OBJECTIVES:To characterise foot strike and observe change in foot strike patterns with increasing distance during a 15km recreational running road race. To assess the impact of foot strike on running performance. DESIGN:Observational cross-sectional study. METHODS:Foot strike patterns were determined at the 3km and 13km checkpoints for 459 participants during the 2017 Melbourne City to Sea recreational running event. Foot strike patterns were categorised as either rearfoot strike (RFS) or non-rearfoot strike (NRFS) at both checkpoints and analyses were conducted on intra-individual change in foot strike as well as relationship to finishing time. RESULTS:The most prevalent foot strike pattern at 3km and 13km was RFS with 76.9% (95% CI: 73.2%-80.5%) and 91.0% (95% CI: 88.7%-93.1%) using this pattern, respectively. Of the 105 participants who ran with a NRFS at 3km, 61% changed to RFS at 13km. Race completion time differed by foot strike pattern, where mean time for consistent NRFS (62.64±11.20min) was significantly faster than consistent RFS (72.58±10.84min; p<0.001) and those who changed from NRFS to RFS between checkpoints (67.93±10.60min; p=0.040). CONCLUSIONS:While the majority of recreational distance runners RFS within race settings, the fastest runners were those who consistently ran with a NRFS. In runners that use a NRFS early, a large proportion change to RFS as distance increases. Further research is warranted to determine whether interventions aimed at reducing muscular fatigue can attenuate this change and enhance running performance.