Hematuria, proteinuria, and albuminuria following exercise in athletes: mechanisms, time course, renal biomarkers, and diagnostic approach - a narrative review.

Abstract

Background: Hematuria, proteinuria, and albuminuria may occur transiently after intense or prolonged exercise, complicating differentiation between a post-exercise response and kidney or urinary tract disease.

Aim: To summarize the mechanisms, time course, renal biomarkers, and features that help distinguish transient post-exercise abnormalities from findings requiring further evaluation.

Material and methods: A structured narrative review was conducted using PubMed. Publications from 2021–2026 were prioritized; 27 publications were included.

Results: Exertional hematuria may be renal or mechanical in origin, whereas post-exercise proteinuria may have glomerular and tubular components. The pattern of changes is influenced by exercise duration and hydration status, whereas interpretation also depends on sample collection timing. Creatinine requires cautious interpretation after intense exercise because muscle metabolism and injury may increase its concentration. Cystatin C may complement renal function assessment. uKIM-1 and uNGAL may provide information on tubular injury, but variable post-exercise responses and lack of standardized cutoff values limit interpretation.

Conclusions: Post-exercise abnormalities should be interpreted in clinical and temporal context. Persistent or recurrent abnormalities, features suggestive of a glomerular origin of hematuria, impaired renal function, or symptoms of rhabdomyolysis warrant further diagnostic evaluation.