High-field magnetic resonance imaging assessment of articular cartilage before and after marathon running: does long-distance running lead to cartilage damage?

Luke AC, Stehling C, Stahl R, et al. · The American Journal of Sports Medicine

T1rho and T2 relaxation times (biochemical cartilage stress markers) rose significantly after the marathon (T1rho 37.0 to 38.9 ms, p<0.001) and T1rho remained elevated at 3 months — cartilage matrix changes outlast the event, arguing for real recovery windows.

Population

10 asymptomatic marathon runners and 10 matched controls, 3T knee MRI before/after race

Intervention

Marathon run

Comparator

Non-running controls

Limitations

Tiny sample; imaging biomarkers, not clinical outcomes; changes may be physiologic adaptation rather than damage.