Introduction
From the 2022/2023 season, gpexe teams competing in the Italian Serie A adopted a new mechanical approach to their monitoring routines, utilising acceleration-speed profiling (ASP) and external power. This method was proposed to overcome the limitations of counting the number of accelerations to isolate the most demanding actions from a neuromuscular perspective. Indeed, relying solely on acceleration – by setting a threshold (typically between 2.5 and 3.0 m⋅s⁻²) and tallying the events that exceed this threshold – fails to account for the corresponding speed at which these actions occur. From another perspective, the chosen acceleration threshold (e.g., 2.5 m⋅s⁻²) represents:
• only 50% of the peak acceleration attainable when the player starts from low speeds, or
• an acceleration that cannot be achieved when the player starts from moderate or high speeds.
If this is the case in team sports (1), where players’ starting speeds vary, the feedback from the number of accelerations could be rather misleading.
To get around this issue, the proposed method is based on a ‘two-step’ process.
1. Acceleration-Speed Profile (ASP)
Profiling players through ASP is essential for recognising their individual acceleration capabilities (2). An examination of the following figure clearly illustrates the relationship between speed and acceleration: as speed increases, the acceleration capacity decreases linearly until maximum speed is reached, at which point acceleration becomes zero. This situation truly highlights how unreasonable a fixed acceleration threshold can be. “Testing the players without testing them” using the in-situ ASP represents a convenient shortcut for determining this individual limit.
2. High External Work positive (hEW⁺) and Bursts
If the ASP establishes each player’s maximum mechanical output capacity, all activities that allow the athlete to exceed 80% of the ASP’s corresponding external power may be considered extreme actions from a neuromuscular standpoint (3). Thus, by ignoring the accelerations, one can quantify the significant mechanical workload through external power. Two parameters allow us to achieve this:
- High External Work positive (hEW⁺) represents the positive mechanical work done by the athlete during the acceleration phases when the power output reaches ‘extreme intensities’, and it is expressed in J⋅kg⁻¹;
- Bursts are provided as the total number of actions (i.e., the number of occurrences that enable the player to enter the ‘extreme intensity zone’).
Outcomes
The 2023/2024 competitive season, which runs from 7 August 2023 to 25 May 2024, was analysed by segmenting it into match cycle units. These units consist of the intervals that begin with a match and conclude with the training session preceding the next match day. Match cycles ranging from 3 to 7 days were examined. The pre-season was excluded.
The table below shows the mechanical workload, expressed in hEW⁺ and Bursts, for each match cycle:
- the total volume for all training days, excluding the first day after the match (which typically focuses on recovery or is a day off), is displayed in green numbers;
- the average values of an official Serie A match are presented in red numbers.
Enjoy!
References
- Sonderegger K, Tschopp M, Taube W (2016) The Challenge of Evaluating the Intensity of Short Actions in Soccer: A New Methodological Approach Using Percentage Acceleration. PLoS ONE 11(11): e0166534. https://doi.org/10.1371/journal.pone.0166534
- Morin J B, Samozino P, Munenori M, Cross M R, Nagahara R (2019) A simple method for computing sprint acceleration kinetics from running velocity data: replication study with improved design. J Biomech 20:94:82-87. https://doi.org/10.1016/j.jbiomech.2019.07.020
- Osgnach C, di Prampero P E, Zamparo P, Morin J B, Pavei G (2024) Mechanical and metabolic power in accelerated running–Part II: team sports. Eur J Appl Physiol 124(2):417-431 https://doi.org/10.1007/s00421-023-05286-1
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