Banana Nutrition: The Original Energy Bar
Potassium, quick carbs, and why athletes eat them by the crate.
The banana is nature’s grab-and-go snack — pre-portioned, biodegradably wrapped, and packed with fuel. A medium banana (about 118 g) delivers roughly:
- 105 calories
- 27 g of carbohydrates, including 14 g of natural sugars for quick energy
- 3 g of fiber, aiding digestion
- 422 mg of potassium — about 9% of your daily needs
- Vitamin B6, vitamin C, and magnesium
The potassium myth (sort of)
Bananas are famous for potassium, and they’re a genuinely good source — but they’re not the richest. Ounce for ounce, potatoes, spinach, white beans, and dried apricots all beat them. The banana just has better PR (and a built-in handle).
Why athletes love them
Bananas hit a sweet spot: fast-digesting carbohydrates for immediate energy, plus potassium and magnesium — electrolytes lost through sweat that help prevent muscle cramps. That’s why you see crates of them at marathon finish lines and tennis changeovers.
The riper, the sweeter
As a banana ripens, enzymes convert its starches into sugars — which is why a spotty banana tastes far sweeter than a green one. Green bananas are higher in resistant starch, which acts more like fiber; brown-speckled ones are easier to digest and better for baking. There’s no single “healthiest” ripeness — it depends what you’re after.