Seven Days of Highbush Blueberry Supplementation Improves Trail Running Performance in Experienced Runners Without Elevating Physiological or Perceptual Stress Markers.
Luisa V Giles, Jason P Brandenburg
✦ AI-curated · Sources linked
In 30 seconds
This randomized controlled trial examined whether seven days of freeze-dried highbush blueberry supplementation affected performance and recovery in nine experienced runners completing a 22.2-km simulated trail race. Race time was significantly faster after blueberry supplementation than after placebo (p = .003), without differences in race heart rate or perceived exertion. Supine heart rate and tiredness were lower with blueberries, and the decline in drop jump height at 24 hr seen after placebo was not observed after blueberry supplementation. The findings suggest a performance benefit without greater measured physiological or perceptual stress.
Key findings
- Race time was significantly faster after blueberry supplementation than placebo (p = .003).
- Race heart rate and ratings of perceived exertion did not differ between supplementation conditions.
- Supine heart rate (p = .031) and feelings of tiredness (p = .005) were lower with blueberry supplementation.
- Drop jump height declined 24 hr after the race with placebo (p = .022) but was preserved with blueberries.
Why it matters
The results indicate that a short period of blueberry supplementation may affect endurance performance and selected recovery measures without increasing perceived effort or race heart rate. This is relevant because trail running can impose substantial muscular and physiological demands. However, the findings come from a very small group and do not establish whether the observed effects generalise to other runners, race settings, or supplementation periods.
What to keep in mind
Only nine runners were studied, and the findings concern a simulated 22.2-km race after seven days of supplementation; broader generalisability is uncertain.