methods: To this aim, an essential step is to assess the individual Acceleration-Speed Profile (ASP) by appropriately analysing training sessions or matches. This allows one to estimate maximal mechanical and metabolic power, including that for running at constant speed, and hence to determine individual thresholds thereof. Results: Several approaches are described and the results, as obtained from 38 official matches of one team (Italian Serie B, season 2020–2021), are reported and discussed. The number of events in which the external mechanical power exceeded 80% of that estimated from the subject’s ASP (# burst) was 1.61 times larger than the number of accelerations above 2.5 m s−2 (# acc). The difference was largest for midfielders and smallest for attackers (2.30 and 1.36 times, respectively) due to (i) a higher starting velocity for midfielders and (ii) a higher external peak power for attackers in performing # burst . From the energetic perspective, the duration and the corresponding metabolic power of high-demanding phases (# MPE) were essentially constant (6 s and 22 W kg−1, respectively) from the beginning to the end of the match, even if their number decreased from 28 in the first to 21 in the last 15-min period, as a consequence of the increased recovery time between # MPE from 26 s in the first to 37 s in the last 15-min period. Conclusion: These data underline the flaws of acceleration counting above fixed thresholds.
