The ketogenic diet or keto diet is probably something you’re at least familiar with because it’s a highly debated lifestyle. It has become a hot topic in the health and diet industry mainly because of the massive amount of misinformation that spread like wildfire about it on the internet. The misinformation can be overwhelming but it really doesn’t have to be so let’s start by clearing up what keto actually is.
The keto diet is a very low-carb and high-fat diet. It is typically less than 20 grams of carbs per day, and just as a general idea of how much fat we’re talking about when we say “high-fat,” it can be up to 80 percent of our caloric intake—maybe even more, depending on how keto is designed for you. No matter the details, keto is defined as a very-low-carbohydrate and high-fat diet with a moderate amount of protein.
The whole point of a ketogenic diet is to shift into a powerful metabolic state during which the body is burning primarily fat (as ketones are derived from fats). It’s becoming increasingly clear that elevated ketones have an array of important signaling functions (e.g., regulating inflammation and gene expression) and the metabolic shift to increased ketone use may be the secret behind most of the benefits of the ketogenic diet.
Now part of the confusion and debate comes in because many believe that when going on a keto lifestyle we’re saying you are never supposed to have carbs again. And that is just not true. There are different types of keto that I want to discuss that I believe are really important to this whole discussion — targeted keto (TKD) and cyclical keto (CKD).
A targeted ketogenic diet (TKD) is incorporating carbohydrates prior to your intense training sessions. For those following TKD, you should consume carbs usually 30-60 minutes before your training session and follow the standard ketogenic diet at all other times. It only takes around 20 grams of high-glycemic carbs to get the benefits of TKD.
Targeted ketogenic diets are most beneficial for individuals training at a high intensity and doing regular hardcore, glycolytic workouts such as Crossfit, high-intensity interval training (HIIT), and sprinting. Lengthy bouts of cardio (read: marathons) also deplete muscle glycogen. TKD is used for enhanced exercise performance.(1)
Eating a small number of fast-absorbing carbs before, during, or after intense workouts can help fuel your session and top off your glycogen stores.
Consuming 15g can be enough to stimulate a response.
Wilson et al. found that recreational bodybuilders adapted to Keto for 10 weeks were unable to reach their strength and power potential.
At week 11, the participants were reintroduced to carbohydrates.
Wilson et al. (2017). The Effects of Ketogenic Dieting on Body Composition, Strength, Power, and Hormonal Profiles in Resistance Training Males. Journal of strength and conditioning research.
After the reintroduction of carbohydrates (over the course of 3 days), these athletes increased their strength and power considerably!
However, the reintroduction of carbohydrates (over the course of 3 days) caused a small amount of fat gain.
Low carb performance may best be enhanced with a targeted keto approach (anecdotally). Although research is very scarce, it makes sense to increase glucose when it is needed most i.e. high intensity performance. If your main goal is performance, TKD may be a good technique to experiment with.
If the goal is purely fat loss, the increase in glucose levels may blunt fat oxidations so sticking with the standard ketogenic diet would be the better option.
A cyclical ketogenic diet (CKD) combines carb-loading day(s) with the standard ketogenic diet. Those who do high-intensity exercise (bodybuilders and athletes) implement carbohydrate refeeding days once or twice a week to fully replenish glycogen stores. The CKD provides us with a simple way to maintain high-intensity exercise performance and promote glycogen replenishment. Again, this involves following the SKD—usually around 20g carbs—for five to six days, followed by one to two days of higher-carb refeeds. These refeeds are important for anyone on a keto diet because they also allow your body to “remember” how to burn carbs. Adhering to strict SKD for too long can hinder your body’s ability to burn carbs via glycolysis—so turning on carb-burning pathways every now and then is useful to maintain your metabolic flexibility.
As mentioned, a cyclical ketogenic diet can benefit those who perform a high-intensity exercise such as a keto adapted individual who is trying to gain muscle or it can also benefit those who have been following SKD for an extended period of time and want to introduce carbs into their diets and to make maintain metabolic flexibility (I.e. efficiently utilize carbs and fat). It can also help those who need to find a way of working carbs into their diet as a treat. I personally follow a cyclical ketogenic diet and have for many years.(2)
The CKD follows the same principles as a Standard Ketogenic Diet (SKD) with the addition of carbohydrate “refeeds” one or two days a week.
Like TKD, there is very little research to date examining the benefits and drawbacks of cyclical ketogenic dieting.
Research on the cyclical keto diet is limited, which means its long-term benefits or side effects are largely unknown.
Until studies on the diet are completed, it’s impossible to determine its full effects.
Additionally, many people do not calculate their refeeding days meaning they may eat too many calories and counteract the weight loss benefits of the standard keto diet.
There are people who may NOT need to “carb-up” such as:
If you want to get the most out of CKD, you want to make sure that you are fully adapted to a Standard Ketogenic Diet before going Cyclic (at least 90 days). You should train with high repetitions (15-30 repetitions) or be very active on “carb-up” days. Lastly, the day AFTER “carbing up,” train with high intensity, as this will:
As always, you should experiment with your diet and lifestyle to find what works best for you. The ketogenic diet has always worked well for me and I do believe it can work well for many people but it is not for all people. But if you’re interested, do some more research and give it a try. Then if one of these other forms of the diet seems like they might work for you, experiment with them as well.