There are an increasing number of inquiries about the consumption of raw nuts, bars prepared with bacon and cheese, or nut butters while competing or training on a bicycle. This development comes as the movement toward eating more authentic foods while riding a bicycle gains momentum. Is it possible that you no longer need those energy bars and gels?

Let’s clear up some confusion about cycling nutrition by explaining why the typical bike racer (as opposed to those who compete in ultra-endurance races that last more than 15 hours) should not depend on lipids as a source of fuel during and soon before a race.

High-Density Carbohydrates

When cycling at a low to moderate effort for less than 70 percent of one’s maximum VO2 capacity, the body burns fatty acids for fuel. Both carbs and fat are used as a source of fuel by the body almost all of the time. However, the fact that fat may be used as fuel in the body does not always suggest that eating fat is a wise decision while competing or training.

The majority of typical racers participate in competitions that last anywhere from one to five hours in length. It is expected that competitions lasting this long would include a significant amount of intense riding. Your reliance on exogenous carbs or glycogen as a fuel source will increase in proportion to the level of difficulty of the race. The level of difficulty and length of the race will both have an effect on the proportion of fat that is utilised.

Foods with a high carbohydrate density but a low fat and protein content should be prioritised as a source of fuel during cycling competitions and strenuous training sessions.

Utilizing Fat As Fuel

It really comes down to gastric emptying time, avoiding GI upset and the ability of the body to utilize fat as fuel during high intensity exercise.

When you eat a meal before a race or training ride, it’s important to give yourself time to digest it. If you want to be able to use that food as energy for the race in question, you need time to absorb it too. What you don’t want to do is set up a scenario where your muscles are competing with your digestive tract for your body’s resources—namely for blood flow.

Starting To Exercise

When you start exercising, blood is required for your working muscles. Blood is also required for digestion. If you start exercising while you have an undigested meal in your gut, you now have to split that blood between muscles and digestion. You’re left with a scenario where both jobs will get done, just not as effectively as they could be, leaving racers with GI upset and heavy legs.

Depending on what your meal consists of, the time to digest and absorb it will differ. For example a meal high in fat, fiber and protein will take longer to digest and absorb than a high carbohydrate dense meal with low fat, fiber and protein. Fat and protein have slower gastric emptying times than carbohydrates.

For a typical pre-race breakfast (events over 90 minutes in duration) most cyclists need 3 to 4 hours to digest 150 or more grams of carbohydrates. Meals should be lower in fat and moderate in protein. After 3 to 4 hours most of the meal will be digested.

As cyclists get closer to race time, let’s say an hour out, the focus should narrow to high carbohydrate-dense foods low in fiber, protein and fat (potatoes, rice bars, sports drinks, bread and jelly, chews, etc.).