Oslo Sports Trauma Research Center

Intoduction

Lena Kristin Bache-Mathiesen is defending her thesis "Improving the methodology of training load and injury risk research: an analysis of analyses".

Disputas: Tuesday April 18^th 2023

Place: NiH Auditorium Innsikt

Time - Trial lecture: 10.15 – 11.00: “Functional data analysis in sports science: past, present and future”

Time - Thesis Defence: 13.00 – 16-00: “Improving the methodology of training load and injury risk research: an analysis of analyses”

Language: English

Committee

Committee chair: Professor Kari Bø, Norwegian School of Sport Science, Department of Sports Medicine

First opponent: Professor Franco Impellizzeri, University of Technology, Sydney, Australia

Second opponent: Professor Norma Bargary, University of Limerick, Limerick, Ireland

WHAT IS THE PROJECT ABOUT:

With the right amount of training load, sports injuries could be prevented. However, researchers do not have the statistical tools necessary to understand how training load can be manipulated to reduce injury risk. This has led to conflicting, inconsistent findings between studies. Some research groups have recommended training load interventions that were later debunked in experimental study designs. This PhD aimed to find and recommend suitable statistical tools for analyzing the relationship between training load and injury risk.

When collecting training load data, missing data is nearly inevitable. Devices may have errors, and athletes may not always respond to the questionnaires. In this PhD-project, we have found optimal ways to deal with missing data in training load-specific measurements. 

Researchers suspect that both too much and too little training load may increase injury risk. From a statistical perspective, this means the relationship between training load and injury risk is likely non-linear. We have found ways to analyze non-linear relationships between training load and injury risk.

A challenge when studying training load is long-term effects. All activities performed in the past, collectively, are thought to contribute to current injury risk. However, activities performed many weeks ago are less likely to contribute much to injury risk compared with recent activities. In this PhD-project, we have determined how to deal with this complexity. 

Finally, one of the greatest challenges in the training load field has been capturing the effect of sudden increases in training load on injury. Previous studies have used suboptimal statistical approaches to deal with this phenomenon. Approaches that cannot accept a training load of 0 and require many subjective choices with strong assumptions. We have found a way to handle this situation and study the effect of sudden increases in training load.

Supervisors:

Main: Morten Wang Fagerland, Associate Professor, Norwegian School of Sport Sciences, Department of Sports Medicine

https://www.nih.no/en/about/employees/morten-wang-fagerland/

Second: Professor Thor Einar Andersen, Norwegian School of Sport Sciences, Department of Sports Medicine and OSTRC

https://www.nih.no/en/about/employees/thor-einar-gjerstad-andersen/

THE THESIS IS BASED ON THE FOLLOWING ARTICLES:

I. Bache-Mathiesen, L., Andersen, T. E., Clarsen, B., Fagerland, M. W. (2021). Handling and reporting missing data in training load and injury risk research. Science and Medicine in Football. doi.org/10.1080/24733938.2021.1998587   

II. Bache-Mathiesen, L., Andersen, T. E., Dalen-Lorentsen, T., Clarsen, B., Fagerland, M. W. (2021). Not straightforward: modelling non-linearity in training load and injury research. BMJ Open Sport & Exercise Medicine, 7, e001119. doi.org/10.1136/bmjsem-2021-001119

III. Bache-Mathiesen, L., Andersen, T. E., Dalen-Lorentsen, T., Clarsen, B., Fagerland, M. W. (2022). Assessing the cumulative effect of long-term training load on the risk of injury in team sports. BMJ Open Sport & Exercise Medicine, 8, e001342. doi.org/10.1136/bmjsem-2022-001342

IV. Bache-Mathiesen, L., Andersen, T. E., Dalen-Lorentsen, T., Tabben, M., Chamari, K., Clarsen, B., Fagerland, M. W. (2022). A new methodological approach to training load and injury risk: separating the acute from the chronic load [Manuscript in peer-review]. Department of sports medicine, Norwegian School of Sport Sciences.