1.It will keep you hydrated and restore your energy. Watermelon is not called so for no reason. 92% of this fruit is made of water. It contains electrolytes and restores the minerals the body loses from sweating due to the heat. Electrolytes help the muscles work. If the body has an insufficient amount of electrolytes, it will become weak or even sick. This is no good if you wish to enjoy your summer activities.