Exhaustive Running Raises Urinary Albumin, Not Cell-Free DNA
A small crossover study of 15 trained men examined whether urinary excretion of cell-free DNA helps clear it from plasma after exhaustive treadmill exercise.
Updated on Nov. 3, 2026 in Running
Researchers tested 15 trained men after an exhaustive treadmill run at 70% of VO2max and a 1.0 h rest condition. Plasma cell-free DNA rose about 25-fold just after exercise and returned to baseline within 4 h, while urinary albumin and creatinine increased without a significant change in urinary cell-free DNA.
Why it matters
The findings suggest that urinary excretion of cell-free DNA does not appear to explain how its levels normalize in plasma after exercise. The result narrows the set of mechanisms researchers consider for clearance of circulating DNA following physical stress.
The study enrolled 15 trained men with a mean VO2max of 45.5 ± 6.25 ml/kg x min, running an average of 11.2 ± 4.7 km over 67 ± 19 min. Urinary cell-free DNA to albumin ratio measured 614.0 ± 586 vs. 324.7 ± 494.8 ng/mg post-exercise vs. rest, but the stub does not explain the significance threshold applied to that comparison.
The details
Participants completed an exhaustive treadmill run compared with a 1.0 h rest condition in a comparative, crossover design. Urinary cell-free DNA was measured alongside albumin and creatinine in post-exercise urine, and participants had no urogenital pathology.
Timeline
Within 4 h after exercise, plasma cell-free DNA returned to baseline while urinary albumin and creatinine had risen.
Big Picture
The study tests whether urinary excretion contributes to plasma normalization of cell-free DNA after exercise, a question raised within the exercise-induced cell-free DNA literature. Its negative finding for urinary cell-free DNA narrows the candidate clearance mechanisms rather than settling them.
The study does not change how runners train or recover, since its measurements were taken in a laboratory setting with 15 men. Readers interested in exercise-related blood markers should treat the result as a single exploratory finding rather than practical guidance.
The takeaway
The study shows that exhaustive running raises urinary albumin and creatinine, but not urinary cell-free DNA, which points away from urine as a route for clearing circulating DNA after exercise. Runners do not need to change training based on this single small study.
Further reading
For more on endurance training research, explore the Running section.
Source note: This article includes information reported by Nature.
