Research·2026-03-14·1 min read

L-Citrulline Supplementation Protects Gut Health During Intense Exercise

New research reveals how L-citrulline supplementation may prevent exercise-induced gut damage by improving blood flow to digestive organs during strenuous workouts.

By Editorial Team
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Key Takeaways

  • L-citrulline supplementation appears to improve blood flow to digestive organs during intense exercise
  • The amino acid may reduce intestinal injury that commonly occurs during strenuous physical activity
  • This protection works by enhancing arginine availability, which supports vascular function

Intense exercise creates a problematic blood flow pattern that starves digestive organs of oxygen and nutrients. This phenomenon, known as splanchnic hypoperfusion, occurs as the body redirects blood from the gut to working muscles during strenuous activity. The resulting intestinal damage contributes to gastrointestinal symptoms that plague endurance athletes and may limit performance.

Researchers investigated whether L-citrulline, an amino acid found naturally in watermelon, could protect the gut during exercise by improving splanchnic blood flow. The hypothesis centers on L-citrulline's ability to boost arginine levels in the body, which supports nitric oxide production and blood vessel dilation. This mechanism could theoretically counteract the blood flow restrictions that damage intestinal tissue during intense workouts.

Key Finding

L-citrulline supplementation improved splanchnic perfusion and reduced intestinal injury during exercise

The amino acid enhanced arginine availability, supporting better blood flow to digestive organs

The study examined how L-citrulline intake affects splanchnic perfusion, intestinal injury markers, and gut barrier function during exercise sessions. Like a highway system during rush hour, blood flow during intense exercise creates bottlenecks that leave some organs — particularly those in the digestive system — inadequately supplied. L-citrulline supplementation appears to act as additional lanes, maintaining better circulation to these vulnerable areas.

These findings could have significant implications for athletes who frequently experience exercise-induced gastrointestinal distress and for researchers developing strategies to protect gut health during physical stress. The research adds to growing evidence that targeted amino acid supplementation may offer protective benefits beyond traditional sports nutrition approaches, potentially opening new avenues for managing exercise-related digestive complications.

Medical Citation

L-citrulline improves splanchnic perfusion and reduces gut injury during exercise.

Medicine and science in sports and exercise2014

Sources & References

  1. van Wijck K, Wijnands KA, Meesters DM, Boonen B, van Loon LJ, Buurman WA, Dejong CH, Lenaerts K, Poeze M. "L-citrulline improves splanchnic perfusion and reduces gut injury during exercise." - Medicine and science in sports and exercise (2014)

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