Objective: The aim of the study was to evaluate long-term damage in the internal structures of the knee joints of recreational long-distance runners.
Materials and methods: Ten years after their participation in a baseline study concerning their knee joints, seven long-distance runners and one who had given up long-distance running were invited to participate in a repeat magnetic resonance imaging (MRI) investigation. The same evaluation criteria and the same technical equipment were used, and the results of the two investigations were compared.
Result: No adverse long-term consequences were observed in six of the seven active runners, regardless of pre-existing damage at the baseline investigation. In one case the arthrotic changes were progressive in nature. The person who had given up running presented with severe deterioration of the internal structures of the knee joint.
Conclusion: Non-physiological maximal loads secondary to the marathon race do not cause any permanent damage in the internal structures of the knee joint in individuals without significant pre-existing damage. A disposition for premature arthrosis was not registered in the population investigated. A protective value of long distance running on the internal structures of the knee joint is discussed.