A Natural Superstar

Use watermelon as a natural source of hydration and replenishment. Here are exerts from a recent clinical trial of Watermelon v Gatorade:

• Drinking watermelon puree is as effective as the sports drink (Gatorade) in supporting performance, with the added advantage of improving antioxidant capacity through increased intake of lycopene and vitamins A and C
• Changes in blood glucose, inflammation, oxidative stress, and innate immune measures were comparable in watermelon and Gatorade
• The antioxidants in watermelon (vitamin A, vitamin C, and lycopene) augmented the exercise-induced increase in plasma antioxidant capacity, a big advantage over Gatorade
• Watermelon helped assist exercise in lowering blood pressure in the subjects
• Related to the decrease in blood pressure, was the release of nitric oxide- a higher amount than was anticipated by the researchers!

 Researchers/facility : R Andrew Shanely (primary investigator)¹, David C Nieman¹, Amy M Knab¹, Penelope Perkins-Veazie², Dru Henson¹, Lynn Ciadella-Kam¹, Wei Sha³, Mary Pat Meaney¹

¹Human Performance Laboratory, Appalachian State University; ²North Carolina State University; ³University of North Carolina-Charlotte; North Carolina Research Campus, Kannapolis, NC

Abstract

The stress and energy demand of vigorous exercise, such as running a marathon, causes significant inflammation, oxidative stress, and immune dysfunction in humans. However, maintaining blood sugar levels by consuming commercially available sport drinks or other carbohydrate (sugar) rich foods improves exercise performance and decreases the stress of vigorous exercise because glucose helps fuels exercising muscles. Watermelon contains large amounts of free water as well as sugars, some electrolytes, vitamin A, vitamin C, and lycopene. Watermelon juice, consisting of the puree from the flesh, was tested against a sports drink (Gatorade™) to determine if endurance exercise performance is comparable when older athletes consume watermelon versus the sports drink, and if the influence of watermelon on exercise-induced oxidative stress, inflammation, immune function changes, and blood pressure are comparable. 

Twenty male competitive cyclists, average age of 48, participated in this randomized, placebo controlled, crossover study. On two different occasions the participants rode their bicycle on a computerized 75 km (46 mile) course after drinking 980 mL (4 cups) of watermelon puree per day for two-weeks or no watermelon puree. During the time trial the participants consumed an equal amount of sugar from either watermelon puree or the sports drink (containing 6% sugar). In this crossover study design beverage intake was switched following the first exercise trial. Measures of arterial stiffness (blood vessel function) were made pre-study and pre-, post-, 1-hour post-exercise. The crossover study is done so that all subjects participate in placebo and watermelon puree treatments, rather than random assignment to one or the other group.  This method helps decrease subject-to-subject variation and increases statistical strength. 

Watermelon puree ingestion versus no watermelon puree for two-weeks did not alter blood biomarkers but decreased augmentation index (a measure of arterial stiffness) by 38% (p=0.007). This result indicates that consumption of watermelon without exercise decreased arterial stiffness (a health-positive result). Neither exercise performance (p=0.194) nor blood sugar levels (p=0.959) differed between the watermelon puree and the sports drink trials. When the participants drank the watermelon puree during the time trial two measures blood antioxidant capacity (FRAP and ORAC) were each 10% higher and total nitrate was 29% higher (all, p

In conclusion, drinking watermelon puree is as effective as the sports drink in supporting performance, with the added advantage of improving antioxidant capacity through increased intake of lycopene and vitamins A and C.  Changes in blood glucose, inflammation, oxidative stress, and innate immune measures were comparable between the watermelon puree and sports drink trials, and similar to what we have previously reported for carbohydrate-fed athletes. The antioxidants in watermelon (vitamin A, vitamin C, and lycopene) augmented the exercise-induced increase in plasma antioxidant capacity. Counter to our hypothesis, watermelon blunted the post-exercise drop in augmentation index. Further research is warranted to determine if this effect on the post-exercise decrease in augmentation index is a beneficial effect in exhausted athletes.

Abstract presented at the annual Experimental Biology meeting (Boston, MA, April 20-24, 2013):

http://www.fasebj.org/cgi/content/meeting_abstract/27/1_MeetingAbstracts/1076.6?sid=5d213fbb-ec73-48f6-b612-a86d33bbbc47