Despite what you might expect, ultra runners who run over 100 miles per week are not increasing their pasta and bagel intake to prepare for a major race. On the contrary, more and more endurance athletes are opting for a low-carb keto diet to provide fuel for their extremely long runs.
Jennifer Silverman, M.S., a nutrition specialist at Tone House in New York, states that the ketogenic diet has been successful for numerous endurance athletes due to the higher energy provided by fat compared to carbs.
Nicole Kalogeropoulos and her fiancé Zach Bitter, who are Altra athletes preparing for the 100-mile Western States Endurance Run, adhere to a low-carb keto diet that includes eggs, salmon, and nuts. Interestingly, they assert that this low-carb lifestyle has actually enhanced their performance.
Aren’t endurance athletes expected to consume pasta as a pre-race meal and rely on energy gels during the race to maintain their energy levels?
If your body is stuck relying on sugar, it seems that you can only break free from this dependency state by following a high-carbohydrate diet. According to Jeff Volek, Ph.D., R.D., an extensively studying professor of human sciences at The Ohio State University, carbohydrates compel your body to burn sugar rather than fat. As a result, your body’s sugar reserves can only sustain intense exercise for a few hours, leading to a constant need for carb consumption to maintain energy levels.
If you break this cycle, your body will be able to utilize fat as a more effective energy source, resulting in reduced reliance on sugary gels and chews during endurance races, potentially leading to increased energy levels.
Furthermore, ketosis could play a significant role in preventing the occurrence of the challenging “wall” sensation that often arises during the latter stages of a lengthy run or bike ride. The reason behind this is that while glucose levels sharply decrease in the brain, blood ketones, which serve as a source of energy for both the brain and body, have a more stable decline, resulting in sustained energy levels and a stable mood. Volek further asserts that ketones have demonstrated notable effectiveness in safeguarding against the manifestations and indications of low blood sugar.
During his runs and races, Bitter has observed this phenomenon. In 2011, he began adhering to a low-carb Atkins diet, initially experiencing slight lethargy (which is a customary reaction as the body adapts to using fat as its primary source of energy). However, he now requires less fuel during events, while simultaneously feeling improved.
Even though you may have been instructed that carbohydrates are crucial for endurance, this advice is actually based on limited research, which may seem counterintuitive. In a review published in the European Journal of Sport Science, Volek explains that there has only been one study conducted with a placebo control on this topic, and it did not demonstrate any performance advantages of consuming high amounts of carbs before an endurance event.
Before deciding to adopt a keto diet for your upcoming marathon, some factors need to be taken into consideration.
Load up on electrolytes
According to Volek, the body that has adapted to using fats as a source of fuel tends to expel more salt. To increase your sodium consumption, he recommends having a few cups of broth daily and being cautious not to select foods without sodium content, such as nuts. Bitter also includes electrolyte supplements in his ultras.
Start in your off-season
“Don’t make sudden changes before a race. Volek explains that the process of adapting to a ketogenic diet fundamentally alters the way your cells utilize fuel, which requires time. Consequently, you may experience a decrease in performance during the initial weeks as your body becomes less reliant on carbohydrates. However, within a month, you should start to feel improvements as your body adapts.”
Figure out what works for you
“It is impossible to make a generalization about what eating plan will benefit everyone, says Silverman, as just as we all won’t get the same results from a workout.”
Both Kalogeropolous and Bitter have distinct approaches to achieving the same goal. Bitter utilizes blood strips to monitor his ketone levels and follows a program he refers to as “periodizing carb intake based on lifestyle.” During recovery or light training, he reduces carb consumption significantly. However, when training at peak volume, he follows a diet consisting of approximately 10 percent carbs, and when training at his highest volume and intensity, he consumes around 20 to 30 percent carbs.
Does the ketogenic diet help endurance athletes
Next, let’s address the million-dollar question that you may be contemplating: “Will the keto diet benefit or have adverse effects on my athletes?” This is a complex matter as researchers have produced contradictory findings while attempting to address this inquiry in recent years. First, let’s examine a few studies that support the keto diet.
The Waterford Institute of Technology in Ireland conducted an experiment involving 20 male endurance athletes, who were divided into two groups. One group followed a diet that was high in fat and low in carbs, while the other group followed the opposite diet. After a period of 12 weeks, both groups participated in tests including a 100-kilometer time trial, a six-second sprint, and a critical power test.
The two groups achieved similar performance on the long time trial, however, individuals in the keto-mimicking group displayed enhanced utilization of fat as an energy source, improvement in body composition and a potential increase in peak sprinting power relative to their body weight, possibly due to a decrease in body fat percentage.
In a review published in the European Journal of Sport Science, a reconsideration was conducted on the common argument of opponents of the keto diet. The review contends that if athletes do not consume carbohydrates prior to and during exercise, they may struggle to sustain their performance and may reach a point where glycogen depletion prevents further continuation.
The authors proposed that when an athlete is unable to properly use their body fat, they may experience ‘bonking’. They suggested that the most effective way to enhance the body’s ability to burn fat is to decrease the consumption of carbohydrates to a point where nutritional ketosis is achieved (i.e., circulating ketone levels >0.5 mmol/L) while increasing fat intake for several weeks.
However, other studies have concluded that despite offering certain health benefits, the ketogenic diet does not enhance performance.
The Journal of Physiology released a review stating that there was only anecdotal evidence connecting increased fat utilization to endurance performance in elite athletes. The review concluded that a higher-carb diet had more evidence supporting its effectiveness in this area.
A study conducted on endurance athletes in New Zealand discovered that adopting a high-fat, low-carb diet brought about improvements in specific skin conditions, decreased inflammation, and enhanced recovery based on self-assessments. However, it also posed challenges for these athletes in completing high-intensity training sessions and resulted in decreased energy levels during training.
Implementing the ketogenic diet
If you have an athlete who is currently following a high carb and/or high protein and low fat diet, it would be unwise to switch them abruptly to a ketogenic approach, as shown in the study conducted on endurance athletes in New Zealand. Therefore, for the purpose of this article, it is important to consider the potential negative consequences of such a sudden dietary change.
When you want to ask an athlete to make a change, just like in programming, it is best to do it slowly and steadily. The first step is to evaluate what each athlete is currently eating and then create a rough breakdown of their macronutrient percentages.
After that, it is possible to begin decreasing their consumption of carbohydrates gradually while increasing the intake of fat from sources such as meat, eggs, fish, nuts, seeds, and full-fat dairy, provided they do not have any allergy or sensitivity related to it.
Due to the inconclusive and sometimes conflicting research, it would be irresponsible to fully support or caution against the keto diet.
Despite their physiological similarities, athletes will have varying responses to the same stimulus, whether it be a training method, recovery technique, or diet. Thus, rather than implementing a standardized program, it is necessary to take into account the unique nutritional requirements of each client individually.
Instead of recommending specific eating approaches, it might be more effective to share Robb Wolf’s advice on nutrition. He emphasizes that, regardless of the dietary approach individuals follow (such as paleo, keto, vegan, etc.), the most important aspect is to prioritize consuming whole, unprocessed foods that are rich in nutrients.
By thinking step by step, individuals can ensure that they meet their macro and micronutrient needs, steer clear of artificial ingredients, and adequately fuel and replenish their bodies without resorting to extreme measures.
