The Energy In Bananas Grab a Banana and stay active!. Bananas have three natural sugars; sucrose, fructose and glucose-combined with a fiber, a banana gives an instant and sustained boost of energy. Research has proven that just two bananas provide enough energy for a strenuous 90 minute work out.Unripe bananas contain r... Similar Editorial : Going Bananas Over Banana Bread Recipe by Mick Call. | Source : Fruit Diet