The Science Behind Ketones:
In most circumstances, during exercise, we burn a mixture of fat and sugar. Technically, all those treadmills at the gym that state you are in a fat burning zone are wrong.
You are not burning entirely fat. Rather, at lower intensities, you burn a higher ratio of fat to carbs. Then as you increase the intensity you begin to burn more sugar and less fat. In other words, the ratio begins to flip from fat to sugar the more intense you train. Eventually, you are burning almost entirely sugar. This whole process is natural. Since at higher intensities, your body is taking in less oxygen and unlike fat, sugar requires less oxygen to burn.
When you are going hard, sugar is an excellent fuel source.
So what’s the problem?
Well, your body has a limited amount of sugar to burn (roughly 2000 calories worth or about 500 grams) That’s about a few Snickers bars. So you need to refuel a lot to keep your body going at that level. It is in refueling that issues begin to arise. Since your body can only absorb so much, it is hard to replenish all the calories you need without getting stomach issues, cramps, and GI distress.
Eventually, you will hit the energy and mental “wall,” and most likely will either slow to a walk or stop altogether.
Why not just use fat then?
Our body has plenty of fat stores to burn. You might have heard that you could run several marathons on just your fat stores, which is true. BUT those marathons would be very slow. Burning fat is not as efficient as sugar during intense (key word there) exercise. You need to be aerobic to burn fat and therefore you have to go slower and slower to keep yourself from switching the ratio over to burning more sugar. Fat is also not that great for fueling the brain and keeping focus. The brain prefers carbs. You might experience brain fog, mental fatigue, lack of focus, and irritability.
Keep in mind, though, that the ratio of fat to sugar burning is NOT linear. If you go out at 60% of your VO2 max and held that pace for 8 hours, then over time, your body will begin to naturally start burning more sugar. Training at lower intensities and eating a low carb diet will help you extend and push out the intensity at which you begin to burn more sugar than fat. But you will always burn sugar.
What is important is how much glucose you are “sparing.”
So, where do ketones come in? When you are on a very low carb diet (or to use the buzz word: a ketosis or ketogenic diet), your body starts to produce ketones to fuel the body. Ketones are even more efficient than carbs at burning oxygen, and the brain can use them as fuel thus helping with focus and mental fatigue. They are nothing new, nor are they really “special.” You actually have the capacity to produce them yourself right now. But there is a catch.
Great! Sign me up for the ketosis program. When do I start producing ketones?
To get into a state of natural ketosis (i.e. your body producing ketones), you can either starve yourself for an extended period of time or you can go on a very low-carb diet. If you have ever tried either of these, then you know that a) it is not very pleasant and b) your training takes a huge hit that it never really recovers from.
When I went into ketosis a few years ago, I went on a very low carb diet. I did the traditional 3-week adaptation phase–which was hell and then some as far as my energy and focus– in which I did very little exercise or training and ate at most 50g of carbs a day.
Eventually, I got into ketosis and started producing ketones, and I resumed training. While I could go forever on my bike at about 75-80% of FTP or zone 2 and maybe zone 3 running, the moment I tried to do threshold work or VO2 max work, I cracked hard. I also started to gain weight. In a 5 month period, I gained almost ten pounds.
My hormones tanked, my cortisol increased, and my thyroid burned out (to quote my endocrinologist). I was sleeping poorly and it was hard to eat.
After I pulled the plug and went back to my higher carb ways, I lost the weight, regained my speed, and returned to normal. Now my story is not to say that the ketosis diet does not work.
You could make the argument that for a sedentary lifestyle it might be healthier (key word there). It just does not work for me nor do I find that it works well for athletes training at high-intensity, glycolytic training. But, is there a way to have the best of both worlds? Burn carbs and ketones? That is where HVMN Ketone comes in.
In the next installment of this trilogy, I will go over the benefits of supplementing with ketones, more of the science and theory, and will be describing how it can work for me. So stay tuned…..
One final note: before you flood my inbox with criticism that I am more oily than a carnival barker, I fully recognize that ketone esters are a new product and an area of investigation. Looking over the literature (not just Coach Google or PubMed), you will find there are not many studies looking at ketone supplementation.
There are quite a few studies that look at ketosis and performance. But not much on supplementation to go into a state of ketosis (i.e. using ketone esters). The studies that are out there also show a mixture of results. However, the majority of scientists say that it is an emerging area of research and ketone esters show promise. BUT more research is necessary.
This is part of the scientific method: reproducing results on larger and larger samples. While I am only one anecdote, I hope it can add to the information that is out there so that you can decide for yourself. I also encourage you to do your own research. Here are a few articles that I have read over the course of the past few weeks that I have found interesting regarding this topic.
- Cox, P. J., & Clarke, K. (2014). Acute nutritional ketosis: implications for exercise performance and metabolism. Extreme Physiology & Medicine, 3(1), 17.
- Cox, P. J., Kirk, T., Ashmore, T., Willerton, K., Evans, R., Smith, A., Clarke, K. (2016). Nutritional Ketosis Alters Fuel Preference and Thereby Endurance Performance in Athletes. Cell Metabolism, 24(2), 256–268. doi:10.1016/j.cmet.2016.07.010
- Holdsworth, D. A., Cox, P. J., Kirk, T., Stradling, H., Impey, S. G., & Clarke, K. (2017). A Ketone Ester Drink Increases Postexercise Muscle Glycogen Synthesis in Humans. Medicine and Science in Sports and Exercise, 49(9), 1789–1795. doi:10.1249/MSS.0000000000001292
- An article that focuses on recovery and how ketones can help with that
- Leckey, J. J., Ross, M. L., Quod, M., Hawley, J. A., & Burke, L. M. (2017). Ketone Diester Ingestion Impairs Time-Trial Performance in Professional Cyclists. Frontiers in Physiology, 8. doi:10.3389/fphys.2017.00806
- One of the few examples that I found that showed impairments so worth a read.
- Pinckaers, P. J. M., Churchward-Venne, T. A., Bailey, D., & Loon, L. J. C. van. (2017). Ketone Bodies and Exercise Performance: The Next Magic Bullet or Merely Hype? Sports Medicine; Auckland, 47(3), 383–391. doi:http://dx.doi.org/10.1007/s40279-016-0577-y
- Please note that this one focuses more on ketosis through diet modifications and reduced carb intake rather than ketone supplementation.
Tri Swim Coach