The sports nutrition experts at EAS Sports Nutrition recently sat down with renowned Ironman champion, coach, and EAS ambassador to discuss the ketogenic diet and how it can be applied to an endurance lifestyle.
We chatted about some of the frequently asked questions Dave fields about the diet, be they from high performing elites and professionals who currently follow the diet, age groupers who are considering the diet, and those athletes who are keto-newbies but once they hear about the diet and the benefits it can deliver, want to learn all there is to know about this way of fueling.
EAS: Dave, many athletes have heard about the diet from training partners, friends, and family but want to know, what are some of the benefits you’ve personally experienced and that athletes might expect once they transition from a traditional (high carb) diet to a high fat, low carb (HFLC) or ketogenic diet for endurance athletes?
DS: There are a number of reasons why I’ve committed myself to a LCHF diet. Some of the benefits I’ve experienced myself and others I’ve seen in my athletes and clients. While the reasons are varied, several of the reasons I’ve choosen to follow this way of fueling include:
- A reduction in appetite; As I’ve transitioned from a high-carb, need to eat every 30 minutes-type diet and moved towards a diet that’s high in fat, moderate in protein, and very low in card, I’ve noticed that I don’t get the sugar high’s and low’s that I once experienced, the fat is very satiating, and transitioning my system to run off ketones rather than sugar results in me rarely being hungry and I certainly don’t need to fuel up or snack all day like I once was forced to.
- Elevates the larger particle LDLs which are less of a cardiovascular risk than the hazardous small dense LDLs that are of more concern to health care practitioners.
- Helps control the key two hormones ghrelin and leptin that regulate our stomach-brain connection signaling hunger or fullness; As I’ve become keto adapted, I’ve noticed that my hunger signals are more in check- likely as a result of no longer having the insulin surges that follow a carbohydrate-rich meal or snack. I feel that I have a better pulse on when I’m really hungry compared to my previous way of eating in which I always felt hungry and my satiety signal was never really, well, satisfied.
- Increases the thermogenic effect; While protein is the key nutrient when it comes to thermogenesis, I’ve found that the moderate blend of protein I consume (approximately 20–30% of daily calories) along with a healthy dose (50–75% of daily calories) of satiating and slow-to-digest fat has effectively increased the thermogenic effect of the diet.
- Supports a reduction in systemic inflammation; Most endurance athletes experience some degree of inflammation as a result of the intense training loads our sport often requires. I’ve found that by incorporating inflammation-fighting oils and fats such as fish oil, avocado, nut butters, and flaxseed, into my diet, my levels of inflammation and even soreness from heavy training have improved.
- Athletes will maintain clarity of mind and reduce spikes in blood sugar; Maybe it’s because I no longer experience sudden drops in blood sugar and glycogen levels that I experienced when relying on carb as fuel but now that I rely on ketones for fuel- and we all have plenty of fat stores and therefore ketones on board- I feel fueled and focused rather than experiencing energy highs and lows. Because I’m keto-adapted, my brain relies on a steady and sustained source of fuel and therefore I don’t bonk or hit the wall like I once did.
- Accessing ketone bodies will provide a steady state of fuel; Rather than relying on the limits of muscle, liver, and blood glycogen for fuel, now that I’ve transitioned to a ketogenic state, I rely on ketones for fuel. This source of energy is not limited the way glycogen is, simply because the human body has a propensity to store plenty of fat! I use this fat- endogenous fat- during training and therefore not only have experienced the body composition benefits many athletes are looking to achieve but also a steady source of fuel without the need to add in a source of sugar every few minutes as I roll along.
- Muscle and blood proteins are spared; While some critics suggest that a low carb diet causes muscle loss and weakness, there is scientific evidence to suggest the exact opposite. For example, a study of trained cyclists showed increased levels of circulating BCAAs when the cyclists followed the ketogenic diet, even though the overall intake of protein on the diet was constant. Usually, BCAAs would be used for fuel but when the athletes relied on ketones instead, the ketones were burned as fuel and the BCAAs – and thus protein (and lean tissue!)- is spared.
- Recovery is facilitated with an LCHF diet; I echo the sentiments stated by Dr. Jeff Volek and Dr. Stephen Phinney in The Art and Science of Low Carbohydrate Performance and have found that my recovery from intense workouts is better when I follow a ketogenic diet. The likely reduction in metabolic stress, improved fuel flow, and healthier membranes all translate into less exercise-induced inflammation, stressed GI system, insulin resistance, muscle damage, and of course soreness!
EAS: Dave, many athletes who are considering the ketogenic diet (or are currently working towards become keto-adapted) wonder how long it might take them to transition from being a high-carb, sugar-hungry athlete to one that begins to burn their own fat as their source of fuel.
DS: The latest scientific studies suggest – and in my personal experience – it takes between 3 to 5 weeks to transition to a low-carb, moderate protein, high healthy fat plan.
Of course, everyone is different, and your transition time to a LCHF diet could vary. In order to make your transition as short as possible, it’s important to be vigilant with your compliance. Many of my athletes find that once they become keto-adapted – they can slowly introduce modest amounts of healthy carbs back into the diet yet still remain in ketosis and continue to rely on ketones for fuel.
EAS: Any insider tips on making the transition a bit easier?
DS: Yes! I encourage my athletes to schedule their harder workouts in the morning, and after they’ve enjoyed their morning coffee (but more on this later). LCHF diets as mentioned have several cardiovascular, hormonal and thermogenic benefits. By including harder sessions in the morning, this tends to elevate your exercise post oxygen consumption (EPOC), which results in a continued metabolic elevation hours after the workout.
I’ve also found coconut oil to be one of my secret weapons for hastening keto-adaptation. Coconut oil is made up of approxately 65% medium-chain triglycerides (MCTs), and these MCTs are quickly metabolized in the liver, boosting the ketones that the brain & body use as fuel while helping to suppress hunger. The MCT component of coconut oil oxidizes quickly, similar to a refined carbohydrate. An additional benefit of coconut oil is its antibacterial and antimicrobial compounds. I prefer coconut oil to pure MCT oils which are often highly refined, expensive, and, in my opinion, overly processed.
EAS: Is there a certain distribution of macronutrients endurance athletes should aim to hit in order to shift to relying on ketones as a fuel source?
DS: I work with my athlete to help them make this shift from relying on all-carbs-all-the-time (or so it seems) to an intake of: 50–70% of calories from healthy fats and oils, protein 20–30% of calories from protein, and 10–20% of calories from carbohydrate. It’s a common misconception to think that as long as carbs are limited, intake of fat AND all the protein is unlimited. Protein is not a free for all because excess protein intake have the ability to stimulate gluconeogenesis - or the creation of glycogen which exacerbates the insulin response and can kick one out of ketosis. Finally, I also recommend endurance athletes take net carbs into consideration. In other words, the fiber content of the food will affect the overall carb content and the more fiber a vegetable provides the better. (Net Carbs = Grams of Carbs – Grams of Fiber). An example of a source of healthy carbs is kale or broccoli; the worst source of carbs is refined grains and fruit juices, the latter two have no place in a ketogenic diet.