What Happens to Your Body When You Eat a Banana Before a Workout

If you’re looking for a portable, sweet, quick and easy pre-workout snack, you can’t beat bananas.

Bananas provide energy in the form of carbs, plus vitamins and minerals to help you power through your workout. But what actually happens in your body when you eat a banana before exercising? 

Here’s what eating a banana before a workout does inside your body, plus when to eat bananas for the best results.

When you eat a banana, your body breaks it down into its individual parts, using it for fuel and more. 

Digestion, or the process of your body breaking down foods and liquids into smaller, digestible parts, takes between 14 to 58 hours for most people.

After you ingest a banana, it’s broken down in the stomach and small intestines by stomach acid and digestive enzymes. The nutrients from the banana are absorbed through the walls of your small intestine into your bloodstream.

When the sugar, or glucose, from the banana enters your bloodstream, it boosts your blood sugar levels. When your blood sugar rises, your pancreas releases insulin, a hormone that shuttles glucose into cells where it can be used for energy.  

Your body can use this readily available glucose to power muscle contractions during your workout. 

Bananas also provide nutrients that are important for active people, like potassium, which plays an essential role in muscle and nerve function. Potassium works alongside other minerals, like sodium, to regulate muscle contractions, so it’s important to prioritize potassium intake when training.

Bananas are an excellent source of complex carbs, plus vitamins and minerals that are essential for overall health, including muscle health.

Here’s the nutritional breakdown for a medium-sized 118-gram banana:

• Calories: 105
• Carbohydrates: 26.9 grams
• Protein: 1.29 grams
• Fat: <1 gram
• Fiber: 3.07 grams
• Vitamin B6: 0.433 milligrams, or 25% of the Daily Value (DV)
• Manganese: 0.319 milligrams, or 14% of the DV
• Vitamin C: 10.3 milligrams, or 11% of the DV
• Copper: 0.092 milligrams, or 10% of the DV
• Potassium: 422 milligrams, or 9% of the DV

Bananas provide a source of readily available energy in the form of carbs, which makes them a good fuel choice for most types of activity. A medium-sized banana contains just under 27 grams of carbs, which equates to 1.8 servings. 

Carb-rich foods, like bananas, are a go-to before workouts as they provide a quick energy source for your muscles and can help replenish glycogen, the storage form of glucose, in muscle cells.

In addition to carbs, bananas provide potassium and vitamin B6, which are nutrients that play roles in muscle function and energy production. B6 is necessary for breaking down carbohydrates into energy and also supports immune health, helps form hemoglobin in red blood cells, and aids in producing neurotransmitters.

The potassium in bananas is needed for proper muscle and nerve function as well as to maintain fluid balance and blood pressure. 

Most people can benefit from eating a banana about half an hour to an hour before starting their workout. This gives you enough time to digest the banana, and for your body to begin releasing glucose into your bloodstream, which you can use for fuel.

Bananas are also a good choice for early-morning exercisers who can’t stomach a full meal, as they’re light and easy on your stomach.   

Keep in mind that while bananas are a great choice for shorter cardio workouts, you might need a bit more sustenance if you’re engaging in more intensive activity. 

For example, research shows that eating a protein-rich meal within 3-4 hours before a strength-training workout can promote muscle growth and enhance muscle recovery. For longer endurance workouts, it’s best to consume a larger, more complete meal a couple of hours before you train.

Since bananas are low in calories and protein, they’re only appropriate for lighter exercise. More intense workouts and longer training sessions require more substantial fuel. People who experience rapid fluctuations in blood sugar levels may also need to pair bananas with a small amount of protein, such as peanut butter to reduce the risk of blood sugar spikes. 

Additionally, ripe bananas are high in fermentable oligo-saccharides, disaccharides, mono-saccharides, and polyols (FODMAPs), which are carbohydrates your digestive system does not absorb well.

Some people, especially those with irritable bowel syndrome (IBS), are sensitive to high-FODMAP foods and experience symptoms like bloating, gas, and diarrhea after eating them. 

Eating a banana before a workout can give your body a quick source of fuel so you can perform at your best. 

Bananas provide an easy source of carbs plus vitamins and minerals needed for energy and muscle function, like potassium and B6. 

While bananas can be a good fit for most people, it’s important to tailor your pre-workout meal or snack to your workout type, health needs, and goals.