Optimal Dose Of Caffeine In Humans

[haidut]

Many people on the forum and elsewhere take caffeine for its pro-metabolic and disease-preventing effects. However, caffeine can induce a stress response. This is especially true in people with poor glycogen stores, liver problems, and hypothyroidism in general. This study says that a human dose of 3mg/kg did not induce any increase in epinephrine (adrenaline) while still being highly ergogenic and not weaker than the higher dose of 6mg/kg. Only the highest dose of 9mg/kg increased free fatty acids, which is what Ray advises against.
Given that caffeine half-life is about 5-6 hours, this means 3mg/kg twice a day should not induce a stress response.

http://www.ncbi.nlm.nih.gov/pubmed/7775331

"...Endurance was enhanced with both 3 and 6 mg/kg of caffeine (increases of 22 +/- 9 and 22 +/- 7%, respectively; both P < 0.05) over the placebo time of 49.4 +/- 4.2 min, whereas there was no significant effect with 9 mg/kg of caffeine. In contrast, plasma epinephrine was not increased with 3 mg/kg of caffeine but was greater with the higher doses (P < 0.05). Similarly only the highest dose of caffeine resulted in increases in glycerol and free fatty acids (P < 0.05). Thus the highest dose had the greatest effect on epinephrine and blood-borne metabolites yet had the least effect on performance. The lowest dose had little or no effect on epinephrine and metabolites but did have an ergogenic effect. These results are not compatible with the traditional theory that caffeine mediates its ergogenic effect via enhanced catecholamines."

 

[Lin]

As a 53 Kg human, I am surprised to see that my max dose of caffeine is only 477 mg!

 

[Lightbringer]

https://raypeatforum.com/forums/posts/98209/ Only the highest dose of 9mg/kg increased free fatty acids, which is what Ray advises against.

Has Ray mentioned a specific upper limit of 9mg/kg? Since 8 oz can have anywhere from 100-200 mg of caffeine, this number seems easy to hit.
For example, a person weighing 100 kg would have a limit of 900 mg which would be covered in about 5 cups of coffee.

 

[haidut]

https://raypeatforum.com/forums/posts/98250/

https://raypeatforum.com/forums/posts/98209/ Only the highest dose of 9mg/kg increased free fatty acids, which is what Ray advises against.

Has Ray mentioned a specific upper limit of 9mg/kg? Since 8 oz can have anywhere from 100-200 mg of caffeine, this number seems easy to hit.
For example, a person weighing 100 kg would have a limit of 900 mg which would be covered in about 5 cups of coffee.

These were one time doses, so it means taking 9mg/kg in one sitting. I don't think anybody on this forum does that much. And I meant Ray's advise against the activation of the stress response and FFA elevation, not him mentioning specific dose of caffeine. However, he did say that even 600mg in one sitting could trigger a stress response in some people.

 

[Lightbringer]

https://raypeatforum.com/forums/posts/98256/ These were one time doses, so it means taking 9mg/kg in one sitting

ohh good, I was getting a tad bit worried there

 

[Such_Saturation]

5 cups of what coffee

 

[Lightbringer]

https://raypeatforum.com/forums/posts/98261/ 5 cups of what coffee

Regular brewed coffee can have that amount:
http://www.mayoclinic.org/healthy-lifes ... t-20049372

I guess the wide range of 100-200 mg is because of multiple factors. For example, a cup at Starbucks can get you about 130-150 mg but I'd suspect a cup at say Peet's Coffee would be stronger.

 

[Such_Saturation]

Yes but still, who drinks a quart and then some of coffee and keeps it down?

 

[Lightbringer]

https://raypeatforum.com/forums/posts/98264/ Yes but still, who drinks a quart and then some of coffee and keeps it down?

I know quite a few people who can drink 5 cups of coffee or more a day (black or with a bit of milk). I myself can do about 3-4 a day with equivalent amounts of milk and good old sugar.

 

[Such_Saturation]

https://raypeatforum.com/forums/posts/98265/

https://raypeatforum.com/forums/posts/98264/ Yes but still, who drinks a quart and then some of coffee and keeps it down?

I know quite a few people who can drink 5 cups of coffee or more a day (black or with a bit of milk). I myself can do about 3-4 a day with equivalent amounts of milk and good old sugar.

Cups as in 236ml?

 

[Lightbringer]

https://raypeatforum.com/forums/posts/98266/

https://raypeatforum.com/forums/posts/98265/

https://raypeatforum.com/forums/posts/98264/ Yes but still, who drinks a quart and then some of coffee and keeps it down?

I know quite a few people who can drink 5 cups of coffee or more a day (black or with a bit of milk). I myself can do about 3-4 a day with equivalent amounts of milk and good old sugar.

Cups as in 236ml?

Yes sir. I think that is about 8 oz. Your surprise had me a bit surprised so I did some googling and per EU guidelines 4 cups seems to be the magic number when things start falling apart :?
http://www.medicaldaily.com/cup-coffee- ... ake-335486

Here is a 120 page report
http://www.efsa.europa.eu/sites/default ... s/4102.pdf

No doubt some scary stuff in there ..

 

[Such_Saturation]

I was just enquiring because people often underestimate how much a cup is.

 

[sladerunner69]

whenever I have any amount of caffeine I crash. Even a soda. I drink OJ ,milk, get all my vitamins and copper and magnesium and zinc and yet even after a can of soda I will be brain-foggy/lethargic afterwords. I think caffiene mimics progesterone which antagonized DHT causing my hypogonad to get bad.

 

[mayweatherking]

how do you know if caffeine is causing a stress response or if it is helping you? it seems to help me a lot with certain things i eat.. however, i feel in the back of my head maybe i'm cheating by drinking coffee and it is actually putting my body into a bad state? but my temperature seems to be good after it.

 

[DaveFoster]

@haidut

Do you think when the 3 mg/kg dosage of caffeine no longer brings the temp and pulse up in mild hypothyroidism (say combined with aspirin, it still doesn't,) do you view this as the proper time to use thyroid, or would you rather use a higher dose of caffeine (the 6 mg/kg dose) to bring up the temp and pulse?

Wouldn't thyroid be preferred in this case, as it won't raise epinephrine and cortisol like the higher caffeine dose?

 

[haidut]

@haidut

Do you think when the 3 mg/kg dosage of caffeine no longer brings the temp and pulse up in mild hypothyroidism (say combined with aspirin, it still doesn't,) do you view this as the proper time to use thyroid, or would you rather use a higher dose of caffeine (the 6 mg/kg dose) to bring up the temp and pulse?

Wouldn't thyroid be preferred in this case, as it won't raise epinephrine and cortisol like the higher caffeine dose?

I would not raise caffeine dose as it often leads to stress symptoms. Thyroid CAN raise both epinephrine and cortisol. In fact, it increase the turnover of both. I think something like higher dose aspirin and vitamin K2 would be better as aspirin does not seem to have the stimulant effects caffeine and thyroid do. Animal studies show that as "little" as 2g - 3g aspirin daily leads to uncoupling and temp increase, without much effect on pulse.

 

[DaveFoster]

I would not raise caffeine dose as it often leads to stress symptoms. Thyroid CAN raise both epinephrine and cortisol. In fact, it increase the turnover of both. I think something like higher dose aspirin and vitamin K2 would be better as aspirin does not seem to have the stimulant effects caffeine and thyroid do. Animal studies show that as "little" as 2g - 3g aspirin daily leads to uncoupling and temp increase, without much effect on pulse.

Very interesting; and that would be around 45 mg K2 you think, or is that just to protect against the bleeding from the aspirin?

 

[haidut]

Very interesting; and that would be around 45 mg K2 you think, or is that just to protect against the bleeding from the aspirin?

I would use the dose for K2 Ray mentioned - 1mg for every 325mg aspirin. No need to go up to 45mg.

 

[DaveFoster]

I would use the dose for K2 Ray mentioned - 1mg for every 325mg aspirin. No need to go up to 45mg.

I assumed that you were referring to the thread where you said K2 raises testosterone, hence a larger dose of K2. Thanks for the info.

 

[haidut]

I assumed that you were referring to the thread where you said K2 raises testosterone, hence a larger dose of K2. Thanks for the info.

If you are using the K2 on the sctorum you may get the best of both worlds - with just 2mg - 3mg daily you can oppose aspirin's bleeding effects and also affect androgen synthesis in the gonads.