Peripheral muscle function during repeated changes of direction in professional soccer players

Area of Science:

• Sports Science
• Exercise Physiology
• Soccer Performance Analysis

Background:

• Peripheral muscle function is critical for athletic performance, particularly in sports requiring repeated high-intensity movements.
• Soccer demands significant neuromuscular capabilities for repeated changes of direction (CODs) and sustained high-intensity efforts.
• Understanding how muscle function relates to competitive level, seasonal demands, and playing position is vital for optimizing training and performance in professional soccer.

Purpose of the Study:

• To evaluate knee extensor peripheral muscle function in professional soccer players during repeated CODs.
• To examine differences in muscle function based on competitive level, season period, and playing position.
• To investigate the relationship between peripheral muscle function and physical activity metrics during matches.

Main Methods:

• Evaluated peripheral muscle function (twitch peak torque, PT) in 593 male professional soccer players from 13 European clubs across 3 competitive levels.
• Measured maximal PT (PT_max), maximal metabolic power (MP_max), and PT decline (PT_dec) during intermittent runs with CODs and electrically evoked contractions.
• Quantified relative total and sprint distances covered during matches from a sub-sample.

Main Results:

• Higher PT_max and MP_max were observed in first division compared to second division and U19 players.
• Pre-season showed lower MP_max and higher PT_dec compared to other periods; MP_max varied by playing position (fullbacks > attackers, defenders).
• PT_max correlated with total match distance; PT_dec correlated with total match distance and short-interval sprint distance.

Conclusions:

• Peripheral muscle function, particularly the ability to sustain repeated COD efforts at high intensities, is a key determinant of soccer physical performance.
• Differences in muscle function exist across competitive levels, season phases, and playing positions, highlighting the need for tailored training.
• Muscle contractility and fatigability are associated with in-match physical demands, underscoring their importance for performance monitoring.