Exploring the Use of Player Load in Elite Soccer Players

The aims of this study were to (1) analyze the distribution of the player load (PL_TOTAL) in 3 axes of movement (PL_AP, anterior-posterior; PL_ML, medial-lateral; PL_V, vertical) during elite soccer matches, (2) investigate the effect of playing position on PL-related variables, and (3) explore the association between PL_TOTAL and distance covered by the players.

Despite different load distribution between axes of movement, PL_TOTAL might be used as a body load indicator for all playing positions.

Longitudinal study.

Level 3.

Data were collected from elite soccer players using WIMU Pro tracking systems, which included inertial sensors.

The axis of movement had a significant effect on the distribution of the load (P < 0.001; conditional R² = 0.91), with the greatest contribution from the PL_V (P < 0.001; d = 5.41-5.86). Moreover, no effect of playing position on PL_TOTAL, PL_V, PL_ML, or PL_AP was observed (P > 0.05). Finally, a large correlation was found between PL_TOTAL and distance covered, and the linear mixed model showed that distance may be predicted by the PL_TOTAL (conditional R² = 0.81; P < 0.001).

Differences in load distribution were based on the axis of movement, although playing position had no effect on any variable. The selection of either distance covered, which is representative of a 2-dimensional analysis, or PL_TOTAL, which is representative of a 3-dimensional analysis, may be adequate for monitoring locomotor demands or accelerometer-derived load.

Training strategies that focus on the vertical component of match play should be adopted. In addition, given that PL_TOTAL is an accelerometry-based metric, which combines the accelerations in anterior-posterior, medial-lateral, and vertical planes, strength and conditioning coaches may use this parameter as a measure of total body load.