Toward a New Conceptual Approach to “Intensity” in Soccer Player's Monitoring: A Narrative Review

Abstract

Pillitteri, G, Clemente, FM, Petrucci, M, Rossi, A, Bellafiore, M, Bianco, A, Palma, A, and Battaglia, G. Toward a new conceptual approach to “intensity” in soccer player's monitoring: A narrative review. J Strength Cond Res 37(9): 1896–1911, 2023—In the last decade, monitoring physiological and match-related demands in soccer has become an increasingly common practice in sports sciences. One of the great challenges during monitoring process is the identification of key indicators that permit to generalize evidence and sustain decision-making process during training prescription. Actually, one of the major debates in the scientific community and among practitioners is the identification of the “intensity” concept. Defining a given training session or exercise based on “intensity” is difficult due to the fact that a huge amount of indicators are available (related both to the performed activities and to the athletes' psychophysiological responses). These indicators can lead to specific outcomes with different interpretations. The current narrative review aims to discuss the different measures approaches used in soccer to describe the intensity for both internal and external demands. In addition, a second purpose of this review is to propose general recommendations for combining intensity indicators with the aim of defining an overall intensity score of a training session or drill.

Calculating Load and Intensity Using Muscle Oxygen Saturation Data

“…Rather, the use of ∇%SmO 2 should be interpreted as a variable that identifies the type of work, which can be more anaerobic or more aerobic metabolism [ 10 ]. However, this can only be determined when comparing the same trial in the same individual [ 1 ]. Finally, the Eff index variables demonstrated how subjects obtained a different stimulus in the two trials, and Eff index shows the exercise economy of an individual when exposed to an external load [ 6 , 29 , 34 ].…”

“…Training load. To assess training load, an integrative model of external and internal load indicators was designed [ 1 , 7 ]. Intensity was calculated as the product of external load and internal load (EL × IL) as indicated by Bourdon et al, Campos-Vázquez et al and Schimpchen et al [ 29 , 32 , 33 ].…”

“…According to Pillitteri et al [ 1 ], intensity should be considered as a relative measure due to individual athlete responses (i.e., through physiological indicators of internal load) or the training outcome (i.e., external load). The meaning of intensity should not be confused with a load indicator (e.g., speed above 25 km·h −1 ) that can only explain if an activity can be considered “intense” compared to another activity (e.g., speed between 0 and 8 km·h −1 ) [ 1 ].…”

“…Finally, to understand the use of SmO 2 as an indicator of training intensity and load, it is appropriate to consider the time or distance of the exercises (i.e., the volume) to provide data on the training effect [ 3 ]. In this sense, the model proposed by Pillitteri et al [ 1 ] can be used to calculate training load intensity by multiplying external load by internal load and to calculate the efficiency index (Eff index ) by dividing external load by internal load. Therefore, to assess the use of SmO 2 in the context of training load, the present study aims to compare intensity calculations using SmO 2 and speed in (m/min) during two differentiated physical tasks (Multiple Shuttle Run Test (MSRT) and a 3000-m time trial).…”

Exploring the interplay between metabolic power and equivalent distance in training games and official matches in soccer: a machine learning approach

“…Additionally, GPS technology can measure equivalent distance (ED) as another metric in soccer, which quantifies the distance a player covers while adjusting for changes in speed and direction. It could provide a more accurate measure of the physical demands of a match or training session than simply measuring the total distance covered ( Pillitteri et al, 2023a ). ED considers that different movements have varying metabolic demands and thus contribute differently to a player’s overall physical workload ( Osgnach et al, 2010 ; Caldeira et al, 2022 ).…”