Mental fatigue question


(Murphy Kismet) #1

I may be way off, but this article intrigued me on many levels. I feel I suffer from mental fatigue unless I take ginseng every day. It’s like my caffeine. However, this long weekend there was some not-so-keto indulgences (ciders, hidden sugars in bbq sauce, soybean oil in dressing) and my brain couldn’t wrap itself around this concept and take it to the next level(s), and I didn’t have my ginseng.

I am wondering about this glucose thing and mental fatigue.

Parts that stood out for me:

Subjects spent 90 minutes sitting in front of a computer screen either watching a bland documentary or playing a simple but focus-demanding computer game. Afterwards, when they hopped on an exercise bike for a time-to-exhaustion test, those who’d played the computer game immediately reported higher levels of perceived effort, and gave up 15 percent earlier than the documentary watchers.

The basic hypothesis that Martin and her colleagues present (drawing on a suggestion from 2014) is that mental fatigue results from the accumulation of a brain chemical called adenosine. In this picture, sustained cognitive activity burns up glucose, particularly in certain regions of the brain associated with “effortful mental processes,” such as the anterior cingulate cortex.

In rats, injections that increase adenosine levels in the brain lead them to make “lazier” decisions, choosing easily available but unappetizing food instead of going to the trouble of pressing a lever to get better food.

These questions aren’t in any particular order…

Adenosine is part of the mitochondrial energy source, ie: AMP, ADP, and ATP. Does this adenosine rise in the brain affect cellular energy, and by proxy mental energy?

What happens if the anterior cingulate cortex doesn’t have glucose? Is this an area of the brain that does better with ketones?

Could mental fatigue post-mental strain be circumvented via keto? (maybe reading the forums before a long bike ride isn’t a good idea lol)

(Full Metal Keto) #2

Interesting article, thanks. :cowboy_hat_face:

(Khara) #3

“mental fatigue results from the accumulation of a brain chemical called adenosine”

I’d be interested in knowing what reduces the adenosine. They mentioned sleep but I didn’t see anything else. (Well, except that coffee/caffeine can counteract it.) As a person who stares at a computer all day, I often feel as though I’m always in a state of fatigue. In my opinion the computer age has not been good for our health. I wish I’d have known before I chose my profession. If ever I have opportunity to converse with a young person, I encourage them to think about the activity level of potential careers. It adds up over the years.

(Libby) #4

This totally explains why I keep putting off going outside to get stuff done while playing cards or learning new things on the internet. Hmm. It DOES seem like a lot of effort. Nice I can blame a chemical instead of my (lack of) character and laziness…:smiley: I’m running with this.

(Khara) #5

Yes. I find I always feel better if I can blame someone or something other than myself! :grin:


I’m late to this party, but there’s some interesting studies out there about adenosine regulation and ATP in relation to ketosis.

…degradation of extracellular ATP is a major source of extracellular adenosine [29, 44, 82], so manipulations that increase extracellular ATP have a net effect on neuromodulation by adenosine [44].
Ketogenic strategies such as fasting or adhering to a ketogenic (high-fat, low-carbohydrate) diet increase ATP and other energy molecules in brain [20, 37, 126, 134]. These metabolic manipulations are known to reduce seizures significantly [194], and have been shown to offer neuroprotection in animal models of brain injury [70, 125]. Emerging evidence suggests that mimicking key cellular aspects of ketogenic metabolism increases extracellular adenosine [96], and furthermore, that an increased influence of adenosine at the A1 subtype plays a key role in the anticonvulsant success of ketogenic strategies [

This reads to me like an explanation of one reason why I feel mentally sharper in ketosis. Another one being that my cerebral glucose metabolism is slightly impaired. Interestingly enough, the hot flashes of menopause and epilepsy are related by how the blood brain barrier handles glucose.