The Profile of the Internal Load of Amateur Soccer Players during Official Matches with Formation 1-4-3-3 and Relationships with Indexes of External Load

Abstract

The purpose of this study was to investigate the internal load of amateur soccer players during official championship matches when playing with the 1-4-3-3 formation. Additionally, the possible relationship between internal load variables and external load indices was explored. The study involved 18 amateur soccer players, and the Polar Team Pro GPS system was used to record external load and heart rate (HR) during official championship matches. Internal load was assessed using %HRmax and Edward’s training impulse (TRIMPEdw). External load indices included total distance (TD), pace (distance/min), number of sprints, distance covered in different speed zones, accelerations (>2 m/s2), and decelerations (<−2 m/s2). Players were categorized as central defenders (CD), side defenders (SD), central midfielders (CM), side midfielders (SM), and forwards (F). The results indicated no differences in internal load indices among playing positions. During matches, SM performed the most sprints, while CD performed the fewest (p < 0.05). CD covered the shortest distances in speed zones >7.20 km/h, whereas CM and SM covered the longest distances (p < 0.05). Additionally, CD had fewer accelerations and decelerations compared to SM (p < 0.05). In the first half, differences were observed in pace (distance/min) (p < 0.05), but not in the second half. Between halves, differences in %HRmax were observed for all positions, while TRIMPEdw differed in CM and F. CM showed the most differences between halves. Throughout the matches, a high correlation was found between %HRmax and pace (distance/min), while TRIMPEdw correlated with TD, as well as distances in high-speed zones (14.40–25.19 km/h). This suggests that TRIMPEdw is a comprehensive indicator dependent on volume (TD) and on high-intensity actions, which are crucial in soccer, influencing players’ and teams’ performances. Therefore, for assessing the internal load of amateur soccer players, TRIMPEdw may be a more useful indicator. This study provides valuable information for coaches of amateur soccer teams using the 1-4-3-3 formation regarding running profiles, accelerations/decelerations, and the profile of internal load in each playing position. This information can be used to individualize training based on players’ playing positions.