Traditional sports nutrition wisdom tells endurance athletes that loading up on carbohydrates prior to long-distance training/events is ideal for optimal performance. However, as sports nutrition research grows, we are learning that there may be more efficacious ways to fuel your endurance training goals.
Enter exogenous ketones (Ketone Supplements). The unique nutritional benefits of exogenous ketones, particularly beta-hydroxybutyrate (BHB) salts, are extensive, ranging from nootropic (brain enhancing) properties, enhanced glucose utilisation, physical performance improvements, and reduced inflammation. For endurance athletes, exogenous ketones present a superior nutritional supplement adjunct to pre-training carbohydrate ingestion.
If you’re not familiar with what exactly exogenous ketones are and how they work, be sure to check out our FREE Exogenous Ketone eBook that teaches you everything you’ll need to know before moving forward.
Why Endurance Athletes Should Use Exogenous Ketones
Before we jump into the data behind exogenous ketones and endurance training, let’s get a better grasp of what exactly exogenous ketones do in the human body.
In short, ketones are an alternative energy source for your body, specifically mitochondria - the ‘engine’ of cells. While endurance athletes typically think of carb-based sports beverages as the ideal energy source for aerobic exercise, recent studies suggest that exogenous ketones, like BHB salts, bolster the benefits of carbohydrates. In other words, combining ketones with carbohydrates results in better performance and recovery than carbohydrates alone. In fact, adding Essential Amino Acids (EAA’s) may prove to be even more effective as previous studies support the combination of Carbohydrates and Amino Acids for improved recovery over either one alone.
Ketones are natural metabolite of fatty acid metabolism when carbohydrate intake is exceptionally low; naturally, endurance athletes who consume a large amount of carbohydrates produce very few ketones endogenously (within the body).
In short, using a BHB salt supplement provides your body with an instant supply of ketones to utilise and amplify the performance-enhancing effects of carbohydrates. Hence, consuming ketones will help mimic the effects of your body being in a state of nutritional ketosis very rapidly (typically within 30 minutes or less after ingestion).
Since exogenous ketones essentially ‘switches on’ ketosis and provides a multitude of benefits, including enhancing aerobic capacity, boosting cognitive function, reducing inflammation, improving carbohydrate utilisation, decreasing food cravings, and increasing energy levels. On that note, let’s look at the research and science behind the many benefits of exogenous ketone use for endurance athletes.
Human Research Behind Exogenous Ketones as an Adjunct Supplement for Endurance Athletes
A pioneer study conducted at the University of Oxford analysed 12 cyclists compared the effects of a non-nutritive beverage and a BHB beverage after depleting their glycogen stores through training. Each group was given glucose along with their respective beverages.
The findings of the study were that cyclists given the BHB beverage experienced more rapid refilling of muscle glycogen than the placebo group. The authors of the study suggest that this was the result of the BHB beverage enhancing insulin sensitivity. This assumption is very likely true based on other literature showing that exogenous ketone supplementation can drastically improve insulin sensitivity, resulting in better shuttling of blood glucose into cells.
Insulin is a peptide hormone manufactured by the pancreas that primarily works to lower blood sugar levels by increasing activity of glucose transport proteins (GLUTs). It is a potent anabolic (storage) hormone that induces protein synthesis throughout the whole body when dietary amino acids are available.
Being highly insulin sensitive means your cells respond efficiently to insulin’s signalling. Essentially, your body becomes more efficient at utilizing carbohydrates and you’re less likely to store them as adipose tissue (body fat). As such, supplementing with ketones and carbohydrates helps endurance athletes recover and replenish themselves rapidly.
Even for everyday gym goers and fitness enthusiasts who don’t train for endurance events, using exogenous ketones for its insulin sensitising benefits is prudent as it puts your body in a better position for partitioning nutrients/carbohydrates to energetically demanding tissues, such as skeletal muscle.
A second study at the University of Oxford examined the effects of a pure carbohydrate beverage and a carbohydrate plus exogenous ketone beverage on cyclist’s performance. Keep in mind that the first study we discussed administered beverages after training.
The two study groups received isocaloric drinks (meaning they had the same amount of energy). Fast-acting carbohydrates were used, including dextrose, fructose, and maltodextrin, all of which are known to replenish glycogen quickly.
The results showed that cyclists who drank the ketone plus carbohydrate beverage could cycle 411 metres further in the allotted time span than cyclists who drank a carbohydrate-only beverage. Moreover, lactate build-up in the ketone plus carbohydrate group was less than 60% as high as it was in the carbohydrate-only group.
This demonstrates that ketones not only increase energy reserves and enhance glucose uptake, but that they also significantly reduce lactate accumulation in the blood as exercise persists. This may result in greater performance and less fatigue.
Further Beneficial Findings
Better Oxygen Utilisation
Though not human data, animal research findings show that BHB supplementation also enhances oxygen utilisation, especially in the central nervous system (CNS). This is a crucial benefit for endurance athletes who take up enormous amounts of oxygen. Therefore, using a BHB supplement before training can significantly reduce build-up of oxygen or reactive oxygen species (ROS) in the CNS/brain. This may result in greater energy per molecule of oxygen and less oxidative stress. In fact your body will use less oxygen to create the same amount of ATP (Adenosine Tri Phosphate) from ketones compared to glucose. ATP is the energy of all of your cells including muscle cells etc.
Better yet, endurance athletes, especially runners, know how tough it can be to keep up with training when joint inflammation is rampant. The good news is exogenous ketones have strong anti-inflammatory properties in many bodily tissues by blocking the actions of a class of proteins known as inflammasomes.
Data shows that increases in plasma ketone concentrations drives the brain to utilise ketone bodies for synthesis of phospholipids, which encourage neuronal growth and myelination (improvements in the production of a protective sheath around nerves for greater neuronal communication). Usually, glucose is the brain’s preferred substrate, despite being much less efficient. As such, using exogenous ketones can enhance cognitive function and the speed at which nerve impulses are conducted.
Dosage Recommendations for Carbohydrates and Ketones Based on Body Size and Training Goals
According the University of Oxford studies that were discussed above, it appears that the amount of exogenous ketones necessary for endurance athletes is roughly 190 mg/kg bodyweight. The amount of carbohydrates should at least double the number of ketones ingested.
For example, here’s how a marathon runner weighing 60 kg would calculate their dosages before a 1-hour training session:
Exogenous ketone dose = 190 mg x 60 kg = 11,400 mg (11.4 g) of BHB salts.
Carbohydrate = 11.4 g x 2 = 22.8 g of fast-acting carbohydrates (e.g. dextrose, maltodextrin, etc.)
If you’re preparing for an event that will last several hours, increase the BHB salt content to 300 mg per kg of bodyweight. BHB salts help sustain blood ketone levels for upwards of 6 hours after ingestion, making them a superb fuel source for endurance events. When tactically combined with carbohydrates, performance and recovery will improve significantly.
Note: You may want to start with a much smaller dose in training prior to your event and titrate up as you get used to Ketones. They can cause lose bowels if you consume too much too soon.
Stacking Ketones: Maximising Supplement Synergy for Elite Performance
Along with utilising ketones plus carbohydrates, there are a few other supplements to maximise the performance benefits of exogenous ketones.
Essential Amino Acids (EAA's)
For endurance athletes looking to maintain their muscle tissue, reduce fatigue, and increase recovery, ketones and amino acids make the ideal tandem. Choose a product with a complete spectrum of nine essential amino acids (EAAs) in the precise human ratio.
Getting one that also contains a balance of electrolytes, co-factors, vitamins and Schisandra chinensis, which help amplify recovery, support hydration, improve performance and regulate cortisol production would be a great idea.
This combination is unrivalled for endurance athletes looking to get leaner and have a little extra kick of energy before training. The right Thermogenic will provide research-backed ingredients, such as caffeine, hordenine, Kucha tea, Synephrine and green tea extract that increase metabolic rate and ramp up energy levels.
Furthermore, the right thermogenic may help reduce appetite and boost energy expenditure from training, meaning you feel less cravings and burn more body fat for fuel during long-lasting events. Doesn’t get much better than that.
This combination is imperative for endurance athletes since your adrenal glands are responsible for producing stress hormones, such as cortisol, adrenaline, and glucagon.
During long training bouts, cortisol tends to increase significantly which ultimately increases breakdown of lean muscle tissue in the body. The ingredients in a good adrenal support formula can help reduce cortisol build up, and thus help maintain lean body mass and cognitive function.
Moreover, many athletes become magnesium deficient at some point. Low magnesium has a myriad of ramifications, especially weakening of muscular contractions. In fact ATP the energy currency of every cell in your body is only biologically active when attached to Magnesium.
Contrary to decades of research suggesting that carbohydrates are the only crucial nutrient to consume prior to endurance training/events, exogenous ketones present a dynamic edge to enhance your long-distance performance.
While using exogenous ketones on there own before training will help performance and recovery, it is ideal to consume it along with a modest amount of fast-acting carbohydrates unless fat loss is your goal. Remember to consume at least 190 mg of BHB salts per kg of bodyweight. For a 60-kg endurance athlete, this means at least 11.4 g of BHB salts prior to training.
If you want to take your performance to even greater levels, try utilising some of the additional synergistic products detailed in this eBook.
You train hard and now its time to supplement smarter for better results than you or your competition would expect.
Disclaimer: The above article is merely a guide and is in no way a recommendation or a treatment protocol for any health conditions or diseases. You should always consult with a qualified health care provider before changing your supplement, training or nutritional strategy. Supplementation should not be attempted by pregnant or breastfeeding women, anyone on prescription medication or children under the age of 15 unless advised by your qualified health care provider.