Tailored advice on running injury prevention in trail running

Rationale: The pandemic of physical inactivity is worrisome worldwide and efforts to reduce its burden should be considered a public health priority. Running is a way to engage people in physical activity and its health benefits are well known. However, running also caries a risk of running-related injuries (RRI), which can lead to substantial health burden to the individual and economic consequences to society.
Participation in trail running is increasing over time. However, the scarcity of epidemiological data on RRIs in trail running preclude proper recommendations for prevention of RRIs in this fast growing sport with a worldwide base of participants.

Objectives: (1) To develop an evidence-based intervention in order to prevent RRIs in trail runners; (2) to evaluate the effectiveness of the evidence-based intervention on the change of preventive behaviour and its determinants; (3) to evaluate the effectiveness of the evidence-based intervention on the prevalence of RRIs repeatedly measured over time; and (4) to evaluate the implementation of the evidence-based intervention.

Study design: Randomised controlled trial with two arms and six months of follow-up.

Study population: Individuals aged 18 or older and involved in trail running.

Main outcomes: (1) Change of preventive behaviour; and (2) prevalence of RRIs repeatedly measured over time.

Methods: After answering the baseline questionnaire, the participants will be randomly assigned to an intervention or a control group. All participants in both groups will receive general advice on RRI prevention in the beginning of the study, and they will be followed-up biweekly in order to assess their RRI status (no RRI, non-substantial RRI or substantial RRI). Based on the RRI status, the participants of the intervention group will receive evidence-based tailored advice on RRI prevention, whilst the participants of the control group will not receive any further intervention. At baseline and after two and six months from baseline, the participants will be asked to answer a preventive behaviour questionnaire. Descriptive and longitudinal regression techniques will be performed to analyse the data.

1. The TrailS6 intervention will be effective on changing running training and general conditioning exercise behaviours towards to running injury prevention;

2. The TrailS6 intervention will be effective on reducing the prevalence of running injuries repeatedly measured over time;

3. With regards to the process evaluation, the TrailS6 intervention will reach acceptable results in terms of effectiveness and implementation.

- Baseline, 2 and 6 months after baseline for the preventive behaviour measurements and its determinants;

- Biweekly repeated measurements throughout the study (6 months) for the prevalence of running-related injuries.

TrailS6 is an evidence-based tailored advice intervention based on the running injury profile given by the Oslo Sports Trauma Research Centre (OSTRC) questionnaire. The intervention is aimed at changing preventive behaviour and consequently reducing the prevalence of running injuries repeatedly measured over time in trail runners.

- Intervention group: After the baseline measurements, the participants assigned to the intervention group will receive evidence-based general advice towards running injury prevention. During the follow-up, participants with no running injuries according to the OSTRC questionnaire will receive a reminder of the evidence-based general advice in order to maintain their no-injured status (primary prevention). Participants with non-substantial running injuries according to the OSTRC questionnaire will receive evidence-based tailored advice in order to prevent the non-substantial running injury to become a substantial running injury (secondary prevention). Participants with substantial running injuries according to the OSTRC questionnaire will receive evidence-based tailored advice in order to prevent further consequences or permanent damage related to running injuries (tertiary prevention).

- Control group: After the baseline measurements, the participants assigned to the control group will receive evidence-based general advice towards running injury prevention. However, during the follow-up they will not receive any further intervention.