A study in the American Journal of Sports Medicine looked at the practice of injecting hyaluronic acid (HA) in runners’ knees to “lubricate” knee joints and protect the cartilage prior to them running in marathons. Researchers randomized 20 runners into those receiving HA and those receiving normal saline (NS) one week before a marathon. MRI scans were done before and after the marathon, and “post-marathon studies revealed no statistically significant changes between the HA and NS groups in all articular cartilage areas of the knee on both T2 and T1ρ relaxation times,” the study concluded. Read the abstract.