Relationship Between External and Internal Loads of Professional Soccer Players During Full Matches in Official Games Using Global Positioning Systems and Heart-Rate Technology

Abstract

Purpose: To analyze the match running profile, distance traveled over successive 15 min of match play, heart rates (HRs), and index of performance efficiency (eff_index) of professional soccer players with a global positioning system (GPS) and HR in official competition.

Methods: Twenty-six professional players were investigated during full matches in competitive club-level matches (N = 223). Time-motion data and HR were collected using GPS and HR technology.

Results: The relative total distance was 113 ± 11 m/min, with substantial differences between halves. For all playing positions, a substantial decrease in total distance and distance covered at >13.0 km/h was observed in the second half in comparison with the first. The decrease during the second half in distance covered at >13.0 km/h was substantially higher than in total distance. The average HR recorded was 86.0% maximal HR, and the relationship between external and internal load (eff_index) was 1.3, with substantial differences between halves in all playing positions, except strikers for eff_index. Wide midfielders reflected substantially the lowest mean HR and highest eff_index, whereas center backs showed substantially the lowest eff_index of all playing positions.

Conclusions: The current study confirmed the decrement in a player's performance toward the end of a match in all playing positions. Wide midfielders displayed the highest and fittest levels of physical and physiological demands, respectively, whereas center backs had the lowest and least-fit levels of physical and physiological demands, respectively. The position-specific relationship between external and internal load confirms that players with more overall running performance during the full match were the best in eff_index.

Keywords: football; team sport; time motion.