Banana
A 2012 study published in PLOS ONE compared bananas to sports drinks in cyclists and found bananas performed equally well at sustaining energy output over a 75-kilometre time trial. The reason is the mix of glucose, fructose, and sucrose alongside fibre, it delivers a fast hit without the sharp drop that follows refined sugar. One medium banana also provides about 9% of the daily magnesium requirement, which matters because magnesium is directly involved in over 300 enzymatic reactions, including ATP synthesis. ATP is the unit of energy every cell spends. Low magnesium means slow ATP production, which reads as tiredness before it reads as anything else.
