Integrating the internal and external training loads in soccer.

Area of Science:

• Sports Science
• Exercise Physiology
• Soccer Performance Analysis

Background:

• Assessing soccer player fitness is crucial for performance optimization.
• Traditional fitness metrics may not fully capture the demands of soccer training.
• Integrating internal and external training load offers a novel approach.

Purpose of the Study:

• To evaluate the relationship between soccer player fitness and a new integration of internal and external training load.
• To determine if combined training load ratios correlate with performance metrics.

Main Methods:

• Ten amateur soccer players underwent a lactate threshold test and a soccer simulation (BEAST90mod).
• Internal training load (iTRIMP) and external training load (total distance, high-intensity distance) were measured.
• Ratios of training load (TD:iTRIMP, HID:iTRIMP) were calculated and correlated with fitness measures (vLT, vOBLA, VO2max) and performance.

Main Results:

• Individual fitness measures (vLT, vOBLA, VO2max) did not significantly correlate with total or high-intensity distance.
• The high-intensity distance to internal training load ratio (HID:iTRIMP) significantly correlated with velocity at the onset of blood lactate accumulation (vOBLA).
• The total distance to internal training load ratio (TD:iTRIMP) significantly correlated with velocity at lactate threshold (vLT).

Conclusions:

• The integrated use of training load ratios may enhance the assessment of soccer player fitness.
• Performance metrics alone showed no significant relationship with fitness measures.
• Novel training load ratios provide valuable insights into player condition and performance potential.