Training Load and Injury: Causal Pathways and Future Directions.

Area of Science:

• Sports Science
• Biomechanics
• Exercise Physiology

Background:

• Causal pathways linking training loads to athletic injury (tissue damage, gradual onset, traumatic) are not well understood.
• Numerous internal and external training load measures exist, often used for injury risk evaluation.
• Current measures struggle to accurately quantify mechanical loads, hindering understanding of tissue-level responses.

Purpose of the Study:

• To examine the relationship between specific training load measures and metrics and the causal pathways of athletic injury.
• To investigate the roles of mechanical and psycho-physiological load-response pathways in injury.
• To identify challenges in quantifying mechanical loads and their validation with current training load measures.

Main Methods:

• Conceptual examination of training load measures and their relation to injury pathways.
• Analysis of the mechanical load-response pathway and its understanding in tissue fatigue and trauma.
• Case study using a common training load metric to assess its conceptual rationale and link to causal mechanisms.

Main Results:

• The mechanical load-response pathway's contribution to tissue fatigue and trauma is poorly understood and difficult to quantify in applied settings.
• A lack of validation exists between current training load measures and actual tissue-level mechanical loads.
• Internal load measures are likely too distant from injury causation to reliably predict injury risk.

Conclusions:

• Accurate quantification of mechanical loads is essential for estimating tissue damage and improving injury risk assessment.
• Psycho-physiological load measures have speculative links to injury and may not be reliable predictors.
• Refined injury risk assessment methods require a sound conceptual rationale and validated links to causal mechanisms, moving beyond current training load metrics.