2020 has been one crazy year so far! We have had citizens throwing down in grocery stores over whether or not they should be wearing a mask, protesting in the streets of most major cities over race relations, crazy online political conspiracy theories, and preparing for a WWE style presidential election in November! So, in keeping with the controversial climate of 2020, I think an article on the ketogenic diet and weightlifting performance should fit somewhere between a fistfight and throwing a Molotov cocktail through a store window. This article will cover a brief history of the ketogenic diet, some of the science and physiological underpinnings behind the ketogenic diet as well as address whether or not this diet has and utility for Olympic weightlifting performance. 

Ketogenic Diets

The earliest use of fasting as a treatment for epilepsy dates back to 500 BC. In the 1920s, the ketogenic diet was developed as a way to mimic fasting in epilepsy patients. Unfortunately, it fell out of favor within the next few decades with the advent of modern chemistry and development of anti-convulsant drugs. In the early 2000s, the ketogenic diet gained renewed interest with Dr. Robert Atkin’s New Diet Revolution book, kicking off a low-carb frenzy. In 2013, a study published in the journal Science showed the anti-aging and health benefits of a ketogenic diet, creating a fever pitch in the paleo and biohacking communities. The ketogenic diet remains popular for three main reasons: weight loss, brain health, and cancer treatment, in fact in 2018 it was the most searched diet on Google. The ketogenic diet has been resurrected in the past few years by various celebrities and has received immense popularity through social media. Various supplement companies are also now selling exogenous or supplemental ketones which can elevate blood levels of ketones transiently for a few hours without people even adhering to a ketogenic diet.

Energy systems 101 

To understand ketosis, one must first understand how the body produces energy, known as adenosine triphosphate (ATP). ATP is found in all known forms of life and is the common energy currency of the body and if productions stops, you stop. Our bodies have several energy systems that are constantly running and often overlapping one another to keep a constant supply of ATP to all the cells in the body. ATP is quickly used up in roughly five or six seconds, enough for a one rep max in most lifts. The creatine phosphate system is good for another few seconds but is also used up in about 10 to12 seconds, about the duration of a 100 meter sprint; this is incidentally why creatine monohydrate is such a popular supplement especially among strength athletes; it helps you with maximum power output under 12 seconds. Next up is the glycolytic system, supplied by ATP, creatine phosphate, and muscle glycogen (stored carbohydrate) which goes from the time the creatine phosphate system depletes at 10-12 seconds up until about 45 seconds of exertion. From about 45 seconds to two minutes, the energy system is anaerobic, lactic acid and relies on muscle glycogen and lactic acid for a fuel substrate. After two-plus minutes, the body shifts from primarily anaerobic energy to aerobic energy and starts to rely on fatty acids as a fuel substrate. This will allow you to continue at a sub maximal exertion for potentially hours, think marathons and ultra-endurance events. The point of all this physiology is to illustrate there are many biochemical pathways your body uses to create ATP for fuel, just as a general rule though, for short, intense duration, you’re burning almost exclusively sugar and for longer, more moderate intensities, you’re burning mostly fat.

So, what is ketosis?

Once you understand this brief 50,000 foot view of the body’s energy systems, the question is, “What is ketosis, and would it help an Olympic weightlifter to be on a ketogenic diet?” Ketosis is the metabolic state we arrive at when we eat mostly fat (70 percent or more of total calories), low to moderate protein (1-1.5g/kg bodyweight), and little to no carbohydrate (no more than 50g/day but preferably under 20g). Of course, due to biochemical individuality, some people fall outside of these ranges, but for most individuals these ranges are acceptable.

The state of ketosis could be viewed as an evolutionary adaptation for our survival as a species, during prolonged periods of starvation. We can actually blame it all on our hungry brain! The brain is only about 2 percent of our bodyweight, but uses around 20 percent of our daily energy. The brain derives its fuel from glucose because it lacks the metabolic equipment to oxidize fat. We can store about 100-120 grams of glucose in the liver and about three times that in the muscles. Unfortunately, the stored glucose in the muscles (muscle glycogen) can’t be released into the bloodstream; it can only be used by the working muscles it’s stored in. So, if we aren’t able to find any glucose we must then rely on the liver to release its stored glycogen to fuel our starving brains. Depending on some variables such as heat production and activity levels, we have about one to three days in a starvation state before the liver runs out of its reserves of glycogen and we get into trouble. The dilemma is that our brain needs energy but it doesn’t have access to the most abundant stored energy in the body, fat. Luckily, we evolved a nifty physiological trick. It turns out that our livers are able to synthesize ketone bodies out of our stored fat and these ketone bodies will not only be used by the brain for fuel, but actually fuel the brain in a more efficient manner! Our bodies were doing biohacking millions of years before it was cool, coming up with an alternative fuel source in prolonged periods without carbohydrates.

Olympic weightlifting and ketogenic diets

So, the question is, does a ketogenic diet help or hurt performance in Olympic weightlifting? If you take some time looking through the evidence, rather than listening to anecdotal stories from people selling exogenous ketones, you will find that there’s just not much data out there. The lion’s share of research regarding ketosis and ketogenic diets, albeit positive, all involves endurance and cycling performance. However, cycling and endurance are NOT Olympic weightlifting. In fact, research suggests either equivocal or null results in regard to athletic performance outside of cycling.  The only advantage that seems to be conferred with using a ketogenic diet in Olympic weightlifting would be dropping a weight class while maintaining strength. Again, this is not to be construed as IMPROVING performance, but rather maintaining performance. The training and especially the competition aspect of Olympic weightlifting rarely involves any of the aerobic energy systems. The competition lifts are so explosive and short duration that there’s not enough time for the body to extract fuel from fat to be used as an energy substrate.

Conclusion

While this article seems to portray a negative opinion of the ketogenic diet, I actually am a big fan of it for nearly everything EXCEPT ultra-high intensity glycolytic exercise like Olympic weightlifting. As outlined earlier, our physiology determines what works best for fueling different activities. While there certainly is room for biochemical individuality, in general performance will not be optimal if the wrong substrates are used for fuel. On a personal note, I have used exogenous ketones in conjunction with a short lived ketogenic diet to drop a weight class in a couple weeks with no loss in snatch and a slight loss in clean and jerk in competition. I wanted to see if I could train in a ketogenic state and while I seemed to maintain focus and energy levels, it seemed that the very high end of my power was just not there. As the old saying goes, just because you CAN doesn’t mean you SHOULD.