Acute Renal Failure with Severe Loin Pain and Patchy Renal Ischemia after Anaerobic Exercise Caused by Rapid Resumption after Prolonged Detraining.

Background: We report a case of acute renal failure with loin pain and patchy renal ischemia after anaerobic exercise (ALPE) caused by sudden training resumption. Case presentation: A 19-year-old Asian man who was a college American football player presented with severe back pain, headache, and malaise. He developed acute kidney injury without myoglobinuria. Based on the typical medical history and symptoms, we made a diagnosis of ALPE. Symptoms improved within a few days, and serum creatinine levels simproved after discharge. He resumed training, adjusting his load step by step. Conclusion: During the coronavirus disease 2019 pandemic, many athletes were unable to undergo adequate training. Long-term de-training leads to decreased various organ function and reduces the anaerobic threshold. Rapid resumption after prolonged de-training may put individuals at risk of developing ALPE.