I always knew watermelons were great recovery food after long or hard training. Why? Because they’re loaded with water and have a high glycemic index. This means they not only help me rehydrate but they also help replace my muscle and liver carbohydrate stores well, even if you need to eat a lot of it to get the energy stores back. Here is some new research suggesting the humble watermelon may also be good for relieving muscle soreness.
Seven healthy and active sport science students (22.7 ± 0.8 years, 68.9 ± 3.8 kg, 170.8 ± 3.6 cm) completed a repeat sprint cycling test once every five days on three occasions. One hour prior to each test, they drank one of three drinks: 500 ml of natural watermelon juice (contains 1.17 grams of the amino acid citrulline), 500 ml of enriched watermelon juice (containing 6 grams of citrulline – 1.17 grams natural plus added 4.83 grams), and a placebo created to look and taste like watermelon juice. One hour after drinking the 500 ml, each subject warmed up on a cycle ergometer for 5 minutes at 75 watts then completed 8 x 30 second sprints separated by one minute of rest followed by a 3 minute cool down. The researchers measured heart rates during each test, blood lactate during and after the tests, and both ratings of perceived exertion (6-20 scale of how the athlete felt with 20 being exhausted) and muscle soreness levels immediately after the test, then 24 and 48 hours after the tests on a 1-5 scale.
There were no differences in cycling performance, ratings of perceived exertion, lactate values or heart rates during the tests. Perceived muscle soreness was no different between the three drinks immediately after or even 48 hours after testing. However, 24 hours after testing, both the watermelon juice and enriched watermelon juice drinks resulted in lower levels of perceived muscle soreness than the placebo drink with no difference between the two watermelon drinks.
The So What?
This Spanish study strongly suggests that (yet again!) natural products such as watermelon juice can help athlete performance, in this case recovery 24 hours after unusual exercise. The theory is that the amino acids found in watermelon (citrulline and argenine) aid blood flow and decrease inflammation. While the study used healthy active sport science students and not trained masters athletes like ourselves, it does suggest that as little as two cups of natural watermelon juice may help us recover from hard training sessions or races.
A team of scientists led by Encarna Aguayo at the Technical University of Cartagena, Spain claims that people who drink watermelon juice shortly after a high-intensity workout need less time to recover.
More precisely, the researchers say that, according to their investigations, watermelon juice significantly reduces the muscle soreness most people experience after spending a tad too much time at the gym or playing sports.
By the looks of it, watermelon juice owes its ability to relieve muscle soreness to the fact that it contains an amino acid known to the scientific community as L-citrulline, Daily Mail reports.
To prove that L-citrulline is indeed the chemical compound that helps athletes recover after intense workouts, the researchers carried out a series of experiments with the help of several volunteers.
The latter were split into three different groups, the same source informs us.
People in the first group were asked to drink natural watermelon juice and the ones in the second group were given watermelon juice enriched in L-citrulline.
The volunteers in the third group were offered a control drink that contained absolutely no L-citrulline.
About an hour after they had enjoyed their beverages, the volunteers were made to exercise.
Later on, the researchers evaluated how much muscle soreness each of them was experiencing.
It was discovered that the people belonging to the first two groups all felt less discomfort than the volunteers who had consumed the control drink.
The watermelon juice enriched with L-citrulline reportedly proved more than the natural one in terms of relieving muscle soreness.
However, the volunteers' bodies responded better to the natural juice, meaning that they processed it significantly easier.
The researchers theorize that L-citrulline helps cut an athlete's recovery time by speeding up the process of lactic acid removal.
A detailed account of this investigation and its findings has recently been published in the Journal of Agricultural and Food Chemistry.