Function
When it comes to bodybuilding, it is essential to have the right amount of fuel to power workouts. The main fuel source utilized during exercise is carbohydrate. Carbohydrates are made up of carbon, hydrogen, and oxygen. They are stored in the body as glycogen which in turn is what drives muscle contractions.
This is where the GI comes into play. If you eat foods that are high on the GI chart, then the pancreas is forced to keep releasing insulin to balance out rising blood sugar levels. This is a vicious cycle that can ultimately lead to diabetes.
In bodybuilding, the main objective is to gain lean muscle mass, so spiking the blood sugar is not the overall strategy.
With that being said, there is a time and place for high GI carbs. That would be the hour after a workout. It is at this point that the muscles are like a dry sponge and are in need of fast glycogen replenishment. Other than that, low GI carbs are the way to go. Bananas are actually a great source of nutrient-dense carbs and they fall right in the center of the GI chart. See Resources below.
Function
Bananas can also be integrated into a body builder's training table. Eating every 2 or 3 hours means eating smaller meals that are nutrient-dense. This gives the body a steady supply of nutrients and keeps blood sugar levels in check so there is no chance of unwanted fat gain.
Many bodybuilders eat this way to build lean muscle and not gaining unwanted fat. See Resources for the second link in which bananas are included in the meal plan.
Benefits
The actual nutritional content of a banana is very bodybuilding friendly. They have 3 gm of fiber, 2 gm of protein, 27gm of carbs, and are loaded with potassium. Potassium helps to relieve muscle soreness. If the diet is lacking in this key nutrient, then muscle soreness will persist causing workouts to suffer. This is never the goal of a bodybuilding routine.
Types
Bananas actually come in several varieties ranging in size from 3 inches up to 8 inches or longer. The most popular one is the Cavendish or Chiquita banana as these are the most heavily recognized and consumed variety in the U.S.
Plantains are a version that are most popular in India and they need to be cooked as they are really bitter. They have gained some acclaim recently in the states, but are not as user friendly as other types.
The Red banana is sweeter than a conventional banana and has more vitamin C and beta carotene. These are a good addition to a bodybuilders diet as they help increase immunity which gets compromised during intense weight training. They also have a pleasant sweeter taste somewhat reminiscent of raspberry.
The Baby or Nina banana is the runt of the litter. They stand in at about 3 inches in length, but they are a powerhouse of nutrition. They have all the benefits of the regular banana with the added addition of a high amount of Vitamin B-6. This is also quintessential for bodybuilding as vitamin B-6 helps with brain function and converting protein to energy. This would be a good reason to eat a banana slathered with peanut butter.
Misconceptions
As I mentioned in the introduction, there are a lot of people who fear eating bananas. There is no reason to fear them especially if you are a bodybuilder. They are a quick, easy snack, pre-workout meal, post-workout meal and an all around great supplement to add to the diet. They are universal enough to be used in any dynamic of a diet plan. They can be used for additional calories if you're looking to bulk up or they can be used by themselves if cutting weight is the goal.
Another myth is that bananas cause tooth decay. What causes tooth decay is simple carbs and sugars that lie on the teeth for long periods of time. Likely culprits are cookies, cakes, bagels and all day sipping of coffee sweetened with sugar. This causes bacteria and bacteria causes destruction and breakdown of enamel. Any residue that is left in the mouth from a banana can easily get rinsed away within a glass of water.