Combining internal- and external-training-load measures in professional rugby league

• Published in: International journal of sports physiology and performance Vol. 9; no. 6; p. 905
• Main Authors: Weaving, Dan, Marshall, Phil, Earle, Keith, Nevill, Alan, Abt, Grant
• Format: Journal Article
• Language: English
• Published: United States 01.11.2014
• Subjects: Accelerometry - methods; Adult; Football - physiology; Football - psychology; Geographic Information Systems; Heart Rate; Humans; Male; Perception; Physical Education and Training - methods; Physical Exertion; Principal Component Analysis; Young Adult
• ISSN: 1555-0265
• DOI: 10.1123/ijspp.2013-0444

This study investigated the effect of training mode on the relationships between measures of training load in professional rugby league players. Five measures of training load (internal: individualized training impulse, session rating of perceived exertion; external-body load, high-speed distance, total impacts) were collected from 17 professional male rugby league players over the course of two 12-wk preseason periods. Training was categorized by mode (small-sided games, conditioning, skills, speed, strongman, and wrestle) and subsequently subjected to a principal-component analysis. Extraction criteria were set at an eigenvalue of greater than 1. Modes that extracted more than 1 principal component were subjected to a varimax rotation. Small-sided games and conditioning extracted 1 principal component, explaining 68% and 52% of the variance, respectively. Skills, wrestle, strongman, and speed extracted 2 principal components each explaining 68%, 71%, 72%, and 67% of the variance, respectively. In certain training modes the inclusion of both internal and external training-load measures explained a greater proportion of the variance than any 1 individual measure. This would suggest that in training modes where 2 principal components were identified, the use of only a single internal or external training-load measure could potentially lead to an underestimation of the training dose. Consequently, a combination of internal- and external-load measures is required during certain training modes.