Serum cartilage oligomeric matrix protein accumulation decreases significantly after 12 weeks of running but not swimming and cycling training – A randomised controlled trial

BackgroundAcute effects of physical exercise on the deformational behaviour of articular cartilage and changes in cartilage oligomeric matrix protein (COMP) are definite. However, conclusive positive effects of fitness exercise on functional adaptation of articular cartilage have not been proved.AimTherefore, in this parallel-group randomised controlled trial, we tested the hypothesis that adequate amount of physical exercise with enough impact would be able to stimulate the functional behaviour of articular cartilage.MethodsWe evaluated 44 healthy males for their physical-fitness levels and their blood samples were obtained before, immediately after and 0.5 h after a 30-min walking exercise. Thereafter, participants were assigned to the running, the cycling, the swimming and the control groups. At the end of 12 weeks of intervention, the same measurement procedures were applied. Mixed repeated-measures analysis of variance (ANOVA) design was used for statistics. (Level of evidence: 2).ResultsPre-test measurements showed that 30 min of walking significantly increased serum-COMP levels in all groups. The post-tests revealed that the COMP level of all groups, except running, showed an increase after a 30-min walking activity.ConclusionOverall, it was concluded that, 12 weeks of regular, weight-bearing, high-impact physical exercise (i.e., running) decreases the deformational effect of walking activity. This finding is an evidence of functional adaptation of articular cartilage to specific environmental requirements.