After running 230 kilometers, the way pressure waves bounce back in the arteries appears to change, but this is entirely due to the heart beating faster—not because the arteries themselves have changed their structure or function.
Claim Context
Augmentation index, a measure of wave reflection and peripheral resistance, decreases after a 230-km ultramarathon in elite runners, but this change is fully explained by elevated heart rate, as heart rate-standardized AIx75 remains unchanged, indicating no intrinsic alteration in arterial wave reflection properties.
“Wave reflection indices at the brachial level decreased (AIx: p = 0.034), whereas heart rate–standardized AIx75 did not change (p = 0.104)...”
Evidence from Studies
No evidence studies found yet.
What Would Prove This
Per GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this claim, ordered from strongest to weakest.
Whether heart rate correction of AIx is consistently necessary and sufficient to isolate true wave reflection changes after endurance exercise.
A systematic review and meta-analysis of all studies measuring AIx and AIx75 before and after endurance events >100 km, comparing the magnitude of change in both metrics and assessing whether correction eliminates confounding by heart rate.
Whether artificially increasing heart rate without exercise replicates the AIx decrease seen after ultramarathons.
A crossover RCT with 30 healthy adults assigned to either 2 hours of paced heart rate elevation (via atrial pacing) or 230-km ultramarathon running, measuring AIx and AIx75 before and after to isolate heart rate effects.
Whether runners with higher resting heart rates show greater AIx reduction after ultramarathons.
A prospective cohort study of 120 ultramarathon runners measuring resting heart rate and AIx75 before a 230-km race, then correlating pre-race heart rate with the magnitude of AIx reduction post-race.
Whether AIx75 differs between elite runners and sedentary controls at rest.
A cross-sectional comparison of AIx75 in 80 elite ultramarathon runners and 80 age-matched sedentary controls, all measured under identical resting conditions.
Whether AIx75 changes abnormally in runners with autonomic dysfunction after ultramarathons.
A case series of 8 ultramarathon runners with diagnosed autonomic neuropathy who complete a 230-km race, measuring AIx and AIx75 before and after to assess abnormal responses.