Overview
- University of Colorado Anschutz researchers analyzed blood from 23 runners immediately before and after 40 km and 171 km mountain trail races using broad protein, lipid, metabolite and trace-element profiling.
- Red blood cells were less flexible after races and showed mechanical stress alongside oxidative and inflammatory molecular damage, patterns consistent with accelerated cellular aging.
- Effects scaled with distance, with the 171 km ultramarathon amplifying damage seen after 40 km and producing a faster shift toward spherical cell shape linked to clearance in the spleen.
- Only ultramarathon participants showed an estimated 10% post-race drop in red blood cell counts, a decrease researchers say is unlikely to cause anemia and may be rapidly reversible.
- Authors note a small, non-diverse cohort and only two sampling time points, and they plan larger longitudinal studies and translational work to inform athlete recovery and improve stored blood preservation.