Mechanical and metabolic workload in professional football

Oct 18, 2023 | ACADEMY, INTERVIEW

Cristian Osgnach answered 8 questions about his recently published paper. “Release by Felis” is an e-mag on innovation and research in health and sports performance, launched by Gregory Dupont. Its aim, which is fully in line with exelio’s vision, is to encourage the transfer of knowledge from researchers to practitioners and to promote scientific evidence. Five sections collect articles on trends, technology, research, studies and methods. Readers include coaches, doctors and directors of the biggest professional teams. 

  

Osgnach et al. (2023), “Mechanical and metabolic power in accelerated running–Part II: team sports” has been recently published in European Journal of Applied Physiology in the training section. 

Quantifying workload is essential in order to optimise the development of physical qualities and prevent injuries using tracking technologies. In this context, it is necessary to understand the concepts of mechanical and metabolic power, especially for one of the most important qualities in football: acceleration. In the manuscript presented here, the authors deal with three common indicators of player performance: (i) speed and acceleration alone, (ii) mechanical power and (iii) metabolic power. In order to better understand this article, we propose to review some terms such as speed, acceleration, mechanical energy, metabolic energy and power. Speed is the rate at which someone or something is able to move or operate => ∆ distance / ∆ time (∆ means ‘change in’) and it is expressed in ms⁻¹ or in kmh⁻¹ . Acceleration corresponds to the change in velocity over a given change in time => ∆ velocity / ∆ time and is expressed in ms⁻². Mechanical energy is the energy associated either with an object’s movement (kinetic energy) or its position (potential energy). Metabolic energy is the energy expenditure of the organism including both aerobic and anaerobic metabolisms. The units of energy are joules (J). To go further, you can read the excellent earlier article by Cristian and his collaborators.

The study involves the assessment of individual Acceleration-Speed Profiles through the analysis of training sessions and matches. This allows the estimation of maximal mechanical and metabolic power, including power for running at constant speed, and the identification of individual thresholds. They analysed 38 official match performance data from a professional football team competing in the Italian second division (Serie B) during the 2020-2021 season.

The results showed that the number of events in which the external mechanical power exceeded 80% of that estimated from the individual’s acceleration-velocity profiles was 1.61 times greater than the number of accelerations above 2.5 ms­­­­­­­­­⁻². This difference was most pronounced for midfielders and least pronounced for strikers, primarily due to the higher initial velocity of midfielders and the higher peak external power of strikers throughout the match. From an energy perspective, the duration and corresponding metabolic power high-demand phases remained relatively constant throughout the match (6 seconds and 22 Wkg⁻¹, respectively), although their number decreased from 28 in the first 15 minutes to 21 in the last 15 minutes due to the increased recovery time between phases, from 26 seconds in the first 15 minutes to 37 seconds in the last 15 minutes.

We put 8 questions to Christian Osgnach, first author of this article, who is Associate of the Department of Sport Science, Exelio srl, Udine, Italy.

You can read the full interview with Cristian Osgnach at this link, after having subscribed to Released by Felis. 

You can read the abstract of this papers at this link.

 

 

Additional references:

 

C. Osgnach, “How easy is to stumble over acceleration and deceleration?
C. Osgnach, “The limits of acceleration

 

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