Comparison of Watermelon and Carbohydrate Beverage on Exercise-Induced Alterations in Systemic Inflammation, Immune Dysfunction, and Plasma Antioxidant Capacity

Nutrients. 2016 Aug 22;8(8):518. doi: 10.3390/nu8080518.


Consuming carbohydrate- and antioxidant-rich fruits during exercise as a means of supporting and enhancing both performance and health is of interest to endurance athletes. Watermelon (WM) contains carbohydrate, lycopene, l-citrulline, and l-arginine. WM may support exercise performance, augment antioxidant capacity, and act as a countermeasure to exercise-induced inflammation and innate immune changes. Trained cyclists (n = 20, 48 ± 2 years) participated in a randomized, placebo controlled, crossover study. Subjects completed two 75 km cycling time trials after either 2 weeks ingestion of 980 mL/day WM puree or no treatment. Subjects drank either WM puree containing 0.2 gm/kg carbohydrate or a 6% carbohydrate beverage every 15 min during the time trials. Blood samples were taken pre-study and pre-, post-, 1 h post-exercise. WM ingestion versus no treatment for 2-weeks increased plasma l-citrulline and l-arginine concentrations (p < 0.0125). Exercise performance did not differ between WM puree or carbohydrate beverage trials (p > 0.05), however, the rating of perceived exertion was greater during the WM trial (p > 0.05). WM puree versus carbohydrate beverage resulted in a similar pattern of increase in blood glucose, and greater increases in post-exercise plasma antioxidant capacity, l-citrulline, l-arginine, and total nitrate (all p < 0.05), but without differences in systemic markers of inflammation or innate immune function. Daily WM puree consumption fully supported the energy demands of exercise, and increased post-exercise blood levels of WM nutritional components (l-citrulline and l-arginine), antioxidant capacity, and total nitrate, but without an influence on post-exercise inflammation and changes in innate immune function.

Keywords: ">l-arginine; ">l-citrulline; endurance exercise performance; ferric reducing ability of plasma (FRAP); oxygen radical absorbance capacity (ORAC); total nitrate.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Antioxidants / metabolism*
  • Beverages / analysis*
  • Carbohydrates / administration & dosage
  • Carbohydrates / chemistry
  • Carbohydrates / pharmacology*
  • Citrullus / chemistry*
  • Cross-Over Studies
  • Exercise*
  • Humans
  • Immune System Diseases
  • Inflammation
  • Male
  • Middle Aged
  • Time Factors


  • Antioxidants
  • Carbohydrates