Physical activity levels and quality of life relate to collagen turnover and inflammation changes after running

The purpose of this study was to determine whether an association existed between self‐reported symptom and function scores and tissue turnover or inflammatory biomarker changes after a running bout among individuals with and without an acute knee‐injury history. A pre‐test/post‐test prospective cohort study design (Level II) of 22 participants was conducted. Eleven physically active individuals with a history of anterior cruciate ligament surgery and/or meniscus surgery within 4 years of study participation were matched to 11 healthy control participants. All participants completed self‐reported outcome measures (Knee Osteoarthritis Outcomes Score and Tegner activity level) assessing knee symptoms and functional levels prior to the run. Blood samples were taken both pre‐ and post‐30‐minute run at a prescribed pace on a treadmill to determine serum biomarker concentration changes. Tegner activity levels were inversely related to type II collagen/type II collagen synthesis marker ratio biomarker changes after the run (r = −0.45, p = 0.01). Quality‐of‐life scores pre‐exercise were inversely related to interleukin‐1β changes after the run (r = −0.50, p = 0.02). No other correlation coefficients were statistically significant (r = −0.39 to 0.36). Ultimately, individuals with lower activity and quality‐of‐life scores experienced greater increases in collagen turnover and inflammation after a running bout, respectively. A gradual increase in activity (e.g., frequency, duration, intensity) may be warranted in this group prior to returning to activities that involve running.