The main aim is to determine whether a gait retraining intervention will improve the strength of the foot-ankle muscle, the running economy and reduce the injury incidence in a one-year follow-up study. The secondary aim is to seek whether a minimal foot-ankle strength is necessary to reduce the risk to sustain to a running-related-injury to transit toward a forefoot strike pattern or toward a minimalist footwear for an endurance runner.

Participants will be assessed at baseline, at 2 month follow-up, at 6 month follow-up and at 12 month follow-up. Assessment will be composed by questionnaires, a foot screening, maximal voluntary isometric strength of foot-ankle muscle with hand held dynamometer. Then, participants will run on a treadmill at self-paced and at 10 km/h with to measure their running economy and their footstrike pattern. In function of their distribution, participants will receive either nothing (control group) or minimalist footwear or a training to modify their footstrike pattern toward a more forefoot strike.

Inclusion Criteria:

• Run 15 km per week since minimum 6 month

Exclusion Criteria:

• No running related injuries in the last 3 month before the participation.
• Have never worn minimalist footwear (minimalist index superior to 70%)
• Have never modified their footstrike pattern