Fat is one of the three macronutrients we consume in our food. It also has a higher energy density than protein and carbs. The amount of energy stored in the bonds of fat molecules is 9 calories per gram vs 4 calories per gram in protein and carbs. Remember, calories is a unit of energy (heat). The biggest result of this that fat is a great way to store energy, and this is why we all have fat tissue. Even the leanest humans have some 50,000 calories worth of fat on their bodies. Nonetheless, for endurance athletes fat ingestion is essential, but in what quantities? Let’s take a little look into fat intake for cyclists.
Fat for Athletes
When we produce energy using one of our energy systems, the body provides the energy for that effort from fat or carbohydrates. Carbohydrates contribute to a larger and larger proportion of the total energy requirement as intensity increases. This means fat metabolism is more important at lower intensities, or during longer events. Not only that, our body can only store a finite amount of carbohydrates, so the importance of fat metabolism is accentuated during longer events where carbohydrate stores may deplete.
To spell out the importance of fat metabolism a bit better, for a Pro/1/2 road race in California, the distance is typically 90 miles (145km) with an average speed of about 26 mph (42kph). I will burn somewhere between 3000 and 3500 calories in a race like this. A human body can maximally store 2000 calories worth of carbohydrates; meaning at least 1000 calories of my effort is coming from fat metabolism. Ensuring sufficient use of fat during efforts and events is essential to maintaining power and energy throughout the day. How does this fat metabolism correlate with fat intake?
On any given day, fat ingestion is almost unimportant. Unlike protein or carbs, there is no immediate need to replenish fat stores, but a diet that has insufficient fat intake over days, weeks, months, can lead to significant problems. Firstly, fat ingestion can help cue the body to increase fat metabolism. We know athletes who ingest fat following a workout have higher fat metabolism than athletes who consume carbs. If an athlete skimps on fat, their fat metabolism during events suffer and their dependence on carbs increases. This dependence limits the total energy storage and total energy output. Top endurance athletes are able to use a lot of fat for their energy demands and this helps them conserve carbohydrates for when they need them in the future.
Another reason to eat fat are the health benefits. Omega-3 fatty acids are highly touted for their recovery benefits and are only available in high fat foods such as fish oil, salmon, walnuts, flax seed, and avocados. Fat ingestion is an important method of ensuring adequate consumption of healthy nutrients and vitamins. Some vitamins are fat soluble, such that they are present in higher abundance and more easily absorbed when consumed in foods with high fat content.
With all this being said, it appears fat intake is usually excessive in elite athletes. One study suggested the Lithuanian Olympic team’s endurance athletes had excessive fat intake for their needs. My own experience is similar. It’s just so easy to eat fat in high quantities. My recommendations would be to transition your fat intake towards healthier fats. Although some fat is important, skimping on saturated fat (animal, solid oils) and focusing on high nutrient density fat can be a good way to mitigate some of the negatives of excessive fat intake.
There is no set amount of fat intake per day for a cyclist. The commonsense recommendation is to have a fat source at every meal; preferably a healthy fat source. Some good options include: nuts or seeds, high fat fish, olive oil, avocado, eggs, and cheese. Cheese is an especially popular option for European cyclists. Don’t worry too much about the exact amount of intake, just focus on a moderate amount. Professional cyclists have shown success in the sport with a large variety of dietary fat intake and the exact balance between fat and carbohydrates is largely unknown.