Ketones
Ketones are molecules generated when your body breaks down fat, but they are not commonly emphasized in conventional nutrition as your body does not heavily depend on ketones for energy when you are properly nourished with a well-balanced diet.
Nevertheless, ketones are significant in scenarios involving fasting and diets that restrict carbohydrate intake.
After approximately four days of fasting or following an extremely low-carb diet, a significant increase in the concentration of ketones occurs in your blood, indicating that your body has successfully transitioned into a state of ketosis.
During exercise, your body becomes more efficient in utilizing ketones as a source of energy in this state. This, in turn, reduces the dependence on carbohydrates and minimizes lactate production, potentially resulting in enhanced performance.
In order to extend their running capabilities, certain ultramarathoners have embraced ketogenic diets which aim to prioritize fat and ketones as a major source of energy, thus reducing reliance on other fuel sources.
Nevertheless, adhering to a ketogenic diet can prove to be exceptionally challenging, and studies indicate that the absence of carbohydrates can truly hinder one’s performance.
Multiple studies have consistently highlighted the detrimental impact of low-carbohydrate diets on high-intensity endurance performance, as outlined in a scientific article published in 2015 by Louise Burke from the Australian Institute for Sport. This occurs due to the body’s reduced utilization of carbohydrates during exercise.
Could an exogenous ketone supplement help you run faster
The latest research in exercise physiology indicates that using “exogenous ketones” as a supplement could enable your body to rely more on ketones during exercise, without the need to limit your carbohydrate consumption.
This assertion was supported by data on cellular metabolism and real-time trial performance from elite cyclists, as demonstrated in a significant study that was published in 2016 in the journal Cell Metabolism.
A group of researchers from Oxford University published a paper revealing that the consumption of a ketone supplement raises ketone levels in the bloodstream, similar to the effects of following a ketogenic diet. Furthermore, taking a ketone supplement successfully reduced blood lactate levels and improved performance during a cycling time trial, even when combined with a conventional sports drink high in sugar.
The exercise physiology community was greatly intrigued by these findings, leading to numerous new studies and a review of previous studies on the potential performance-enhancing advantages of exogenous ketones.
Improved mitochondrial efficiency
The potential energy-enhancing benefits of ketones, particularly ATP, were extensively discussed in a significant paper published in 2015, which played a fundamental role in establishing the foundation for this concept.
The research revealed that the oxidation of ketones leads to highly efficient ATP production, reaching up to 28%. Consequently, this allows the muscles to contract with stronger force while requiring less oxygen.
Furthermore, the study revealed that utilizing ketones as a source of energy yields reduced oxidative stress, thereby minimizing potential harm to cellular organelles. A limitation of the study lies in its use of rats rather than human subjects engaged in physical activity. Evaluating actual endurance athletes remains the benchmark for accurate assessment.
Fortunately, the positive outcomes of this paper did indeed prompt further investigation, particularly in a 2021 study that examined mitochondrial efficiency and exogenous ketones as well.
Endurance-trained athletes in this study engaged in an incremental cycling exercise lasting 60 minutes, during which they maintained intensities at 25%, 50%, and 75% of their VO2max. When compared to the control condition, the ingestion of exogenous ketones resulted in a 7% enhancement in mitochondrial efficiency. This improvement allowed the athletes to achieve greater performance using less oxygen.
Glycogen sparing
Another significant advantage of ketones is a reduced dependency on glycogen as the main source of fuel.
The 2016 study confirmed the potential advantage by having endurance-trained athletes cycle for 2 hours at 70% VO2max intensity on two occasions. On one occasion, they consumed solely a carbohydrate solution, while on the other, they ingested carbohydrates along with a deltaG exogenous ketone product.
After exercising for 2 hours, muscle biopsies were carried out to analyze muscle glycogen levels. Drinking the deltaG and carbohydrate mixture resulted in a notable increase in the preservation of glycogen.
The findings indicate that increasing your blood ketones can postpone the utilization of glycogen during the early phases of endurance exercise. Consequently, there will be a greater amount of glycogen accessible during the final stages of the race, which can help avoid experiencing a sudden depletion of energy.
Overall performance
Researchers discovered another interesting advantage of exogenous ketones – they found that it directly enhanced overall performance.
In the same 2016 study on glycogen, cyclists trained for one hour at 75% Wmax, and after that, they completed a 30-minute time trial. The participants carried out the exercise twice, first consuming only a carbohydrate drink, and then consuming a deltaG and carbohydrate drink.
After consuming deltaG, athletes had an average increase of 411 meters in cycling distance, resulting in a 2% enhancement in performance.
Workout recovery
Since 2016, there have been notable studies focusing on the recovery benefits of ketone supplementation. A research article published in Frontiers in Physiology showed that the inclusion of ketone esters in the recovery process enhances the activity of mTORC1, a cellular signaling pathway closely associated with muscle growth and recuperation.
The results indicate that incorporating ketone supplementation may serve as an effective method for recovery, especially following demanding training sessions that cause muscle fiber damage, such as a hill workout. Additionally, utilizing external sources of ketones has been proven to enhance recovery and sustain performance during intense training periods.
A group of researchers set out in 2019 to examine whether deltaG, a prominent ketone supplement, could avert a decrease in performance caused by overreaching.
The recruited athletes underwent rigorous training, exercising twice a day for six days a week over the span of three weeks. Throughout this period, the intensity of their training gradually increased. In the experimental group, participants were provided with deltaG and a standard carbohydrate+protein shake after each training session and 30 minutes prior to bedtime. On the other hand, individuals in the control group were given solely carbohydrate+protein shakes.
The workload during the initial two weeks was similar among the groups; however, individuals who consumed deltaG displayed a 15% increase in training load during the third week. Additionally, participants in the deltaG group exhibited a 15% higher power output in the concluding 30-minute time trial of the study.
Rocket fuel
In 2016, Cell Metabolism published research conducted by the University of Oxford, University of Cambridge, UK Sport, and the National Institutes of Health, which suggests that there is a potential for a 2 percent improvement in performance.
During the study, a group of eight elite cyclists engaged in an hour of moderate cycling followed by a 30-minute time trial. On average, their performance witnessed a 2 percent enhancement as they covered an additional one quarter-mile distance when they consumed a ketone ester drink (equivalent to about two shots) prior to the initial hour of cycling, compared to consuming a placebo with the same calorie content.
At present, Brendan Egan, who is an associate professor of Sport and Exercise Physiology at Dublin City University, and his colleagues are in the process of conducting a runner-based study that replicates the previous research protocol.
Although initial findings indicate similar outcomes, Egan advises against assuming that ketone esters will universally enhance performance. He believes that ketones may prove advantageous in specific situations, rather than in every circumstance.
He emphasizes that ketones become less effective when the event duration is shorter and intensity is higher. Egan recently illustrated that ketone ester did not improve performance in high-intensity intermittent running, mimicking a soccer game protocol. This occurs because the body requires energy more rapidly when pushing its limits.
The composition of fuel being burned by your body, which includes glucose, fat, and ketones if they are present, is always influenced by several factors like gender and dietary intake. When the intensity exceeds a certain point, your body will prioritize burning carbohydrates as they provide the fastest energy source.
Consider your body as a hybrid car that aims to maximize fuel utilization for optimal efficiency. During lower intensity activities, your body can predominantly use fat (or ketones), which can be accessed at a slower rate but are abundant in supply. As you increase your exertion level, reliance on carbohydrates becomes more significant; during a 10K race, carbohydrates become almost the sole source of fuel.
Egan says that there is strong evidence indicating that people who are the fittest are most likely to benefit from using ketones. Studies on animals have demonstrated that both wheel and treadmill running lead to an increase in the enzymes required for breaking down ketones for energy, as well as the transporter proteins needed to transport ketone fuel into muscles.
It is also hypothesized that individuals with higher proportions of slow-twitch muscle fibers, often considered as more natural endurance athletes, will have better ketone utilization than those who do not exercise, mainly due to the increased activity of ketone-specific enzymes and transporter proteins in these fibers.
The “Third Fuel Tank”
Once again, your body relies mainly on two sources of fuel: carbohydrates (which are predominantly used during tempo runs and interval workouts) and fat (which is more utilized during long, easy runs). Although the storage capacity for carbohydrates is limited to approximately 1,500 to 2,000 calories (4 calories per gram), fat storage capacity is nearly limitless, making it optimal for endurance events such as marathons.
However, there are disadvantages to depending excessively on fat. Fat burning necessitates a greater amount of oxygen compared to carb burning. Therefore, when you reach a point where you exhaust your carb supply and “hit the wall,” you must decelerate.
By following low-carb diets such as Keto, Atkins, Whole30, or Paleo, or running long distances at a certain pace, you can enhance your fat-burning efficiency while running. This helps your body conserve glycogen, or stored carbs, as it learns to burn a larger proportion of fat during exertion. Adapting to burn fat may require a considerable period ranging from weeks to months, or even years.
Ketone esters can serve as a valuable “third tank” in that specific context.
Geoffrey Woo, CEO and cofounder of HVMN, explains that with ketone ester, one can maintain a regular diet while achieving elevated ketone levels. HVMN is known for selling HVMN Ketone, the inaugural commercially accessible ketone ester drink, priced at $99 for a package of three 2.2-ounce bottles. Athletes can benefit from consuming exogenous ketones as it provides them with an extra fuel source, enabling the preservation of glycogen by burning the ketones first.
Ketone esters contribute to a reduction in lactate production by offering an alternative fuel source devoid of carbohydrates. Unlike carbohydrates, which convert into lactate, ketones burn efficiently without any lactate conversion. This decrease in lactate levels leads to reduced muscle fatigue. Consequently, ketone esters might contribute to a decreased sense of exertion and a more consistent energy level during a run.
Recovery elixir
Egan and colleagues conducted a review article in the Journal of Physiology last year, where they explored the impact of ketones on the body during and after training. This study provides evidence that ketones not only improve performance but also facilitate enhanced recovery.
The researchers reached the conclusion that post-exercise ketosis, whether obtained through diet or supplements, is probable to assist in the recovery process by aiding in the restoration of glycogen and muscle synthesis. During post-exercise ketosis, the body utilizes ketones for energy, thereby preserving carbohydrates (essential for glycogen) and protein (essential for muscle).
Nevertheless, for runners striving to trigger ketosis through their diet, they must abstain from consuming carbohydrates, which is conventionally recommended as the necessary post-workout fuel to rapidly replenish glycogen stores in the body.
