Background The knowledge on the relation between running patterns and Running Related Injuries (RRIs) is sparse. Studies have tried to document a relationship. However, no firm conclusions can be made. Still it is necessary to identify which running exposures increase the risk of injuries and which exposures might be considered safe.

Objective The purpose of this study is to investigate the link between the running volume and the development of RRIs.

Design Observational prospective follow up study.

Setting Clinical setting on novice and recreational athletes.

Participants Healthy individuals (N=1000) who have not been running the past 1 year is included. All participants receive a global positioning system (GPS) watch (Garmin FR 110) and a pair of neutral running shoes (Adidas Glide 2). They are instructed to start running as much as they want, two times a week as a minimum. They must wear their GPS watch at each training session and upload data to an internet based database. All participants are followed for 1 year.

Assessment of risk factors Running volume measured as absolute number of kilometres and the graduation in kilometres pr. week over a period of 3 weeks.

Main outcome measurement RRI is defined as any musculoskeletal complaint of the lower extremity or back causing a restriction of running for at least 1 week.

Results Time to RRI is compared between groups with different absolute running volumes. In a similar way time to injury is compared between individuals with different weekly training graduations.

Conclusion This study may be the first study to adequately measure running patterns reliably in a large sample. The exposure is quantified by GPS, which is not affected by subject recall and is therefore a clear methodological improvement compared to previous studies. If absolute volume or running graduation over time seems to lead to injury, the study findings and methodology create a solid foundation for future randomised controlled trials in this field.