Research
Mixed
Ultra-marathon running can lead to temporary pathological changes in organ systems, including the heart, liver, kidneys, and immune system, which typically normalize after the race.
Don't panic if you feel unwell or see abnormal blood work after an ultra-marathon. The paper notes that changes in heart, liver, and kidney biomarkers are common but usually temporary and normalize after recovery. Focus on rest and hydration to allow your body to heal.
GoodSupportsHIGH confidence
An ultra-marathon can also lead to changes in biomarkers indicating a pathological process in specific organs or organ systems such as skeletal muscles, heart, liver, kidney, immune and endocrine system. These changes are usually temporary, depending on intensity and duration of the performance, and usually normalize after the race.
Why this rating
Supported by a review of multiple studies on biomarkers and organ function.
Source
Physiology and Pathophysiology in Ultra-Marathon Running
Beat Knechtle et al. · Frontiers in Physiology · 2018
DOI 10.3389/fphys.2018.00634
narrative_reviewCited 309×
Read the paper DOI resolved against Crossref · corpus check 2026-06-10
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