What they are thought to do, what science says, and what they did for me.
I'll keep this short and simple, because many people were not happy with explanations I wrote on twitter in the past days.
Also, I want to be clear, I'm not a scientist, never done or designed ant studies, but I am interested in human physiology, metabolism, biochemistry.
Firstly, reading comments, that Ketones might be dangerous, damaging liver, is total BS. As of now, Ketone esters are recognised as GRAS (generally recognised as safe) by FDA. And to be able to get GRAS stamp is not so easy.
What I believe is happening, is people who know nothing about human physiology, let alone Ketone esters, are faced with something new, something that is being used by others....
They are feeling threatened, and rather than doing the work educating themselves, they attack teams/individuals who are utilising these products.
There are way more dangerous drugs being used consistently, that are very damaging to human body, one being paracetamol . Paracetamol in doses of 4.000mg will already cause severe liver toxicity. In some people, doses of 2.000mg caused liver failure.
Another one is alcohol, and everybody loves their booze.
So, what do Ketone esters do?
There are few studies showing ergogenic (performance enhancing effects).
One of them showed increase of glycogen resynthesis after workout, another one showed prevention of overreaching syndrom when cyclists were training continuously, few days/weeks in a row.
Both of those studies have some huge flaws.
The study, showing enhanced recovery (glycogen resynthesis) was done in way it could never happen in real life.
Subjects were given glucose drink or glucose+ketone drink. Then they put a an IV canula in their veins and controlled IV glucose solution flow in a way they maintained steady blood glucose levels of 10mmol or 180mg/dl. In this way they were able to determine glucose+ketone group were able to take in more glucose and store more glycogen. Glucose+ketone group also had way higher insulin levels. Insulin driver glucose in your cells.
Now, it's easy to criticise the study, but we need to be aware there are always limitations how the study can be designed and performed.
The next step in my opinion would be a study, where they compared oral glucose and glucose+ketone group, but instead feeding them glucose through IV canula, they would give them certain amount of glucose (dextrose) orally over period of time (usually 1-1,2g/h)
Next study, showing prevention of overreaching:
In this study all the subject ate at libitum, their energy intake was not controlled. That's first red flag.
Control group was consistently eating less calories, which by itself could have negative effects on performance/recovery.
Next, while Ketone group were given Ketone ester after workout, Control group got MCT drink, which is notorious for causing GI distress and appetite suppression. So this could be one of the reasons, why CON were eating less.
My N=1 experiment
Full disclosure, I was given Ketone ester for free by Ketonaid CEO, Frank Llosa.
My first test was in Boulder CO, in late 2017. I had lactate meter, ketone meter, and glucose measuring device.
15min after taking 30g of KE4 (ester) and 30g of carbs my glucose came down to low 70mg/dl (~4mmol), ketones shot up to mid 3mmol.
I performed an all out test on a famous Flagstaff mountain climb. I felt good but, the downside was I only had one gear. And it was just below the threshold ~345W
Ketones will partially inhibit glycolysis (sugar burning simply said), thus, lactate will also be lower than usually. (btw Exogenous Ketones also stop fat burning )
At the top of the mountain, I took my Lactate ( ~2.8mmol) Ketone (~2mmol) , blood glucose( 4mmol or 72mg/dl)
What does that tell me?
Ketones work, but in specific context.
The downside is, once you run out, it sucks, it feels pretty much the same as bonking. It's because there's a lag between Ketone burning to glucose burning.
The primary benefit IMO is the mental clarity Ketones give you. You can think clearly, it improves mood etc...
Ketones also work on inflammation, simply said, are able to modulate gene expression in a way, it has positive effects on inflammation.
To conclude, are Ketone esters dangerous?
As of now, we have not found any bad side effects from them.
Are they a "game changer" ?
Probably not, but it's possible there might be some positive effects. And in a such a competitive sport as cycling is, every little thing counts.
Thanks for reading
Love you all.