Multiple Measures are Needed to Quantify Training Loads in Professional Rugby League

Area of Science:

• Sports Science
• Biomechanics
• Exercise Physiology

Background:

• Understanding training load is crucial for optimizing athlete performance and preventing injury.
• Multivariate analysis of training load metrics can reveal complex relationships.
• Different training modes may elicit distinct physiological and biomechanical responses.

Purpose of the Study:

• To examine how training mode (skills vs. conditioning) influences the multivariate relationships among various training load measures.
• To determine if different training types capture different aspects of overall training load.
• To inform optimal monitoring strategies in professional rugby league.

Main Methods:

• Principal Component Analysis (PCA) was used to analyze four training load measures (heart rate exertion index, session rating of perceived exertion, PlayerLoad™, individualised high-speed distance).
• Data were collected from 23 professional male rugby league players over a 12-week preseason period.
• Training sessions were categorized as either skills or conditioning, and PCA was applied to each category.

Main Results:

• Skills training extracted one principal component, explaining 57% of the variance in training load.
• Conditioning training extracted two principal components, explaining 85% of the variance (one for internal load, one for external load).
• This indicates that conditioning training involves more distinct dimensions of load than skills training.

Conclusions:

• The training mode significantly influences the multivariate structure of training load.
• Conditioning sessions require a combination of internal and external load measures to fully capture training variance.
• Monitoring strategies should consider the specific training mode to ensure comprehensive load assessment.