Running decreases knee intra-articular cytokine and cartilage oligomeric matrix concentrations: a pilot study

Introduction
Regular exercise protects against degenerative joint disorders, yet the mechanisms that underlie these benefits are poorly understood. Chronic, low-grade inflammation is widely implicated in the onset and progression of degenerative joint disease.

Purpose
To examine the effect of running on knee intra-articular and circulating markers of inflammation and cartilage turnover in healthy men and women.

Methods
Six recreational runners completed a running (30 min) and control (unloaded for 30 min) session in a counterbalanced order. Synovial fluid (SF) and serum samples were taken before and after each session. Cytokine concentration was measured in SF and serum using a multiplexed cytokine magnetic bead array. Ground reaction forces were measured during the run.

Conclusions
Running appears to decrease knee intra-articular pro-inflammatory cytokine concentration and facilitates the movement of COMP from the joint space to the serum.