Biochemical cartilage alteration and unexpected signal recovery in T2* mapping observed in ankle joints with mobile MRI during a transcontinental multistage footrace over 4486 km The trans-Europa run over almost 4500 km was measured by a group of runners the cartoon thickness in the ankle.
It showed that it came to a cartilage regeneration in the second half of the run. The work can be found under https://pubmed.ncbi.nlm.nih.gov/25132208/