Should You Eat a Banana Before a Workout? We Asked a Dietitian

Bananas before a workout

Stocksy/Design by Cristina Cianci

If there was a competition for most popular foods, bananas would have a strong claim to the title: They’re a ubiquitous portable snack that's available everywhere from gas stations to gyms. Bananas are beloved by people of all ages, and are known for their easy-to-digest nature, how quick and simple they are to transport, their soft texture, and their sweet taste. While they take days to ripen, bananas have a several-day window of ripeness once they get there, and they require no refrigeration. Their thick skin makes packaging unnecessary, and their creamy texture feels indulgent while being moderately low in calories.

As a healthful whole food containing naturally occurring vitamins and minerals, few health professionals or wellness experts find fault with this inexpensive fruit. It makes perfect sense then that bananas are an ideal pre-workout snack. We tapped Kiely Wilkins, MS, RDN, LDN, to help explain why.

They've Got Plenty of Potassium

A medium banana offers about 10% of the recommended dietary allowance (RDA) for potassium. When it comes to exercise, potassium is one of the most important minerals for your body: Replacing electrolytes helps with everything from preventing muscle cramps to regulating blood pressure. “The body expels electrolytes through sweat during exercise. Bananas can replenish the electrolytes... to prevent muscle fatigue," says Wilkins. "Replacement of carbohydrates and electrolytes are essential when exercising for longer than 60–90 minutes.“

They're Full of Fiber 

When consuming sugar, eating fiber at the same time is vital so the sugar is absorbed slowly and doesn’t cause a spike in blood sugar (which can then lead to a sudden drop). Interestingly, as bananas ripen, the type of fiber in them changes. They’re one food where eating them at different stages of ripeness offers different benefits: Unripe green bananas contain lots of an insoluble fiber called resistant starch, aka prebiotic starch, which passes through the digestive system unprocessed and feeds the probiotic colony in our guts. When ripe, some of the fiber in bananas changes to the soluble version. They also contain pectin, a soluble form of fiber that can assist with weight management. Pectin is slow to move through the digestive system, so it can create a feeling of fullness that lasts—something that’s particularly helpful before a workout, when you don’t want to have to pause midway because of hunger.   

They Boost Vitamin B6

Bananas have about half the RDA for B6, a vitamin that, while we need only a small amount daily, is integral for keeping our nerves working correctly. It also helps modulate blood sugar and make red blood cells. B6 also assists with metabolizing protein, a macronutrient we need when working out to aid muscle growth. Women who exercise tend to get less of it in their diets than men, so bananas are an easy way to ensure you eat enough B6. 

They're a Good Source of Carbs 

Protein gets all the airtime when it comes to what macronutrients you need for exercise, but carbohydrates are just as important—and even more so when it comes to the timing before exercise. Carbs provide quick fuel for bodies, and one banana contains about 30 grams. However, Wilkins cautions that “bananas will raise your blood sugar, so it is important to consider a 'wide lens' of overall daily blood sugar trends to achieve optimal performance.”

They're Quickly Digestible 

Bananas are the “B” in the BRAT (Bananas, Rice, Applesauce, and Toast) diet, a temporary eating plan prescribed by doctors and healthcare professionals for people dealing with nausea or stomach conditions. That’s because bananas are so easy for our bodies to break down and assimilate. When looking for a pre-workout snack, this is a huge benefit, as the last thing anyone wants is fuel that will lead to stomachaches, cramps, or bloating while working out. Wilkins' thoughts? “Bananas are a convenient and effective pre-workout snack... They are an easily digested carbohydrate source that boosts glycogen stores to provide energy.”

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