PurposeThe purpose of this study was to explore self-perceived changes in athlete journey trajectory, or shifts, after ACLR that facilitate or hinder physical activity participation among youth. MethodsTen participants were included in this study at a median of 5.9 years after adolescent ACLR. Using an interpretive phenomenological methodology, semi-structured interviews with each participant were recorded and transcribed verbatim. Data collection focused on participants’ lived experiences of reintegration to physical activity after ACLR. Thematic analyses were guided by the procedures of the constant comparative method. ResultsNineteen distinct shifts were identified from participants’ perspectives, categorized into the main classification scheme of 1) environmental shifts (extrinsic demands, built environment, social network), 2) psychological shifts (expectations, motivation, meaning of sports, accountability, priorities, athlete identity, mental health, confidence, knowledge, character, participation mentality), and 3) physical shifts (movement competence, sport participation, physical activity, normalization, knee health). Factors perceived to induce shifts were categorized as natural, injury-driven, or life transition-driven. ConclusionIn the years following adolescent ACLR, young athletes experience physical, psychological, and environment shifts that impact physical activity participation. These findings provide important insight for future work that aims to optimize physical activity outcomes after an injury-related disruption in the athlete journey.