Selecting Training-Load Measures to Explain Variability in Football Training Games

Area of Science:

• Sports Science
• Exercise Physiology
• Soccer Performance Analysis

Background:

• Accurate assessment of training load in soccer is crucial for performance optimization and injury prevention.
• Existing research often focuses on isolated training metrics, lacking a comprehensive understanding of their interrelationships within game-based scenarios.

Purpose of the Study:

• To investigate the interrelationships between external (eT) and internal (iT) training intensity metrics in soccer.
• To determine how these relationships vary across different small-sided and simulated game formats.

Main Methods:

• Collected data on 16 semi-professional soccer players across seven game formats (small, medium, large-sided, simulated games).
• Measured external training variables (peak velocity, total distance, velocity zones, player load, acceleration/deceleration) and internal training variables (Edwards units, %max heart rate).
• Utilized principal component analysis (PCA) to analyze the structure of interrelationships among these variables.

Main Results:

• Principal component analysis revealed three main components explaining 66.9–76.0% of the variance across all game formats.
• Interrelationships clustered into dimensions related to strength/neuromuscular (e.g., player load, acceleration), endurance/cardiovascular (e.g., Edwards units), and velocity/locomotion (e.g., peak velocity).
• Specific combinations of eT and iT metrics were identified as necessary to fully describe the training load of different game formats.

Conclusions:

• The structure of training intensity metrics in soccer games is multi-dimensional, reflecting distinct physiological demands.
• A combination of external and internal training intensity measures is essential for a holistic evaluation of training load in various soccer game formats.
• These findings can inform more precise training prescription and load management strategies in soccer.