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Information about a piece of news titled Torstein Dalen-Lorentsen is defending his thesis on the 16 th of December 2021

Torstein Dalen-Lorentsen is defending his thesis on the 16 th of December 2021


Torstein Dalen-Lorentsen is defending his thesis "Training load and health problems in football – More complex than we first thought?".

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  • Committee chair: Hege Grindem, Associate Professor, Department of Sports Medicine, NIH

  • First opponent: Dr. Michel S. Brink, Center for Human Movement Sciences, University of Groningen
  • Second opponent: Professor Franco Impellizzeri, Human Performance Research Centre, Faculty of Health, University of Technology



Sudden increase in training load has been linked to increased risk of injuries and illnesses (health problems). In the past years, researchers have claimed that easy-to-use calculations can precisely estimate how much training load can increase without increasing the risk of health problems. In this PhD-project, we found that it’s not possible to assess risk of health problems based on training load, and that the studies claiming this has substantial methodological weaknesses. Moreover, we found that using an one-size-fits-all approach of training load management did not reduce the risk of health problems among almost 500 elite-youth footballers of both sexes.

Despite a lack of models accurately estimating risk based on training load and lack of evidence for its preventive effect, we should still use training load management. Without more complex models, we should lean on the basic training principles and follow an even progression of training load that is based on the coaches’ experience and the players’ need.

This PhD-project also investigated whether the match congested 2020 Norwegian premier league (Eliteserien) had different injury characteristics compared to the normal 2019-season. We found no differences and concluded that a match congested season like the 2020-season can be a safe alternative.



Professor Thor Einar Andersen, OSTRC


Benjamin Clarsen, Researcher, OSTRC


John Bjørneboe, Researcher, OSTRC




  1. Dalen-Lorentsen T, Andersen TE, Bjørneboe J, Vagle M, Martin KN, Kleppen M, Fagerland MW, Clarsen B. A cherry, ripe for picking: The relationship between the acute:chronic workload ratio and health problems J Orthop Sports Phys Ther, Epub the 20th of January 2021. doi:10.2519/jospt.2021.9893
  2. Dalen-Lorentsen T, Bjørneboe J, Clarsen B, Vagle M, Fagerland MW, Andersen, TE. Does load management using the acute:chronic workload ratio prevent health problems? A cluster randomised trial of 482 elite youth footballers of both sexes Br J Sports Med Med 2021;55:108-114
  3. Dalen-Lorentsen T, Ranvik A, Bjørneboe J, Clarsen B, Andersen TE.Facilitators and barriers for implementation of a load management intervention in football. BMJ Open Sport & Exercise Medicine 2021;7:e001046. doi: 10.1136/bmjsem-2021-001046
  4. Dalen-Lorentsen T, Clarsen B, Thorbjørnsen C, Brown, M. Tovi D, Braastad A, Lindinger TG, Andersen TE, Bjørneboe J. Injury patterns in Norwegian elite football: a comparison between a normal season and a season in the pandemic. In review, Science & Medicine in Football