The Relationship Between Training Load and Injury in Athletes: A Systematic Review
The relationship between training load and musculoskeletal injury is a rapidly advancing area of research in need of an updated systematic review.
This systematic review examined the evidence for the relationship between training load and musculoskeletal injury risk in athlete, military, and first responder (i.e. law enforcement, firefighting, rescue service) populations.
The CINAHL, EMBASE, MEDLINE, SportDISCUS, and SCOPUS databases were searched using a comprehensive strategy. Studies published prior to July 2017 were included if they prospectively examined the relationship between training load and injury risk. Study quality was assessed using the Newcastle–Ottawa Quality Assessment Scale (NOS) and Oxford Centre for Evidence-Based Medicine levels of evidence. A narrative synthesis of findings was conducted.
A total of 2047 articles were examined for potential inclusion. Forty-six met the inclusion criteria and 11 known to the authors but not found in the search were added, for a total of 57 articles. Overall, 47 studies had at least partially statistically significant results, demonstrating a relationship between training load and injury risk. Included articles were rated as poor (n = 15), fair (n = 6), and good (n = 36) based on NOS score. Articles assessed as ‘good’ were considered level 2b evidence on the Oxford Centre for Evidence-Based Medicine Model, and articles assessed as ‘fair’ or ‘poor’ were considered level 4 evidence.
Our results demonstrate that the existence of a relationship between training load and injury continues to be well supported in the literature and is strongest for subjective internal training load. The directionality of this relationship appears to depend on the type and timeframe of load measured.
The authors would like to acknowledge and thank Ms. Rachael Posey and Ms. Chana Kraus Friedberg for their help in developing and executing the search strategy.
Compliance with Ethical Standards
Timothy Eckard is supported by a Promotional of Doctoral Studies scholarship from the (US) Foundation for Physical Therapy. No other sources of funding were used to assist in the preparation of this article.
Conflicts of Interest
Timothy Eckard, Darin Padua, Darren Hearn and Barnett Frank declare that they have no conflicts of interest relevant to the content of this review.
- 22.Grier T, Canham-Chervak M, McNulty V, Jones BH. Extreme conditioning programs and injury risk in a US Army brigade combat team. US Army Med Dep J. 2013:36–47.Google Scholar
- 25.US Department of the Army. Army Physical Readiness Training, Field Manual 7–22. Washington, DC: Department of the Army; 2012.Google Scholar
- 28.The Cochrane Collaboration. Study design guide for review authors. 2013. http://cccrg.cochrane.org/sites/cccrg.cochrane.org/files/public/uploads/Study_design_guide2013.pdf. Accessed 20 July 2017.
- 29.Wells G, Shea B, O’Connell D, Peterson J, Welch V, Losos M, et al. Newcastle-Ottawa quality assessment scale cohort studies. 2014. http://www.ohri.ca/programs/clinical_epidemiology/oxford.asp. Accessed 21 Dec 2016.
- 31.Higgins J, Green S (editors). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. Available from http://www.handbook.cochrane.org.
- 33.Oxford Centre for Evidence-Based Medicine: levels of evidence (March 2009). 2009. http://www.cebm.net/oxford-centre-evidence-based-medicine-levels-evidence-march-2009/. Accessed 22 July 2017.
- 35.Ball S, Halaki M, Sharp T, Orr R. Injury patterns, physiological profile, and performance in university rugby union. Int J Sports Physiol Perform. 2017;13(1):1–18.Google Scholar
- 73.Viswanathan M, Ansari MT, Berkman ND, Chang S, Hartling L, McPheeters M, et al. Assessing the risk of bias of individual studies in systematic reviews of health care interventions. In: AHRQ methods for effective health care. Methods guide for effectiveness and comparative effectiveness reviews. Rockville: Agency for Healthcare Research and Quality; 2008.Google Scholar
- 75.Vilamitjana J, Lentini N, Masabeu E. The influence of match frequency on the risk of injury in professional soccer. Int J Sport Med. 2013;14(3):139–47.Google Scholar